TW201702251A - Migration preventing agent, adhesive agent, and adhesive sheet capable of effectively preventing and inhibiting migration - Google Patents

Abstract

The present invention provides a migration preventing agent, an adhesive agent, and an adhesive sheet which are capable of effectively preventing and inhibiting migration. The aforementioned migration preventing agent comprises a silane coupling agent having a mercapto group, the aforementioned adhesive agent is produced from an adhesive composition containing the migration prevention agent, and the aforementioned adhesive sheet comprises an adhesive layer composed of the adhesive agent. The aforementioned adhesive composition contains (meth) acrylate polymer (A) and preferably a silane coupling agent having a mercapto group (B) as the aforementioned migration preventing agent.

Description

Migration inhibitor, adhesive and adhesive sheet

The present invention relates to a migration preventing agent, an adhesive, and an adhesive sheet capable of preventing and suppressing migration of a metal member or the like of a metal member such as a touch panel.

In recent years, in various mobile electronic devices such as smart phones and tablet computers, a touch panel has been frequently used as a display. As a method of the touch panel, there are a resistive film method, an electrostatic capacitance method, and the like, and in the mobile electronic device as described above, a capacitance type is mainly employed.

Recently, as the electrode material for such a touch panel has been demanded, the mesh metal electrode, for example, a copper electrode or a silver electrode, has been studied. However, when a conventional adhesive is used in contact with a metal electrode, particularly a copper electrode or a silver electrode, ion migration (=electrochemical migration; hereinafter, simply referred to as "migration") may occur. Specifically, in the positive electrode, the electrode is dissolved to cause disconnection, or in the negative electrode, a branch crystal is formed by precipitation of the positive electrode component to cause a short circuit.

This migration is particularly likely to occur when a voltage is applied to the electrodes under high temperature and high humidity. If this kind of migration occurs, the touch panel will not drive properly. In particular, the miniaturization and narrow pitch of electrodes have been progressing recently, and disconnection and short-circuiting of electrodes due to migration are likely to occur.

However, Patent Document 1 discloses an adhesive composition for a touch panel containing a benzotriazole compound as a rust preventive.

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Laid-Open Patent Publication No. 2014-177611

However, the benzotriazole compound as a rust preventive agent cannot sufficiently prevent and inhibit migration even if it has an anticorrosive effect of metal wiring.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a migration preventing agent, an adhesive, and an adhesive sheet which can effectively prevent and suppress migration.

In order to achieve the above object, the present invention provides a migration preventing agent comprising a decane coupling agent having a mercapto group (Invention 1).

According to the invention (Invention 1), when the material to which the migration preventing agent is added is brought into contact with a target member such as a metal electrode such as a touch panel such as a metal member, migration in the target member can be effectively prevented and suppressed.

In the above invention (Invention 1), the decane coupling agent is preferably a fluorenyl group-containing oligomer-type decane coupling agent (Invention 2).

In the above inventions (Inventions 1 and 2), the sulfhydryl equivalent of the organic hydrazine compound constituting the decane coupling agent is preferably 100 g/mol or more and 1000 g/mole or less (Invention 3).

Secondly, the present invention provides an adhesive characterized by: The adhesive composition having the above-described migration preventing agent (Inventions 1 to 3) was obtained (Invention 4).

In the above invention (Invention 4), it is preferred that the adhesive composition contains a (meth) acrylate polymer (A) and a decane coupling agent (B) having a mercapto group as the migration preventing agent (Invention 5).

In the above invention (Invention 5), the (meth) acrylate polymer (A) contains 3% by mass or more and 35% by mass or less of a hydroxyl group-containing monomer as a monomer unit constituting the polymer. 6).

In the above invention (Inventions 5 and 6), it is preferred that the adhesive composition further contains a crosslinking agent (C) (Invention 7).

In the above invention (Inventions 5 to 7), the content of the decane coupling agent (B) having a mercapto group in the adhesive composition is 0.01 by mass based on 100 parts by mass of the (meth)acrylate polymer (A). More than 5 parts by weight or less is preferred (Invention 8).

Thirdly, the present invention provides an adhesive sheet comprising: two release sheets; and an adhesive layer sandwiched by the release sheet in contact with the release faces of the two release sheets, the adhesive layer It is composed of the above-mentioned adhesive (Inventions 4 to 8) (Invention 9).

In the above invention (Invention 9), it is preferable that the pressure-sensitive adhesive layer is disposed on the touch panel so as to be in contact with the electrode (Invention 10).

According to the migration preventing agent, the adhesive, and the adhesive sheet of the present invention, migration can be effectively prevented and suppressed.

1‧‧‧Adhesive film

11‧‧‧Adhesive layer

12a, 12b‧‧‧ peeling film

2‧‧‧ touch panel

3‧‧‧Display body module

4‧‧‧Adhesive layer

5a‧‧‧1st film sensor

5b‧‧‧2nd film sensor

51‧‧‧Substrate film

52‧‧‧Printing layer

6‧‧‧ Covering materials

7‧‧‧Printing layer

Fig. 1 is a cross-sectional view showing an adhesive sheet according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a configuration example of a touch panel.

