JP2020163788A - High-frequency dielectric heating adhesive sheet for footwear, footwear, and method for manufacturing footwear - Google Patents

Abstract

To provide a high-frequency dielectric heating adhesive sheet for footwear which can join members for footwear with high strength while preventing a damage by heat of the members for footwear.SOLUTION: A high-frequency dielectric heating adhesive sheet 1 for footwear has a high-frequency dielectric adhesive layer, in which the high-frequency dielectric adhesive layer contains a thermoplastic resin (A) and a dielectric filler (B), and the high-frequency dielectric adhesive layer contains 10 vol.% or more and 50 vol.% or less of the dielectric filler (B) and is used for joining members for footwear constituting the footwear.SELECTED DRAWING: Figure 2

Description

The present invention relates to a high-frequency dielectric heating adhesive sheet for footwear, footwear, and a method for manufacturing footwear.

As a method of joining a plurality of footwear members constituting the footwear to each other, for example, suturing or adhesion can be mentioned.

For example, Patent Document 1 describes a technique for joining an insole and an outsole by high-frequency welding using a bottom sheet made of a thermoplastic resin.

Japanese Unexamined Patent Publication No. 2010-273695

In the joining technique according to Patent Document 1, thermoplastic polyurethane resin, polyvinyl chloride resin, etc., which are thermoplastic resins capable of high-frequency welding, are used as the material of the outer material constituting the instep and the material of the bottom sheet made of thermoplastic resin. It is stated that it will be used. According to Patent Document 1, a shoe body is assembled by joining a bottom sheet made of a thermoplastic resin made of such a material and an instep by high-frequency welding with a welder, and the shoe body and the outsole are bonded to each other. To obtain waterproof shoes.
Therefore, when the joining technique described in Patent Document 1 is adopted, since the instep cover is made of a material capable of high frequency welding, the instep cover may be heated during high frequency welding and may be damaged by heat. Further, since the shoe body and the outsole are bonded by an adhesive instead of high-frequency welding, there is a possibility that a problem of solvent or a problem of bonding strength may occur.

Further, there is a demand for a high-frequency dielectric heating adhesive sheet capable of more firmly joining various footwear members without stitching.

An object of the present invention is to provide a high-frequency dielectric heating adhesive sheet for footwear capable of joining footwear members with high strength while preventing damage to the footwear members due to heat.
Another object of the present invention is also to provide a footwear using the high-frequency dielectric heating adhesive sheet for footwear, and a method for manufacturing the footwear.

According to one aspect of the present invention, the high frequency dielectric adhesive layer has a high frequency dielectric adhesive layer, and the high frequency dielectric adhesive layer contains a thermoplastic resin (A) and a dielectric filler (B), and the high frequency dielectric adhesive. The layer contains the dielectric filler (B) in an amount of 10% by volume or more and 50% by volume or less, and provides a high-frequency dielectric heating adhesive sheet for footwear used for joining the footwear members constituting the footwear.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the dielectric filler (B) is preferably zinc oxide, silicon carbide, or barium titanate.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the thermoplastic resin (A) is preferably a polyolefin resin having a polar portion.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the Young's modulus of the high-frequency dielectric heating adhesive sheet for footwear is preferably 40 MPa or more and 600 MPa or less.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the softening temperature of the high-frequency dielectric heating adhesive sheet for footwear measured in accordance with JIS K 7196: 2012 is 50 ° C. or higher and 210 ° C. or lower. Is preferable.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the melt flow rate of the high-frequency dielectric adhesive layer is preferably 1 g / 10 minutes or more and 80 g / 10 minutes or less.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the loss tangent peak temperature of the high-frequency dielectric adhesive layer at 1 Hz is preferably 0 ° C. or lower.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the footwear member is at least one selected from the group consisting of natural leather, synthetic leather, natural fiber, chemical fiber, resin molded body, and rubber molded body. Is preferable.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, it is preferable that at least one of the footwear members is a foam.

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the rate of change R1 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the wet heat test is 80% or more and 120% or less. Is preferable.
Rate of change R1 = {(tensile fracture stress after wet heat test) / (tensile fracture stress before wet heat test)} × 100
(The moist heat test is a test in which the high-frequency dielectric heating adhesive sheet for footwear is placed under the conditions of a temperature of 85 ° C. and a humidity of 85% RH for 7 days.
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear is measured in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999. )

In the high-frequency dielectric heating adhesive sheet for footwear according to one aspect of the present invention, the rate of change R2 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the dynamic flexibility test is 80% or more and 120% or less. Is preferable.
Rate of change R2 = {(tensile fracture stress after dynamic flexibility test) / (tensile fracture stress before dynamic flexibility test)} × 100
(In the dynamic flexibility test, a sample having a size of 150 mm (MD direction) × 15 mm (TD direction) was prepared from the high-frequency dielectric heating adhesive sheet for footwear, and the bending conditions were a minimum bending diameter of 10 mmφ and the number of bendings. This test is performed 30,000 times under the condition that the bending speed is 30 rpm.
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear is measured in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999.

According to one aspect of the present invention, the first footwear member and the second footwear member as the footwear member are joined by the high-frequency dielectric heating adhesive sheet for footwear according to the above-described aspect of the present invention. Footwear is provided.

According to one aspect of the present invention, there is provided a method for manufacturing footwear, which comprises a step of joining the footwear members using the high-frequency dielectric heating adhesive sheet for footwear according to the above-described aspect of the present invention.

In the method for manufacturing footwear according to one aspect of the present invention.
The footwear member includes a first footwear member and a second footwear member.
A step of arranging the high-frequency dielectric heating adhesive sheet for footwear between the first footwear member and the second footwear member, and
A step of performing a dielectric heating treatment on a high-frequency dielectric heating adhesive sheet for footwear arranged between the first footwear member and the second footwear member under conditions of a frequency of 1 MHz or more and 100 MHz or less. , Are preferably included.

In the method for manufacturing footwear according to one aspect of the present invention.
It is preferable that the high frequency output in the step of performing the dielectric heating treatment is 0.01 kW or more and 20 kW or less, and the high frequency application time is 1 second or more and 60 seconds or less.

According to one aspect of the present invention, it is possible to provide a high-frequency dielectric heating adhesive sheet for footwear capable of joining footwear members with high strength while preventing damage to the footwear members due to heat.
Further, according to another aspect of the present invention, it is possible to provide a footwear using the high-frequency dielectric heating adhesive sheet for footwear, and a method for manufacturing the footwear.

(A) is a side view of the footwear according to the first embodiment, and (B) is a side view showing the footwear members constituting the footwear according to the first embodiment separately. It is sectional drawing explaining the manufacturing method of the footwear which concerns on 1st Embodiment. (A) is a side view of the footwear according to the second embodiment, and (B) is a side view showing the footwear members constituting the footwear according to the second embodiment separately. It is sectional drawing which explains the manufacturing method of the footwear which concerns on the modification.

[First Embodiment]
[High-frequency dielectric heating adhesive sheet for footwear]
The high-frequency dielectric heating adhesive sheet for footwear according to the present embodiment includes a high-frequency dielectric adhesive layer. The high frequency dielectric adhesive layer contains a thermoplastic resin (A) and a dielectric filler (B). The high-frequency dielectric heating adhesive sheet for footwear according to the present embodiment is used for joining members for footwear. In the present specification, the thermoplastic resin (A) may be referred to as a component A. In the present specification, the dielectric filler (B) may be referred to as a B component.
Details of the high-frequency dielectric heating adhesive sheet for footwear and the high-frequency dielectric adhesive layer will be described later.

(1) Usage of High Frequency Dielectric Heating Adhesive Sheet The high frequency dielectric heating adhesive sheet for footwear according to the present embodiment is used for joining members for footwear. Footwear can be manufactured by joining footwear members using the high-frequency dielectric heating adhesive sheet for footwear according to the present embodiment. As one aspect of the footwear according to the present embodiment, for example, the first footwear member and the second footwear member as the footwear member are joined by the high-frequency dielectric heating adhesive sheet for footwear according to the present embodiment. Footwear can be mentioned. In the present specification, the high-frequency dielectric heating adhesive sheet for footwear may be referred to as "high-frequency dielectric heating adhesive sheet".

(footwear)
FIG. 1A shows a side view of the footwear 3 according to the first embodiment.
FIG. 1B shows a side view showing a plurality of footwear members constituting the footwear 3 according to the first embodiment separately from each other.
The footwear 3 according to the present embodiment is shoes. The footwear 3 has an instep 11, an insole 12, and an outsole 21. In the footwear 3 according to the present embodiment, the insole 12 is a member for the first footwear, the outsole 21 is a member for the second footwear, and the insole 12 and the outsole 21 are high-frequency dielectric heating adhesive sheets 1 for footwear. It is joined. Further, in the footwear 3 according to the present embodiment, the instep cover 11 is used as a third footwear member, and the instep cover 11 and the outsole 21 are joined by a high-frequency dielectric heating adhesive sheet 1 for footwear. As described above, the number of footwear members according to the present embodiment is at least two, and may be three or more.
Further, the footwear member is not limited to the instep, the insole and the outsole, and may be a conventionally known member (for example, a toecap, a lunar core, etc.) used for other footwear. The instep may be referred to as the upper. The insole is sometimes called an insole. The outsole is sometimes referred to as the outsole.

(Footwear materials)
The members (footwear members) constituting the footwear according to the present embodiment are not particularly limited.
The footwear member is preferably at least one selected from the group consisting of natural leather, synthetic leather, natural fiber, chemical fiber, resin molded product and rubber molded product.

Examples of the resin in synthetic leather, chemical fiber and resin molded body include polyolefin-based (polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin (EVA) and polystyrene, etc.), polyester-based (polyethylene terephthalate, polybutylene terephthalate and polycarbonate). PC), etc.), acrylics, acrylonitrile-butadiene-styrene copolymer (ABS), polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyurethane, nylon, polylactic acid and the like. The synthetic leather in the footwear member, the chemical fiber, and the resin in the resin molded product may be one kind of resin or a combination of two or more kinds of resins.

Examples of the rubber in the rubber molded body include natural rubber and synthetic rubber, and examples of the synthetic rubber include butadiene rubber, styrene-butadiene rubber, acrylonitrile rubber, nitrile-butadiene rubber, isoprene rubber, and urethane rubber. ..

