JP2022045334A - Adhesion method - Google Patents

Abstract

To provide an adhesion method that can shorten an application time of a high-frequency electric field and improve adhesive strength even when the field is applied for a short time.SOLUTION: A method for bonding an adherend by means of a high-frequency dielectric heating adhesive sheet 1A containing a thermoplastic resin (A) includes: a first process of applying a high-frequency electric field of applied output V1 per unit area to the high-frequency dielectric heating adhesive sheet 1A; and a second process of applying a high-frequency electric field of applied output V2 per unit area to the high-frequency dielectric heating adhesive sheet 1A after the first process. The applied output V1 per unit area of the first process and the applied output V2 per unit area of the second process satisfy a condition expressed in a following formula (number 1). V1>V2...(number 1)SELECTED DRAWING: Figure 1

Description

The present invention relates to an bonding method.

In recent years, as a method of adhering adherends that are generally difficult to adhere to each other, for example, an adhesive made by blending a heat-generating material in a predetermined resin is interposed between the adherends and subjected to an induction heat treatment. , Induction heat treatment, ultrasonic welding treatment, laser welding treatment and the like have been proposed.

For example, Patent Document 1 describes a high-frequency dielectric heating adhesive sheet for adhering a plurality of adherends made of the same material or different materials, and the high-frequency dielectric heating adhesive sheet is blended in a predetermined ratio. It contains a predetermined thermoplastic resin and a dielectric filler.

International Publication No. 2018/147351

According to Patent Document 1, the application time of a high-frequency electric field can be shortened, but from the viewpoint of production efficiency, it is required to further shorten the application time.

An object of the present invention is to provide a bonding method capable of shortening the application time of a high-frequency electric field and improving the bonding strength even when the high-frequency electric field is applied for a short time.

According to one aspect of the present invention, it is a method of adhering an adherend by a high frequency dielectric heating adhesive sheet, wherein the high frequency dielectric heating adhesive sheet contains a thermoplastic resin (A) and is attached to the high frequency dielectric heating adhesive sheet. The first step of applying the high frequency electric field of the applied output V1 per unit area, and the second step of applying the high frequency electric field of the applied output V2 per unit area to the high frequency dielectric heating adhesive sheet after the first step. Provided is an bonding method in which the applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 1). Will be done.
V1> V2 ... (number 1)

In the bonding method according to one aspect of the present invention, the applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step are expressed by the following mathematical formula (Equation 1-1). It is preferable to satisfy the conditions to be satisfied.
0.8 × V1 ≧ V2 ... (Equation 1-1)

In the bonding method according to one aspect of the present invention, the applied output V1 per unit area of the first step is preferably 0.18 W / mm ² or more and 2.00 W / mm ² or less.

In the bonding method according to one aspect of the present invention, the application time T1 of the first step is preferably 1 second or more and less than 25 seconds.

In the bonding method according to one aspect of the present invention, the applied output V2 per unit area of the second step is preferably 0.09 W / mm ² or more and 0.30 W / mm ² or less.

In the bonding method according to one aspect of the present invention, the application time T2 of the second step is preferably 5 seconds or more.

In the bonding method according to one aspect of the present invention, it is preferable that the application time T1 of the first step and the application time T2 of the second step satisfy the conditions represented by the following mathematical formula (Equation 2).
(T1 + T2) <60 seconds ... (number 2)

According to one aspect of the present invention, it is a method of adhering an adherend by a high frequency dielectric heating adhesive sheet, wherein the high frequency dielectric heating adhesive sheet contains a thermoplastic resin (A) and is attached to the high frequency dielectric heating adhesive sheet. The first step of applying the high frequency electric field of the applied energy J1 per unit area, and the second step of applying the high frequency electric field of the applied energy J2 per unit area to the high frequency dielectric heating adhesive sheet after the first step. Provided is an bonding method in which the applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 3). Will be done.
J1> 0.75 x J2 ... (number 3)

In the bonding method according to one aspect of the present invention, the applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step are expressed by the following mathematical formula (Equation 3-1). It is preferable to satisfy the conditions to be satisfied.
0.9> J1 / (J1 + J2)> 0.4 ... (Equation 3-1)

In the bonding method according to one aspect of the present invention, the thermoplastic resin (A) is preferably a polyolefin resin.

In the bonding method according to one aspect of the present invention, it is preferable that the high-frequency dielectric heating adhesive sheet further contains a dielectric filler (B) that generates heat by applying a high-frequency electric field.

In the bonding method according to one aspect of the present invention, the dielectric filler (B) preferably contains at least one selected from the group consisting of zinc oxide, silicon carbide, barium titanate and titanium oxide.

According to one aspect of the present invention, it is possible to provide a bonding method capable of shortening the application time of a high frequency electric field and improving the bonding strength even when the high frequency electric field is applied for a short time.

It is a schematic diagram explaining the high-frequency dielectric heating treatment using the high-frequency dielectric heating adhesive sheet and the dielectric heating apparatus which concerns on one aspect. (A), (B) and (C) are schematic cross-sectional views of a high-frequency dielectric heating adhesive sheet according to each embodiment.

[First Embodiment]
[Adhesion method]
The bonding method according to the present embodiment is a method of adhering an adherend with a high-frequency dielectric heating adhesive sheet. This high frequency dielectric heating adhesive sheet contains a thermoplastic resin (A).
The bonding method according to the present embodiment is a first step of applying a high frequency electric field of an applied output V1 per unit area to the high frequency dielectric heating adhesive sheet, and a unit area of the high frequency dielectric heating adhesive sheet after the first step. A second step of applying a high-frequency electric field of the applied output V2 per unit is provided, and the applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step are the following mathematical formulas. The condition represented by (Equation 1) is satisfied. The high-frequency electric field is an electric field whose direction is reversed at high frequencies.
V1> V2 ... (number 1)

Hereinafter, as an example of the bonding method according to the present embodiment, an embodiment in which a first adherend and a second adherend are adhered to each other by using a high-frequency dielectric heating adhesive sheet composed of a single adhesive layer will be given. As described, the invention is not limited to this aspect. The materials of the first adherend and the second adherend are also not particularly limited.

The bonding method according to the present embodiment includes the following first step and second step.
In the first step and the second step, a high-frequency electric field is applied to the high-frequency dielectric heating adhesive sheet sandwiched between the first adherend and the second adherend, and the first adherend is applied. This is a step of adhering the second adherend and the second adherend with a high-frequency dielectric heating adhesive sheet.
Normally, the step of applying a high frequency electric field is not divided into two steps. On the other hand, in the present embodiment, the degree of melting and heating of the resin in the high-frequency dielectric heating adhesive sheet is adjusted by dividing into two specific steps, a first step and a second step. As a result, according to the present embodiment, it is presumed that the adhesive strength can be improved even if the application is applied for a short time.