Fig. 3 is a reference image of the evaluation criteria in the evaluation of the migration prevention effect of Test Example 3.

Hereinafter, embodiments of the present invention will be described.

[migration preventive agent]

The migration preventive agent according to one embodiment of the present invention contains a decane coupling agent having a mercapto group. The migration preventing agent of the present embodiment may be composed only of a decane coupling agent having a mercapto group, and may contain other components.

The migration preventing agent of the present embodiment is added to a material (hereinafter sometimes referred to as "contact material") which is in contact with a member (hereinafter sometimes referred to as "target member") which is required to prevent and suppress migration. Preferably. Examples of the target member include a metal electrode (including a mesh) made of copper or silver, a transparent conductive film made of tin-doped indium oxide (ITO) or the like (including a pattern), and a metal nanoparticle. Line film, wire grid polarizing film, etc. Among the above metal electrodes, a metal electrode mainly composed of an unoxidized metal, specifically, a metal electrode made of copper or silver is preferable as the target member. In addition, as the contact material, for example, an adhesive, a hard coat agent, and the like may be mentioned in addition to the adhesive described later.

When the contact material to which the migration preventing agent containing the decane coupling agent is added is brought into contact with the target member, the decane coupling agent having a mercapto group can prevent and suppress dissolution of the electrode in the positive electrode, and formation of dendrites can be prevented and suppressed in the negative electrode. That is, migration in the target member can be effectively prevented and suppressed (this effect is sometimes referred to as "migration prevention effect"). Thereby, even if the electrode is micro The object to be thinned and narrowly pitched can also prevent wire breakage and short circuit. In particular, when the target member is an electrode of the touch panel, it is possible to prevent driving failure of the touch panel caused by disconnection and short circuit of the electrode.

The decane coupling agent having a mercapto group is composed of an organic onium compound having at least one mercapto group and at least one alkoxyalkyl group in the molecule. When the target member is an optical member such as a touch panel, it is preferable that the decane coupling agent having a mercapto group is light transmissive, for example, substantially transparent.

Specific examples of the decane coupling agent having a mercapto group include a mercapto group such as 3-mercaptopropyltrimethoxydecane, 3-mercaptopropyltriethoxydecane or 3-mercaptopropyldimethoxymethylnonane. Low molecular type decane coupling agent; decyl-containing decane compound and methyl group such as 3-mercaptopropyltrimethoxydecane, 3-mercaptopropyltriethoxydecane, 3-mercaptopropyldimethoxymethylnonane a thiol-containing oligomer-type decane coupling agent such as a cocondensate of an alkyl group-containing decane compound such as triethoxy decane, ethyl triethoxy decane, methyl trimethoxy decane or ethyl trimethoxy decane . Among them, a mercapto group-containing oligomer-type decane coupling agent which is more excellent in migration prevention effect and workability is preferable, and a co-condensation product of a mercapto group-containing decane compound and an alkyl group-containing decane compound is particularly preferable. A cocondensate of a trimethoxy decane and methyl triethoxy decane is further preferred. These may be used alone or in combination of two or more.

The lower limit of the thiol equivalent of the organic hydrazine compound constituting the decane coupling agent having a mercapto group is preferably 100 g/mole or more, more preferably 120 g/mole or more, and still more preferably 150 g/mole or more. When the lower limit is set as described above, when the contact material is used as an adhesive, the polarity difference from the polymer component serving as the main component can be set within an appropriate range, and the decane coupling agent can be used. The dispersibility in the adhesive is preferred.

The upper limit of the thiol equivalent of the organic hydrazine compound constituting the decane coupling agent having a mercapto group is preferably 1000 g/mole or less, more preferably 800 g/mole or less, and further preferably 500 g/mole or less. By setting the upper limit as described above, when the contact material is used as an adhesive, deterioration of optical characteristics due to phase separation from the polymer component serving as the main component can be prevented.

The amount of the lower limit of the content of the component derived from the decane coupling agent having a mercapto group in the contact material is preferably 0.01% by mass or more, and is 0.05% by mass or more. It is especially preferable that it is more preferably 0.1 mass % or more. In addition, the amount of the above-mentioned component in the contact material is preferably 5% by mass or less, more preferably 2.5% by mass or less, and more preferably 1% by mass or less. Preferably. When the amount of the migration preventing agent added is in the above range, the migration prevention effect is further excellent.

[adhesive]

The adhesive of the present embodiment is obtained from an adhesive composition containing the migration preventing agent. The type of the adhesive is not particularly limited as long as it exhibits a migration preventing effect by the migration preventing agent, and may be, for example, an acrylic adhesive, a rubber adhesive, an anthrone adhesive, or a urethane adhesive. Any one of a solvent, a polyester-based adhesive, and a polyvinyl ether-based adhesive. Further, the adhesive may be any of an emulsion type, a solvent type, or a solventless type, or may be either a crosslinked type or a non-crosslinked type. Further, it may be any of an active energy ray-curing type or an active energy ray non-hardening type.