Examples of natural leather include cowhide (calf, kip, steer), horse skin, pig skin, sheep skin, goat skin, kangaroo skin, ostrich skin (ostrich) and reptile skin.

Examples of the synthetic leather include synthetic leather in which a base cloth is coated with a resin such as polyurethane, nylon or polyvinyl chloride.

Examples of chemical fibers include regenerated fibers, semi-synthetic fibers, synthetic fibers and inorganic fibers.

Examples of the recycled fiber include viscous fiber (rayon and polynosic), cuprammonium rayon fiber (cupra), peanut protein fiber, corn protein fiber, soybean protein fiber, mannan fiber, rubber fiber, argin fiber, chitin fiber and casein fiber. Can be mentioned.

Semi-synthetic fibers include, for example, acetate fibers (acetate and triacetate) and promix fibers (promix).

Examples of synthetic fibers include nylon fibers, polyester fibers, aramid fibers, vinylon fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, acrylic fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, and polyurethane fibers. , Polyclar fiber, polylactic acid fiber and the like.

Examples of the inorganic fiber include glass fiber, carbon fiber and metal fiber.

Examples of natural fibers include plant fibers and animal fibers.

Plant fibers include, for example, cotton, cabock, wood pulp, non-wood pulp, hemp, Manila hemp, sisal, New Zealand hemp, Rafu hemp, coconut, rush, and straw.

Animal fibers include animal hair (wool, angora, mohair, cashmere, alpaca, camel, vicuna), silk (silk) and feathers (down, feather).
The footwear member may be composed of one type of fiber or may be composed of two or more types of fibers.

Examples of the material of the instep (upper) include natural leather, artificial leather, synthetic leather, natural fiber, chemical fiber, resin molded body, rubber molded body and the like.

Examples of the material of the insole include a resin molded product, natural fiber, natural leather and the like.

Examples of the material of the outsole include natural leather, rubber molded body, resin molded body and the like. The outsole is also preferably made of foam. When the outsole has a multi-layer structure composed of a midsole and an outsole, examples of the material of the outsole include natural leather, a rubber molded body and a resin molded body, and examples of the material of the midsole include. , Resin molded body and the like.
The footwear member may be composed of one kind of material, or may be made of two or more kinds of materials.

(2) Footwear Manufacturing Method The footwear manufacturing method according to the present embodiment is a step of joining members (footwear members) constituting the footwear using a high-frequency dielectric heating adhesive sheet according to the present embodiment (joining step). Has.
The joining step preferably includes a joining method of joining footwear members by dielectric heating treatment. It is more preferable that the method of joining the footwear members includes the following steps (P1) and (P2).

Step (P1): A step of arranging a high-frequency dielectric heating adhesive sheet for footwear between the first footwear member and the second footwear member.

Step (P2): A step of performing a dielectric heating treatment on a high-frequency dielectric heating adhesive sheet for footwear arranged between a first footwear member and a second footwear member by using a dielectric heating adhesive device.

The step (P1) is a step of arranging the high-frequency dielectric heating adhesive sheet for footwear in a predetermined place. Specifically, the step (P1) is a step of sandwiching a high-frequency dielectric heating adhesive sheet for footwear between the first footwear member and the second footwear member.

The high-frequency dielectric heating adhesive sheet for footwear may be sandwiched between the first footwear member and the second footwear member so that the first footwear member and the second footwear member can be joined. The high-frequency dielectric heating adhesive sheet for footwear may be sandwiched between the first footwear member and the second footwear member at a plurality of places or on the entire surface. From the viewpoint of improving the joint strength between the first footwear member and the second footwear member, the high-frequency dielectric heating adhesive sheet for footwear is sandwiched over the entire joint surface between the first footwear member and the second footwear member. Is preferable.

Further, as one aspect of sandwiching the high-frequency dielectric heating adhesive sheet for footwear in a part between the first footwear member and the second footwear member, the joint surface between the first footwear member and the second footwear member An embodiment in which a high-frequency dielectric heating adhesive sheet for footwear is arranged in a frame shape along the outer periphery of the footwear and sandwiched between the first footwear member and the second footwear member can be mentioned. By arranging the high-frequency dielectric heating adhesive sheet for footwear in a frame shape in this way, the joint strength between the first footwear member and the second footwear member can be obtained, and the high-frequency dielectric heating adhesion for footwear can be obtained over the entire joint surface. The weight of the footwear can be reduced compared to the case where the seat is placed.

Further, according to one aspect in which the high-frequency dielectric heating adhesive sheet for footwear is sandwiched between a part between the first footwear member and the second footwear member, the size of the high-frequency dielectric heating adhesive sheet for footwear to be used can be reduced. The high-frequency dielectric heating treatment time can be shortened as compared with the case where the high-frequency dielectric heating adhesive sheet for footwear is arranged over the entire joint surface.

The step (P2) is a step of performing a dielectric heating treatment on a high-frequency dielectric heating adhesive sheet for footwear arranged between the first footwear member and the second footwear member by using a dielectric heating adhesive device. is there.
Next, the dielectric heating adhesive device used in the step (P2) and the conditions for the dielectric heating treatment thereof will be described. Here, an example of manufacturing the footwear 3 will be described.

(3) Dielectric Heat Adhesive Device FIG. 2 shows a schematic cross-sectional view for explaining a method of joining footwear members (steps (P1) and steps (P2)), which is a part of the footwear manufacturing method. Has been done. Further, FIG. 2 also shows a schematic view of the dielectric heating adhesive device 100 used in the method for joining footwear members according to the present embodiment.
The dielectric heating adhesive device 100 includes a first high frequency application electrode 160, a second high frequency application electrode 180, and a high frequency power supply 200.
The first high frequency application electrode 160 and the second high frequency application electrode 180 are arranged to face each other. The first high frequency application electrode 160 and the second high frequency application electrode 180 have a press mechanism. With this press mechanism, the insole 12, the high-frequency dielectric heating adhesive sheet 1 for footwear, and the outsole 21 can be pressurized between the first high-frequency application electrode 160 and the second high-frequency application electrode 180.
In the joining method according to the present embodiment, the first high frequency application electrode 160 is arranged inside the main body 10 composed of the instep 11 and the insole 12, and the second high frequency application electrode is placed on the lower surface side of the outsole 21. 180 is arranged. As shown in FIG. 2, the first high-frequency application electrode 160 arranged inside the main body 10 preferably has a shape that follows the shape of the insole 12. Since the shape of the first high frequency application electrode 160 follows the shape of the insole 12, the first high frequency application electrode 160 can be easily brought into contact with the insole 12. As a result, the insole 12, the high-frequency dielectric heating adhesive sheet 1 for footwear, and the outsole 21 can be easily sandwiched between the first high-frequency application electrode 160 and the second high-frequency application electrode 180.

When the first high frequency application electrode 160 and the second high frequency application electrode 180 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. In the case of a parallel flat plate type high frequency dielectric heating device, since the high frequency penetrates the high frequency dielectric heating adhesive sheet located between the electrodes, the entire high frequency dielectric heating adhesive sheet can be warmed, 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 200 for applying a high frequency of, for example, a frequency of about 27.12 MHz or a frequency of about 40.68 MHz is connected to each of the first high frequency application electrode 160 and the second high frequency application electrode 180.
As shown in FIG. 2, the dielectric heating adhesive device 100 performs a dielectric heating treatment via a high-frequency dielectric heating adhesive sheet 1 for footwear sandwiched between an insole 12 and an outsole 21. Further, the dielectric heat bonding device 100 adheres the insole 12 and the outsole 21 by a pressure treatment by the first high frequency application electrode 160 and the second high frequency application electrode 180 in addition to the dielectric heat treatment.

When a high-frequency electric field is applied between the first high-frequency application electrode 160 and the second high-frequency application electrode 180, in the overlapping portion of the insole 12 and the outsole 21, the adhesive component in the high-frequency dielectric heating adhesive sheet 1 for footwear The dispersed dielectric filler (not shown) absorbs high frequency energy.
Then, the dielectric filler as the B component functions as a heat generating source, and the heat generated melts the thermoplastic resin component as the A component, and even if the treatment is performed for a short time, the insole 12 and the main body are finally obtained. It can be firmly adhered to the bottom 21.

Since the first high frequency application electrode 160 and the second high frequency application electrode 180 have a press mechanism, they also function as a press device. Therefore, the insole 12 and the outsole 21 can be more firmly bonded by the pressurization in the compression direction by the first high frequency application electrode 160 and the second high frequency application electrode 180 and the heating and melting of the high frequency dielectric heating adhesive sheet 1 for footwear. ..

(4) High Frequency Dielectric Heating Adhesion Conditions The high frequency dielectric heating bonding conditions can be changed as appropriate, but the following conditions are preferable.

The high frequency output is preferably 10 W or more, more preferably 50 W or more, and even more preferably 100 kW or more.
The high frequency output is preferably 50 kW or less, preferably 20 kW or less, more preferably 15 kW or less, further preferably 10 kW or less, still more preferably 1 kW or less.
When the high frequency output is 10 W or more, it is easy to prevent the problem that the temperature does not easily rise due to the dielectric heating treatment and good adhesive force cannot be obtained.
When the high frequency output is 50 kW or less, it is easy to prevent a problem that temperature control by dielectric heating treatment becomes difficult. From the viewpoint of power consumption, a small high frequency output is preferable, but it is preferable to appropriately set the high frequency output in consideration of the balance with the adhesive force.

The high frequency application time is preferably 1 second or longer.
The application time of the high frequency is preferably 60 seconds or less, preferably 45 seconds or less, preferably 35 seconds or less, more preferably 25 seconds or less, and further preferably 10 seconds or less.
If the high frequency application time is 1 second or more, it is easy to prevent the problem that the temperature does not easily rise due to the dielectric heating treatment and good adhesive force cannot be obtained.
If the application time of the high frequency is 60 seconds or less, the manufacturing efficiency of the footwear 3 is lowered, the manufacturing cost is high, and the footwear members (instep 11, insole 12 and outsole 21) and footwear It is easy to prevent problems such as thermal deterioration of 3.

