WO2021132058A1 - Electronic tag adhesive and electronic tag - Google Patents

Abstract

The present invention pertains to an electronic tag adhesive and an electronic tag. The electronic tag adhesive includes a thermoplastic elastomer and fulfills conditions (1) and (2).　(1) The dielectric constant of a layer obtained from the adhesive and measured at a frequency of 1 kHz is no more than 4. (2) The dielectric tangents for a layer obtained from the adhesive and measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz, and 10 GHz are no more than 0.10, respectively.

Description

Adhesives for electronic tags and electronic tags

One embodiment of the present invention relates to an adhesive for an electronic tag or an electronic tag.

Generally, an electronic tag such as a non-contact type IC tag has an IC chip and an antenna in which identification information of each article is input in advance.
Electronic tags are used by attaching or embedding them in articles. For example, in the industrial world, electronic tags can be attached to articles to identify and manage articles (Electronic Article Sureillannce, EAS). It is done. For example, the non-contact type IC tag enables a communication distance of several meters by radio mainly using UHF waves including microwaves, and the articles are identified and managed by this communication.

As a method for manufacturing an electronic tag, for example, a circuit pattern is formed on one surface of a base material with a conductive material, an IC chip is mounted on the circuit pattern to form an electronic circuit, and a surface film having an adhesive layer is placed on the electronic circuit. There is known a method of manufacturing an electronic tag by laminating and laminating the electronic tag.
Further, in the electronic tag manufacturing line, a long manufacturing device is used to continuously manufacture each IC module in a series, roll it, and separate it for each IC module at the time of use to obtain a large number of electrons. I'm getting a tag.

Various adhesives are used as the adhesive for forming the adhesive layer. For example, in Patent Document 1, a base sheet with an electronic circuit in which an electronic circuit including a circuit line and an IC chip connected to the circuit is provided on one surface of the base sheet is a specific cushioning material and a surface layer. The IC tag that is sequentially covered with the above is disclosed, and the IC tag in which the base material sheet and the electronic circuit are laminated via an adhesive layer is disclosed.

Japanese Patent No. 4274867

However, since the adhesive layer formed from the conventional adhesive for electronic circuits such as the adhesive described in Patent Document 1 has insufficient insulating properties and a large dielectric loss, the adhesive layer was used. The electronic tag has a risk of shortening the communication distance.
Further, since the adhesive layer formed from the conventional adhesive for electronic circuits has low water resistance, when an electronic tag using the adhesive layer is used in a high humidity environment, water is a substance having high radio wave absorption. There was a risk that the operation of the electronic tag would become unstable due to the influence of.

Further, the adhesive layer formed from the conventional adhesive for electronic circuits has low chemical resistance. Therefore, when a metal material is laminated on one surface of the base material via an adhesive layer and the metal material is etched to form a circuit pattern, the adhesive layer may be peeled off during the etching.
Further, the adhesive layer formed from the conventional adhesive for electronic circuits has a strong tack property. For this reason, for example, there are cases where it is desired to wind up a surface film with an adhesive layer obtained by applying an adhesive to the surface film, but if it is wound up in this way, it will stick together and cannot be stretched later. After all, there were cases where it could not be wound up.

One embodiment of the present invention provides an adhesive suitable for an electronic tag and an electronic tag using the same.

The present invention has been completed by finding that the above problems can be solved according to the following configuration example.
A configuration example of the present invention is as follows.

[1] An adhesive for electronic tags containing a thermoplastic elastomer and satisfying the following requirements (1) and (2).
(1) The relative permittivity of the layer obtained from the adhesive measured at a frequency of 1 kHz is 4 or less. (2) The layer obtained from the adhesive is measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 GHz. The dielectric loss tangent is 0.10 or less.

[2] The adhesive for electronic tags according to [1], wherein the thermoplastic elastomer is one or more thermoplastic elastomers selected from olefin-based elastomers and styrene-based elastomers.

[3] The adhesive for an electronic tag according to [1] or [2], wherein the thermoplastic elastomer contains a modified thermoplastic elastomer modified with a monomer having a functional group.
[4] The adhesive for an electronic tag according to [3], wherein the functional group is a carboxyl group and / or an acid anhydride group.

[5] The thermoplastic elastomer is an olefin-based elastomer containing a polymer derived from an α-olefin having 2 to 20 carbon atoms.
The polymer derived from an α-olefin having 2 to 20 carbon atoms contains a structural unit derived from an α-olefin having 4 to 20 carbon atoms.
The olefin-based elastomer has a heat of fusion measured according to JIS K7122 of 0 to 50 J / g.
The adhesive for an electronic tag according to any one of [1] to [4].

[6] The adhesive for an electronic tag according to any one of [1] to [5], further containing a polar component other than the modified thermoplastic elastomer modified with a monomer having a functional group.
[7] The adhesive for an electronic tag according to any one of [1] to [6], which further contains a hydrocarbon-based synthetic oil.

[8] At least one electron selected from a circuit line and an IC chip via an adhesive layer formed from the adhesive for electronic tags according to any one of [1] to [7] on a base material. An electronic tag having a member.

[9] At least one electronic member selected from a circuit line and an IC chip is arranged on the base material, and the electronic member has a surface layer on the opposite side of the base material, and the electronic member and the surface layer. Is an electronic tag bonded with the adhesive for an electronic tag according to any one of [1] to [7].

[10] At least one electronic member selected from a circuit line and an IC chip is arranged on the base material, and the electronic member has a surface layer on the opposite side of the base material, and the base material and the surface layer. Is an electronic tag bonded with the adhesive for an electronic tag according to any one of [1] to [7].

According to one embodiment of the present invention, for an electronic tag capable of forming an adhesive layer having a good balance of high insulation, low dielectric loss, water resistance, chemical resistance, adhesive strength and low tackiness, preferably non-contact. An adhesive for a formula IC tag (RFID tag) can be provided.
Further, according to one embodiment of the present invention, it is possible to easily obtain an electronic tag that has a long communication distance and operates stably even in a high humidity environment.

FIG. 1 is a schematic cross-sectional view showing an example of an electronic tag. FIG. 2 is a schematic cross-sectional view showing an example of the vicinity of an electronic member of an electronic tag. FIG. 3 is a schematic cross-sectional view showing an example of an electronic tag.

≪Adhesive for electronic tags≫
The adhesive for electronic tags according to an embodiment of the present invention (hereinafter, also referred to as “the present adhesive”) contains a thermoplastic elastomer and satisfies the following requirements (1) and (2).
(1) The relative permittivity of the layer obtained from the present adhesive measured at a frequency of 1 kHz is 4 or less. (2) The layer obtained from the present adhesive is measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 GHz. The dielectric loss tangent is 0.10 or less.

The adhesive may be used anywhere on the electronic tag. Further, it may be used in two places or two or more layers of the electronic tag.
For example, an interlayer between the base material and the electronic member (hereinafter adhesive layer 6), an interlayer between the electronic member and the surface layer (hereinafter adhesive layer 2), an interlayer between the base material and the surface layer (hereinafter adhesive layer 2), Examples thereof include use between the base material and the support (the adhesive layer 7 below) and between the base material and the release layer.

The adhesive has a relative permittivity of 4 or less, preferably 3 or less, more preferably 2.5 or less, and particularly preferably 2 or less, as measured at a frequency of 1 kHz for the layer obtained from the adhesive.

In this adhesive, the dielectric loss tangent measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 GHz of the layer obtained from the adhesive is 0.10 or less, preferably 0.020 or less. It is more preferably 0.010 or less, and more preferably 0.0050 or less.

Since the present adhesive satisfying the above requirements (1) and (2) has high insulating properties and small dielectric loss, it is possible to increase the communication distance of the electronic tag obtained when it is used as an adhesive for an electronic tag. it can.
The method for measuring the relative permittivity and the dielectric loss tangent of the present adhesive and the method for preparing a sample for measurement are as described in Examples described later.
The present adhesive satisfying the above requirements (1) and (2) can be easily obtained by using, for example, a thermoplastic elastomer at the following content.

The adhesive preferably further satisfies the following requirements (3) and / or (4), and more preferably the following requirements (3) and (4).
(3) The absolute value of the difference between the relative permittivity measured at a frequency of 1 kHz and the relative permittivity measured at a frequency of 10 GHz of the layer obtained from the present adhesive is preferably 1 or less, more preferably 0.1 or less. (4) The difference between the maximum value and the minimum value of the dielectric loss tangent measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 GHz of the layer obtained from the present adhesive is preferably 0.02 or less, more preferably 0. It is 01 or less, particularly preferably 0.0020 or less.

When the above (3) and / or (4) are satisfied, the relative permittivity and the dielectric loss tangent have little frequency dependence, and the electronic tag can be used in a wide frequency range.

<Thermoplastic elastomer>
The adhesive comprises a thermoplastic elastomer.
Examples of the thermoplastic elastomer include olefin-based elastomers and styrene-based elastomers, and olefin-based elastomers and styrene-based elastomers can be used in combination at any ratio.
Further, the thermoplastic elastomer is preferably a modified thermoplastic elastomer modified with a monomer having a functional group.
The thermoplastic elastomer contained in the present adhesive may be one kind or two or more kinds.