When the object member is an electrode of a touch panel, in the above, C An olefinic adhesive is preferred. In this case, the adhesive of the present embodiment is an adhesive composition containing a (meth) acrylate polymer (A) and a decane coupling agent (B) having a mercapto group as the migration preventing agent (hereinafter, It is called "adhesive composition P".) The winner is preferred. It is preferable that the adhesive composition P further contains a crosslinking agent (C). In this case, the adhesive of the present embodiment is obtained by crosslinking the adhesive composition P. In the present specification, (meth) acrylate means both acrylate and methacrylate. Other similar terms are also the same. Moreover, the concept of "copolymer" is also included in "polymer".

The adhesive layer composed of the adhesive comprising the adhesive composition P having a mercapto group-containing decane coupling agent (B) not only exhibits the above-described migration preventing effect, but also has a thiol group derived from the interface with the target member. The component of the decane coupling agent (B) has high adhesion to the target member, and is excellent in step followability when the target member has a step. Specifically, even if the adhesive layer is attached to a target member having a step and exposed to high temperature and high humidity for a predetermined period of time (for example, at 85 ° C, 85% RH for 72 hours), it can be suppressed. Air bubbles, floating, peeling, and the like occur in the vicinity of the step (excellent followability of the step under high temperature and high humidity conditions). Thereby, when the target member is a touch panel, it is possible to suppress the occurrence of reflection loss of light in the vicinity of the step, and it is possible to satisfactorily maintain the image quality of the touch panel.

(1) (meth) acrylate polymer (A)

The (meth) acrylate polymer (A) can exhibit a good adhesion by using an alkyl (meth) acrylate having an alkyl group and having 1 to 20 carbon atoms as a monomer unit constituting the polymer. . From such a viewpoint, the carbon number of the alkyl group containing the lower limit value of 50% by mass or more of the (meth) acrylate polymer (A) is The alkyl (meth)acrylate of 1 to 20 is preferably a monomer unit constituting the polymer, more preferably 60% by mass or more, and still more preferably 70% by mass or more. When the (meth)acrylic acid alkyl ester is contained in an amount of 50% by mass or more, the (meth)acrylate polymer (A) can exhibit better adhesion. Further, the (meth) acrylate polymer (A) contains the above (meth)acrylic acid alkyl ester having an upper limit of 97% by mass or less, preferably as a monomer unit constituting the polymer, and contains 90% by mass. The following is particularly preferable, and it is further preferable to contain 85% by mass or less. A preferred amount of the other monomer component can be introduced into the (meth) acrylate polymer (A) by containing 97% by mass or less of the above alkyl (meth) acrylate.

Examples of the (meth)acrylic acid alkyl ester having 1 to 20 carbon atoms in the alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. N-butyl acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylic acid N-decyl ester, n-dodecyl (meth)acrylate, tetradecyl (meth)acrylate, cetyl (meth)acrylate, octadecyl (meth)acrylate, ( Methyl)cyclohexyl acrylate, isobornyl (meth)acrylate, adamantyl (meth) acrylate, etc., wherein the carbon number of the alkyl group is 4 to 8 from the viewpoint of further improving the adhesion. (Meth) acrylate is preferred. These may be used singly or in combination of two or more. Further, the alkyl group in the alkyl (meth)acrylate having 1 to 20 carbon atoms in the alkyl group means a linear, branched or cyclic alkyl group.

Further, as the alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms, the glass transition temperature (Tg) used as a homopolymer is more than 0. It is also preferred that a hard monomer (which is preferably 70 ° C or higher) and a soft monomer having a glass transition temperature (Tg) of 0 ° C or less as a homopolymer are also preferable. This is because the soft monomer maintains adhesion and flexibility, and the cohesive force is increased by the hard monomer, whereby the step difference in the display panel (touch panel) can be further improved. In comparison, the mass ratio of the hard monomer to the soft monomer is preferably 5:95 to 40:60, and particularly preferably 20:80 to 30:70.

Examples of the hard monomer include methyl acrylate (Tg 10 ° C), methyl methacrylate (Tg 105 ° C), isobornyl acrylate (Tg 94 ° C), isobornyl methacrylate (Tg 180 ° C), and acrylic acid. Adamantyl ester (Tg 115 ° C), adamantyl methacrylate (Tg 141 ° C), and the like. These may be used singly or in combination of two or more.

Among the above hard monomers, methyl acrylate, methyl methacrylate and isobornyl acrylate are preferred from the viewpoint of preventing adverse effects on other properties such as adhesion and transparency and further exerting the performance of the hard monomer. . Methyl acrylate and methyl methacrylate are more preferred if adhesion is also considered, and methyl methacrylate is particularly preferred.

As the soft monomer, an alkyl acrylate having a linear or branched alkyl group having 2 to 12 carbon atoms is preferable. For example, 2-ethylhexyl acrylate (Tg-70 ° C), n-butyl acrylate (Tg-54 ° C), and the like are preferable. These may be used singly or in combination of two or more.

The (meth) acrylate polymer (A) preferably contains a reactive functional group-containing monomer as a monomer unit constituting the polymer. The reactive functional group derived from the reactive functional group-containing monomer is reacted with a crosslinking agent (C) to be described later to form a crosslinked structure (three-dimensional network structure), and a desired desired one can be obtained. Cohesive adhesive.