The high frequency frequency is preferably 1 kHz or higher, more preferably 1 MHz or higher, further preferably 5 MHz or higher, and even more preferably 10 MHz or higher.
The high frequency frequency 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 high frequency dielectric heating bonding method of the present embodiment.

(5) High Frequency Dielectric Heating Adhesive Sheet and High Frequency Dielectric Adhesive Layer The high frequency dielectric heating adhesive sheet according to the present embodiment comprises only one layer of the high frequency dielectric adhesive layer in one embodiment. The high-frequency dielectric heating adhesive sheet according to the present invention is not limited to an embodiment consisting of only one layer of the high-frequency dielectric adhesive layer, and as a modification of the high-frequency dielectric heating adhesive sheet, layers other than the high-frequency dielectric adhesive layer are laminated. There are also aspects that have been used.
As described above, the high-frequency dielectric heating adhesive sheet may consist of only one layer of the high-frequency dielectric adhesive layer. Therefore, in the present specification, the terms "high-frequency dielectric heating adhesive sheet" and "high-frequency dielectric adhesive layer" are used. The terms can be interchanged with each other in some cases.

By appropriately changing the composition of the high-frequency dielectric heating adhesive sheet (for example, the thermoplastic resin (A) and the dielectric filler (B)), it is possible to firmly bond to footwear members of various materials.

(5.1) 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 polyolefin resin having a polar moiety, a styrene resin, a polyacetal resin, a polycarbonate resin, etc. from the viewpoint of being easily melted and having a predetermined heat resistance. It is preferably at least one selected from the group consisting of polyacrylic resins, polyamide resins, polyimide resins, polyvinyl acetate resins, phenoxy resins and polyester resins.

The thermoplastic resin (A) is preferably a polyolefin-based resin or a polyolefin-based resin having a polar moiety.

The polyolefin-based resin as the thermoplastic resin (A) may be a polyolefin-based resin having no polar moiety.

(Polyolefin resin)
The polyolefin-based resin as the thermoplastic resin (A) is composed of, for example, a resin made of a homopolymer such as polyethylene, polypropylene, polybutene and polymethylpentene, and ethylene, propylene, butene, hexene, octene and 4-methylpentene. Examples thereof include α-olefin resins made of copolymers of monomers selected from the group. The polyolefin-based resin as the thermoplastic resin (A) may be a single resin or a combination of two or more resins.

(Polyolefin-based resin with polar parts)
The polar portion of the polyolefin-based resin having a polar moiety is not particularly limited as long as it can impart polarity to the polyolefin-based resin. Polyolefin-based resins having polar portions are preferable because they exhibit high adhesive strength to footwear members.
The thermoplastic resin (A) may be a copolymer of an olefin-based monomer and a monomer having a polar moiety. Further, the thermoplastic resin (A) 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 the polar moiety as the thermoplastic resin (A) 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 propylene-derived structural unit.

Examples of the polar moiety include a hydroxyl group, a carboxy group, a vinyl acetate structure, an acid anhydride structure, and an acid-modified structure introduced into a polyolefin resin by acid modification.

The acid-modified structure as a polar site is a site introduced by acid-modifying a polyolefin resin. Examples of the compound used for graft-modifying a polyolefin resin include an unsaturated carboxylic acid derivative component derived from any one of an unsaturated carboxylic acid, an acid anhydride of the unsaturated carboxylic acid, and an ester of the unsaturated carboxylic acid.

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

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

Examples of the ester of unsaturated carboxylic acid include methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, dimethyl fumarate, diethyl fumarate, and dimethyl itaconic acid. , Esters of unsaturated carboxylic acids such as diethyl itaconic acid, dimethyl citraconic acid, diethyl citraconic acid and dimethyl tetrahydrohydride phthalate.

When the thermoplastic resin (A) is a copolymer of an olefin-based monomer and a monomer having a polar moiety, the copolymer preferably contains 2% by mass or more of a structural unit derived from the monomer having a polar moiety. It is more preferably contained in an amount of 4% by mass or more, further preferably contained in an amount of 5% by mass or more, and further preferably contained in an amount of 6% by mass or more. Further, the copolymer preferably contains 30% by mass or less of a constituent unit derived from a monomer having a polar moiety, more preferably 25% by mass or less, further preferably 20% by mass or less, and 15% by mass. It is more preferable to include the following.
When the copolymer contains 2% by mass or more of a monomer-derived structural unit having a polar moiety, the adhesive strength of the high-frequency dielectric heating adhesive sheet is improved. By improving the adhesive strength, the insole and the outsole of the footwear 3 can be firmly joined. As a result, the outsole is insole even when a large stress is applied to the interface between the insole and the outsole, such as when walking with footwear 3, running, or climbing a mountain. It is possible to prevent the problem of peeling from.
Further, when the copolymer contains 30% by mass or less of a constituent unit derived from a monomer having a polar moiety, it is possible to prevent the thermoplastic resin (A) from becoming too tacky. As a result, it is possible to prevent the molding process of the high-frequency dielectric heating adhesive sheet from becoming difficult. Further, when the copolymer contains 30% by mass or less of a constituent unit derived from a monomer having a polar moiety, it is possible to suppress deterioration of water resistance and solvent resistance of the high-frequency dielectric adhesive layer.

When the polyolefin resin as the thermoplastic resin (A) has an acid-modified structure, the acid modification rate is preferably 0.01% by mass or more, more preferably 0.1% by mass or more. It is more preferably 0.2% by mass or more.
When the polyolefin resin as the thermoplastic resin (A) has an acid-modified structure, the acid modification rate is preferably 30% by mass or less, more preferably 20% by mass or less, and 10% by mass or less. Is more preferable.
When the thermoplastic resin (A) has an acid-modified structure, the adhesive strength of the high-frequency dielectric heating adhesive sheet is improved when the acid modification rate is 0.01% by mass or more. Further, when the modification rate by acid is 30% by mass or less, it is possible to prevent the thermoplastic resin (A) from becoming too tacky. As a result, it is possible to prevent the molding process of the high-frequency dielectric heating adhesive sheet from becoming difficult. Further, when the modification rate of the copolymer by acid is 30% by mass or less, it is possible to suppress the deterioration of the water resistance and heat resistance of the high-frequency dielectric adhesive layer.
As used herein, the modification rate is a percentage of the mass of the acid-derived portion with respect to the total mass of the acid-modified polyolefin.

(Maleic anhydride-modified polyolefin)
The polyolefin-based resin as the thermoplastic resin (A) more preferably has an acid anhydride structure as an acid-modified structure. The acid anhydride structure is preferably a structure introduced when the polyolefin resin is modified with maleic anhydride.
In the maleic anhydride-modified polyolefin as the component A, the modification rate with maleic anhydride is preferably in the same range as the modification rate when the polyolefin-based resin as the thermoplastic resin (A) has an acid-modified structure. The effect obtained within this range is also the same as when the polyolefin-based resin as the thermoplastic resin (A) has an acid-modified structure.

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

(Olefin-vinyl acetate copolymer resin)
The thermoplastic resin (A) according to the present embodiment is also preferably a copolymer (olefin-vinyl acetate copolymer resin) containing a structural unit derived from olefin and a structural unit derived from vinyl acetate.
The olefin-vinyl acetate copolymer resin as the thermoplastic resin (A) has a structural unit derived from vinyl acetate, and the thermoplastic resin (A) has a polar moiety in a copolymer of an olefin-based monomer and a monomer having a polar moiety. It is preferable to have it in the same range as the constituent unit derived from the monomer to have, and the effect obtained within the range is also when the thermoplastic resin (A) is a copolymer of an olefin-based monomer and a monomer having a polar moiety. The same is true.

The olefin-derived structural unit in the olefin-vinyl acetate copolymer resin is preferably a structural unit derived from ethylene or propylene from the viewpoint of excellent mechanical strength and stable adhesiveness.
Therefore, the thermoplastic resin (A) is preferably at least one of an ethylene-vinyl acetate copolymer resin and a propylene-vinyl acetate copolymer resin, and more preferably an ethylene-vinyl acetate copolymer resin. The structural units derived from vinyl acetate in the ethylene-vinyl acetate copolymer resin and the propylene-vinyl acetate copolymer resin are also preferably in the same range as the percentage (mass%) described for the olefin-vinyl acetate copolymer resin.

(Softening temperature)
The softening temperature of the thermoplastic resin (A) measured in accordance with JIS K 7196: 2012 is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, and further preferably 60 ° C. or higher. preferable.
The softening temperature of the thermoplastic resin (A) measured in accordance with JIS K 7196: 2012 is preferably 200 ° C. or lower, preferably 150 ° C. or lower, and more preferably 130 ° C. or lower. , 100 ° C. or lower is more preferable.
When the softening temperature of the thermoplastic resin (A) is 40 ° C. or higher, the heat resistance of the high-frequency dielectric adhesive layer can be improved. Even if the footwear 3 obtained by joining the footwear members using the high-frequency dielectric heating adhesive sheet according to the present embodiment is placed in a high temperature environment (for example, a high temperature environment such as midsummer), between the footwear members (for example). For example, the joint state (between the insole 12 and the outsole 21) can be secured.
When the softening temperature of the thermoplastic resin (A) is 200 ° C. or lower, stable bonding strength can be easily obtained in a short time. If a stable joint strength can be obtained in a short time, the influence of heat on the footwear member can be suppressed.

(Average molecular weight)
The average molecular weight (mass average molecular weight) of the thermoplastic resin (A) is usually preferably 5000 or more, more preferably 10,000 or more, and further preferably 20,000 or more.
The average molecular weight (mass average molecular weight) of the thermoplastic resin (A) is preferably 300,000 or less, more preferably 200,000 or less, and even more preferably 100,000 or less.
When the mass average molecular weight of the thermoplastic resin (A) is 5000 or more, it is possible to prevent the heat resistance and the adhesive strength from being significantly lowered.
When the mass average molecular weight of the thermoplastic resin (A) is 300,000 or less, it is possible to prevent the weldability and the like when the dielectric heat treatment is carried out from being significantly lowered.
The mass average molecular weight of the thermoplastic resin (A) can be measured by the SEC method according to, for example, JIS K 7252-4: 2016.