In the first step, a high-frequency electric field with an applied output V1 per unit area is applied to the high-frequency dielectric heating adhesive sheet.
In the second step, a high frequency electric field of the applied output V2 per unit area is applied to the high frequency dielectric heating adhesive sheet after the first step.

It is necessary that the applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 1).
V1> V2 ... (number 1)
If the condition expressed by the above mathematical formula (Equation 1) is not satisfied, the adhesive strength cannot be improved while shortening the application time of the high frequency electric field.

In the present embodiment, the applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 1-1). preferable.
0.8 × V1 ≧ V2 ... (Equation 1-1)
When the condition expressed by the above formula (Equation 1-1) is satisfied, it is easy to improve the adhesive strength.
From the same viewpoint, the upper limit of the applied output V2 per unit area of the second step is preferably 0.75 times or less of the value of the applied output V1 per unit area of the first step, and it is preferable that the upper limit is 0.75 times or less. It is more preferably 0.7 times or less of the value of the applied output V1 per unit area, further preferably 0.65 times or less of the value of the applied output V1 per unit area, and the applied output per unit area. It is particularly preferable that the value is 0.6 times or less the value of V1.
Further, from the viewpoint of shortening the application time, the lower limit of the applied output V2 per unit area of the second step is preferably 0.1 times or more the value of the applied output V1 per unit area of the first step. , It is more preferably 0.2 times or more the value of the applied output V1 per unit area of the first step, and 0.3 times or more the value of the applied output V1 per unit area of the first step. It is more preferably 0.4 times or more the value of the applied output V1 per unit area of the first step.

The applied output V1 per unit area in the first step is preferably 0.18 W / mm ² or more, more preferably 0.20 W / mm ² or more, and 0.22 W / mm ² or more. Is more preferable. The applied output V1 per unit area in the first step is preferably 2.00 W / mm ² or less, more preferably 1.75 W / mm ² or less, and 1.50 W / mm ² or less. Is even more preferably 1.25 W / mm ² or less, even more preferably 1.00 W / mm ² or less, even more preferably 0.75 W / mm ² or less, and 0. It is particularly preferable that it is 5.5 W / mm ² or less.
When the applied output V1 per unit area in the first step is 0.18 W / mm ² or more, it is possible to prevent the problem that the resin is unlikely to be in a molten state, so that good adhesive strength can be easily obtained.
If the applied output V1 per unit area in the first step is 2.00 W / mm ² or less, it is possible to prevent the problem that the resin foams and the adhesive strength decreases, so that good adhesive strength can be easily obtained.

The application time T1 in the first step is preferably 1 second or longer, more preferably 3 seconds or longer, further preferably 5 seconds or longer, and even more preferably 7 seconds or longer. It is particularly preferable that it is at least seconds. The application time T1 in the first step is preferably less than 25 seconds, more preferably 24 seconds or less, and even more preferably 20 seconds or less.
When the application time T1 in the first step is 1 second or more, it is possible to prevent the problem that the temperature does not easily rise during the dielectric heat treatment, so that it is easy to obtain a good adhesive force.
If the application time T1 of the first step is less than 25 seconds, the application time of the high frequency electric field can be further shortened.

The applied output V2 per unit area in the second step is preferably 0.09 W / mm ² or more, more preferably 0.10 W / mm ² or more, and 0.11 W / mm ² or more. Is more preferable. The applied output V2 per unit area in the second step is preferably 0.30 W / mm ² or less, more preferably 0.25 W / mm ² or less, and 0.20 W / mm ² or less. Is more preferable, and 0.18 W / mm ² or less is particularly preferable.
When the applied output V2 per unit area of the second step is 0.09 W / mm ² or more, the processing temperature after the first step can be maintained, so that good adhesive strength can be easily obtained.
If the applied output V2 per unit area in the second step is 0.30 W / mm ² or less, it is possible to prevent the problem that the resin foams and the adhesive strength decreases, so that good adhesive strength can be easily obtained.

The application time T2 in the second step is preferably 5 seconds or longer, more preferably 7 seconds or longer, further preferably 9 seconds or longer, and particularly preferably 10 seconds or longer. The application time T2 in the second step is preferably less than 60 seconds, more preferably 50 seconds or less, further preferably 40 seconds or less, and particularly preferably 30 seconds or less.
When the application time T2 of the second step is 5 seconds or more, it is possible to secure a time for maintaining the processing temperature after the first step, so that it is easy to obtain a good adhesive force.
If the application time T2 in the second step is less than 60 seconds, the application time of the high frequency electric field can be further shortened.

In the present embodiment, it is preferable that the application time T1 of the first step and the application time T2 of the second step satisfy the conditions represented by the following mathematical formula (Equation 2).
(T1 + T2) <60 seconds ... (number 2)
When the condition expressed by the above mathematical formula (Equation 2) is satisfied, the application time of the high frequency electric field can be further shortened.
From the same viewpoint, the total (T1 + T2) of the applied time T1 and the applied time T2 is more preferably 50 seconds or less, further preferably 40 seconds or less, and particularly preferably 30 seconds or less. ..

In the first step and the second step, the frequency of the high frequency electric field to be applied is preferably 1 kHz or more, more preferably 1 MHz or more, further preferably 5 MHz or more, and more preferably 10 MHz or more. More preferred.
The frequency of the high frequency electric field to be applied is preferably 300 MHz or less, more preferably 100 MHz or less, further 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 bonding method according to the present embodiment.

The bonding method according to the present embodiment may include step P1 before the above-mentioned first step and second step.

・ Process P1
Step P1 is a step of arranging the high-frequency dielectric heating adhesive sheet according to the present embodiment between the first adherend and the second adherend. In step P1, the first adherend is brought into contact with the first surface of the high frequency dielectric heating adhesive sheet. Further, in step P1, the second adherend is brought into contact with the second surface of the high-frequency dielectric heating adhesive sheet.