The reactive functional group monomer contained as the monomer unit constituting the polymer in the (meth) acrylate polymer (A) is preferably a monomer having a hydroxyl group in the molecule (hydroxy group-containing) Monomer), a monomer having a carboxyl group in a molecule (a carboxyl group-containing monomer), a monomer having an amine group in a molecule (an amine group-containing monomer), and the like. Among these, a hydroxyl group-containing monomer which is excellent in reactivity with a crosslinking agent (C) and wet heat whitening resistance and which has little influence on the electrode of the target member is particularly preferable.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-(meth)acrylate. A hydroxyalkyl (meth)acrylate such as hydroxybutyl ester, 3-hydroxybutyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate. Among them, from the viewpoint of the reactivity of the hydroxyl group in the obtained (meth) acrylate polymer (A) with the crosslinking agent (C) and the copolymerizability with other monomers, 2-hydroxyl (meth) acrylate Ethyl ester or 4-hydroxybutyl (meth)acrylate is preferred. These may be used alone or in combination of two or more.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Among them, acrylic acid is preferred from the viewpoints of the reactivity of the carboxyl group in the obtained (meth)acrylate polymer (A) with the crosslinking agent (C) and the copolymerizability with other monomers. These may be used alone or in combination of two or more.

Examples of the amine group-containing monomer include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These may be used singly or in combination of two or more.

The (meth) acrylate polymer (A) has a lower limit of 3 The hydroxyl group-containing monomer is preferably a monomer unit constituting the polymer, more preferably 10% by mass or more, and even more preferably 15% by mass or more. In addition, the (meth) acrylate polymer (A) contains a hydroxyl group-containing monomer having an upper limit of 35% by mass or less, and is preferably a monomer unit constituting the polymer, and particularly preferably contains 30% by mass or less. 25 mass% or less is further preferable. When the (meth) acrylate polymer (A) contains a hydroxyl group-containing monomer as a monomer unit in the above amount, a predetermined amount of a hydroxyl group remains in the obtained adhesive. a hydroxy-based hydrophilic group, if the hydrophilic group is present in the adhesive, even if the adhesive is placed under high temperature and high humidity conditions, and immersed in the adhesive under the high temperature and high humidity conditions The compatibility is also good, and as a result, it is possible to suppress whitening (excellent resistance to moist heat whitening) of the adhesive when the normal temperature and normal humidity are restored.

However, if the hydrophilic group is present in the adhesive as described above, the adhesive easily absorbs water, and migration is likely to occur in the member to be in contact with the adhesive. However, the adhesive composition P of the present embodiment contains a decane coupling agent (B) having a mercapto group as a migration preventing agent, and can effectively prevent and suppress migration in the member to be contacted.

The (meth) acrylate polymer (A) does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer, but it is allowed to contain a predetermined amount. This is because the carboxyl group-based acid component is generally worried about the migration of the target member. However, the adhesive of the present embodiment is obtained from the adhesive composition P containing the decane coupling agent (B) having a mercapto group as a migration preventing agent. Even if a carboxyl group is present, the migration prevention effect can be exhibited. Specifically, in the (meth) acrylate polymer (A), the carboxyl group-containing monomer is contained in an amount of 5% by mass or less as the monomer unit, and it is preferable to contain the carboxyl group-containing monomer in an amount of 2% by mass or less. .

The (meth) acrylate polymer (A) may contain other monomers as a monomer unit constituting the polymer, as needed. As the other monomer, in order not to hinder the action of the reactive functional group-containing monomer, a monomer having no reactive functional group is preferable. Examples of such other monomers include (meth)acrylic acid alkoxyalkyl esters such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, and (meth)acrylic acid. Non-crosslinkable tertiary amine group such as N,N-dimethylaminoethyl ester, N,N-dimethylaminopropyl (meth)acrylate, or (meth)propenylmorpholine (Meth) acrylate, (meth) acrylamide, dimethyl methacrylate, vinyl acetate, styrene, and the like. These may be used singly or in combination of two or more.

The polymerization form of the (meth) acrylate polymer (A) may be a random copolymer or a block copolymer.

The lower limit of the weight average molecular weight of the (meth) acrylate polymer (A) is preferably 200,000 or more, more preferably 300,000 or more, and still more preferably 400,000 or more. Further, the weight average molecular weight in the present specification is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method. When the lower limit of the weight average molecular weight of the (meth) acrylate polymer (A) is at least the above, the adhesive is excellent in the step-following property under high-temperature and high-humidity conditions.

Further, the upper limit of the weight average molecular weight of the (meth) acrylate polymer (A) is preferably 1,000,000 or less, more preferably 900,000 or less, and still more preferably 700,000 or less. When the upper limit of the weight average molecular weight of the (meth) acrylate polymer (A) is the above or less, the adhesive is excellent in the step-followability at the time of attachment.

In addition, in the adhesive composition P, (meth) acrylate The polymer (A) may be used alone or in combination of two or more.