The content of the thermoplastic elastomer may be 100% by mass with respect to 100% by mass of the non-volatile content (components other than the solvent) of the present adhesive. In this case, it is preferable to use an olefin-based elastomer and a styrene-based elastomer as the thermoplastic elastomer, and it is more preferable to use a modified olefin-based elastomer and a modified styrene-based elastomer.
Further, it is more preferable to use a modified olefin-based elastomer as the thermoplastic elastomer. When the modified styrene elastomer and the modified olefin elastomer are used in combination, the content of the modified olefin elastomer / the content (mass ratio) of the modified styrene elastomer is preferably 100/0 to 60/40, preferably 100. It is / 0 to 55/45.
When the present adhesive contains the following other polar components, the content of the thermoplastic elastomer is preferably 40% by mass or more, more preferably 50% by mass, based on 100% by mass of the total of the thermoplastic elastomer and the other polar components. % Or more, more preferably 60% by mass or more, and preferably 98% by mass or less, particularly preferably 96% by mass or less.
When the content of the thermoplastic elastomer is within the above range, an adhesive layer having excellent adhesive strength and chemical resistance can be easily obtained.

<Olefin-based elastomer>
Examples of the olefin-based elastomer include a polymer (a) derived from an α-olefin having 2 to 20 carbon atoms, which may be a modified polymer (b) modified with a monomer having a functional group. preferable.

[Polymer (a) derived from α-olefin having 2 to 20 carbon atoms]
The polymer (a) is not particularly limited as long as it contains a structural unit derived from an α-olefin having 2 to 20 carbon atoms, and may be a polymer composed of an α-olefin having 4 to 20 carbon atoms. It may be a copolymer obtained by using an α-olefin having a number of 4 to 20 and an α-olefin having 2 to 3 carbon atoms, and if necessary, an unsaturated monomer other than the α-olefin (hereinafter, “other”). It may be a polymer containing a structural unit derived from "unsaturated monomer".

When the polymer (a) has a structural unit derived from an α-olefin having 4 to 20 carbon atoms, the long-term stability, adhesive strength and chemical resistance of the adhesive containing the polymer (a) and the solvent are high. It is preferable because it is well-balanced and excellent.

The α-olefin used as a raw material for the polymer (a) may be used alone or in combination of two or more. That is, the polymer (a) may be a homopolymer of an α-olefin having 2 to 20 carbon atoms, or may be a copolymer obtained by using the α-olefin, and one or more of them. The copolymer (a1) may be obtained by using an α-olefin having 4 to 20 carbon atoms and one or more α-olefins having 2 to 3 carbon atoms.
Examples of the copolymer include a random copolymer and a block copolymer, and a random copolymer is preferable.

Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, and 1-tetradecene. , 1-Hexadecene, 1-Octadecene, 1-Eicocene and other linear or branched α-olefins.

The α-olefin having 4 to 20 carbon atoms is preferably a linear olefin having 4 to 10 carbon atoms from the viewpoint that a polymer having excellent solubility in a solvent and excellent strength can be easily obtained. Yes, more preferably it is a linear olefin having 4 to 6 carbon atoms, and it is more preferable to contain 1-butene, and 1-butene is particularly preferable, from the viewpoint of obtaining a polymer having particularly excellent effects. ..

Examples of the α-olefin having 2 to 3 carbon atoms include ethylene and propylene, and propylene is preferably contained from the viewpoint of easily obtaining a polymer having excellent solubility in a solvent and strength. Propylene is particularly preferred.

Examples of the other unsaturated monomer include conjugated polyenes such as butadiene and isoprene, 1,4-hexadiene, 1,7-octadien, dicyclopentadiene, 5-ethylidene-2-norbornene, and 5-vinyl-. Examples thereof include unconjugated polyenes such as 2-norbornene, 5-methylene-2-norbornene, and 2,5-norbornene.

As the polymer (a), the copolymer (a1) is preferable from the viewpoint that a polymer having excellent solubility in a solvent and excellent strength can be easily obtained, and the polymer (a1) is preferably propylene and has 4 to 20 carbon atoms. A copolymer with an α-olefin is more preferable, and in particular, a polymer in which all the structural units other than the structural unit derived from propylene are the structural units derived from the α-olefin having 4 to 20 carbon atoms is more preferable. It is more preferable that the α-olefin having 4 to 20 carbon atoms contains 1-butene, and a copolymer of 1-butene and propylene is particularly preferable.

In the polymer (a), the content ratio of the structural unit derived from the α-olefin having 4 to 20 carbon atoms is preferably 100 mol% with respect to 100 mol% of the structural unit derived from the α-olefin having 2 to 20 carbon atoms. For example, 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, and for example 100 mol% or less, preferably 100 mol% or more, based on 100 mol% of all the constituent units constituting the polymer (a). Is 60 mol% or less, more preferably 50 mol% or less, still more preferably 40 mol% or less, and particularly preferably 35 mol% or less.
When the content ratio of the structural unit derived from the α-olefin having 4 to 20 carbon atoms satisfies the above upper limit, a polymer having higher strength can be obtained, and when the lower limit is satisfied, the solvent becomes more solvent. A polymer having excellent solubility can be obtained.

In the polymer (a), the content ratio of the structural unit derived from α-olefin (preferably propylene) having 2 to 3 carbon atoms is 100 mol% of the structural unit derived from α-olefin having 2 to 20 carbon atoms. On the other hand, preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, particularly preferably 65, based on 100 mol% of all the constituent units constituting the polymer (a). It is mol% or more, preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 80 mol% or less.
When the content ratio of the structural unit derived from the α-olefin having 2 to 3 carbon atoms satisfies the above upper limit, the melting point (Tm) and the heat of fusion (ΔH) of the copolymer can be lowered, and the lower limit can be lowered. When the above-mentioned regulations are satisfied, a polymer having higher strength can be obtained.

The polymer (a) is obtained by polymerizing an α-olefin having 2 to 20 carbon atoms in the presence of a known solid Ti catalyst, metallocene catalyst, etc., which are usually used for producing an α-olefin polymer. be able to. Examples of the metallocene catalyst include metallocene compounds such as rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride, organoaluminum oxy compounds such as methylaluminoxane, and triisobutylaluminum. Examples include catalysts containing organoaluminum compounds. More specifically, the polymer (a) can be obtained, for example, by the method described in International Publication No. 2004/87775.

The polymer (a), measured by gel permeation chromatography (GPC), the weight average molecular weight which is converted by the standard polystyrene (Mw) of, preferably 1 × 10 ⁴ or more, preferably 1 It is × ¹⁰⁷ or less, and the molecular weight distribution (Mw / Mn) is preferably 1 or more, and preferably 3 or less.

When Mw and Mw / Mn satisfy the above lower limit, an adhesive layer having sufficiently high adhesive strength can be easily obtained, and the adhesive layer and an adherend (eg, a base material, an electronic member, etc.) When the adhesive strength with the surface layer) becomes better and the above upper limit is satisfied, a polymer having good solubility in a solvent can be obtained, and an adhesive that does not easily solidify and precipitate can be obtained.

In the present invention, Mw and Mw / Mn can be specifically measured by the method described in the following Examples.

The melting point (Tm) of the polymer (a) is preferably less than 120 ° C, more preferably less than 100 ° C.
When Tm is in the above range, an adhesive layer having excellent adhesive strength can be obtained even if an adhesive layer is formed from the present adhesive under low temperature curing conditions.

In the present invention, Tm is determined by differential scanning calorimetry (DSC measurement) according to JIS K7122. Specifically, the temperature is raised from 30 ° C. to 180 ° C. at 10 ° C./min and then held at that temperature for 3 minutes. Then, in the process of lowering the temperature to 0 ° C. at 10 ° C./min, holding at that temperature for 3 minutes, and then raising the temperature again to 150 ° C. at 10 ° C./min, from the thermogram at the time of the second temperature rise. , JIS K 7122.

The heat of fusion (ΔH) of the polymer (a) is preferably 0 J / g or more, more preferably 3 J / g or more, particularly preferably 5 J / g or more, preferably 50 J / g or less, and more preferably. It is 40 J / g or less.
When ΔH satisfies the above upper limit, an adhesive layer having excellent adhesive strength can be obtained even if an adhesive layer is formed from the present adhesive under low temperature curing conditions, and when ΔH satisfies the above lower limit, adhesion is achieved. An adhesive layer having excellent strength can be obtained.

In the present invention, ΔH is determined by differential scanning calorimetry (DSC measurement) according to JIS K7122, and is specifically calculated from the peak area of the thermogram obtained in the heating process of 10 ° C./min. More specifically, for the purpose of canceling the heat history before measurement, the temperature is raised to 180 ° C. at 10 ° C./min, held at that temperature for 3 minutes, and then lowered to 0 ° C. at 10 ° C./min. Then, after holding at that temperature for 3 minutes, ΔH is measured.

[Modified polymer (b)]
The modified polymer (b) is not particularly limited as long as it is a modified thermoplastic elastomer modified with a monomer having a functional group, but the monomer having one or more functional groups and one or more kinds of the weights thereof. It is preferably a polymer obtained by reacting with the coalescence (a).
The modified polymer (b) can be synthesized according to a conventional method, for example, as disclosed in International Publication No. 2017/126520.

Examples of the functional group include a group having an active hydrogen, and specific examples thereof include a hydroxyl group, an amino group, a carboxyl group, an acid anhydride group, an ester group, and a thiol group.
The monomer having a functional group may have one kind of functional group or may have two or more kinds of functional groups. Further, the number of functional groups may be one or two or more.

The monomer having a functional group reacts efficiently when forming an adhesive layer, and the following base material / surface layer (eg, synthetic resin, paper) or conductive material (eg, circuit line) It is possible to further improve the adhesive strength between the adhesive layer and the adherend by increasing the affinity for the adhesive layer, and it is possible to improve the chemical resistance of the obtained adhesive layer. Monomers having an acid anhydride group or a carboxyl group are preferable.