It is preferable to sandwich the high frequency dielectric heating adhesive sheet between the first adherend and the second adherend so that the first adherend and the second adherend can be adhered to each other. A high-frequency dielectric heating adhesive sheet may be sandwiched in a part between the first adherend and the second adherend at a plurality of places or on the entire surface. From the viewpoint of improving the adhesive strength between the first adherend and the second adherend, a high-frequency dielectric heating adhesive sheet is applied over the entire adhesive surface between the first adherend and the second adherend. It is preferable to pinch it.
Further, as one aspect of sandwiching the high-frequency dielectric heating adhesive sheet in a part between the first adherend and the second adherend, the first adherend and the second adherend are used. An embodiment in which a high-frequency dielectric heating adhesive sheet is arranged in a frame shape along the outer periphery of the adhesive surface and is sandwiched between the first adherend and the second adherend can be mentioned. By arranging the high-frequency dielectric heating adhesive sheet in a frame shape in this way, the adhesive strength between the first adherend and the second adherend can be obtained, and the high-frequency dielectric heating adhesive sheet can be provided over the entire adhesive surface. The weight of the bonded body can be reduced as compared with the case where it is arranged.
Further, according to one aspect in which the high-frequency dielectric heating adhesive sheet is sandwiched between a part of 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 adhesive can be adhered. 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 surface.

(Applied body)
The material of the first adherend and the second adherend is not particularly limited. The material of the adherend may be any material of an organic material and an inorganic material (including a metal material and the like), and may be a composite material of an organic material and an inorganic material.
Examples of the organic material as the material of the adherend include a plastic material and a rubber material. 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 and nylon 66, etc.), and polyester resin. (Polyethylene terephthalate (PET resin) and polybutylene terephthalate resin (PBT resin) and the like), polyacetal resin (POM resin), polymethylmethacrylate resin, polystyrene resin and the like can be mentioned. Examples of the rubber material include styrene-butadiene rubber (SBR), ethylene propylene rubber (EPR), and silicone rubber. Further, the adherend may be a foaming material made of an organic material.
Examples of the inorganic material as the material of the adherend include a glass material, a cement material, a ceramic material, a metal material and the like. Further, the adherend may be a fiber reinforced resin (FRP) which is a composite material of the fiber and the above-mentioned plastic material. The plastic material in this fiber reinforced resin is, 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), polybutylene terephthalate resin (PBT resin), etc.), polyacetal resin (POM resin), polymethylmethacrylate resin, polystyrene resin, etc. .. Examples of the fiber in the fiber reinforced resin include glass fiber, Kevlar fiber, carbon fiber and the like.
When a plurality of adherends are bonded to each other by using the high-frequency dielectric heating adhesive sheet according to the present embodiment, the plurality of adherends are made of the same material or different materials from each other.
The high-frequency dielectric heating adhesive sheet according to this embodiment can be suitably used for adhesion to an adherend.
The shape of the adherend is not particularly limited, but it is preferable to have a surface on which the high-frequency dielectric heating adhesive sheet can be bonded, and it is preferable that the adherend has a sheet shape or a plate shape. When a plurality of adherends are adhered to each other, the shapes and dimensions of the adherends may be the same or different from each other.

(Dielectric heating adhesive device)
In the above-mentioned first step and the second step, for example, by using a dielectric heating adhesive device, a high frequency electric field can be applied to the high frequency dielectric heating adhesive sheet.
FIG. 1 shows a schematic diagram illustrating a high-frequency dielectric heating process using the high-frequency dielectric heating adhesive sheet and the dielectric heating device according to the present embodiment.
FIG. 1 shows a schematic view of the dielectric heating adhesive device 50.
The dielectric heating adhesive 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 so as to face each other. The first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 have a press mechanism. By this press mechanism, the first adherend 110, the high frequency dielectric heating adhesive sheet 1A and the second adherend 120 are pressed between the first high frequency electric field application electrode 51 and the second high frequency electric field application electrode 52. Can be processed.

When the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 form a pair of flat plate electrodes parallel to each other, such an electrode arrangement type 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 a high frequency electric field. If it is a parallel plate type high frequency dielectric heating device, the high frequency penetrates the high frequency dielectric heating adhesive sheet located between the electrodes, so that the entire high frequency dielectric heating adhesive sheet can be heated, and the adherend and the high frequency dielectric heating adhesive sheet can be heated. Can be bonded in a short time.

A high-frequency power supply 53 for applying a high-frequency electric field having a frequency of about 13.56 MHz, a frequency of about 27.12 MHz, or a frequency of about 40.68 MHz is provided to each of the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52, for example. It is connected.
As shown in FIG. 1, the dielectric heating adhesive device 50 performs a dielectric heating treatment via a high-frequency dielectric heating adhesive sheet 1A sandwiched between the first adherend 110 and the second adherend 120. Further, in the dielectric heating and bonding device 50, in addition to the dielectric heating treatment, the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 pressurize the first adherend 110 and the second adherend. Adhere to the body 120.

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, the high frequency dielectric heating adhesive sheet 1A absorbs high frequency energy.
Then, the thermoplastic resin component of the high-frequency dielectric heating adhesive sheet 1A is melted, and finally, the first adherend 110 and the second adherend 120 can be firmly adhered to each other.

Since the first high frequency electric field application electrode 51 and the second high frequency electric field application electrode 52 have a press mechanism, they also function as a press device. Therefore, the first adherend 110 and the second adherend are formed by pressurizing the first high-frequency electric field application electrode 51 and the second high-frequency electric field application electrode 52 in the compression direction and heating and melting the high-frequency dielectric heating adhesive sheet 1A. It can be more firmly bonded to 120.

The bonded body according to the present embodiment includes a first adherend, a second adherend, and a high-frequency dielectric heating adhesive sheet according to the present embodiment. The first adherend and the second adherend are joined by a high-frequency dielectric heating adhesive sheet.
As one aspect of the bonded body according to the present embodiment, for example, as shown in FIG. 1, a bonded body having a first adherend 110, a high-frequency dielectric heating adhesive sheet 1A, and a second adherend 120 can be mentioned. ..

[High frequency dielectric heating adhesive sheet]
Next, a high-frequency dielectric heating adhesive sheet used in the adhesive method according to the present embodiment will be described. The high-frequency dielectric heating adhesive sheet according to this embodiment has an adhesive layer. The adhesive layer contains the thermoplastic resin (A).

(Thermoplastic resin (A))
The type of the thermoplastic resin (A) is not particularly limited.
The thermoplastic resin (A) is, for example, a polyolefin resin, a styrene resin, a polyacetal resin, a polycarbonate resin, a polyacrylic resin, or a polyamide resin from the viewpoint of being easily melted and having a predetermined heat resistance. , At least one selected from the group consisting of a polyimide resin, a polyvinyl acetate resin, a phenoxy resin and a polyester resin is preferable.
The thermoplastic resin (A) is preferably a polyolefin resin from the viewpoint of being inexpensive but having excellent moldability and mechanical strength.
In the present specification, the polyolefin-based resin includes a polyolefin-based resin having a polar moiety and a polyolefin-based resin having no polar moiety, and when specifying the presence or absence of a polar moiety, the polyolefin-based resin having a polar moiety or the polar moiety is specified. It is described as a polyolefin-based resin that does not have.