(2) a decane coupling agent having a mercapto group (B)

The decane coupling agent (B) having a mercapto group contained in the adhesive composition P is a decane coupling agent having a mercapto group as the migration preventing agent.

The content of the decane coupling agent (B) having a mercapto group in the adhesive composition P is preferably 0.01 parts by mass or less, and preferably 0.05 parts by mass based on 100 parts by mass of the (meth) acrylate polymer (A). More preferably, it is more preferably 0.1 part by mass or more. Further, the upper limit is preferably 5 parts by mass or less, more preferably 1.5 parts by mass or less, and still more preferably 1.0 part by mass or less. When the content of the decane coupling agent (B) having a mercapto group is in the above range, the migration preventing effect is further excellent.

The lower limit of the molar number (the amount of sulfhydryl groups) of the fluorenyl group in the decane coupling agent (B) per 100 g of the (meth) acrylate polymer (A) is preferably 0.01 mmol or more, more preferably 0.1 mmol or more. More preferably, it is 0.2 mmol or more. Further, the upper limit of the molar number is preferably 30 mmol or less, more preferably 5 mmol or less, and still more preferably 1.5 mmol or less. When the molar ratio of the fluorenyl group of the decane coupling agent (B) to the (meth) acrylate polymer (A) is in the above range, it is possible to further improve the migration prevention effect.

(3) Crosslinking agent (C)

It is preferred that the adhesive composition P contains a crosslinking agent (C). The adhesive composition P crosslinks the (meth) acrylate polymer (A) by a crosslinking agent (C) to form a three-dimensional network structure, thereby improving the cohesive force of the obtained adhesive, thereby increasing the high temperature and high The difference in follow-up under wet conditions.

As the crosslinking agent (C), as long as it is polymerized with (meth) acrylate The reactive group of the compound (A) may be reacted, and examples thereof include an isocyanate crosslinking agent, an epoxy crosslinking agent, an amine crosslinking agent, a melamine crosslinking agent, and an aziridine system. Crosslinking agent, hydrazine crosslinking agent, aldehyde crosslinking agent, oxazoline crosslinking agent, metal alkoxide crosslinking agent, metal chelating crosslinking agent, metal salt crosslinking agent, ammonium salt A crosslinking agent or the like. When the (meth) acrylate polymer (A) contains a hydroxyl group-containing monomer as a monomer unit constituting the polymer, an isocyanate crosslinking agent excellent in reactivity with the hydroxy group is preferably used. Further, the crosslinking agent (C) may be used alone or in combination of two or more.

The isocyanate crosslinking agent is a compound containing at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate and benzodimethyl diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; and isophorone diisocyanate. And alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate and the like, and the biuret, isocyanurate, and ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and hydrazine Sesame oil or the like is an adduct of a reactant with a low molecular weight active hydrogen compound. Among them, trimethylolpropane-modified aromatic polyisocyanate is preferred from the viewpoint of reactivity with a hydroxyl group, and trimethylolpropane-modified toluene diisocyanate is particularly preferred.

The content of the crosslinking agent (C) in the adhesive composition P is preferably 0.001 parts by mass or more based on 100 parts by mass of the (meth) acrylate polymer (A), and more preferably 0.01 parts by mass or more. Preferably, 0.02 parts by mass or more is further preferred. Further, the upper limit is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 1 part by mass or less.

The content of the crosslinking agent (C) is in the above range, and the result is obtained. When the cohesive force of the adhesive is better, the step followability of the adhesive under high temperature and high humidity conditions is improved.

(4) Various additives

The adhesive composition P may be added with various additives commonly used in acrylic adhesives, such as an antistatic agent, a tackifier, an antioxidant, an ultraviolet absorber, a light stabilizer, a softener, a filler, and a refractive index. Adjusting agent, etc. Further, in addition to the above-described decane coupling agent (B) having a mercapto group, another decane coupling agent is additionally added. However, the rust preventive agent, particularly the benzotriazole-based rust preventive agent, has an effect of inhibiting the crosslinking of the adhesive composition P, and therefore it is preferably not added.

Further, the adhesive composition P may contain an active energy ray-curable component such as a polyfunctional acrylate monomer having a molecular weight of less than 1,000 as needed. When the adhesive composition P contains an active energy ray-curable component, the adhesive layer is attached to the target member, and the adhesive layer is irradiated with an active energy ray to cure the adhesive layer, whereby excellent durability can be obtained. Adhesive layer.

In addition, the adhesive composition P is a mixture of various components remaining in the original state or the reaction state in the adhesive layer, and the component removed in the drying process or the like, for example, a polymerization solvent and a diluent solvent to be described later are not contained in the adhesive. In the composition P.

(5) Manufacture of adhesive composition

The adhesive composition P can be produced by mixing the (meth) acrylate polymer (A) and the obtained (meth) acrylate polymer (A), a decane coupling agent (B) having a mercapto group, and It is required to be produced by adding a crosslinking agent (C) and an additive.

(Meth)acrylate polymer (A) can be formed by The mixture of the monomer units of the compound is produced by polymerization by a usual radical polymerization method. The polymerization of the (meth) acrylate polymer (A) can be carried out by a solution polymerization method or the like using a polymerization initiator as needed. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more kinds thereof may be used in combination.