Examples of the monomer having a functional group include a hydroxyl group-containing unsaturated compound, an amino group-containing unsaturated compound, an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, a vinyl ester compound, a thiol group-containing unsaturated compound, and the like. , These derivatives are mentioned.

Examples of the hydroxyl group-containing unsaturated compound include hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxy-3-phenoxy-propyl (meth) acrylate. 3-Chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, pentaerythritol mono (meth) acrylate, trimethylolpropane mono (meth) acrylate, tetramethylol ethanemono (meth) acrylate, butanediol mono (meth) Hydroxyl-containing (meth) acrylic acid esters such as meta) acrylate, polyethylene glycol mono (meth) acrylate, 2- (6-hydrohexanoyloxy) ethyl (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate; 10-Undecene-1-ol, 1-octen-3-ol, 2-methanol norbornene, hydroxystyrene, N-methylol (meth) acrylamide, glycerin monoallyl ether, allyl alcohol, allyloxyethanol, 2-butene-1, Examples include 4-diol and glycerin monoalcohol.

Examples of the amino group-containing unsaturated compound include vinyl-based monomers having at least one amino group represented by ^{−NHR 1 or a substituted amino group.}
Examples of the R ¹ include a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, or a cycloalkyl group having 4 to 12 carbon atoms, preferably 6 to 9 carbon atoms. The R ¹ may also include a group in which a part of the alkyl group and the cycloalkyl group is substituted with a substituent.

Examples of the amino group-containing unsaturated compound include aminomethyl (meth) acrylate, aminoethyl (meth) atacrylate, aminopropyl (meth) atacrylate, propylaminoethyl (meth) acrylate, and (meth) acrylic acid. Dimethylaminoethyl, phenylaminomethyl (meth) acrylate, cyclohexylaminoethyl (meth) acrylate, N-vinyldiethylamine, N-acetylvinylamine, (meth) acrylamide, N-methyl (meth) acrylamide, N, N- Examples thereof include dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, p-aminohexyl succinate imide, and 2-aminoethyl succinate imide.

Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornenedicarboxylic acid, and bicyclo [2.2.1]. Hept-2-ene-5,6-dicarboxylic acid can be mentioned.

Examples of the unsaturated carboxylic acid anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo [2.2.1] hept-2-ene-5,6-dicarboxylic acid anhydride. Things can be mentioned.

Examples of the vinyl ester compound include vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatic acid, vinyl laurate, vinyl stearate, vinyl benzoate, and salicylic acid. Examples include vinyl and vinyl cyclohexanecarboxylate.

Examples of the thiol group-containing unsaturated compound include thiophenol derivatives such as allyl mercaptan, 2-vinylbenzyl mercaptan, 3-vinylbenzyl mercaptan, 4-vinylbenzyl mercaptan, and vinyl thiophenol.

Examples of the derivative include malenyl chloride, malenylimide, dimethyl maleate, monomethyl maleate, diethyl maleate, diethyl fumarate, dimethyl itaconic acid, diethyl citraconic acid, dimethyl tetrahydrophthalate, and bicyclo [2.2.1] hepto. Examples thereof include dimethyl-2-ene-5,6-dicarboxylic acid.

The monomer having a functional group reacts efficiently when forming the adhesive layer, enhances the affinity for the base material / surface layer and the conductive material, and causes the adhesive layer and the adherend to interact with each other. Unsaturated carboxylic acid and unsaturated carboxylic acid anhydride from the viewpoints of being able to further improve the adhesive strength of the adhesive layer, and being able to improve the chemical resistance and electrolytic solution resistance of the obtained adhesive layer. Is preferable, unsaturated carboxylic acid anhydride is more preferable, and maleic anhydride is further preferable.

The Mw of the modified polymer (b) measured by GPC and converted into standard polystyrene is preferably 1 × 10 ⁴ or more, more preferably 2 × 10 ⁴ or more, and particularly preferably 3 × 10 ⁴ or more. Further, it is preferably 1 × 10 ⁷ or less, more preferably 1 × 10 ⁶ or less, and particularly preferably 5 × 10 ⁵ or less.

When the Mw of the modified polymer (b) satisfies the above-mentioned lower limit, an adhesive layer having sufficiently high adhesive strength and excellent adhesive strength with the adherend can be easily obtained, and the above-mentioned upper limit is specified. When the above conditions are met, a modified polymer (b) having good solubility in a solvent and less likely to solidify and precipitate can be obtained. In particular, when the Mw of the modified polymer (b) is at 5 × 10 ⁵ or less, it is possible to obtain an adhesive layer excellent in adhesion strength to an adherend.

The Mw / Mn of the modified polymer (b) is preferably 1 or more, more preferably 1.5 or more, preferably 3 or less, and more preferably 2.5 or less.
When Mw / Mn satisfies the above lower limit, a modified polymer (b) having good solubility in a solvent and less likely to solidify and precipitate can be obtained, and when the above upper limit is satisfied, the adhesive strength Is sufficiently high, and an adhesive layer having excellent adhesive strength with the adherend can be easily obtained.

The Tm of the modified polymer (b) is preferably less than 120 ° C., more preferably less than 100 ° C., still more preferably 90 ° C. or lower, particularly preferably 87 ° C. or lower, and preferably 40 ° C. or higher, more preferably. It is 50 ° C. or higher.
When the Tm of the modified polymer (b) satisfies the above upper limit, even if an adhesive layer is formed from the present adhesive under low temperature curing conditions, a decrease in adhesive strength can be suppressed, and the above lower limit is specified. When the above conditions are met, an adhesive layer having excellent adhesive strength and durability can be obtained.
The modified polymer (b) having Tm can be obtained, for example, by appropriately adjusting the content ratio of the structural unit derived from the α-olefin having 2 to 3 carbon atoms in the modified polymer (b). ..

The ΔH of the modified polymer (b) is preferably 0 J / g or more, more preferably 3 J / g or more, particularly preferably 5 J / g or more, and preferably 50 J / g or less, more preferably 40 J / g. Below, it is particularly preferably 35 J / g or less.
When ΔH of the modified polymer (b) satisfies the above upper limit, an adhesive layer having excellent adhesive strength can be obtained even if an adhesive layer is formed from the present adhesive under low temperature curing conditions, and the lower limit can be obtained. When the above-mentioned regulations are satisfied, an adhesive layer having excellent adhesive strength can be easily obtained.
The modified polymer (b) having ΔH can be obtained, for example, by appropriately adjusting the content ratio of the structural unit derived from the α-olefin having 2 to 3 carbon atoms in the modified polymer (b). ..

The semi-crystallization time of the modified polymer (b) at 50 ° C. is preferably 100 seconds or longer, more preferably 150 seconds or longer, still more preferably 200 seconds or longer. Further, the semi-crystallization time includes a case where crystallization does not substantially occur, or the value of the semi-crystallization time is too large to be obtained, that is, the semi-crystallization time becomes infinite. Is done.
When the semi-crystallization time of the modified polymer (b) satisfies the above lower limit, the modified polymer (b) reacts with the following curing agent while or after infiltrating into the unevenness of the surface of the adherend. The anchor effect can further improve the adhesive strength of the resulting adhesive layer.
The semi-crystallization time can be determined by isothermal crystallization measurement with a differential scanning calorimeter.

The kinematic viscosity of the modified polymer (b) at 40 ° C. preferably exceeds 500,000 cSt. Here, when the kinematic viscosity exceeds 500,000 cSt, there is a case where the fluidity is low and the kinematic viscosity cannot be measured.
In the present invention, the kinematic viscosity at 40 ° C. is measured based on ASTM D 445.

The content ratio (modification amount) of the structural unit derived from the monomer having a functional group in the modified polymer (b) is preferably 0.1% by mass or more with respect to 100% by mass of the modified polymer (b). , More preferably 0.5% by mass or more, and preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, particularly preferably 4% by mass or less, still more preferably 2. It is mass% or less.
When the amount of modification is within the above range, the modified polymer (b) reacts efficiently when the adhesive layer is formed, and the affinity of the modified polymer (b) with respect to the adherend is enhanced to increase the adhesive. The adhesive strength between the layer and the adherend can be further improved, and the chemical resistance of the obtained adhesive layer can be improved.

<Styrene-based elastomer>
The type and production method of the styrene-based elastomer are not particularly limited, and examples thereof include copolymers containing a structural unit derived from a monovinyl aromatic hydrocarbon such as styrene.
The styrene-based elastomer may be a modified styrene-based elastomer modified with a monomer having a functional group. The modification can be carried out by a conventionally known method.

Examples of the styrene-based elastomer include a copolymer containing a monovinyl-substituted aromatic hydrocarbon (styrene-based aromatic hydrocarbon) as a copolymerization component, and specific examples thereof include styrene-ethylene-butylene-styrene block. Polymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-butylene-butadylene-styrene block copolymer (SBBS), styrene-butadiene rubber (SBR), styrene-isoprene rubber (SIR) ), Styrene-ethylene copolymer, styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), poly (α-methylstyrene) -polybutadiene-poly (α-methylstyrene) (Α-MeSBα-MeS), poly (α-methylstyrene) -polyisoprene-poly (α-methylstyrene) (α-MeSIα-MeS) can be mentioned. Further, a conjugated diene moiety constituting these copolymers, specifically, a copolymer in which a constituent unit derived from butadylene or isoprene is hydrogenated can be mentioned. Among these, SEBS and SEPS are preferable.