(Melt flow rate)
The melt flow rate (MFR) of the thermoplastic resin (A) is usually preferably in the following range.
The MFR of the thermoplastic resin (A) is preferably 0.5 g / 10 minutes or more, more preferably 2 g / 10 minutes or more, and 5 g / 10 minutes or more under the conditions described below. More preferred.
The MFR of the thermoplastic resin (A) is preferably 50 g / 10 minutes or less, more preferably 40 g / 10 minutes or less, and further preferably 30 g / 10 minutes or less under the conditions described below. ..
When the MFR of the thermoplastic resin (A) is 0.5 g / 10 minutes or more, the fluidity can be maintained and the film thickness accuracy can be easily obtained. Further, when the MFR of the thermoplastic resin (A) is 0.5 g / 10 minutes or more, the followability of the high-frequency dielectric heating adhesive sheet to the footwear member having irregularities on the surface is improved. Further, the molten high-frequency dielectric adhesive layer invades the unevenness of the surface of the footwear member, and then the high-frequency dielectric adhesive layer solidifies, so that a so-called anchor effect is generated, and the high-frequency dielectric adhesive layer is joined to the footwear member. The strength is further improved.
When the MFR of the thermoplastic resin (A) is 50 g / 10 minutes or less, film forming property can be easily obtained.
The MFR of the thermoplastic resin (A) can be measured by the method described in the item of Examples described later.
The test temperature conforms to JIS K 7210-1: 2014. For example, when the structural unit derived from olefin in the thermoplastic resin (A) is polyethylene, the test temperature is 190 ° C. When the structural unit derived from olefin in the thermoplastic resin (A) is polypropylene, the test temperature is 230 ° C.

(5.2) Dielectric filler (B)
The dielectric filler (B) preferably generates heat when a high frequency of 1 kHz or more and 300 MHz or less is applied. Further, the dielectric filler (B) is preferably a high-frequency absorbent filler having a dielectric property capable of generating heat by applying a high frequency such as a frequency of 27.12 MHz or 40.68 MHz.

(Volume content)
The high-frequency dielectric adhesive layer according to the present embodiment contains the dielectric filler (B) in an amount of 10% by volume or more and 50% by volume or less.
The high-frequency dielectric heating adhesive sheet for footwear according to the present embodiment more preferably contains the dielectric filler (B) in an amount of 11% by volume or more, more preferably 13% by volume or more, in the high-frequency dielectric adhesive layer. It is even more preferable to contain 15% by volume or more.
The high-frequency dielectric heating adhesive sheet according to the present embodiment more preferably contains the dielectric filler (B) in an amount of 45% by volume or less, more preferably 35% by volume or less, and 25% by volume, in the high-frequency dielectric adhesive layer. It is more preferably contained in% or less.
When the volume content of the dielectric filler (B) is 10% by volume or more, it is possible to prevent the heat generation from becoming poor during the dielectric heat treatment. As a result, it is possible to prevent the problem that the high-frequency dielectric heating adhesive layer does not easily generate heat and the footwear member generates heat. Further, it is possible to prevent a problem that the meltability of the thermoplastic resin (A) is excessively lowered and a strong adhesive force cannot be obtained.
If the volume content of the dielectric filler (B) is 50% by volume or less, the fluidity of the high-frequency dielectric heating adhesive sheet decreases during the dielectric heat treatment, or electricity is applied between the electrodes when a high frequency is applied. It is possible to prevent it from happening. Further, when the volume content of the dielectric filler (B) is 50% by volume or less, it is possible to prevent deterioration of the film-forming property, flexibility and toughness of the high-frequency dielectric heating adhesive sheet. Since the high-frequency dielectric heating adhesive layer has flexibility, for example, when the footwear 3 is bent, the high-frequency dielectric heating adhesive layer can also follow the bending. When the volume content of the dielectric filler (B) is 50% by volume or less, it is possible to prevent the weight of the high-frequency dielectric adhesive layer from increasing and to reduce the weight of the footwear 3.
If the volume content of the dielectric filler (B) exceeds 50% by volume, the high-frequency dielectric adhesive layer becomes brittle, so the high-frequency dielectric heating adhesive sheet may not be suitable for footwear applications.

Since the high-frequency dielectric adhesive layer according to the present embodiment contains the thermoplastic resin (A) and the dielectric filler (B), the total volume of the thermoplastic resin (A) and the dielectric filler (B) is relative to the total volume. , Dielectric filler (B) is preferably contained in an amount of 10% by volume or more, more preferably 11% by volume or more, further preferably 13% by volume or more, and containing 15% by volume or more. It is even more preferable to do so.
The high-frequency dielectric adhesive layer according to the present embodiment preferably contains 50% by volume or less of the dielectric filler (B) with respect to the total volume of the thermoplastic resin (A) and the dielectric filler (B). It is more preferably contained in an amount of 35% by volume or less, further preferably contained in an amount of 35% by volume or less, and further preferably contained in an amount of 25% by volume or less.

(Number of copies)
The high-frequency dielectric adhesive layer according to the present embodiment preferably contains 50 parts by mass or more, and 60 parts by mass or more of the dielectric filler (B) with respect to 100 parts by mass of the thermoplastic resin (A). It is more preferable to contain 80 parts by mass or more, and more preferably 100 parts by mass or more.
The high-frequency dielectric adhesive layer according to the present embodiment preferably contains the dielectric filler (B) in an amount of 600 parts by mass or less, preferably 400 parts by mass or less, based on 100 parts by mass of the thermoplastic resin (A). It is more preferable to contain 300 parts by mass or less, and further preferably 200 parts by mass or less.
When the number of parts by mass of the dielectric filler (B) is 50 parts by mass or more, it is easy to prevent the heat generation from becoming poor during the dielectric heat treatment. As a result, it is easy to prevent a problem that the meltability of the thermoplastic resin (A) is excessively lowered and a strong adhesive force cannot be obtained.
When the number of parts by mass of the dielectric filler (B) is 600 parts by mass or less, the fluidity of the high-frequency dielectric heating adhesive sheet decreases during the dielectric heat treatment, or electricity is applied between the electrodes when a high frequency is applied. It is easy to prevent this. Further, when the number of parts by mass of the dielectric filler (B) is 800 parts by mass or less, it is easy to prevent deterioration of film forming property, flexibility and toughness of the high frequency dielectric heating adhesive sheet.

In the high-frequency dielectric heating adhesive sheet for footwear according to the present embodiment, the total mass of the thermoplastic resin (A) and the dielectric filler (B) is 80% by mass or more with respect to the total mass of the high-frequency dielectric adhesive layer. It is more preferable, 90% by mass or more is more preferable, and 99% by mass or more is further preferable.

(type)
Dielectric fillers (B) include zinc oxide, silicon carbide (SiC), anatase-type titanium oxide, barium titanate, barium titanate, lead titanate, potassium niobate, rutyl-type titanium oxide, 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.

In one aspect of this embodiment, the dielectric filler (B) is more preferably zinc oxide, silicon carbide, or barium titanate.

In one embodiment of the present embodiment, the dielectric filler (B) is preferably a metal oxide, more preferably zinc oxide. Zinc oxide as the dielectric filler (B) has high dielectric properties and has little effect on the thermoplastic resin (A). In addition, zinc oxide is abundant in variety and can be selected from various shapes and sizes. Further, if the dielectric filler (B) is zinc oxide, the adhesive properties and mechanical properties of the high-frequency dielectric heating adhesive sheet can be improved according to the application.
Zinc oxide as the dielectric filler (B) can be easily uniformly mixed in the thermoplastic resin (A) which is an adhesive component. Therefore, even if the amount of zinc oxide in the high-frequency dielectric adhesive layer is relatively small, it is superior to the high-frequency dielectric heating adhesive sheet containing other dielectric fillers in a predetermined dielectric heating treatment. It can exert a heat generating effect.
Therefore, since the high-frequency dielectric adhesive layer contains zinc oxide as the dielectric filler (B), excellent weldability can be obtained in the dielectric heat treatment for joining the footwear members. According to the high-frequency dielectric adhesive layer containing zinc oxide as the dielectric filler (B), it is possible to exhibit adhesive properties and mechanical properties according to the material of the footwear member as an adherend and the variation of the application of the footwear.

The high-frequency dielectric adhesive layer according to this embodiment preferably does not contain a conductive substance. Examples of the conductive substance include carbon or a carbon compound containing carbon as a main component (for example, carbon black) and a metal. The content of the conductive substance is preferably 5% by mass or less, more preferably 1% by mass or less, and preferably 0.1% by mass or less, based on the total amount of the high-frequency dielectric adhesive layer. It is even more preferably 0% by mass. When the content of the conductive substance in the high-frequency dielectric adhesive layer is 5% by mass or less, it is easy to prevent the problem of carbonization of the adhesive portion and the footwear member due to electrical dielectric breakdown during the dielectric heat treatment.

(Average particle size)
The average particle diameter (median diameter, D50) measured in accordance with JIS Z 8819-2: 2001 of the dielectric filler (B) is preferably 1 μm or more, more preferably 2 μm or more, and 3 μm or more. It is more preferably 5 μm or more.
The average particle diameter (median diameter, D50) measured in accordance with JIS Z 8819-2: 2001 of the dielectric filler (B) is preferably 30 μm or less, more preferably 25 μm or less, and 20 μm or less. It is more preferably 15 μm or less.
If the average particle size of the dielectric filler (B) is too small, the reversal motion when a high frequency is applied is reduced, so that the dielectric heating adhesiveness is excessively lowered, and it may be difficult to firmly bond the footwear members. is there.
On the other hand, as the average particle size of the dielectric filler (B) increases, the distance that can be polarized inside the filler increases. Therefore, the degree of polarization becomes large, the reversal motion becomes intense when a high frequency is applied, and the dielectric heating adhesiveness is improved.
Therefore, if the average particle size of the dielectric filler (B) is 1 μm or more, the distance that can be polarized inside the filler does not become too small, and the degree of polarization can be prevented from becoming small, although it depends on the type of filler. ..
If the average particle size of the dielectric filler (B) is too large, the distance from the surrounding dielectric filler is short, so that the reversal motion when a high frequency is applied is reduced due to the influence of the electric charge, and the dielectric heating adhesiveness becomes excessive. It may be lowered or it may be difficult to firmly bond the footwear members together.
Therefore, when the average particle size of the dielectric filler (B) is 30 μm or less, it is possible to prevent the dielectric heating adhesiveness from being excessively lowered and the difficulty of strong adhesion between the footwear members.
The average particle size (median diameter, D50) of zinc oxide as the dielectric filler (B) measured in accordance with JIS Z 8819-2: 2001 is preferably 1 μm or more, more preferably 2 μm or more. It is more preferably 3 μm or more, and even more preferably 5 μm or more.
The average particle diameter (median diameter, D50) of zinc oxide as the dielectric filler (B) measured in accordance with JIS Z 8819-2: 2001 is preferably 30 μm or less, more preferably 25 μm or less. , 20 μm or more, and even more preferably 15 μm or less.
The average particle size of the dielectric filler (B) is preferably smaller than the thickness of the high-frequency dielectric adhesive layer.