Examples of the polymerization initiator include an azo compound, an organic peroxide, and the like, and two or more types may be used in combination. Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and 1,1'-azobis (cyclohexane). Alkane 1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxypentyl) Nitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis 2-hydroxymethylpropionitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane, and the like.

Examples of the organic peroxide include benzammonium peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, and (2-ethoxyethyl)peroxydicarbonate, tert-butyl peroxy neodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexyl) peroxide, Dipropylene peroxide, diethyl hydrazine peroxide, etc.

Further, in the above polymerization process, the weight average molecular weight of the obtained polymer can be adjusted by blending a chain transfer agent such as 2-mercaptoethanol.

When the (meth) acrylate polymer (A) is obtained, a decane coupling agent (B) having a mercapto group and a crosslinking agent (C) as needed are added to the solution of the (meth) acrylate polymer (A). The additive and the diluent solvent are mixed well, whereby an adhesive composition P (coating solution) diluted with a solvent is obtained.

As the above diluent solvent, for example, hexane, heptane, or cyclohexane is used. An aliphatic hydrocarbon such as an alkane, an aromatic hydrocarbon such as toluene or xylene, a halogenated hydrocarbon such as dichloromethane or dichloroethane, or an alcohol such as methanol, ethanol, propanol, butanol or 1-methoxy-2-propanol. A ketone such as acetone, methyl ethyl ketone, 2-pentanone, isophorone or cyclohexanone, an ester such as ethyl acetate or butyl acetate, or a cellosolve such as ethyl cellosolve.

The concentration and viscosity of the coating solution thus prepared are not particularly limited as long as they are within the range of the coatable layer, and may be appropriately selected depending on the situation. For example, the concentration of the adhesive composition P diluted is 10 to 40% by mass. Further, when the coating solution is obtained, the addition of a diluent solvent or the like is not a requirement, and the diluent solvent may not be added as long as the adhesive composition P is a coatable viscosity or the like. At this time, the adhesive composition P is a coating solution in which the polymerization solvent of the (meth) acrylate polymer (A) is directly used as a diluent solvent.

(6) Manufacture of adhesives

The adhesive can be obtained by heat-treating the above-mentioned adhesive composition P. The drying treatment when the diluent solvent or the like of the adhesive composition P is volatilized may also serve as the heat treatment.

When the heat treatment is performed, the heating temperature is preferably 50 to 150 ° C, and particularly preferably 70 to 120 ° C. Further, the heating time is preferably 30 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes. After the heat treatment, a aging period of about 1 to 2 weeks at normal temperature (for example, 23 ° C, 50% RH) may be provided as needed. When the aging period is required, the adhesive layer is formed after the aging period, and when the aging period is not required, the adhesive layer is formed after the heat treatment is completed.

The lower limit of the gel fraction of the adhesive obtained from the adhesive composition P is preferably 30% or more, more preferably 40% or more, and still more preferably 50% or more. If the lower limit of the gel fraction of the adhesive is more than the above, the inside of the adhesive The cohesion becomes high, and it becomes excellent in the followability of the step under high temperature and high humidity conditions. Further, the upper limit of the gel fraction is preferably 90% or less, more preferably 85% or less, and still more preferably 80% or less. When the upper limit of the gel fraction of the adhesive is not more than the above, the adhesive does not become too hard, and the step-following property at the time of attachment is excellent. The method for measuring the gel fraction of the adhesive is as shown in the test examples described later.

The adhesive of the present embodiment contains a decane coupling agent having a mercapto group as a migration preventing agent, and is adhered to a metal electrode composed of, for example, copper or silver, and a transparent conductive material composed of tin-doped indium oxide (ITO) or the like. The target member such as a film, a metal nanowire film, or a wire grid polarizing film can also effectively suppress migration in the target member. In particular, even when the target member is a metal electrode of a touch panel such as copper or silver having a higher ionization tendency than a metal oxide such as ITO, it is possible to prevent the touch panel from being broken or short-circuited by the electrode. Bad drive.

[adhesive sheet]

As shown in Fig. 1, the adhesive sheet 1 of the present embodiment is composed of two release sheets 12a and 12b and two release sheets which are in contact with the peeling surfaces of the two release sheets 12a and 12b. Adhesive layer 11 held by 12a, 12b. However, in the adhesive sheet 1, the release sheets 12a and 12b are not necessarily required to be formed, and are peeled off or removed when the adhesive sheet 1 is used. In addition, the peeling surface of the peeling sheet in this specification is the surface which has the peeling property in the peeling sheet, and is the surface which carried out the peeling process, and the surface which shows the peeling-

(1) Adhesive layer

The adhesive layer 11 is composed of the aforementioned adhesive. The lower limit of the thickness of the adhesive layer 11 (the value measured in accordance with JIS K7130) is preferably 10 μm or more, and is preferably 25 μm. The above is particularly preferable, and 50 μm or more is further preferable. When the lower limit of the thickness of the adhesive layer 11 is at least the above, excellent adhesion can be sufficiently exhibited. Further, the upper limit of the thickness of the adhesive layer 11 is preferably 300 μm or less, more preferably 250 μm or less, and further preferably 100 μm or less. When the upper limit of the thickness of the pressure-sensitive adhesive layer 11 is the above or lower, the workability is good. Further, the adhesive layer 11 may be formed in a single layer or may be formed by laminating a plurality of layers.