Examples of the monomer having a functional group for modifying the styrene-based elastomer include the monomer having a functional group described in the column of the modified polymer (b). Of these, unsaturated carboxylic acids or unsaturated carboxylic acid anhydrides are preferred, unsaturated carboxylic acid anhydrides are more preferred, and maleic anhydride is even more preferred.

The content ratio (modification amount) of the structural unit derived from the monomer having a functional group in the modified styrene-based elastomer is preferably 0.1% by mass or more, more preferably 0.1% by mass or more, based on 100% by mass of the modified styrene-based elastomer. 0.5% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, particularly preferably 4% by mass or less, still more preferably 3% by mass or less. is there.

Commercially available products can also be used as the modified styrene elastomer. Specific examples of the commercially available product include Dynaron 8630P (manufactured by JSR (example)) and Tough Tech M1913 (manufactured by Asahi Kasei Corporation).

<Other polar components>
The present adhesive may further contain other polar components for the purpose of improving the adhesion to the base material / surface layer and the conductive material, improving the low temperature curability, and the like. The other polar component is a polar component other than the modified thermoplastic elastomer modified with the above-mentioned monomer having a functional group.
When the present adhesive contains other polar components, the other polar components contained in the present adhesive may be one kind or two or more kinds respectively.

When a modified thermoplastic elastomer (eg, modified polymer (b), modified styrene-based elastomer) is used as the thermoplastic elastomer, at least one curing selected from an isocyanate compound, an epoxy compound and an oxazoline compound is used as the polar component. It is preferable to use an agent.

[Isocyanate compound]
Examples of the isocyanate compound include a polyisocyanate monomer and a polyisocyanate modified product.

Examples of the polyisocyanate monomer include aromatic polyisocyanates, aromatic aliphatic polyisocyanates, and aliphatic polyisocyanates.

Examples of the aromatic polyisocyanate include tolylene diisocyanate (eg, 2,4- or 2,6-toluene diisocyanate or a mixture thereof) (TDI), phenylenedi isocyanate (eg, m- or p-phenylenediocyanate or a mixture thereof). , 4,4'-diphenyldiisocyanate, 1,5-naphthalenediocyanate (NDI), diphenylmethane diisocyanate (eg 4,4'-, 2,4'-or 2,2'-diphenylmethane diisocyanate Or a mixture thereof) (MDI), 4,4'-toluene diisocyanate (TODI), 4,4'-diphenyl ether diisocyanate and other aromatic diisocyanates.

Examples of the aromatic aliphatic polyisocyanate include xylylene diisocyanate (eg 1,3- or 1,4-xylene diisocyanate or a mixture thereof) (XDI) and tetramethylxylene diisocyanate (eg 1,3- or a mixture thereof). 1,4-Tetramethylxylene diisocyanate or a mixture thereof) (TMXDI), ω, ω'-diisocyanate-1,4-diisocyanate and other aromatic aliphatic diisocyanates can be mentioned.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, and butylene diisocyanate (eg, tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate). , 1,5-Pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate and other aliphatic diisocyanates.

In addition, the aliphatic polyisocyanate includes an alicyclic polyisocyanate. Examples of the alicyclic polyisocyanate include 1,3-cyclopentanediisocyanate, 1,3-cyclopentenediisocyanate, cyclohexanediisocyanate (eg, 1,4-cyclohexanediisocyanate, 1,3-cyclohexanediisocyanate), and 3-isocyanato. Methyl-3,5,5-trimethylcyclohexylisocyanate (isoholodiisocyanate) (IPDI), methylenebis (cyclohexylisocyanate) (eg, 4,4'-, 2,4'-or 2,2'-methylenebis (cyclohexylisocyanate) , These Trans, Trans-form, Trans, Cis-form, Cis, Cis-form, or a mixture thereof)) (H12MDI), methylcyclohexanediisocyanate (eg, methyl-2,4-cyclohexanediisocyanate, methyl-2, 6-Cyclohexanediisocyanate), norbornandiisocyanate (including various isomers or mixtures thereof) (NBDI), bis (isocyanatomethyl) cyclohexane (eg 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane or Examples thereof include alicyclic diisocyanates such as (H6XDI) (H6XDI).

As the polyisocyanate monomer, an aliphatic polyisocyanate and an alicyclic polyisocyanate are preferable, PDI, H6XDI and HDI are more preferable, and HDI is further preferable.

Examples of the polyisocyanate modified product include compounds having an average number of functional groups of more than 2, and examples thereof include multimers of the polyisocyanate monomers (eg, dimer and trimeric (eg, isocyanurate modified product, iminooxa). Diazindione modified product), pentamer, heptameric body), allophanate modified product (eg, the polyisocyanate monomer and monool (eg, monool having 1 to 20 carbon atoms such as octadecanol) (Alofanate modified product produced by the reaction of), polyol modified product (eg, the polyisocyanate monomer and low molecular weight polyol (compound having two or more hydroxylates and having a number average molecular weight of 40 or more and less than 400, for example, Polyol modified product (alcohol adduct) produced by reaction with trimetylolpropane (trivalent alcohol such as trimethylolpropane)), biuret modified product (eg, biuret produced by reaction of the polyisocyanate monomer with water or amines) Modified product), urea modified product (eg, urea modified product produced by the reaction of the polyisocyanate monomer with diamine), oxadiazine trione modified product (example: reaction between the polyisocyanate monomer and carbon dioxide gas) Oxaziazine trione produced by the above), carbodiimide modified product (eg, carbodiimide modified product produced by decarbonate condensation reaction of the polyisocyanate monomer), uretdione modified product, uretonimine modified product, and the like.

Further, as the polyisocyanate modified product, polymethylene polyphenyl polyisocyanate (crude MDI, polypeptide MDI) and the like can also be mentioned.

As the polyisocyanate modified product, a multimer of the polyisocyanate monomer and a polyol modified product are preferable, and a trimer of the polyisocyanate monomer is more preferable.

These polyisocyanate modified products may be prepared by a known method, or commercially available products may be used. Examples of the commercially available product include Takenate D-170N (a trimer-modified form of 1,6-hexamethylene diisocyanate (trimer), manufactured by Mitsui Chemicals, Inc.), Takenate D-120N (a polyol-modified form of H6XDI, Mitsui). (Made by Chemicals Co., Ltd.).

[Epoxy compound]
The epoxy compound is preferably a crosslinkable compound having two or more epoxy groups in one molecule. Examples of such epoxy compounds include bisphenol type epoxy resins such as bisphenol A type epoxy resin (different from hydrogenated bisphenol A type epoxy resin) and bisphenol F type epoxy resin; hydrogenated bisphenol type epoxy resin; novolak type epoxy. Resin; Biphenyl type epoxy resin; Stillben type epoxy resin; Hydroquinone type epoxy resin; Naphthalene skeleton type epoxy resin; Tetraphenylol ethane type epoxy resin; Trishydroxyphenylmethane type epoxy resin; Dicyclopentadienephenol type epoxy resin; 3', Alicyclic such as 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol Formula Epoxy compounds; Polyglycidyl esters of polybasic acids such as diglycidyl ester of hexahydrophthalic anhydride; Sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, pentaerythritol polyglycidyl ether, trimethylpropane polyglycidyl ether, polypropylene glycol diglycidyl ether , Diglycerol polyglycidyl ether, glycerol polyglycidyl ether, hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether and cyclohexanedimethanol diglycidyl ether, etc. Examples thereof include glycidylamine-type epoxy resins such as glycidyldiaminodiphenylmethane, tetraglycidylbisaminomethylcyclohexane, diglycidylaniline, and tetraglycidylmethoxylylylene diamine; and heterocyclic-containing epoxy resins such as triazine or hydantin.

Among the epoxy compounds, the bisphenol A type liquid epoxy resin and the oil ring are excellent in adhesive strength, and in particular, an adhesive layer capable of forming an adhesive layer capable of adhering to an adherend with higher strength can be formed. Formula epoxy compounds, trimethylolpropane polyglycidyl ethers are preferred.

The bisphenol A type liquid epoxy resin is not particularly limited as long as it is a resin that is liquid at room temperature (25 ° C.), and a commercially available product may be used.
Examples of the commercially available products include EPICLON840, 840-S, 850, 850-S, EXA-850CRP, 850-LC (manufactured by DIC Corporation), jER828EL, 827 (manufactured by Mitsubishi Chemical Corporation), and Epomic R-. 140P (manufactured by Mitsui Chemicals, Inc.) can be mentioned.

The alicyclic epoxy compound is a compound having at least one epoxycycloalkyl group or an epoxycycloalkenyl group in the molecule, or at least a group in which at least one epoxy group is bonded to the alicyclic by a single bond in the molecule. It refers to a compound having one.

Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexenylmethyl-3', 4'-epoxycyclohexene carboxylate, 3', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. 3,4-Epoxycyclohexyloctyl-3,4-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-m-dioxane, bis (3,4) -Epoxycyclohexylmethyl) adipate, vinylcyclohexendioxide, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3,4-epoxy-6-methylcyclohexanecarboxy Rate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxyside, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate), 1,2,8 , 9-Diepoxy limonene, 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol, the compound described in JP-A-2008-214555 Can be mentioned.

As the alicyclic epoxy compound, a commercially available product may be used, and examples of the commercially available product include celloxide 2021P, EHPE3150, EHPE3150CE, and Epolide GT401 (all manufactured by Daicel Corporation).