(Polyolefin resin)
The polyolefin-based resin as the thermoplastic resin is selected from the group consisting of homopolymers such as polyethylene, polypropylene, polybutene and polymethylpentene, and the group consisting of ethylene, propylene, butene, hexene, octene and 4-methylpentene. Examples thereof include an α-olefin resin made of a copolymer of the monomers to be formed. The polyolefin-based resin as the thermoplastic resin may be a single resin or a combination of two or more resins.

(Polyolefin-based resin with polar regions)
The polar moiety in the polyolefin-based resin having a polar moiety is not particularly limited as long as it is a moiety that can impart polarity to the polyolefin-based resin. Polyolefin-based resins having polar moieties are preferable because they exhibit high adhesive strength to the adherend.
The thermoplastic resin may be a copolymer of an olefin-based monomer and a monomer having a polar moiety. Further, the thermoplastic resin may be a resin obtained by introducing a polar moiety into an olefin polymer obtained by polymerizing an olefin monomer by modification such as an addition reaction.

The type of the olefin-based monomer constituting the polyolefin-based resin having a polar moiety as the thermoplastic resin is not particularly limited. Examples of the olefin-based monomer include ethylene, propylene, butene, hexene, octene, 4-methyl-1-pentene and the like. The olefin-based monomer may be used alone or in combination of two or more.
Ethylene and polypropylene are preferable as the olefin-based monomer from the viewpoint of excellent mechanical strength and stable adhesive properties.
The olefin-derived structural unit in the polyolefin-based resin having a polar moiety is preferably ethylene or a structural unit derived from propylene.

Examples of the polar moiety include a hydroxyl group, a carboxy group, a vinyl acetate structure, an acid anhydride structure, and the like.

(Dielectric filler (B))
The high-frequency dielectric heating adhesive sheet according to the present embodiment preferably further contains a dielectric filler (B) that generates heat by applying a high-frequency electric field.
The dielectric filler (B) is preferably a filler that generates heat when a high frequency electric field having a frequency range of 3 MHz or more and 300 MHz or less is applied. The dielectric filler (B) is preferably a filler that generates heat by applying a high frequency electric field having a frequency of 13.56 MHz, 27.12 MHz, 40.68 MHz, etc., in a frequency range of 3 MHz or more and 300 MHz or less.

(kinds)
The dielectric filler (B) includes zinc oxide, silicon carbide (SiC), anatase-type titanium oxide, barium titanate, barium titanate, lead titanate, potassium niobate, rutyl-type titanium oxide, and hydrated aluminum silicate. It is preferable to use one kind or a combination of two or more kinds of an inorganic material having crystalline water such as hydrated aluminosilicate of an alkali metal or an inorganic material having crystalline water such as hydrated aluminosilicate of an alkaline earth metal.

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

Among the exemplified dielectric fillers, the dielectric filler (B) is oxidized because there are a wide variety of types, which can be selected from various shapes and sizes, and the adhesive properties and mechanical properties of the high-frequency dielectric heating adhesive sheet can be improved according to the application. Zinc is even more preferred. By using zinc oxide as the dielectric filler (B), a colorless high-frequency dielectric heating adhesive sheet can be obtained. Since zinc oxide has the lowest density among the dielectric fillers, when the adherend is bonded using a high-frequency dielectric heating adhesive sheet containing zinc oxide as the dielectric filler (B), a sheet containing another dielectric filler is used. It is difficult to increase the total weight of the bonded body as compared with the case where it was used. Zinc oxide is not too hard among ceramics, so it does not easily damage the equipment for manufacturing high-frequency dielectric heating adhesive sheets. Since zinc oxide is an inert oxide, even if it is mixed with a thermoplastic resin, it causes less damage to the thermoplastic resin.
Further, the titanium oxide as the dielectric filler (B) is preferably at least one of anatase-type titanium oxide and rutile-type titanium oxide, and more preferably anatase-type titanium oxide from the viewpoint of excellent dielectric properties. ..

(Volume content)
The volume content of the dielectric filler (B) in the adhesive layer is preferably 10% by volume or more, more preferably 15% by volume or more.
The volume content of the dielectric filler (B) in the adhesive layer is preferably 50% by volume or less, more preferably 40% by volume or less, further preferably 35% by volume or less, and 25% by volume. The following is even more preferable.
When the volume content of the dielectric filler (B) in the adhesive layer is 10% by volume or more, the application time can be further shortened.
Since the volume content of the dielectric filler (B) in the adhesive layer is 50% by volume or less, it is less likely to become brittle, and therefore adhesive strength can be easily obtained.

(Average particle size)
The volume average particle diameter of the dielectric filler (B) is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more.
The volume average particle size of the dielectric filler (B) is preferably 30 μm or less, more preferably 25 μm or less, and further preferably 20 μm or less.
When the volume average particle diameter of the dielectric filler (B) is 1 μm or more, the high-frequency dielectric heating adhesive sheet exhibits high heat generation performance when a high-frequency electric field is applied, and the adhesive layer is firmly attached to the adherend in a short time. Can be glued.
Since the volume average particle diameter of the dielectric filler (B) is 30 μm or less, the high-frequency dielectric heating adhesive sheet exhibits high heat generation performance when a high-frequency electric field is applied, and the adhesive layer is firmly attached to the adherend in a short time. Can be glued. Further, when the volume average particle diameter of the dielectric filler (B) is 30 μm or less, it is possible to prevent the strength of the high-frequency dielectric heating adhesive sheet from decreasing.

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

In the high-frequency dielectric heating adhesive sheet according to the present embodiment, it is preferable that the average particle diameter _DF of the dielectric filler (B) and the thickness T of the adhesive layer satisfy the relationship of 1 ≦ T / _DF ≦ 2500.
The 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 the T / D _F is 1 or more, it is possible to prevent a decrease in adhesive strength due to contact between the dielectric filler (B) and the adherend during adhesion.
The T / D _F is preferably 2500 or less, preferably 2000 or less, preferably 1750 or less, more preferably 1000 or less, further preferably 500 or less, and even more preferably 100 or less. Is even more preferable, and 50 or less is even more preferable. When the T / D _F is 2500 or less, the load on the sheet manufacturing apparatus can be suppressed when the high-frequency dielectric heating adhesive sheet is manufactured.