(2) peeling sheet

The release sheets 12a and 12b are not particularly limited, and a known plastic film can be used. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, or a polyethylene terephthalate film can be used. , polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene ‧ (meth) acrylate copolymer film, vinyl ‧ (A Acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, and the like. Further, these crosslinked films can also be used. Alternatively, these laminated films may be used.

It is preferable that the release surface of the release sheets 12a and 12b (especially the surface in contact with the adhesive layer 11) is subjected to a release treatment. Examples of the release agent used in the release treatment include an alkyd type, an anthrone type, a fluorine type, an unsaturated polyester type, a polyolefin type, and a wax type release agent. Further, in the release sheets 12a and 12b, one release sheet is a heavy release type release sheet having a large peeling force, and the other release sheet is preferably a light release type release sheet having a small peeling force.

The thickness of the release sheets 12a and 12b is not particularly limited, and is usually about 20 to 150 μm.

(3) Manufacture of adhesive sheets

As a manufacturing example of the adhesive sheet 1, the coating liquid of the above-mentioned adhesive composition P is applied to the peeling surface of one peeling sheet 12a (or 12b), and after heat-treating, the adhesive composition P is cross-linked to form a coating layer. The peeling surface of the other release sheet 12b (or 12a) is superposed on the coating layer. When the aging period is required, the coating layer becomes the adhesive layer 11 by the aging period, and when the aging period is not required, the coating layer directly becomes the adhesive layer 11. Thereby, the above-mentioned adhesive sheet 1 is obtained. The heat treatment and ripening conditions are as described above.

In another example of the production of the adhesive sheet 1, the coating liquid of the adhesive composition P is applied onto the peeling surface of one of the release sheets 12a, and heat treatment is performed to crosslink the adhesive composition P to form a coating layer, thereby obtaining a belt. The release sheet 12a of the coating layer. Then, the coating liquid of the above-mentioned adhesive composition P is applied to the peeling surface of the other release sheet 12b, and heat-treated to crosslink the adhesive composition P to form a coating layer, thereby obtaining a peeling sheet 12b with a coating layer. Further, the release sheet 12a with the coating layer and the release sheet 12b with the coating layer are bonded to each other so that the two coating layers are in contact with each other. When the aging period is required, the layered coating layer becomes the adhesive layer 11 by the aging period, and when the aging period is not required, the layered coating layer directly becomes the adhesive layer 11. Thereby, the above-mentioned adhesive sheet 1 is obtained. According to this manufacturing example, even when the adhesive layer 11 is thick, it can be stably manufactured.

As a method of applying the coating liquid of the above-mentioned adhesive composition P, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like can be used. .

(4) Adhesion

The lower limit of the adhesion of the adhesive sheet 1 to the soda lime glass of the present embodiment is preferably 5 N/25 mm or more, more preferably 8 N/25 mm or more, and still more preferably 10 N/25 mm or more. When the lower limit of the adhesive force of the adhesive sheet 1 is more than the above, it is excellent in the step-followability in the high-temperature and high-humidity conditions. On the other hand, the upper limit of the adhesive force is not particularly limited, and when it is considered that the release sheets 12a and 12b are easily peeled off from the adhesive layer 11 during use, 50 N/25 mm or less is preferable, and 30 N/25 mm or less is preferable. Especially good. Further, when reworkability is also considered, 26 N/25 mm or less is preferable. In this case, the components can be easily reused even if a misfit occurs.

Here, the adhesive force in the present specification basically means an adhesive force measured by a 180-degree peeling method according to JIS Z0237:2009, and the measurement sample is set to a width of 25 mm and a length of 100 mm, and the measurement sample is attached to the adhered sample. After pressurizing for 20 minutes at 0.5 MPa and 50 ° C, the mixture was allowed to stand under normal pressure, 23 ° C, and 50% RH for 24 hours, and then measured at a peeling speed of 300 mm/min.

(5) Use of adhesive sheets

By using the above-described adhesive sheet 1, for example, the electrostatic capacitance type touch panel 2 shown in Fig. 2 can be manufactured. The touch panel 2 includes a display body module 3, a first film sensor 5a laminated thereon via an adhesive layer 4, and a second film sensor 5b laminated thereon via an adhesive layer 11 and The cover material 6 laminated on the adhesive layer 11 is formed.

The adhesive layer 11 in the touch panel 2 is the adhesive layer 11 of the adhesive sheet 1.

Examples of the display body module 3 include a liquid crystal (LCD) module, a light emitting diode (LED) module, and an organic electroluminescence (organic EL) mode. Group, electronic paper, etc.