As the alicyclic epoxy compound, 3', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate is preferable from the viewpoint that an adhesive layer having more excellent adhesive strength can be obtained.

Examples of the trimethylolpropane polyglycidyl ether include trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, and mixtures thereof.
As the trimethylolpropane polyglycidyl ether, a commercially available product may be used, and examples of the commercially available product include EX-321L (manufactured by Nagase ChemteX Corporation).

[Oxazoline compound]
The oxazoline compound is preferably a crosslinkable compound having two or more oxazoline groups in one molecule. Examples of such an oxazoline compound include a polymer of an oxazoline group-containing monomer and an oxazoline group-containing polymer such as a copolymer of an oxazoline group-containing monomer and another monomer.

Examples of the oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, and 2-isopropenyl-2-oxazoline. , 2-Isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2-isopropenyl-4,4-dimethyl-2-oxazoline. One type may be used for these, and two or more types may be used.

Examples of the other monomer include alkyl (meth) acrylate (alkyl group having about 1 to 14 carbon atoms); acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and salts thereof. Unsaturated carboxylic acids such as (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; (meth) acrylamide, N-alkyl (meth) acrylamide, N , N-dialkyl (meth) acrylamide, (Examples of these alkyl groups: methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl Unsaturated amides such as group); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; vinyl chloride, vinylidene chloride, vinyl fluoride Halogen-containing α, β-unsaturated monomers such as; α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene. One type may be used for these, and two or more types may be used.

As the oxazoline compound, an oxazoline compound containing 2-isopropenyl-2-oxazoline is preferable from the viewpoint that an adhesive layer having more excellent adhesive strength can be obtained.
Examples of commercially available products of the oxazoline compound include the "Epocross" series manufactured by Nippon Shokubai Co., Ltd.

The epoxy equivalent of the epoxy compound and the oxazoline equivalent of the oxazoline compound are preferably 100 g / eq or more, more preferably 100 g / eq or more, from the viewpoints of obtaining an adhesive layer having more excellent adhesive strength, chemical resistance, and electrolytic solution resistance. Is 125 g / eq or more, preferably 1,600 g / eq or less, and more preferably 500 g / eq or less.
The equivalent can be measured based on JIS K 7236.

The amount of the curing agent blended is such that the equivalent of isocyanate group, epoxy group and oxazoline group in the curing agent / equivalent of the functional group in the modified thermoplastic elastomer is preferably 0.01 or more, more preferably 0.1 or more. Further, it is desirable to mix the mixture so as to be preferably 50 or less, more preferably 30 or less, still more preferably 20 or less, and particularly preferably 10 or less.
When the blending amount of the curing agent is within the above range, an adhesive layer having more excellent adhesive strength and chemical resistance can be obtained.

[Polar components other than curing agent]
Examples of polar components other than the curing agent include acrylic polymers, polyesters, polyvinyl ethers, and silicone polymers. Among these, an acrylic polymer is preferable.

Specific examples of the acrylic polymer include homopolymers such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and acrylonitrile, or co-polymers. Examples include polymers.

When the present adhesive contains an acrylic polymer, the content of the acrylic polymer is preferably 2% by mass or more, more preferably 2% by mass or more, based on 100% by mass of the total of the thermoplastic elastomer and the acrylic polymer. It is 4% by mass or more, preferably 60% by mass or less, and more preferably 50% by mass or less.

Examples of the polyester include a copolymer of a polyhydric alcohol and a polybasic acid, examples of the polyhydric alcohol include ethylene glycol, propylene glycol and butanediol, and examples of the polybasic acid include terephthalic acid. Examples include adipic acid and maleic acid.

Examples of polyvinyl ether include polyvinyl ether and polyvinyl isobutyl ether.

Examples of the silicone-based polymer include dimethylpolysiloxane.

<Hydrocarbon-based synthetic oil>
The present adhesive may further contain a hydrocarbon-based synthetic oil in addition to the above-mentioned components from the viewpoint that an adhesive layer having high adhesive strength can be easily obtained. The hydrocarbon-based synthetic oil is a component other than the thermoplastic elastomer and other polar components.
The hydrocarbon-based synthetic oil may be used alone or in combination of two or more.

Examples of the hydrocarbon-based synthetic oil include polymers of olefins having 2 to 20 carbon atoms. Among them, an oligomer obtained by homopolymerizing an olefin having 2 to 20 carbon atoms and an oligomer obtained by copolymerizing two or more of these olefins are preferable.

Examples of the olefin having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-octene, 1-decene and 1-dodecene.

As the hydrocarbon-based synthetic oil, an ethylene-based copolymer containing a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 to 20 carbon atoms can be preferably used. In this case, the amount of the structural unit derived from ethylene is preferably 30 mol% or more, based on 100 mol% in total of the structural unit derived from ethylene and the structural unit derived from α-olefin having 3 to 20 carbon atoms. It is preferably 40 mol% or more, preferably 70 mol% or less, and more preferably 60 mol% or less.

The hydrocarbon-based synthetic oil has a kinematic viscosity at 40 ° C., preferably 30 cSt or more, more preferably 300 cSt or more, more preferably 5,000 cSt or more, preferably 500,000 cSt or less, more preferably 400,000 cSt or less. More preferably, it is 300,000 cSt or less.
The kinematic viscosity of the hydrocarbon-based synthetic oil at 200 ° C. is preferably 10 cSt or more, more preferably 20 cSt or more, more preferably 30 cSt or more, preferably 100,000 cSt or less, more preferably 80,000 cSt or less. More preferably, it is 60,000 cSt or less.
When the kinematic viscosity of the hydrocarbon-based synthetic oil at 40 ° C. or 200 ° C. is within the above range, an adhesive layer having high adhesive strength can be easily obtained.

When the present adhesive contains a hydrocarbon-based synthetic oil, the content of the hydrocarbon-based synthetic oil is preferably 1 part by mass or more with respect to 100 parts by mass of the total of the thermoplastic elastomer and other polar components. It is preferably 80 parts by mass or less.
When the blending amount of the hydrocarbon-based synthetic oil is within the above range, an adhesive layer having excellent strength and adhesive strength can be easily obtained.

<Preparation method of this adhesive>
The present adhesive can be prepared by mixing a thermoplastic elastomer with, if necessary, the other polar components and hydrocarbon-based synthetic oil.

In addition, the present adhesive includes additives other than the above-mentioned components, for example, curing catalysts, leveling agents, antifoaming agents, antioxidants, heat stabilizers, ultraviolet absorbers, etc., as long as the effects of the present invention are not impaired. Light stabilizers, plasticizers, surfactants, pigments such as titanium oxide (rutyl type), zinc oxide, carbon black, rocking agents, thickeners, rosin resins, tackifiers such as terpene resin, surface conditioners, Anti-settling agents, weather resistant agents, pigment dispersants, antistatic agents, fillers, organic or inorganic fine particles, antifungal agents, and silane coupling agents may be blended.

Further, the present adhesive may be a varnish in which a solvent is blended in addition to the above-mentioned components from the viewpoint of improving processability.
Examples of the solvent include solvents similar to those that can be used in the synthesis of modified thermoplastic elastomers, such as toluene, methylcyclohexane / methylisobutylketone mixed solvent, methylcyclohexane / methylethylketone mixed solvent, and methylcyclohexane / ethylacetate mixed solvent. A solvent, a methylcyclohexane / n-propyl acetate mixed solvent, a cyclohexane / methylethylketone mixed solvent, a cyclohexane / ethyl acetate mixed solvent, and a cellosolve / cyclohexanone mixed solvent are preferable. Water can also be used as a dispersion medium.

The solvent is blended so that the content of the non-volatile component in 100% by mass of the varnish is, for example, 5% by mass or more, preferably 10% by mass or more, and for example, 50% by mass or less, preferably 40% by mass or less. It is desirable to do.

<Adhesive layer>
The present adhesive is applied to an adherend, or the adherend is immersed in the present adhesive to take out the adherend, and if necessary, the adhesive is dried to form an adhesive layer (on the adherend). Hereinafter, it may also be referred to as “this adhesive layer”). Further, a curing step may be performed. When forming the present adhesive layer between the two adherends, after the drying, the adhesive (layer) is brought into contact with another adherend, and then the curing step is performed while applying pressure as necessary. The so-called dry laminating method is desirable.
Since the present adhesive layer is obtained from the present adhesive, it is excellent in a good balance of high insulation property, low dielectric loss, water resistance, chemical resistance, adhesive strength and low tack property.

The adherend is not particularly limited as long as it is an object to be adhered using the present adhesive, and examples thereof include the following base materials, surface layers, and electronic members.

The coating method is not particularly limited, and for example, a die coating method, a flow coating method, a spray coating method, a bar coating method, a gravure coating method, a gravure reverse coating method, a kiss reverse coating method, a micro gravure coating method, a roll coating method, and the like. Adopt coating methods such as blade coating method, rod coating method, roll doctor coating method, air knife coating method, comma roll coating method, reverse roll coating method, transfer roll coating method, kiss roll coating method, curtain coating method, and printing method. be able to.

Examples of the method for drying the present adhesive include a method of leaving the present adhesive at room temperature (about 20 ° C.) and normal pressure, a method of drying the present adhesive under reduced pressure, and a method of heating the present adhesive. This heating may be performed in one step or in two or more steps.
The heating conditions are not particularly limited as long as the volatile components such as a solvent volatilize, but are, for example, 120 ° C. or lower, preferably 100 ° C. or lower, for example 40 ° C. or higher, for example, 3 seconds or longer, preferably 1. Examples thereof include a condition of heating for a time of 1 minute or more, for example, a time of 1 hour or less.