(5.3) Additive The high-frequency dielectric adhesive layer according to the present embodiment may or may not contain an additive.

When the high-frequency dielectric adhesive layer according to the present embodiment contains an additive, examples of the additive include a tackifier, a plasticizer, a wax, a colorant, an antioxidant, an ultraviolet absorber, an antibacterial agent, and a deodorant. Examples thereof include fragrances, humidity control materials, coupling agents, viscosity modifiers, organic fillers and inorganic fillers. Organic fillers and inorganic fillers as additives are different from dielectric fillers as component B.

The tackifier and the plasticizer can improve the melting property and the adhesive property of the high frequency dielectric adhesive layer.
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 petroleum resins.
Examples of the plasticizer include petroleum-based process oils, natural oils, dialkyl dibasic acids, and low molecular weight liquid polymers. Examples of petroleum-based process oils include paraffin-based process oils, naphthenic process oils, aromatic process oils, and the like. Examples of natural oils include castor oil and tall oil. Examples of the dialkyl dibasic acid include dibutyl phthalate, di-2-ethylhexyl phthalate, and dibutyl adipate. Examples of the low molecular weight liquid polymer include liquid polybutene and liquid polyisoprene.

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

In the high-frequency dielectric adhesive layer according to the present embodiment, the above-mentioned components (thermoplastic resin (A) and dielectric filler (B); if necessary, additional additives) are premixed, and a known kneading device is used. It can be kneaded and manufactured by a known molding method. Examples of the kneading device include an extruder and a heat roll. Examples of the molding method include extrusion molding, calendar molding, injection molding, casting molding and the like.

(6) Form and Characteristics of High Frequency Dielectric Heating Adhesive Sheet When the high frequency dielectric heating adhesive sheet according to the present embodiment consists of only one layer of the high frequency dielectric heating adhesive layer, the form and characteristics of the high frequency dielectric heating adhesive sheet are high frequency dielectric. Corresponds to the morphology and properties of the adhesive layer.

(Young's modulus)
The Young's modulus of the high-frequency dielectric heating adhesive sheet is preferably 40 MPa or more, more preferably 60 MPa or more, further preferably 80 MPa or more, and even more preferably 100 MPa or more.
The Young's modulus of the high-frequency dielectric heating adhesive sheet is preferably 600 MPa or less, more preferably 400 MPa or less, further preferably 300 MPa or less, and even more preferably 200 MPa or less.
When the Young's modulus of the high-frequency dielectric heating adhesive sheet is 40 MPa or more, the self-supporting property of the sheet is not reduced and the sheet can be easily handled during the manufacture of footwear.
When the Young's modulus of the high-frequency dielectric heating adhesive sheet is 600 MPa or less, the high-frequency dielectric heating adhesive sheet easily follows the bending of the insole 12 or the outsole 21 of the footwear 3. As a result, the comfort of the footwear 3 is improved.
The Young's modulus of the high frequency dielectric heating adhesive sheet can be measured by JIS K 7161-1: 2014 and JIS K 7127: 1999.

(Softening temperature)
The softening temperature of the high-frequency dielectric heating adhesive sheet measured in accordance with JIS K 7196: 2012 is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. ..
The softening temperature of the high-frequency dielectric heating adhesive sheet measured in accordance with JIS K 7196: 2012 is preferably 210 ° C. or lower, more preferably 160 ° C. or lower, and even more preferably 140 ° C. or lower. , 110 ° C. or lower is even more preferable.
When the softening temperature of the high-frequency dielectric heating adhesive sheet is 50 ° C. or higher, the heat resistance of the high-frequency dielectric adhesive layer can be improved. Even if the footwear 3 obtained by joining the footwear members using the high-frequency dielectric heating adhesive sheet according to the present embodiment is placed in a high temperature environment (for example, a high temperature environment such as midsummer), between the footwear members (for example). For example, the joint state (between the insole 12 and the outsole 21) can be secured. In addition, when the footwear 3 is worn, it is possible to prevent the joint strength from being lowered due to the frictional heat between the insole 12 and the foot.
When the softening temperature of the high-frequency dielectric heating adhesive sheet is 210 ° C. or lower, stable bonding strength can be easily obtained in a short time. If a stable joint strength can be obtained in a short time, the influence of heat on the footwear member can be suppressed.

(Melt flow rate)
The melt flow rate (MFR) of the high-frequency dielectric adhesive layer according to the present embodiment is preferably 1 g / 10 minutes or more, more preferably 3 g / 10 minutes or more, and 5 g / 10 minutes or more. Is more preferable, and 10 g / 10 minutes or more is particularly preferable.
The melt flow rate of the high-frequency dielectric adhesive layer according to the present embodiment is preferably 80 g / 10 minutes or less, more preferably 60 g / 10 minutes or less, and further preferably 45 g / 10 minutes or less. , 35 g / 10 minutes or less is particularly preferable.
In the present specification, the test temperature for measuring the MFR of the high-frequency dielectric adhesive layer is 230 ° C., and the load is 5 kg.
When the MFR of the high-frequency dielectric adhesive layer is 1 g / 10 minutes or more, the fluidity can be maintained and the film thickness accuracy can be easily obtained. If the MFR of the high-frequency dielectric adhesive layer is 1 g / 10 minutes or more, the melted high-frequency dielectric adhesive layer invades the uneven surface of the footwear member (for example, the insole 12 or the outsole 21), and then By solidifying the high-frequency dielectric adhesive layer, a so-called anchor effect is generated, and the bonding strength of the high-frequency dielectric adhesive layer to the footwear member is further improved.
When the MFR of the high-frequency dielectric adhesive layer is 80 g / 10 minutes or less, film-forming property can be easily obtained.
The MFR of the high frequency dielectric adhesive layer can be measured by the method described in the item of Examples described later.

(Loss tangent peak temperature at 1 Hz)
The loss tangent peak temperature at 1 Hz of the high-frequency dielectric adhesive layer according to the present embodiment is preferably 0 ° C. or lower, more preferably −10 ° C. or lower, and even more preferably −20 ° C. or lower. The loss tangent peak temperature of the high-frequency dielectric adhesive layer at 1 Hz is usually −60 ° C. or higher.
When the loss tangent peak temperature at 1 Hz of the high-frequency dielectric adhesive layer is 0 ° C. or lower, it is easy to secure the bonding strength even when the footwear 3 is placed in a low temperature environment. For example, even when wearing footwear 3 and spending time in a cold region or working in a freezer, it is easy to prevent the insole 12 and the outsole 21 from peeling off.
The loss tangent peak temperature at 1 Hz of the high-frequency dielectric adhesive layer can be measured by the method described in the item of Examples described later.

(Ratio of change in tensile fracture stress R1)
The rate of change R1 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the moist heat test is calculated by the following formula.
Rate of change R1 = {(tensile fracture stress after wet heat test) / (tensile fracture stress before wet heat test)} × 100

The moist heat test is a test in which the high-frequency dielectric heating adhesive sheet for footwear is placed under the conditions of a temperature of 85 ° C. and a humidity of 85% RH for 7 days.
The tensile fracture stress of the high frequency dielectric heating adhesive sheet for footwear is measured according to JIS K 7161-1: 2014 and JIS K 7127: 1999.

The rate of change R1 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the moist heat test is preferably 80% or more, more preferably 85% or more, and 90% or more. Is even more preferable, and 95% or more is even more preferable.
The rate of change R1 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the moist heat test is preferably 120% or less, more preferably 115% or less, and more preferably 110% or less. Is even more preferable, and 105% or less is even more preferable.
When the rate of change R1 is 80% or more, the joint portion between the insole 12 and the outsole 21 is unlikely to become brittle when walking or running in a hot and humid area with the footwear 3.
When the rate of change R1 is 120% or less, it is unlikely that the composition of the sheet has changed, so that quality stability can be easily obtained even if the footwear is stored for a long period of time.

The tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the moist heat test is preferably 3 MPa or more, more preferably 4 MPa or more, and further preferably 5 MPa or more.
If the tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the moist heat test is 3 MPa or more, when the joint portion between the insole 12 and the outsole 21 is walking or running in a hot and humid area with footwear 3 on. In addition, the sheet is not easily damaged.
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the moist heat test is preferably 40 MPa or less, more preferably 25 MPa or less, and even more preferably 15 MPa or less.
If the tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the moist heat test is 40 MPa or less, workability can be obtained even after a long period of time has passed since the footwear members were joined. For example, when replacing a worn or damaged footwear member such as an outsole with a new footwear member, the replacement work becomes easier.

(Ratio of change in tensile fracture stress R2)
The rate of change R2 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the dynamic flexibility test is calculated by the following formula: rate of change R2 = {(tensile fracture stress after the dynamic flexibility test) / (Tensile fracture stress before dynamic flexibility test)} × 100

In the dynamic flexibility test, a sample of 15 mm (TD) × 150 mm (MD) size was prepared from the high-frequency dielectric heating adhesive sheet 1 for footwear, and the bending conditions were a minimum bending diameter of 10 mmφ and a bending count of 30,000 times. This is a test performed under the condition that the bending speed is 30 rpm.
The tensile fracture stress of the high frequency dielectric heating adhesive sheet for footwear is measured according to JIS K 7161-1: 2014 and JIS K 7127: 1999.