(Additive)
The high-frequency dielectric heating adhesive sheet according to the present embodiment may or may not contain an additive. When the high-frequency dielectric heating adhesive sheet according to the present embodiment is 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, the adhesive layer may or may not contain the additive.

When the high-frequency dielectric heating adhesive sheet according to the present embodiment contains an additive, the additive may be, for example, a tackifier, a plasticizer, a silane coupling agent, a wax, a colorant, an antioxidant, an ultraviolet absorber, and an antibacterial agent. Agents, viscosity modifiers, organic fillers, inorganic fillers and the like can be mentioned. Organic fillers and inorganic fillers as additives are different from dielectric fillers.

The tackifier and the plasticizer can improve the melting property and the bonding property of the high frequency dielectric heating adhesive sheet.
Examples of the tackifier include rosin derivatives, polyterpene resins, aromatic-modified terpene resins, hydrides of aromatic-modified terpene resins, terpene phenol resins, kumaron inden resins, aliphatic petroleum resins, aromatic petroleum resins, and aromatics. Examples include hydrides of group petroleum resins.
Examples of the plasticizer include petroleum-based process oils, natural oils, dialkyl dibasates, and low molecular weight liquid polymers. Examples of the petroleum-based process oil include paraffin-based process oils, naphthen-based process oils, aromatic process oils, and the like. Examples of the natural oil include castor oil, tall oil and the like. Examples of the dialkyl dibasic acid include dibutyl phthalate, dioctyl phthalate, and dibutyl adipate. Examples of the low molecular weight liquid polymer include liquid polybutene and liquid polyisoprene.

When the high-frequency dielectric heating adhesive sheet according to the present embodiment contains an additive, the content of the additive in the high-frequency dielectric heating adhesive sheet is usually 0.01% by mass or more based on the total amount of the high-frequency dielectric heating adhesive sheet. Is more preferable, 0.05% by mass or more is more preferable, and 0.1% by mass or more is further preferable. The content of the additive in the high-frequency dielectric heating adhesive sheet is preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less.

The high-frequency dielectric heating adhesive sheet according to this embodiment preferably does not contain a solvent. According to the high-frequency dielectric heating adhesive sheet containing no solvent, the problem of VOC (Volatile Organic Compounds) caused by the adhesive used for adhesion to the adherend is unlikely to occur.

The adhesive layer of the high-frequency dielectric heating adhesive sheet according to the present embodiment preferably does not contain carbon or a carbon compound containing carbon as a main component (for example, carbon black or the like) and a conductive substance such as 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.

When the adhesive layer contains a conductive substance, the content of the conductive substance in the adhesive layer is preferably 20% by mass or less, preferably 10% by mass or less, based on the total amount of the adhesive layer. It is more preferably 5% by mass or less, further preferably 1% by mass or less, and even more preferably 0.1% by mass or less.
The content of the conductive substance in the adhesive layer is particularly preferably 0% by mass.
When the content of the conductive substance in the adhesive layer is 20% by mass or less, it becomes easy to prevent the problem of carbonization of the adhesive portion and the adherend due to electrical dielectric breakdown during the dielectric heat treatment.

The total content of the thermoplastic resin (A) and the dielectric filler (B) in the adhesive layer of the high-frequency dielectric heating adhesive sheet according to the present embodiment is preferably 80% by mass or more, preferably 90% by mass or more. More preferably, it is more preferably 99% by mass or more.

The high-frequency dielectric heating adhesive sheet according to the present embodiment comprises only one layer of the high-frequency dielectric heating-adhesive adhesive layer in one embodiment. The high-frequency dielectric heating adhesive sheet according to the present invention is not limited to the embodiment consisting of only one layer of the adhesive layer, and another aspect of the high-frequency dielectric heating adhesive sheet is an embodiment in which layers other than the adhesive layer are laminated. Can be mentioned.
As described above, since the high-frequency dielectric heating adhesive sheet may consist of only one layer of the high-frequency dielectric heating adhesive layer, the terms "high-frequency dielectric heating adhesive sheet" and "adhesive layer" are used in the present specification. The terms can be interchanged with each other in some cases.
FIGS. 2A to 2C exemplify schematic views of a plurality of embodiments of the high-frequency dielectric heating adhesive sheet according to the present embodiment.

The high-frequency dielectric heating adhesive sheet 1A shown in FIG. 2A is composed of only a single adhesive layer 10.
The high frequency dielectric heating adhesive sheet preferably comprises only a single adhesive layer. Since it is composed of only a single adhesive layer, the thickness of the high-frequency dielectric heating adhesive sheet can be reduced, and it can be easily molded.

The high-frequency dielectric heating adhesive sheet 1B shown in FIG. 2B 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 layer. It has one surface 11. The base material 30 is not particularly limited as long as it is a member capable of supporting the adhesive layer 10, but for example, a polyolefin resin such as polyethylene resin or polypropylene resin, a polyester resin such as polybutylene terephthalate resin or polyethylene terephthalate resin, an acetate resin, or ABS. Examples thereof include a resin film or a resin sheet containing at least one resin selected from the group consisting of a resin, a polystyrene resin, a vinyl chloride resin and the like. 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 are the same as or different from each other.

The high frequency dielectric heating adhesive sheet 1C shown in FIG. 2C has an intermediate layer 40 arranged 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. The adhesive layer 10 in the high-frequency dielectric heating adhesive sheet 1C may be referred to as a first adhesive layer, and the adhesive layer 20 may be referred to as a second adhesive layer. In the high-frequency dielectric heat-bonded sheet having an intermediate layer arranged between the first adhesive layer and the second adhesive layer, the first adhesive layer satisfies the conditions of the adhesive layer of the high-frequency dielectric heat-bonded sheet according to the present embodiment. In one embodiment, both the first adhesive layer and the second adhesive layer are layers having the same composition and characteristics, and in one embodiment, the second adhesive layer has the same composition and composition as the first adhesive layer. High frequency dielectric heat-adhesive layers that differ in at least any one of their properties, and in one embodiment, the second adhesive layer is a general adhesive layer that is not a high frequency dielectric heat adhesive layer and is a high frequency dielectric. The second adhesive layer that is not heat-adhesive is, for example, a dry-solidified adhesive layer that evaporates and solidifies with water or a solvent, or a pressure-sensitive adhesive layer formed of a pressure-sensitive adhesive (pressure-sensitive adhesive). ..