Examples of the curing step include a method of heating the coating film. This heating may be performed in one step or in two or more steps.
As the heating conditions, appropriate conditions are selected, but at a low temperature, for example, 80 ° C. or lower, preferably 70 ° C. or lower, particularly preferably 60 ° C. or lower, and for example, 40 ° C. or higher, for example, one day or longer. A method of curing for a time of 3 days or more, for example, 7 days or less (low temperature curing method), a high temperature, for example, 100 ° C. or higher, preferably 120 ° C. or higher, and for example, 200 ° C. or lower, for example, 0. Examples thereof include a method of curing for 1 second or longer, preferably 0.5 seconds or longer, and for example, 60 seconds or shorter (high temperature curing method). Of these, the low temperature regimen is preferred.

The pressure is, for example, 0.1 MPa or more, preferably 0.2 MPa or more, and preferably 2 MPa or less.

The thickness of the adhesive layer may be appropriately selected depending on the desired application and the like, and is not particularly limited, but is, for example, 0.2 μm or more, preferably 1 μm or more, for example, 100 μm or less, preferably 50 μm or less.

According to the present adhesive, it is possible to obtain an adhesive layer having high insulating properties and small dielectric loss without the need for air bubbles. Therefore, it is preferable that the present adhesive layer is substantially non-foaming. Substantially non-foaming refers to a case where the foaming ratio is, for example, 1.01 times or less.
The relative permittivity tends to decrease as the bubble content in the adhesive layer increases, but it is necessary to control the bubble content, and the bubble content may differ depending on the location of the adhesive layer, or the film thickness may increase. It may be non-uniform.

≪Electronic tag≫
The electronic tag according to the embodiment of the present invention may have the same configuration as the conventional electronic tag as long as it has the present adhesive layer, but for example, the present adhesive layer, the base material, the circuit line, and the like. Examples thereof include an electronic tag having at least one electronic member selected from the IC chip.
Since the electronic tag according to the embodiment of the present invention has the adhesive layer, it is an electronic tag that has a long communication distance and operates stably even in a high humidity environment.

If necessary, the electronic tag may have a surface layer for protecting the electronic member, an adhesive layer other than the present adhesive layer, an adhesive layer, a mold release layer, and the like.
Each of these layers and members may be one layer (one) or two or more layers (two). When there are two or more layers, they may be the same layer (member) or different layers (members).

Specifically, as one embodiment of the electronic tag,
An electronic tag having at least one electronic member selected from a circuit line and an IC chip on a substrate via an adhesive layer (eg, FIG. 2),
At least one electronic member selected from a circuit line and an IC chip is arranged on the base material, and the electronic member has a surface layer on the opposite side of the base material, and the electronic member and the surface layer are formed on the base material. Electronic tags glued together (eg, FIGS. 1 and 3),
At least one electronic member selected from a circuit line and an IC chip is arranged on the base material, and the electronic member has a surface layer on the opposite side of the base material, and the base material and the surface layer are formed on the base material. Electronic tags bonded with adhesive (eg, Fig. 1 and Fig. 3)
Can be mentioned.

Hereinafter, description will be given with reference to FIG.
The electronic tag 10 in FIG. 1 has an adhesive layer 2 on a base material 1 (eg, an inlet film) having an electronic member (on which the electronic member is mounted) including a circuit line 4 and an IC chip 5. It has, and further has a surface layer 3 on it.
The circuit line 4 and the IC chip 5 in the electronic tag 10 function as a non-contact type electronic tag by communicating with an external reader and writer.

The thickness and forming method of the adhesive layer 2 are not particularly limited, and examples thereof include the same thickness and forming method as in the above-mentioned column of the present adhesive layer.
The adhesive layer 2 may be the present adhesive layer or a layer formed from a conventionally known adhesive, but the present adhesive layer that exerts the above-mentioned effect is preferable.

The electronic member may include other constituent members in addition to the IC chip and the circuit line. Examples of such a component include a capacitor and a resistor.

The circuit line 4 may be, for example, a coiled circuit in which a wire made of a conductive substance is wound to form a coil, and the laminate of the circuit line 4 and the base material 1 has a circuit pattern on a substrate. It may be a printed circuit board (printed wiring board) on which is formed. The circuit line 4 may be a so-called antenna.
Examples of the circuit line 4 include a film such as a foil, a thin film, and a thin film produced by sputtering, and are usually formed of a conductive substance. Examples of the conductive substance include metals (including alloys) such as gold, silver, copper, nickel, and aluminum, and conductive pastes containing these metal particles and a binder.

The thickness of the circuit line 4 is not particularly limited, but is preferably 5 to 50 μm in the case of a metal foil, and preferably 0.01 to 1 μm in the case of a vapor-deposited film or a metal film produced by sputtering. In the case, it is preferably 5 to 30 μm.
The width of the circuit line 4 is not particularly limited, but is preferably 0.01 to 10 mm, more preferably 0.1 to 3 mm.

In FIG. 1, the IC chip 5 is provided above the circuit line 4, but may be provided inside the circuit line 4 or outside the circuit line 4. The IC chip 5 is preferably provided at the tip of the circuit line 4.
In order to connect the outermost ring and the innermost ring of the circuit line 4 to the IC chip 5, a jumper wiring portion (not shown) is used so as not to short-circuit (conduct) with the ring-shaped circuit line 4 intermediate between the outermost ring and the innermost ring. You may.
The thickness of the IC chip 5 may be appropriately selected depending on the intended use, and is, for example, about 50 to 400 μm.

As a method of forming the circuit line 4 on the base material 1, for example, a metal foil is attached to the base material using an adhesive layer, and the metal foil is etched to remove a portion other than the circuit. A method of forming a circuit line can be mentioned. Examples of the etching treatment include the same methods as those of conventionally known etching treatments. In this method, for example, an electronic tag having a structure near the electronic member as shown in FIG. 2 can be obtained. The adhesive layer 6 in FIG. 2 may be the present adhesive layer or a layer formed from a conventionally known adhesive, but the present adhesive layer that exerts the above-mentioned effect is preferable.
Further, as a method of forming the circuit line 4 on the base material 1, a conductive paste is printed on the base material or on the adhesive layer of the base material having an adhesive layer in a desired circuit line shape. A method such as coating can also be mentioned.

Examples of the material of the base material 1 include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene terephthalate / isophthalate copolymer; polyethylene (PE), polypropylene (PP), and polymethyl. Polyethylene-based resins such as penten; Polyethylene-based resins such as polyvinyl fluoride, vinylidene polyvinylfluoride, poly4-ethylene fluoride, ethylene / 4-ethylene fluoride copolymer; 6-nylon, 6,6-nylon, etc. Polyethylene resin; vinyl chloride resin such as polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / vinyl acetate copolymer, polyethylene / vinyl alcohol copolymer, polyvinyl alcohol, vinylon, etc .; cellulose triacetate, cellophane, etc. Cellular resin; acrylic resin such as polymethyl methacrylate, ethyl polymethacrylate, ethyl polyacrylate, butyl polyacrylate; synthetic resin such as polystyrene, polycarbonate, polyarylate, and polyimide is preferable.

The base material 1 is preferably a base material sheet in the form of a sheet (including a plate shape, a film shape, etc.). In this case, the thickness of the base material sheet is not particularly limited, but is, for example, 10 to 300 μm. is there.

The surface layer 3 is preferably a layer that covers the electronic member, and more preferably a layer that protects the electronic member and retains the shape of the electronic tag.
As the surface layer 3, a layer made of the same material as the material constituting the base material 1 can be used. Paper can also be used.
Printing can also be applied to the surface of the surface layer 3 opposite to the adhesive layer 2.
The thickness of the surface layer 3 is not particularly limited, but is, for example, about 30 to 500 μm.

A support or a release layer 8 may be present on the side of the base material 1 opposite to the electronic member, and in this case, the support 8 may be present via the adhesive layer 7. The release layer 8 may be present via the adhesive layer 7 (FIG. 3). The base material 1, the adhesive layer 2, the surface layer 3, the circuit line 4, and the IC chip 5 in FIG. 3 are the same as those in FIG.

As the support 8, a layer made of the same material as the material constituting the base material 1 can be used. Paper can also be used.
The adhesive layer 7 may be the present adhesive layer or a layer formed from a conventionally known adhesive, but the present adhesive layer that exerts the above-mentioned effect is preferable.

Examples of the adhesive layer 7 include a layer for attaching the electronic tag to a desired article when the electronic tag is used. As the adhesive layer 7, a conventionally known adhesive layer can be used. Further, a layer obtained from the present adhesive as in Examples 6 and 7 below can also be used.
The release layer 8 is a layer for protecting the adhesive layer 7 at the time of storage of the electronic tag or the like in order to prevent foreign matter from adhering to the adhesive layer 7 and lowering the adhesive force, and the use of the electronic tag is used. Occasionally, the release layer 8 is peeled off to expose the adhesive layer 7 for use.
As the release layer 8, a layer made of the same material as the material constituting the base material 1 can be used. Paper can also be used.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

<Content ratio of constituent units derived from propylene, ethylene and 1-butene>
The content ratio of the structural units derived from each of propylene, ethylene and 1-butene in the polymer obtained in the following production example was ^{determined by using 13} C-NMR.

<Melting point (Tm) and heat of fusion (ΔH)>
Using a differential scanning calorimeter (manufactured by TA Instruments; DSC-Q1000), the melting point (Tm) and heat of fusion (ΔH) of the polymers obtained in the following production examples were determined. The specific method is as described above.