The rate of change R2 of the breaking strength tensile breaking stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the dynamic flexibility test is preferably 80% or more, more preferably 85% or more, and 90%. It is more preferably% or more, and even more preferably 95% or more.
The rate of change R2 of the breaking strength tensile breaking stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the dynamic flexibility test is preferably 120% or less, more preferably 115% or less, 110 It is more preferably% or less, and even more preferably 105% or less.
If the rate of change R2 is 80% or more, the seat becomes brittle even if the joint portion between the insole 12 and the outsole 21 is bent multiple times while walking or running while wearing the footwear 3. hard.
When the rate of change R2 is 120% or less, it is unlikely that the composition of the sheet has changed, so that quality stability can be easily obtained even after walking.

The tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the dynamic flexibility test is preferably 3 MPa or more, more preferably 4 MPa or more, and further preferably 5 MPa or more.
If the tensile fracture stress after the dynamic flexibility test of the high-frequency dielectric heating adhesive sheet is 3 MPa or more, the joint portion between the insole 12 and the outsole 21 is walking or running while wearing the footwear 3. The sheet is not easily damaged even if it is bent multiple times.
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the dynamic flexibility test is preferably 40 MPa or less, more preferably 25 MPa or less, and even more preferably 15 MPa or less.
If the tensile fracture stress of the high-frequency dielectric heating adhesive sheet after the dynamic flexibility test is 40 MPa or less, workability can be obtained even after long-term use of footwear. For example, when replacing a worn or damaged footwear member such as an outsole with a new footwear member, the replacement work becomes easier.

(Joint strength test)
It is preferable that the high-frequency dielectric heating adhesive sheet 1 for footwear passes the evaluation result when the following joint strength test is performed.
-Joint strength test A pair of footwear members (in this embodiment, a first footwear member and a second footwear member) are joined with a high-frequency dielectric heating adhesive sheet according to the present embodiment to prepare a test piece. Passed if the tensile shear force measured according to JIS K 6850: 1999 for the test piece corresponds to at least one of 3 MPa or more and at least one of the pair of footwear members is destroyed. Is determined.

As a method for producing the footwear 3 satisfying the above-mentioned bonding strength, for example, a method for producing the footwear 3 by using the above-mentioned high-frequency dielectric heating adhesive sheet and the above-mentioned dielectric heating bonding device under the above-mentioned high-frequency dielectric heating bonding conditions. Can be mentioned.

(thickness)
The thickness of the high-frequency dielectric adhesive layer according to the present embodiment is usually preferably 10 μm or more, more preferably 50 μm or more, and further preferably 100 μm or more.
The thickness of the high-frequency dielectric adhesive layer according to the present embodiment is preferably 2,000 μm or less, more preferably 1,000 μm or less, and further preferably 600 μm or less.
When the thickness of the high-frequency dielectric adhesive layer is 10 μm or more, it is possible to prevent the adhesive force between the insole 12 and the outsole 21 from suddenly decreasing. Further, if the thickness of the high-frequency dielectric adhesive layer is 10 μm or more, if at least one of the adhesive surfaces of the insole 12 and the outsole 21 has irregularities, the high-frequency dielectric adhesive layer can follow the irregularities. Therefore, the adhesive strength is easily developed.
As long as the thickness of the high-frequency dielectric adhesive layer is 2,000 μm or less, it can be rolled into a roll or applied to a roll-to-roll method. In addition, the high-frequency dielectric heating adhesive sheet can be easily handled in the next process such as punching. Further, as the thickness of the high-frequency dielectric adhesive layer increases, the weight of the footwear 3 also increases, so that the thickness is preferably within a range that does not cause a problem in use.

(Dielectric property (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 according to the present embodiment can be measured according to JIS C 2138: 2007, but according to the impedance material method. Therefore, it can be measured easily and accurately.
The dielectric property (tan δ / ε') of the high-frequency dielectric heating adhesive sheet according to the present embodiment is preferably 0.005 or more, more preferably 0.008 or more, and preferably 0.01 or more. More preferred.
The dielectric property (tan δ / ε') of the high-frequency dielectric heating adhesive sheet according to the present embodiment is preferably 0.06 or less, more preferably 0.05 or less, and preferably 0.04 or less. More preferred. 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, it is difficult to firmly bond the insole 12 and the outsole 21 without generating a predetermined heat when the dielectric heat treatment is performed. It is easy to prevent the problem of becoming.
When the dielectric property of the high-frequency dielectric heating adhesive sheet is 0.06 or less, it is easy to prevent damage to the footwear members (instep 11, insole 12 and outsole 21) and footwear 3 at the time of joining by applying high frequency.
The details of the method for measuring the dielectric properties of the high-frequency dielectric heating adhesive sheet are as follows. A high-frequency dielectric heating adhesive sheet cut to a predetermined size is subjected to dielectric constant (ε') and dielectric loss tangent (tan δ) under the condition of a frequency of 40.68 MHz at 23 ° C. using an impedance material analyzer E4991 (manufactured by Agent). Each is measured and the value of the dielectric property (tan δ / ε') is calculated.

(density)
The density of the high-frequency dielectric heating adhesive sheet according to the present embodiment, is preferably 3 g / cm ³ or less, more preferably 2.5 g / cm ³ or less, still more preferably 2 g / cm ³ or less ..
The density of the high-frequency dielectric heating adhesive sheet is preferably 1.00 g / cm ³ or more, more preferably 1.20 g / cm ³ or more, 1.40 g / cm ³ or more, is 1.5 or more Is even more preferable.
If the density of the high-frequency dielectric heating adhesive sheet is 3 g / cm ³ or less, the weight of the footwear 3 can be reduced. As a result, according to the present embodiment, it is possible to provide footwear with a more comfortable fit.
Further, when the density of the high-frequency dielectric heating adhesive sheet is 1.00 g / cm ³ or more, it becomes easy to suppress fluttering when the sheet is formed by the roll-to-roll method.
The density of the high-frequency dielectric heating adhesive sheet can be measured according to the method A (underwater substitution method) of JIS K 7112: 1999.

(Effect of embodiment)
According to the high-frequency dielectric heating adhesive sheet according to the present embodiment, since the high-frequency dielectric adhesive layer contains a dielectric filler, it can be used as a member for the first footwear with high strength even with low-power and short-time high-frequency dielectric heating treatment. It can be joined to the second footwear member. Further, damage to the footwear member due to heat can be prevented. In addition, the high-frequency dielectric heating adhesive sheet according to the present embodiment can bond footwear members in a short time and with high strength as compared with the conventionally used hot melt adhesives.

Further, according to the high-frequency dielectric heating adhesive sheet according to the present embodiment, since the footwear members can be joined with high strength without suturing, no seams appear on the surface of the footwear, and the appearance is excellent.

Since the high-frequency dielectric heating adhesive sheet according to the present embodiment is heated by high-frequency dielectric heating, the surface side of the footwear member in contact with the high-frequency dielectric heating adhesive sheet is only locally heated. Therefore, according to the high-frequency dielectric heating adhesive sheet according to the present embodiment, the problem that the footwear member melts at the time of joining with the footwear member can be solved.

The high-frequency dielectric heating adhesive sheet according to the present embodiment can be peeled off from the first footwear member and the second footwear member by high-frequency dielectric heating. Thereby, for example, the instep 11, the insole 12, and the outsole 21 constituting the footwear 3 can be replaced with other footwear members. Therefore, when the footwear 3 is scratched or soiled, the scratched or soiled footwear member (instep 11, insole 12 or outsole 21) is peeled off, and another footwear member is subjected to high-frequency dielectric heating. It can be joined by heating. If the outsole 21 is worn out, the life of the footwear 3 can be extended by peeling the worn outsole 21 from the insole 12 and adhering a new outsole to the insole 12 by high frequency dielectric heating. it can. In particular, when the footwear member is joined without suturing, the footwear member can be easily separated from the footwear.

According to the high-frequency dielectric heating adhesive sheet according to the present embodiment, unlike a discontinuous suture structure such as sewing, a joint structure in which the first footwear member and the second footwear member are continuously joined. Can be obtained. Therefore, in the footwear manufactured by using the high-frequency dielectric heating adhesive sheet according to the present embodiment, there is no gap that may occur in the suture structure, and foreign matter (for example, dust, water, chemicals, etc.) enters between the footwear members. Can be prevented.

The high-frequency dielectric heating adhesive sheet according to the present embodiment can join the first footwear member and the second footwear member in a short time by high-frequency dielectric heating. Therefore, the high-frequency dielectric heating adhesive sheet according to the present embodiment is preferable from the viewpoint of footwear manufacturing efficiency.

The high-frequency dielectric heating adhesive sheet according to the present embodiment has excellent water resistance and moisture resistance as compared with general adhesives. The footwear according to the present embodiment is also suitable for applications such as being exposed to wind and rain or being used in an environment where the temperature becomes high due to exposure to sunlight, and the joint strength is unlikely to decrease due to aged deterioration.

Since the high-frequency dielectric heating adhesive sheet according to the present embodiment does not contain a solvent, the problem of VOC (Volatile Organic Compounds) caused by the adhesive used when joining the footwear members is unlikely to occur.

[Second Embodiment]
Next, the second embodiment of the present invention will be described.
In the second embodiment, the structure of the footwear is different from that of the first embodiment.
In the following description, the parts related to the differences from the first embodiment will be mainly described, and the overlapping description will be omitted or simplified. The same reference numerals are given to the same configurations as those in the first embodiment, and the description thereof will be omitted or simplified.

FIG. 3A shows a side view of the footwear 3A according to the second embodiment.
FIG. 3B shows a side view showing a plurality of footwear members constituting the footwear 3A according to the second embodiment separately from each other.
The footwear 3A according to the present embodiment is also a shoe. Footwear 3A has an instep 13, an insole 14, and an outsole 22. The main body 10A of the footwear 3A is composed of an instep 13 and an insole 14. In the footwear 3A according to the present embodiment, the insole 14 is a member for the first footwear, the outsole 22 is a member for the second footwear, and the insole 14 and the outsole 22 are high-frequency dielectric heating adhesive sheets 1 for footwear. It is joined. Further, in the footwear 3A according to the present embodiment, the instep 13 is used as a third footwear member, and the instep 13 and the outsole 22 are joined by a high-frequency dielectric heating adhesive sheet 1 for footwear. As described above, the number of footwear members according to the present embodiment is at least two, and may be three or more.