(Form and characteristics of high-frequency dielectric heating adhesive sheet)
The high-frequency dielectric heating adhesive sheet according to the present embodiment may be composed of only one layer of the adhesive layer in one embodiment, and may be composed of a plurality of layers in another embodiment. When the high-frequency dielectric heating adhesive sheet consists of only one layer of the adhesive layer, the adhesive layer itself corresponds to the high-frequency dielectric heating adhesive sheet, so that the form and characteristics of the high-frequency dielectric heating adhesive sheet correspond to the form and characteristics of the adhesive layer. ..

(Thickness of 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, still more preferably 50 μm or more. ..
When the thickness of the high-frequency dielectric heating adhesive sheet is 5 μm or more, the high-frequency dielectric heating adhesive sheet easily follows the unevenness of the adherend when adhering to the adherend, and the adhesive strength is easily developed.
When the high-frequency dielectric heating adhesive sheet has a multi-layer 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 further preferably 50 μm. The above is even more preferable.
When the high-frequency dielectric heating adhesive sheet is a multi-layered sheet, if the thickness of the adhesive layer is 5 μm or more, the adhesive layer easily follows the unevenness of the adherend when adhering to the adherend, and the adhesive strength is high. Is more likely to occur.
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 adhering the high-frequency dielectric heating adhesive sheet and the adherend also increases, so that the high-frequency dielectric heating adhesive sheet has no problem in actual use. It is preferably in the range of thickness. 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 further preferably 600 μm or less. ..

(Dielectric characteristics of high-frequency dielectric heating adhesive sheet (tan δ / ε'))
The dielectric loss tangent (tan δ) and the dielectric constant (ε') as the dielectric properties of the high-frequency dielectric heating adhesive sheet can be measured according to JIS C 2138: 2007, but they are simple and easy to measure according to the impedance material method. It can be measured accurately.
The dielectric property (tan δ / ε') of the high-frequency dielectric heating adhesive sheet is preferably 0.005 or more, more preferably 0.008 or more, and further preferably 0.01 or more. Further, the dielectric property (tan δ / ε') of the high-frequency dielectric heating adhesive sheet is preferably 0.08 or less, and more preferably 0.05 or less. The dielectric property (tan δ / ε') is a value obtained by dividing the dielectric loss tangent (tan δ) measured using an impedance material device or the like by the dielectric constant (ε') measured using an impedance material device or the like.
If the dielectric property of the high-frequency dielectric heating adhesive sheet is 0.005 or more, there is a problem that it becomes difficult to firmly bond the adherends to each other without generating a predetermined heat when the dielectric heat treatment is performed. Can be prevented.
If the dielectric property of the high-frequency dielectric heating adhesive sheet is 0.08 or less, damage to the adherend is unlikely to occur.
The details of the method for measuring the dielectric properties of the high-frequency dielectric heating adhesive sheet are as follows. Dielectric constant (ε') and dielectric loss tangent (tanδ) of a high-frequency dielectric heating adhesive sheet cut to a predetermined size using an impedance material analyzer E4991 (manufactured by Agent) under the condition of a frequency of 40.68 MHz at 23 ° C. Are measured respectively, and the value of the dielectric property (tan δ / ε') is calculated.

(Manufacturing method of high-frequency dielectric heating adhesive sheet)
In the single-layer high-frequency dielectric heating adhesive sheet, each of the above components is premixed and kneaded using a known kneading device such as an extruder and a heat roll, and extrusion molding, calendar molding, injection molding, and casting molding are performed. It can be manufactured by a known molding method such as.
When the high-frequency dielectric heating adhesive sheet according to the present embodiment has a multi-layer structure, for example, each of the above components can be premixed and manufactured by a coextrusion method using a multi-layer extruder. In addition, a single-layer sheet of each layer (for example, a first adhesive layer, an intermediate layer, and a second adhesive layer) constituting the high-frequency dielectric heating adhesive sheet according to the present embodiment is individually produced, and a plurality of single-layer sheets are formed. A multi-layered sheet can also be manufactured by laminating and laminating. When laminating a plurality of single-layer sheets, for example, a thermal laminator is used.
Further, the high-frequency dielectric heat-bonded sheet according to the present embodiment can also be produced by a hot-extrusion coating in which a melted adhesive layer is coated on a base material, or a hot-melt coating, and the adhesive layer composition is dispersed or dissolved in a solvent. It can also be produced by a wet coating in which the coated liquid is coated on the substrate.

[Second Embodiment]
Next, the second embodiment of the present invention will be described.
In this embodiment, the configuration is the same as that of the first embodiment except that the first step and the second step are specified based on the applied energy per unit area instead of the applied output per unit area. The first step and the second step will be described, and the other description will be omitted.
The bonding method according to the present embodiment is a first step of applying a high frequency electric field of applied energy J1 per unit area to the high frequency dielectric heating adhesive sheet, and a unit area of the high frequency dielectric heating adhesive sheet after the first step. A second step of applying a high-frequency electric field of the applied energy J2 per unit is provided, and the applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step are the following mathematical formulas. The condition represented by (Equation 3) is satisfied. In the present embodiment, as in the first embodiment, a mode in which the first adherend and the second adherend are adhered to each other by using a high-frequency dielectric heating adhesive sheet composed of a single adhesive layer. I will explain it by citing it.
J1> 0.75 x J2 ... (number 3)
Here, J1 and J2 can be calculated by the following mathematical formulas (Equation 4-1) and (Equation 4-2), respectively.
J1 (W / mm ² · sec) = T1 × V1 ... (Equation 4-1)
J2 (W / mm ² · sec) = T2 × V2 ... (Equation 4-2)

If the condition expressed by the above mathematical formula (Equation 3) is not satisfied, the adhesive strength cannot be improved while shortening the application time of the high frequency electric field. The applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step are both more than 0 W / mm ² · sec.
From the same viewpoint, the lower limit of the applied energy J1 per unit area of the first step is preferably 0.85 times or more the value of the applied energy J2 per unit area of the second step, and the second step. It is more preferable that the applied energy is 1 times or more the value of J2 per unit area.
Further, from the viewpoint of shortening the application time, the upper limit of the applied energy J1 per unit area of the first step is preferably 10 times or less the value of the applied energy J2 per unit area of the second step. It is more preferable that it is 5 times or less the value of the applied energy J2 per unit area of the two steps.