<Weight average molecular weight (Mw)>
The weight average molecular weight (Mw) was measured using a gel permeation chromatograph (manufactured by Shimadzu Corporation; LC-10 series) under the following conditions. From the obtained measurement results, the Mw of the polymer obtained in the following production example was calculated using a calibration curve prepared from monodisperse standard polystyrene.

・ Detector: Shimadzu Corporation; C-R4A
-Column: TSKG 6000H-TSKG 4000H-TSKG 3000H-TSKG 2000H (both manufactured by Tosoh Corporation)
・ Mobile phase: tetrahydrofuran ・ Temperature: 40 ℃
・ Flow rate: 0.8 mL / min

<Degeneration amount>
The content ratio (modification amount) of maleic anhydride in the polymer obtained in the following production example was ^{determined by 1} H-NMR measurement. The specific method is as follows.

The amount of denaturation was ECX400 type nuclear magnetic resonance equipment (manufactured by JEOL Ltd.), the solvent was deuterated orthodichlorobenzene, the sample concentration was 20 mg / 0.6 mL, the measurement temperature was 120 ° C, and the observed nucleus was ¹ H. The measurement was performed under the conditions of (400 MHz), the sequence was a single pulse, the pulse width was 5.12 μsec (45 ° pulse), the repetition time was 7.0 seconds, and the number of integrations was 500 or more.
In the reference chemical shift, the peak derived from hydrogen of tetramethylsilane is set to 0 ppm, but the same result can be obtained by setting the peak derived from residual hydrogen of deuterated orthodichlorobenzene to 7.10 ppm, for example. Can be done.
Peak, such as ¹ H derived from maleic anhydride, can be assigned in a conventional manner.

<Dynamic viscosity at 40 ° C or 200 ° C>
The kinematic viscosity of the polymer obtained in the following production example at 40 ° C. or 200 ° C. was measured based on ASTM D 445.

[Production Example 1-1]: Synthesis of thermoplastic elastomer (A-1) 900 ml of hexane and 90 g of 1-butene were added to a 2 liter autoclave sufficiently substituted with nitrogen, 1 mmol of triisobutylaluminum was added, and the temperature was 70 ° C. After the temperature was raised to, propylene was supplied to bring the total pressure to 7 kg / cm ² G, methylaluminoxane 0.30 mmol, rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride. Was converted to Zr atoms and 0.001 mmol was added, and propylene was continuously supplied to carry out polymerization for 30 minutes while maintaining ^{the total pressure at 7 kg / cm 2 G.} After the polymerization, the polymer was degassed, the polymer was recovered in a large amount of methanol, and dried under reduced pressure at 110 ° C. for 12 hours. The obtained propylene / 1-butene copolymer (hereinafter, also referred to as "thermoplastic elastomer (A-1)") has a melting point of 78.3 ° C., a heat of fusion of 29.2 J / g, and Mw of 330,000. The propylene content was 67.2 mol%.

[Production Example 1-2]: Synthesis of thermoplastic elastomer (A-2) 900 ml of hexane and 80 g of 1-butene were added to a 2 liter autoclave sufficiently substituted with nitrogen, 1 mmol of triisobutylaluminum was added, and the temperature was 70 ° C. After the temperature was raised to, propylene was supplied to bring the total pressure to 7 kg / cm ² G, methylaluminoxane 0.30 mmol, rac-dimethylsilylene-bis {1- (2-methyl-4-phenylindenyl)} zirconium dichloride. Was converted to Zr atoms and 0.001 mmol was added, and propylene was continuously supplied to carry out polymerization for 30 minutes while maintaining ^{the total pressure at 7 kg / cm 2 G.} After the polymerization, the polymer was degassed, the polymer was recovered in a large amount of methanol, and dried under reduced pressure at 110 ° C. for 12 hours. The obtained propylene / 1-butene copolymer (hereinafter, also referred to as "thermoplastic elastomer (A-2)") has a melting point of 89.2 ° C., a heat of fusion of 31.5 J / g, and Mw of 330,000. The propylene content was 73.5 mol%.

[Production Example 1-3]: Synthesis of thermoplastic elastomer (A-3) 3 kg of the thermoplastic elastomer (A-2) is added to 10 L of toluene, and the temperature is raised to 145 ° C. under a nitrogen atmosphere to heat the elastomer (A-). 2) was dissolved in toluene. There, 382 g of maleic anhydride and 175 g of di-tert-butyl peroxide were supplied over 4 hours under stirring, followed by stirring at 145 ° C. for 2 hours. After cooling, a large amount of acetone was added to precipitate the modified copolymer, and the precipitate was filtered, washed with acetone, and then vacuum dried.
The obtained maleic anhydride-modified propylene / 1-butene copolymer (hereinafter, also referred to as “thermoplastic elastomer (A-3)”) has a melting point of 85.9 ° C., a heat of fusion of 29.9 J / g, and Mw. The amount of modification of maleic anhydride was 110,000, which was 1% by mass based on 100% by mass of the elastomer (A-3).

[Production Example 1-4]: Synthesis of thermoplastic elastomer (A-4) 1.5 kg of the thermoplastic elastomer (A-1) and 1.5 kg of Septon 2002 (SEPS, manufactured by Kuraray Co., Ltd.) are combined with 10 L of toluene. In addition, the temperature was raised to 145 ° C. under a nitrogen atmosphere, and these copolymers were dissolved in toluene. There, 382 g of maleic anhydride and 175 g of di-tert-butyl peroxide were supplied over 4 hours under stirring, followed by stirring at 145 ° C. for 2 hours. After cooling, a large amount of acetone was added to precipitate the modified copolymer, and the precipitate was filtered, washed with acetone, and then vacuum dried.
The obtained maleic anhydride-modified propylene / 1-butene copolymer-SEPS mixture (hereinafter, also referred to as "thermoplastic elastomer (A-4)") has a melting point of 75.6 ° C. and a heat of melting of 14.7 J / g. , Mw was 98,000, and the amount of modification of maleic anhydride was 1% by mass with respect to 100% by mass of the elastomer (A-4).
The thermoplastic elastomer (A-4) is considered to contain maleic anhydride-modified propylene / 1-butene copolymer and maleic anhydride-modified SEPS in substantially equal amounts.

[Production Example 1-5]: Synthesis of thermoplastic elastomer (A-5) 3 kg of Clayton G1652M (SEBS, manufactured by Clayton) was added to 10 L of toluene, the temperature was raised to 145 ° C. under a nitrogen atmosphere, and the copolymer was used. Was dissolved in toluene. There, 382 g of maleic anhydride and 175 g of di-tert-butyl peroxide were supplied over 4 hours under stirring, followed by stirring at 145 ° C. for 2 hours. After cooling, a large amount of acetone was added to precipitate the modified copolymer, and the precipitate was filtered, washed with acetone, and then vacuum dried.
The melting point and heat of fusion of the obtained maleic anhydride-modified SEBS (hereinafter, also referred to as "thermoplastic elastomer (A-5)") were not observed, Mw was 100,000, and the amount of modification of maleic anhydride was the elastomer (A). -5) It was 2% by mass with respect to 100% by mass.

[Production Example 2-1]: Synthesis of hydrocarbon-based synthetic oil (B-1) Ethyl adjusted to 96 mmol / L by adding 1 liter of dehydrated and purified hexane to a continuous polymerization reactor with a stirring blade that has been sufficiently substituted with nitrogen. A hexane solution of aluminum sesquichloride (Al (C ₂ H ₅ ) _1.5 · Cl _1.5 ) was continuously supplied at an amount of 500 ml / h for 1 hour, and then further adjusted to 16 mmol / L as a catalyst for VO (OC ₂ H). ₅ ) _{A hexane solution of Cl 2} was continuously supplied at 500 ml / h and hexane was continuously supplied at 500 ml / h. At this time, the polymer solution was continuously withdrawn from the upper part of the reactor so that the amount of the polymer solution in the reactor was always 1 liter.
Next, a bubbling tube was used to supply ethylene gas at 47 L / h, propylene gas at 47 L / h, and hydrogen gas at 20 L / h. The copolymerization reaction was carried out at 35 ° C. by circulating the refrigerant through a jacket attached to the outside of the reactor. The obtained polymerization solution was decalcified with hydrochloric acid, then poured into a large amount of methanol to precipitate a precipitate, and then the precipitate was dried under reduced pressure at 130 ° C. for 24 hours.
The obtained ethylene / propylene copolymer (hereinafter, also referred to as "hydrocarbon-based synthetic oil (B-1)") has an ethylene content of 55.9 mol%, Mw of 14,000, and a kinematic viscosity at 40 ° C. of 37. The kinematic viscosity at 500 cSt and 200 ° C. was 132 cSt.

[Example 1]
Adhesive A was prepared by heating and dissolving 100 g of thermoplastic elastomer (A-4) in 400 g of a mixed solvent of methylcyclohexane / ethyl acetate = 75/25 (mass ratio).

[Example 2]
80 g of thermoplastic elastomer (A-3) and 20 g of hydrocarbon-based synthetic oil (B-1) are dissolved by heating in 400 g of a mixed solvent of methylcyclohexane / ethyl acetate = 80/20 (mass ratio), cooled, and then Stavio. Adhesive B was prepared by blending 5 g of D-370N (isocyanate curing agent, manufactured by Mitsui Kagaku Co., Ltd.).