In this embodiment, it is preferable that at least one of the footwear members is a foam. The outsole 22 as a footwear member in this embodiment is a foam. Since the foam is a material having excellent impact resistance, it is attracting attention as a material for the outsole of shoes as footwear (particularly sports shoes).
The foam as the footwear member is preferably a resin foam. Examples of the resin foam include styrofoam, urethane foam, polypropylene foam, polyethylene foam, and phenol foam.

According to the high-frequency dielectric heating adhesive sheet 1 for footwear, the outsole 22 and the insole 14 which are foams can be firmly bonded in a short time. Therefore, the high-frequency dielectric heating adhesive sheet 1 for footwear is strong against other footwear members while suppressing the influence of heat (for example, deformation or deterioration) even if the footwear member is sensitive to heat such as foam. Can be joined to. Further, since the surface of the foam has a large number of holes, the molten high-frequency dielectric heating adhesive sheet enters the holes to generate an anchor effect, and the bonding strength becomes stronger.
In footwear 3A, the outsole 22 and the insole 14 which are foams are firmly joined without being affected by heat even if there is no suture structure.
Therefore, according to the present embodiment, it is possible to provide footwear 3A having excellent appearance and impact resistance.

[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.

The high-frequency dielectric heating adhesive sheet may have an adhesive portion. By having the adhesive portion, when the high-frequency dielectric heating adhesive sheet is attached to the footwear member, it is possible to prevent misalignment and arrange it at an accurate position. The adhesive portion may be provided on one surface of the high-frequency dielectric adhesive layer or may be provided on both sides. Further, the adhesive portion may be provided on the entire surface or partially with respect to the surface of the high-frequency dielectric adhesive layer.

Further, holes and protrusions for temporary fixing may be provided in a part of the high-frequency dielectric heating adhesive sheet. By having holes and protrusions for temporary fixing, it is possible to prevent misalignment and arrange the high-frequency dielectric heating adhesive sheet at an accurate position when it is attached to the footwear member.

The footwear produced by the joining method using the high-frequency dielectric heating adhesive sheet is not limited to the embodiment shown in FIG. 1 or FIG.

In the first embodiment, the embodiment in which the insole 12 and the outsole 21 are joined has been described as an example, but the present invention is not limited to such an embodiment.
For example, the contact portion between the instep 11 and the outsole 21 may also be joined via the high-frequency dielectric heating adhesive sheet 1 for footwear in the same manner as the joining method according to the embodiment.

Further, for example, one of the instep 11 and the insole 12 is used as a member for the first footwear, the other is used as a member for the second footwear, and the instep 11 and the insole 12 are provided via a high-frequency dielectric heating adhesive sheet 1 for footwear. , May be joined in the same manner as the joining method according to the above embodiment.

Further, for example, when the outsole has a multi-layer structure, a plurality of outsole members may be joined to each other by using a high-frequency dielectric heating adhesive sheet in the same manner as the joining method according to the embodiment. For example, when the outsole is composed of an outsole and a midsole, the outsole and the midsole are joined by using a high-frequency dielectric heating adhesive sheet in the same manner as the joining method according to the above embodiment to form a multilayer structure. You may get an outsole. Further, the insole and the midsole in the outsole having a multi-layer structure may be joined by using a high-frequency dielectric heating adhesive sheet in the same manner as the joining method according to the embodiment.

The number of footwear members used in the joining method using the high-frequency dielectric heating adhesive sheet is not particularly limited.
For example, the insole is a member for the first footwear, the outsole is a member for the second footwear, the instep is a member for the third footwear, and thus three footwear members (instep, insole and outsole). May be joined.
Further, for example, a label-shaped footwear member (decorative member) on which numbers, letters, symbols, figures and the like are represented may be joined to the side surface of the instep cover via a high-frequency dielectric heating adhesive sheet. In this case, one of the label-shaped footwear member and the instep cover corresponds to the first footwear member, and the other corresponds to the second footwear member.

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 and bonding device may be used. The lattice electrode type high-frequency dielectric heating adhesive device has lattice electrodes in which a first electrode and a second electrode having the opposite polarity to the first electrode are alternately arranged on the same plane at regular intervals.

For example, FIG. 4 shows a schematic cross-sectional view illustrating a method of manufacturing footwear using a lattice electrode type high-frequency dielectric heating adhesive device 100A.
The high frequency dielectric heating and bonding device 100A is a high frequency dielectric heating and bonding device which is also called a lattice electrode type. In the lattice electrode type high-frequency dielectric heating and bonding device 100A, the first high-frequency application electrode 161 and the second high-frequency application electrode 181 having the opposite polarity to the first high-frequency application electrode 161 are placed on the same plane at regular intervals. It has lattice electrodes arranged alternately in.

The high-frequency dielectric heating adhesive device 100A includes a first high-frequency application electrode 161 having one polarity, a second high-frequency application electrode 181 having the other polarity, and a high-frequency power supply 200. In FIG. 4, a high-frequency dielectric heating and bonding device 100A provided with three first high-frequency application electrodes 161 and three second high-frequency application electrodes 181 is given as an example, but induction heating and bonding used for manufacturing footwear 3 is shown as an example. The number of electrodes in the apparatus (lattice electrode type) is not limited to three, and may be one, two, or four or more. Polarities different from each other are applied to the first high-frequency application electrode 161 and the second high-frequency application electrode 181 so as to be interchanged at a predetermined frequency. The first high frequency application electrode 161 and the second high frequency application electrode 181 are arranged alternately. The first high-frequency application electrode 161 and the second high-frequency application electrode 181 are arranged apart from each other. The first high frequency application electrode 161 and the second high frequency application electrode 181 are preferably rod-shaped electrodes.

FIG. 4 illustrates a mode in which the longitudinal directions of the first high-frequency application electrode 161 and the second high-frequency application electrode are arranged along a direction intersecting the direction from the toe portion to the heel portion of the instep cover 11. However, the present invention is not limited to such an embodiment. For example, the present invention may include an embodiment in which the longitudinal directions of the first high-frequency application electrode 161 and the second high-frequency application electrode are arranged along the direction from the toe portion to the heel portion of the instep cover 11.

The method of joining the footwear member using the lattice electrode type high-frequency dielectric heating adhesive device 100A includes, for example, the following steps (PX1) and steps (PX2).

Step (PX1): A step of arranging the high-frequency dielectric heating adhesive sheet 1 for footwear between the first footwear member (insole 12) and the second footwear member (outsole 21).

Step (PX2): The first high-frequency application electrode 161 and the second high-frequency application electrode 181 are brought into contact with the bottom surface of the outsole 21, and the first footwear member (insole 12) and the second footwear member (main). Step of performing high frequency dielectric heating treatment on the high frequency dielectric heating adhesive sheet 1 for footwear arranged between the bottom 21)

The insole 12 and the outsole 21 can be firmly joined by the method of joining the footwear member including the step (PX1) and the step (PX2). The same conditions as in the first embodiment can be applied to the conditions of the high frequency dielectric heating treatment using the lattice electrode type high frequency dielectric heating adhesive device 100A. The high-frequency dielectric heating adhesive device 100A may be used to carry out the first embodiment, the second embodiment, and other embodiments and other modifications.

By using the lattice electrode type high-frequency dielectric heating adhesive device 100A, the high-frequency dielectric heating treatment can be performed without arranging the electrodes inside the main body 10 composed of the instep 11 and the insole 12, so that the footwear The manufacturing process can be simplified.
The first high frequency application electrode 161 and the second high frequency application electrode 181 may be arranged inside the main body 10, or the first high frequency application electrode 161 and the second high frequency application may be arranged inside the main body 10. One of the electrodes 181 may be arranged and brought into contact with the insole 12, and the other may be brought into contact with the bottom surface of the outsole 21.
Further, the first lattice electrode is arranged on the side of the first footwear member (insole 12), the second lattice electrode is arranged on the side of the second footwear member (outsole 21), and high frequencies are simultaneously applied from both sides. It may be applied.
Further, a grid electrode is arranged on one surface side of the first footwear member (insole 12) and the second footwear member (outsole 21), a high frequency is applied, and then the lattice electrode is placed on the other surface side. It may be arranged and a high frequency may be applied.

It is also preferable to use a lattice electrode type high frequency dielectric heating adhesive device as described above for applying a high frequency. By using a lattice electrode type high-frequency dielectric heating adhesive device, dielectric heating is performed from the surface layer side of the footwear member, for example, the surface layer side where the distance to the high-frequency dielectric heating adhesive sheet is short, without being affected by the thickness of the footwear member. The footwear members can be firmly bonded by performing induction heating from the surface side where the electrodes can be easily arranged. Further, by using a lattice electrode type high frequency dielectric heating adhesive device, it is possible to realize energy saving at the time of manufacturing footwear.

Even when a lattice electrode type high-frequency dielectric heating adhesive device is used, the high-frequency dielectric heating adhesive sheet exhibits the same effects as those described in the first embodiment and the second embodiment.

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

[Manufacturing of high-frequency dielectric heating adhesive sheet]
[Example 1]
Maleic anhydride-modified polyethylene (manufactured by Mitsubishi Chemical Corporation, product name "Modic L504", softening temperature: 84 ° C., melt flow rate: 20 g / 10 min, density: 0.92 g / cm ³ ) 80.0% by volume as component A And zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "LPZINC11", average particle size: 11 μm, described as ZnO in Table 1) as component B, 20.0% by volume, are weighed in the container, respectively. did. Table 1 shows the mixing ratio of each component. In Table 1, the blending ratio of each component is a value expressed in% by volume.
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, melt-kneaded, and then pelletized with a pelletizer. processed.
Next, the obtained pellets are put into the hopper of a single-screw extruder equipped with a T-die, and a sheet-like melt-kneaded product is extruded from the T-die under the conditions of a cylinder temperature of 200 ° C. and a die temperature of 200 ° C. and cooled. By cooling with a roll, a high-frequency dielectric heating adhesive sheet having a thickness of 400 μm was produced. A synthetic fiber sheet as the first footwear member and a foamed polyurethane sheet as the second footwear member were prepared, and the obtained high-frequency dielectric heating adhesive sheet was attached between the two sheets. Then, they were adhered under the following high-frequency application conditions to obtain a footwear joint of Example 1.