In the present embodiment, the applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 3-1). preferable.
0.9> J1 / (J1 + J2)> 0.4 ... (Equation 3-1)
When the condition expressed by the above formula (Equation 3-1) is satisfied, it is easy to improve the adhesive strength.
From the same viewpoint, the upper limit of the value of J1 / (J1 + J2) is preferably 0.85 or less, more preferably 0.8 or less, and particularly preferably 0.75 or less. The lower limit of the value of J1 / (J1 + J2) is preferably 0.42 or more, more preferably 0.44 or more, and particularly preferably 0.5 or more.

The applied energy J1 per unit area in the first step is preferably 2 W / mm ² · sec or more, more preferably 3 W / mm ² · sec or more, and 3.5 W / mm ² · sec or more. It is particularly preferable to have. The applied energy J1 per unit area in the first step is preferably 9 W / mm ² · sec or less, more preferably 7 W / mm ² · sec or less, and 5 W / mm ² · sec or less. Is particularly preferable.
When the applied energy J1 per unit area in the first step is 2 W / mm ² · sec or more, it is possible to prevent the problem that the resin is unlikely to be in a molten state, so that it is easy to obtain a good adhesive force.
If the applied energy J1 per unit area in the first step is 9 W / mm ² · sec or less, it is possible to prevent the problem that the resin foams and the adhesive strength decreases, so that good adhesive strength can be easily obtained.

The total applied energy (J1 + J2), which is the total of the applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step, is preferably 3 W / mm ² · sec or more. It is more preferably 4.5 W / mm ² · sec or more, and particularly preferably 6 W / mm ² · sec or more. The total applied energy (J1 + J2) is preferably 20 W / mm ² · sec or less, more preferably 15 W / mm ² · sec or less, and particularly preferably 10 W / mm ² · sec or less.
When the value of the total applied energy (J1 + J2) is within the above range, the adhesive strength can be easily improved.

[Modification of Embodiment]
The present invention is not limited to the above embodiment. The present invention can include modifications and improvements to the extent that the object of the present invention can be achieved.

In the above embodiment, the second step is performed following the first step, but the present invention is not limited to this. For example, another step may be performed between the first step and the second step as long as the effect of the present invention is not impaired. Here, as another step, as the first step, a step of performing high-frequency dielectric heating in the first step and then leaving it for a while may be mentioned.

The high-frequency dielectric heating treatment is not limited to the dielectric heating and bonding device in which the electrodes described in the above embodiment are arranged to face each other, and a lattice electrode type high-frequency dielectric heating device may be used. The lattice electrode type high-frequency dielectric heating device has lattice electrodes in which electrodes of the first polarity and electrodes of the second polarity opposite to the electrodes of the first polarity are alternately arranged on the same plane at regular intervals. ..
For example, in the case of manufacturing a bonded body in which the end portion of the first adherend and the end portion of the second adherend are overlapped and adhered, the end portion is on the first adherend side or the second adherend side. A lattice electrode type high frequency dielectric heating device is arranged to apply a high frequency electric field.

When the first adherend and the second adherend are adhered to each other by using a lattice electrode type high frequency dielectric heating device, the first lattice electrode is arranged on the side of the first adherend, and the second A second lattice electrode is arranged on the adherend side, and the first adherend, the high-frequency dielectric heating adhesive sheet and the second adherend are placed between the first lattice electrode and the second lattice electrode. A high-frequency electric field may be applied at the same time by sandwiching the mixture.

When the first adherend and the second adherend are adhered to each other by using a lattice electrode type high frequency dielectric heating device, the first adherend and the second adherend are placed on one surface side. A lattice electrode may be arranged and a high frequency electric field may be applied, and then the lattice electrode may be arranged on the other surface side of the first adherend and the second adherend and the high frequency electric field may be applied.

It is also preferable to use a lattice electrode type high frequency dielectric heating device for applying a high frequency electric field. By using a lattice electrode type high-frequency dielectric heating device, the surface layer of the first adherend and the second adherend is not affected by the thickness of the first adherend and the second adherend. The adherends can be bonded to each other by dielectric heating from the side, for example, from the adherend side where the distance to the high-frequency dielectric heating adhesive sheet is short. Further, by using a lattice electrode type high frequency dielectric heating device, it is possible to realize energy saving in the manufacture of the bonded body.

In addition, in the figure, an embodiment using a dielectric heating adhesive device in which electrodes are arranged facing each other is exemplified for simplification.

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

[Making a high-frequency dielectric heating adhesive sheet]
Maleic anhydride copolymer polypropylene (manufactured by Mitsubishi Chemical Corporation, Modic P565, hereinafter referred to as component A) as a thermoplastic resin component is 80.0% by volume, and zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd.) is used as a component B. LPZINC11, average particle size: 11 μm, hereinafter referred to as component B.) 20.0% by volume were weighed in the container.
The weighed components A and B were premixed in a container. After premixing each component, it is supplied to the hopper of a 30 mmΦ twin-screw extruder, the cylinder set temperature is set to 180 ° C or higher and 200 ° C or lower, the die temperature is set to 200 ° C, and melt-kneading is performed to obtain granular pellets. rice field.
Next, the obtained granular pellets were put into a hopper of a single-screw extruder equipped with a T-die, and a film-like melt-kneaded product was obtained from the T-die under the conditions of a cylinder temperature of 200 ° C. and a die temperature of 200 ° C. By extruding and cooling with a cooling roll, a high-frequency dielectric heating adhesive sheet having a thickness of 400 μm was produced.
With respect to the obtained sheet, the dielectric material test fixture 16453A (manufactured by Agilent) was attached to the impedance material analyzer E4991ARF (manufactured by Agilent), and the ratio was obtained by the parallel plate method under the condition of a frequency of 40.68 MHz at 23 ° C. The permittivity (ε'r) and the dielectric loss tangent (tanδ) were measured. Based on the measurement results, the value of the dielectric property (tan δ / ε'r) was calculated. The dielectric property (tan δ / ε'r) of the obtained high-frequency dielectric heating adhesive sheet was 0.014.