[Example 3]
In Example 2, the adhesive C was prepared in the same manner as in Example 2 except that 5 g of Selokiside 2021P (epoxy curing agent, manufactured by Daicel Corporation) was used instead of 5 g of Stavio D-370N.

[Example 4]
Adhesive D was prepared in the same manner as in Example 2 except that Stavio D-370N was not used in Example 2.

[Example 5]
After heat-dissolving 63 g of Clayton G1652 in 152 g of a mixed solvent of methylcyclohexane / n-propyl acetate = 4/15 (mass ratio), 46.3 g of methyl methacrylate and 2.5 g of n-butyl acrylate were added thereto. A monomer solution in which 11.7 g of n-butyl methacrylate, 2.5 g of methacrylic acid, 0.76 g of perbutyl O (manufactured by Nichiyu Co., Ltd.), and 107 g of n-propyl acetate were uniformly mixed was added dropwise over 2 hours. , 95 ° C. Finally, 114 g of n-propyl acetate was added to prepare an adhesive E.

[Example 6]
Adhesive F was prepared by heating and dissolving 100 g of a thermoplastic elastomer (A-5) in 400 g of a mixed solvent of methylcyclohexane / methylethylketone = 6/4 (mass ratio).

[Example 7]
100 g of a thermoplastic elastomer (A-5) was dissolved by heating in 400 g of a mixed solvent of methylcyclohexane / methyl ethyl ketone = 6/4 (mass ratio), cooled, and then 5 g of celoxide 2021P was added to prepare an adhesive G.

[Comparative Example 1]
150 g of Takelac A-969V (manufactured by Mitsui Chemicals, Inc.) is diluted with 350 g of ethyl acetate, and 50 g of Takenate A-5 (manufactured by Mitsui Chemicals, Inc.) is blended therein to make an adhesive H (urethane adhesive). Was prepared.

<Measurement of relative permittivity and dielectric loss tangent>
The adhesives of Examples 1 to 7 and Comparative Example 1 were each applied on a 100 μm-thick release PET so that the dry film thickness was about 60 μm, dried at 100 ° C. for 3 minutes, and 3 at 60 ° C. A coating film was formed on the release PET by curing for a day. After measuring the film thickness of the coating film obtained with a film thickness meter, the tin foil was placed on the coating film from which the release PET was peeled off, and the measurement frequency was 1 kHz using a 4284A precision LCR meter (manufactured by Keysight Technology Co., Ltd.). The relative permittivity and dielectric loss tangent of the coating film at 10 kHz, 100 kHz, and 1 MHz were measured. For the measurement frequency of 10 GHz, the coating film is formed into strips, and the relative permittivity and dielectric constant are measured by the cavity resonator method (Vector Network Analyzer HP8510B (manufactured by Keysight Technologies, Inc.)) according to JIS R 1641: 2007. The normal contact was measured. The results are shown in Table 1.
Further, the absolute value of the difference between the relative permittivity measured at a frequency of 1 kHz and the relative permittivity measured at a frequency of 10 GHz is set as requirement (3), and the maximum value of the dielectric loss tangent measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 GHz. The difference between the minimum value and the minimum value is shown in Table 1 as requirement (4).

<Measurement of Al / PET peel strength>
The adhesives of Examples 1 to 7 and Comparative Example 1 were applied to the Al foil (thickness: 30 μm) and dried at 100 ° C. for 1 minute to form an Al foil with a coating film having a dry film thickness of about 3 μm. A PET film (manufactured by Toray Industries, Inc., thickness: 100 μm) was placed on the coating film of the Al foil with a coating film, and the PET film was thermocompression bonded under the conditions of 180 ° C., 0.3 MPa, and 3 seconds. Further, it was cured at 60 ° C. for 3 days. The obtained laminate was cut into a size of 15 mm in width to prepare a test piece, and the test piece was subjected to a crosshead speed of 50 mm / min using a universal tensile measuring device (manufactured by Intesco Co., Ltd., model 210). Then, a 180 ° peeling test was carried out, and the peeling strength (Al / PET peeling strength, initial peeling strength, unit: N / 15 mm) between the Al foil and the PET film was measured. The results are shown in Table 1.
In the measurement of the peel strength, a PET film generally used as a base material or a surface layer was used in consideration of the electronic tag, and an Al foil was used in consideration of the circuit line.

<Water resistance test>
A test piece was prepared in the same manner as in the measurement of Al / PET peel strength, and the obtained test piece was allowed to stand at 60 ° C. and a relative humidity of 95% for 30 days, and then the peel strength (peeling strength after the water resistance test, Unit: N / 15 mm) was measured in the same manner as in the measurement of Al / PET peel strength.
The ratio of the peel strength after the water resistance test to the initial peel strength was calculated as the peel strength retention rate, and the water resistance was evaluated according to the following criteria. The results are shown in Table 1.
⊚: Peel strength retention rate is 90% or more ○: Peel strength retention rate is 80% or more and less than 90% Δ: Peel strength retention rate is 60% or more and less than 80% ×: Peel strength retention rate is less than 60%

<Chemical resistance test>
A test piece was prepared in the same manner as in the measurement of Al / PET peel strength, and the obtained test piece was immersed in a 10% sodium hydroxide aqueous solution at 40 ° C. for 30 days, and then the peel strength (after the chemical resistance test). The peel strength, unit: N / 15 mm) was measured in the same manner as in the measurement of the Al / PET peel strength.
The ratio of the peel strength after the chemical resistance test to the initial peel strength was calculated as the peel strength retention rate, and the chemical resistance was evaluated according to the following criteria. The results are shown in Table 1.
⊚: Peel strength retention rate is 80% or more ○: Peel strength retention rate is 70% or more and less than 80% Δ: Peel strength retention rate is 60% or more and less than 70% ×: Peel strength retention rate is less than 60%

<Tackiness of coating film>
The adhesives of Examples 1 to 7 and Comparative Example 1 were applied to the Al foil (thickness: 30 μm) and dried at 100 ° C. for 1 minute (dry film thickness: about 3 μm). It was further cured at 60 ° C. for 3 days. The tackiness of the obtained coating film was evaluated by touch with a finger, and the judgment was made according to the following criteria. The results are shown in Table 1.
◎: No stickiness at all ○: Slight stickiness is observed △: Sticky ×: Very strong stickiness

An electronic tag was produced by adhering a PET film (surface layer) to an inlet film having a circuit line and an IC chip on the PET film using the adhesives obtained in Examples 1 to 7 and Comparative Example 1. ..
When the reading distance was measured in a non-contact transmission / reception test using the obtained electronic tag, the adhesive obtained in Comparative Example 1 was used as the electronic tag using the adhesive obtained in Examples 1 to 7. The reading distance was longer than that of the electronic tag that was used. In particular, the electronic tags using the adhesives obtained in Examples 1 to 3 had a long reading distance. Further, the electronic tags using the adhesives obtained in Examples 1 to 7 have the same operability after storage at 60 ° C. and 95% humidity for 30 days, and the electronic tags using the adhesives obtained in Comparative Example 1 are also used. It was better than.

1: Base material 2: Adhesive layer 3: Surface layer 4: Circuit line 5: IC chip 6: Adhesive layer 7: Adhesive layer or adhesive layer 8: Support or mold release layer 10: Electronic tag

Claims (10)

1. An adhesive for electronic tags that contains a thermoplastic elastomer and meets the following requirements (1) and (2).
   (1) The relative permittivity of the layer obtained from the adhesive measured at a frequency of 1 kHz is 4 or less. (2) The layer obtained from the adhesive is measured at frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 GHz. The dielectric loss tangent is 0.10 or less.
2. The adhesive for electronic tags according to claim 1, wherein the thermoplastic elastomer is one or more thermoplastic elastomers selected from olefin-based elastomers and styrene-based elastomers.
3. The adhesive for an electronic tag according to claim 1 or 2, wherein the thermoplastic elastomer contains a modified thermoplastic elastomer modified with a monomer having a functional group.
4. The adhesive for electronic tags according to claim 3, wherein the functional group is a carboxyl group and / or an acid anhydride group.
5. The thermoplastic elastomer is an olefin-based elastomer containing a polymer derived from an α-olefin having 2 to 20 carbon atoms.
   The polymer derived from an α-olefin having 2 to 20 carbon atoms contains a structural unit derived from an α-olefin having 4 to 20 carbon atoms.
   The olefin-based elastomer has a heat of fusion measured according to JIS K7122 of 0 to 50 J / g.
   The adhesive for an electronic tag according to any one of claims 1 to 4.
6. The adhesive for electronic tags according to any one of claims 1 to 5, further comprising a polar component other than the modified thermoplastic elastomer modified with a monomer having a functional group.
7. The adhesive for electronic tags according to any one of claims 1 to 6, further comprising a hydrocarbon-based synthetic oil.
8. The substrate has at least one electronic member selected from a circuit line and an IC chip via an adhesive layer formed from the adhesive for electronic tags according to any one of claims 1 to 7. , Electronic tag.
9. At least one electronic member selected from a circuit line and an IC chip is arranged on the base material, and the electronic member has a surface layer on the opposite side of the base material, and the electronic member and the surface layer are formed on the base material. An electronic tag bonded with the adhesive for an electronic tag according to any one of claims 1 to 7.
10. At least one electronic member selected from a circuit line and an IC chip is arranged on the base material, and the electronic member has a surface layer on the opposite side of the base material, and the base material and the surface layer are formed on the base material. An electronic tag bonded with the adhesive for an electronic tag according to any one of claims 1 to 7.

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