<High frequency application conditions>
Samples were prepared according to JIS K 6850: 1999. That is, a synthetic fiber sheet (25 mm × 100 mm) as the first footwear member and a foamed polyurethane sheet (25 mm × 100 mm) as the second footwear member were prepared. Next, the obtained high-frequency dielectric heating adhesive sheet was attached between the two sheets so that the attachment surface was 25 mm × 12.5 mm. Then, a high frequency was applied for 10 seconds under the conditions of a frequency of 40.68 MHz and an output of 200 W while being fixed between the electrodes of a high frequency dielectric heating device (YRP-400t-RC manufactured by Yamamoto Vinita Co., Ltd.).

[Examples 2 to 10]
The same as in Example 1 except that the component A, the type of footwear member, and the composition of the high-frequency dielectric heating adhesive layer were changed as shown in Table 1 below, and the temperature during kneading and film formation was appropriately adjusted. High-frequency dielectric heating adhesive sheets and footwear joints according to Examples 2 to 10 were obtained.
As the component A of Example 5, an ethylene-vinyl acetate copolymer (manufactured by Tosoh Corporation, product name "Ultrasen 626", softening temperature: 65 ° C., melt flow rate: 12 g / 10 min, density: 0.936 g / cm) ^3. Vinyl acetate content: 15% by mass.) Was used.

The following materials were used as footwear members.
-Synthetic fiber: White cloth nylon attached for dyeing fastness test
Size: 25mm x 100mm
・ Natural fiber: White cloth cotton attached for dyeing fastness test
Size: 25mm x 100mm
-Polyurethane foam: 2021 type outsole manufactured by Vibram
Size: 20mm x 100mm x 2.0mm
-Rubber: Vibram 4014 type outsole
Size: 20mm x 100mm x 2.0mm
・ Natural leather: Cowhide
Size: 25mm x 100mm x 1.5mm

[Evaluation of high-frequency dielectric heating adhesive sheet]
Table 1 shows the evaluation results of the high-frequency dielectric heating adhesive sheet.

(Dielectric property)
The produced high-frequency dielectric heating adhesive sheet was cut into a size of 30 mm × 30 mm. The cut high-frequency dielectric heating adhesive sheet was measured for dielectric constant (ε') and dielectric loss tangent (tan δ), respectively, using an impedance material analyzer E4991 (manufactured by Agilent) under the condition of a frequency of 40.68 MHz at 23 ° C. Based on the measurement results, the value of the dielectric property (tan δ / ε') was calculated.

(Softening temperature)
The softening temperature of the high-frequency dielectric heating adhesive sheet was measured according to JIS K 7196: 2012.

(density)
The density (g / cm ³ ) of the high-frequency dielectric heating adhesive sheet was measured according to the method A (underwater substitution method) of JIS K 7112: 1999.

(Melt flow rate)
The MFR of the measurement sample was measured by changing the test conditions described in JIS K 7210-1: 2014 as follows.
・ Test temperature: 230 ℃
・ Load: 5 kg
・ Die: Hole shape φ2.0 mm, length 5.0 mm
・ Cylinder diameter: 11.329 mm
In the thermoplastic resin (A) of the example, since the constituent unit derived from olefin is polyethylene, the test temperature at the time of measuring the MFR of the component A was set to 190 ° C.

(Loss tangent peak temperature at 1 Hz)
The loss tangential peak temperature at 1 Hz is pulled in the range of -100 ° C to 100 ° C at a frequency of 1 Hz and a temperature rise of 4 ° C / min using a dynamic viscoelastic automatic measuring instrument (Vibron DDV-01FP manufactured by Orientec). The viscoelasticity of the high-frequency dielectric adhesive layer according to the mode was measured and used as the temperature at the maximum point of the obtained tan δ (loss elastic modulus / storage elastic modulus).

(Young's modulus)
The high-frequency dielectric heating adhesive sheet produced in the above Examples and Comparative Examples was cut into test pieces of 15 mm (TD direction) × 150 mm (MD direction), and in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999. , Young's modulus (MPa) at 23 ° C. was measured. Specifically, the above test piece is set to a distance between chucks of 100 mm with a tensile tester (manufactured by Shimadzu Corporation, Autograph AG-IS 500N), and then a tensile test is performed at a speed of 200 mm / min to obtain Young's modulus. (MPa) was measured.

(Joint strength test)
The tensile shear force of the prepared footwear joint was measured according to JIS K 6850: 1999. If the measured tensile shear force is 3 MPa or more, or at least one of the pair of footwear members is destroyed, the test is judged to be acceptable. In Table 1, if it passes, it is indicated as "A", and if it fails, it is indicated as "F". The size of the sticking surface between one footwear member and the other footwear member was 25 mm × 12.5 mm.

(Ratio of change in tensile fracture stress R1)
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear was measured before and after the moist heat test described below, and the rate of change R1 of the tensile fracture stress was calculated based on the following formula.
Rate of change R1 = {(tensile fracture stress after wet heat test) / (tensile fracture stress before wet heat test)} × 100

A sample having a size of 150 mm (MD direction) × 15 mm (TD direction) was prepared from a high-frequency dielectric heating adhesive sheet for footwear, and a wet heat test was carried out under the following conditions.
As a moist heat test, a test was carried out in which the prepared high-frequency dielectric heating adhesive sheet was placed under the conditions of a temperature of 85 ° C. and a humidity of 85% RH for 7 days.
After completing the moist heat test, it was allowed to stand in an environment of 25 ° C. and 50% RH for 24 hours, and then the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear was applied to JIS K 7161-1: 2014 and JIS K 7127: Measured according to 1999.

(Ratio of change in tensile fracture stress R2)
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear was measured before and after the following dynamic flexibility test, and the tensile fracture stress was calculated based on the following formula.
Rate of change R2 = {(tensile fracture stress after dynamic flexibility test) / (tensile fracture stress before dynamic flexibility test)} × 100

A sample having a size of 150 mm (MD direction) × 15 mm (TD direction) was prepared from a high-frequency dielectric heating adhesive sheet for footwear, and a dynamic flexibility test was carried out under the following bending conditions.
<Bending condition>
Test temperature: 23 ° C
Minimum bending diameter: 10 mmφ
Number of bending: 30,000 times Bending speed: 30 rpm
A planar unloaded U-shaped expansion / contraction tester (manufactured by Yuasa System Co., Ltd.) was used for the dynamic flexibility test.
After completing the flexibility test, it was allowed to stand in an environment of 25 ° C. and 50% RH for 24 hours, and then a tensile test was performed in the same manner as the method for measuring Young's modulus to determine the tensile fracture stress. The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear was measured in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999.

1, 1A ... High-frequency dielectric heating adhesive sheet for footwear, 3, 3A ... Footwear.

Claims (15)

Has a high frequency dielectric adhesive layer,
The high-frequency dielectric adhesive layer contains a thermoplastic resin (A) and a dielectric filler (B).
The high-frequency dielectric adhesive layer contains the dielectric filler (B) in an amount of 10% by volume or more and 50% by volume or less.
A high-frequency dielectric heating adhesive sheet for footwear used to join footwear members that make up footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to claim 1,
The dielectric filler (B) is zinc oxide, silicon carbide, or barium titanate.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to claim 1 or 2.
The thermoplastic resin (A) is a polyolefin resin having a polar moiety.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 3.
The Young's modulus of the high-frequency dielectric heating adhesive sheet for footwear is 40 MPa or more and 600 MPa or less.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 4.
The softening temperature measured in accordance with JIS K 7196: 2012 of the high-frequency dielectric heating adhesive sheet for footwear is 50 ° C. or higher and 210 ° C. or lower.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 5.
The melt flow rate of the high-frequency dielectric adhesive layer is 1 g / 10 minutes or more and 80 g / 10 minutes or less.
High frequency dielectric heating adhesive sheet for footwear. The high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 6.
The loss tangent peak temperature at 1 Hz of the high-frequency dielectric adhesive layer is 0 ° C. or lower.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 7.
The footwear member is at least one selected from the group consisting of natural leather, synthetic leather, natural fiber, chemical fiber, resin molded product, and rubber molded product.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 7.
At least one of the footwear members is a foam.
High frequency dielectric heating adhesive sheet for footwear. In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 9.
The rate of change R1 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the moist heat test is 80% or more and 120% or less.
High frequency dielectric heating adhesive sheet for footwear.
Rate of change R1 = {(tensile fracture stress after wet heat test) / (tensile fracture stress before wet heat test)} × 100
(The moist heat test is a test in which the high-frequency dielectric heating adhesive sheet for footwear is placed under the conditions of a temperature of 85 ° C. and a humidity of 85% RH for 7 days.
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear is measured in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999. ) In the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 10.
The rate of change R2 of the tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear before and after the dynamic flexibility test is 80% or more and 120% or less.
High frequency dielectric heating adhesive sheet for footwear.
Rate of change R2 = {(tensile fracture stress after dynamic flexibility test) / (tensile fracture stress before dynamic flexibility test)} × 100
(In the dynamic flexibility test, a sample having a size of 150 mm (MD direction) × 15 mm (TD direction) was prepared from the high-frequency dielectric heating adhesive sheet for footwear, and the bending conditions were a minimum bending diameter of 10 mmφ and the number of bendings. This test is performed 30,000 times under the condition that the bending speed is 30 rpm.
The tensile fracture stress of the high-frequency dielectric heating adhesive sheet for footwear is measured in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999. A footwear in which a first footwear member and a second footwear member as the footwear member are joined by the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 11. A step of joining the footwear members using the high-frequency dielectric heating adhesive sheet for footwear according to any one of claims 1 to 11.
How to make footwear. The method for manufacturing footwear according to claim 13.
The footwear member includes a first footwear member and a second footwear member.
A step of arranging the high-frequency dielectric heating adhesive sheet for footwear between the first footwear member and the second footwear member, and
A step of performing a dielectric heating treatment on a high-frequency dielectric heating adhesive sheet for footwear arranged between the first footwear member and the second footwear member under conditions of a frequency of 1 MHz or more and 100 MHz or less. ,including,
How to make footwear. The method for manufacturing footwear according to claim 14.
The high frequency output in the step of performing the dielectric heating treatment is 0.01 kW or more and 20 kW or less, and the high frequency application time is 1 second or more and 60 seconds or less.
How to make footwear.

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