[Example 1]
The produced high-frequency dielectric heating adhesive sheet was cut into a size of 25 mm × 12.5 mm. After sandwiching the cut high-frequency dielectric heating adhesive sheet between epoxy glass plates (25 mm x 100 mm x 1.5 mm) as a pair of adherends, a high-frequency dielectric heating device (manufactured by Yamamoto Vinita Co., Ltd., TRP-400T-) The frequency was set to 40.68 MHz and the estimated pressing pressure was set to 192.8 N in a state of being fixed between the electrodes of RC).
Then, as the first step, the applied area is set to 312.5 mm ² , the applied output is set to 100 W (the applied output V1 per unit area is 0.32 W / mm ² ), and the applied time is set to 15 seconds. High frequency dielectric heating was performed. Next, as the second step, the applied area is set to 312.5 mm ² , the applied output is set to 50 W (the applied output V2 per unit area is 0.16 W / mm ² ), and the applied time is set to 10 seconds, and the second step is performed. High-frequency dielectric heating of the eyes was performed to prepare a bonded body. Table 1 shows the applied output, the applied time T1, and the applied output V1 per unit area in the first step, and the applied output, the applied time T2, and the applied output V2 per unit area in the second step. Further, the applied energy J1 per unit area in the first step, the applied energy J2 per unit area in the second step, the total applied time (T1 + T2), the total applied energy (J1 + J2), and the values of J1 / (J1 + J2) are set. , Table 2.
The bonding strength of the obtained bonded body was measured according to JIS K 6850. The results obtained are shown in Table 1.

[Examples 2 to 8]
A bonded body was produced in the same manner as in Example 1 except that the conditions of the first step and the second step were changed as shown in Table 1 below. Moreover, the bonding strength of the obtained bonded body was measured by the same method as in Example 1. The results obtained are shown in Table 1. Further, the values of the applied energy J1 per unit area in the first step, the applied energy J2 per unit area in the second step, the total applied time (T1 + T2), the total applied energy (J1 + J2), and J1 / (J1 + J2) are set. , Table 2.

[Comparative Example 1]
In the same manner as in Example 1, the cut high-frequency dielectric heating adhesive sheet was sandwiched between a pair of epoxy glass plates as adherends, and then set in the high-frequency dielectric heating device.
Then, without dividing the high-frequency dielectric heating into two stages, the applied area is set to 312 mm ² , the applied output is set to 100 W (the applied output V1 per unit area is 0.32 W / mm ² ), and the applied time is set to 30 seconds. High-frequency dielectric heating was performed to prepare a bonded body. Table 1 shows the applied output, the applied time, and the applied output V1 per unit area in high-frequency dielectric heating. Table 2 shows the applied energy J1 per unit area in high-frequency dielectric heating, the total applied time (T1 + T2), the total applied energy (J1 + J2), and the values of J1 / (J1 + J2).

[Comparative Examples 2 to 4]
A bonded body was produced in the same manner as in Comparative Example 1 except that the conditions for high-frequency dielectric heating were changed as shown in Table 1 below. Moreover, the bonding strength of the obtained bonded body was measured by the same method as in Example 1. The results obtained are shown in Table 1. Table 2 shows the applied energy J1 per unit area in high-frequency dielectric heating, the total applied time (T1 + T2), the total applied energy (J1 + J2), and the values of J1 / (J1 + J2).

[Comparative Example 5]
A bonded body was produced in the same manner as in Example 1 except that the conditions of the first step and the second step were changed as shown in Table 1 below. Moreover, the bonding strength of the obtained bonded body was measured by the same method as in Example 1. The results obtained are shown in Table 1. Further, the values of the applied energy J1 per unit area in the first step, the applied energy J2 per unit area in the second step, the total applied time (T1 + T2), the total applied energy (J1 + J2), and J1 / (J1 + J2) are set. , Table 2.

According to the bonding methods of Examples 1 to 8, it was possible to shorten the application time of the high frequency electric field and improve the bonding strength even when the high frequency electric field was applied for a short time.

10 ... Adhesive layer (first adhesive layer), 11 ... First surface, 110 ... Adhesive, 120 ... Adhesive, 1A ... High frequency dielectric heating adhesive sheet, 1B ... High frequency dielectric heating adhesive sheet, 1C ... High frequency dielectric heating Adhesive sheet, 20 ... Adhesive layer (second adhesive layer), 21 ... Second surface, 30 ... Substrate, 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 (12)

It is a method of adhering an adherend with a high-frequency dielectric heating adhesive sheet.
The high-frequency dielectric heating adhesive sheet contains a thermoplastic resin (A) and contains.
The first step of applying a high-frequency electric field of an applied output V1 per unit area to the high-frequency dielectric heating adhesive sheet,
The high-frequency dielectric heating adhesive sheet after the first step is provided with a second step of applying a high-frequency electric field of an applied output V2 per unit area.
The applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 1).
Adhesion method.
V1> V2 ... (number 1) The applied output V1 per unit area of the first step and the applied output V2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 1-1).
The bonding method according to claim 1.
0.8 × V1 ≧ V2 ... (Equation 1-1) The applied output V1 per unit area in the first step is 0.18 W / mm ² or more and 2.00 W / mm ² or less.
The bonding method according to claim 1 or 2. The application time T1 of the first step is 1 second or more and less than 25 seconds.
The bonding method according to any one of claims 1 to 3. The applied output V2 per unit area in the second step is 0.09 W / mm ² or more and 0.30 W / mm ² or less.
The bonding method according to any one of claims 1 to 4. The application time T2 of the second step is 5 seconds or more.
The bonding method according to any one of claims 1 to 5. The application time T1 of the first step and the application time T2 of the second step satisfy the condition represented by the following mathematical formula (Equation 2).
The bonding method according to any one of claims 1 to 6.
(T1 + T2) <60 seconds ... (number 2) It is a method of adhering an adherend with a high-frequency dielectric heating adhesive sheet.
The high-frequency dielectric heating adhesive sheet contains a thermoplastic resin (A) and contains.
The first step of applying a high-frequency electric field of applied energy J1 per unit area to the high-frequency dielectric heating adhesive sheet, and
The high-frequency dielectric heating adhesive sheet after the first step is provided with a second step of applying a high-frequency electric field of applied energy J2 per unit area.
The applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 3).
Adhesion method.
J1> 0.75 x J2 ... (number 3) The applied energy J1 per unit area of the first step and the applied energy J2 per unit area of the second step satisfy the conditions represented by the following mathematical formula (Equation 3-1).
The bonding method according to claim 8.
0.9> J1 / (J1 + J2)> 0.4 ... (Equation 3-1) The thermoplastic resin (A) is a polyolefin resin.
The bonding method according to any one of claims 1 to 9. The high-frequency dielectric heating adhesive sheet further contains a dielectric filler (B) that generates heat by applying a high-frequency electric field.
The bonding method according to any one of claims 1 to 10. The dielectric filler (B) comprises at least one selected from the group consisting of zinc oxide, silicon carbide, barium titanate and titanium oxide.
The bonding method according to claim 11.

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