The adhesive layer 4 may be formed of the adhesive layer 11 of the above-mentioned adhesive sheet 1, or may be formed of other adhesives or adhesive sheets. In the latter case, examples of the adhesive constituting the adhesive layer 4 include an acrylic adhesive, a rubber adhesive, an anthrone adhesive, a urethane adhesive, a polyester adhesive, and a poly A vinyl ether adhesive or the like is preferred, and an acrylic adhesive is preferred.

The first film sensor 5a and the second film sensor 5b in the present embodiment each include a base film 51 and an electrode 52 formed on the base film 51. The base film 51 is not particularly limited, and for example, a polyethylene terephthalate film, an acrylic film, a polycarbonate film, or the like can be used.

The electrode 52 is composed of, for example, a metal electrode, a patterned transparent conductive film, or the like, and the metal electrode is made of copper, silver, or the like, and the patterned transparent conductive film is made of tin-doped indium oxide (ITO) or the like.

The electrode 52 of the first thin film sensor 5a and the electrode 52 of the second thin film sensor 5b are generally one circuit pattern constituting the X-axis direction, and the other is a circuit pattern in the Y-axis direction.

The electrode 52 of the second thin film sensor 5b in the present embodiment is located on the upper side of the second thin film sensor 5b in Fig. 2 . On the other hand, the electrode 52 of the first thin film sensor 5a is located above the first thin film sensor 5a in Fig. 2, but the invention is not limited thereto, and may be located on the lower side of the first thin film sensor 5a. .

The cover material 6 is usually mainly made of a glass plate or a plastic plate. The glass plate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda lime glass, bismuth/niobium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, and bismuth boron bismuth. Acid glass, etc. As a plastic plate, there is no special limit. For example, an acrylic plate made of polymethyl methacrylate or the like, a polycarbonate plate or the like can be given.

Further, a functional layer such as a hard coat layer, an antireflection layer, or an antiglare layer may be provided on one or both sides of the glass plate or the plastic plate, and an optical member such as a hard coat film, an antireflection film, or an antiglare film may be laminated.

In the present embodiment, the cover material 6 has a step on the surface on the side of the adhesive layer 11, and specifically has a step formed by the presence or absence of the printed layer 7. The printed layer 7 is generally formed in a frame shape on the side of the adhesive layer 11 of the cover material 6.

The material constituting the printing layer 7 is not particularly limited, and a known material for printing can be used. The thickness of the printed layer 7, that is, the lower limit of the height of the step is preferably 3 μm or more, more preferably 5 μm or more, and particularly preferably 7 μm or more. Further, the upper limit is preferably 50 μm or less, more preferably 25 μm or less, and particularly preferably 15 μm or less.

Hereinafter, an example of the method of manufacturing the touch panel 2 will be described.

As the adhesive sheet 1, the first adhesive sheet 1 and the second adhesive sheet 1 are prepared. One of the release sheets 12a is peeled off from the first adhesive sheet 1, and the exposed adhesive layer 11 (first adhesive layer 11) is brought into contact with the electrode 52 of the second thin film sensor 5b. The detector 5b is attached. Then, one of the release sheets 12a is peeled off from the second adhesive sheet 1, and the exposed adhesive layer 11 (second adhesive layer) is brought into contact with the electrode 52 of the first thin film sensor 5a and the first thin film. The sensor 5a is attached.

Further, the other of the second adhesive sheets 12b is peeled off, and the exposed second adhesive layer 11 and the second thin film sensor 5b are separated from each other. The surface on the side opposite to the side on which the first adhesive layer 11 is laminated (the exposed surface of the base film 51 of the second film sensor 5b) is brought into contact with each other. Thereby, a laminate in which the release sheet 12b, the first adhesive layer 11, the second thin film sensor 5b, the second adhesive layer 11, and the first thin film sensor 5a are laminated in this order is obtained.

Then, the adhesive layer 4 provided on the release sheet is bonded to the surface of the laminate on the side of the first thin film sensor 5a (the exposed surface of the base film 51 of the first thin film sensor 5a). Then, the release sheet 12b is peeled off from the laminated body, and the exposed cover material 6 is bonded to the exposed first adhesive layer 11 so that the printed layer 7 side of the cover material 6 comes into contact with the adhesive layer 11. Thereby, the cover material 6, the first adhesive layer 11, the second thin film sensor 5b, the second adhesive layer 11, the first thin film sensor 5a, the adhesive layer 4, and the release sheet can be sequentially laminated. The composition.

Finally, the release sheet is peeled off from the above-described constituent body, and the exposed adhesive layer 4 is brought into contact with the display module 3 so that the constituent body is bonded to the display module 3. Thereby, the touch panel 2 shown in FIG. 2 is manufactured.

Even when the touch panel 2 is placed under high temperature and high humidity conditions and a voltage is applied to the electrode 52 in this state, the adhesive layer 11 in contact with the electrode 52 contains the migration preventing agent derived from the present embodiment (having a thiol group) The component of the decane coupling agent can effectively suppress the migration of the electrode 52. Thereby, it is possible to prevent the driving failure of the touch panel 2 caused by the disconnection and short circuit of the electrode 52.

The embodiments described above are described in order to facilitate the understanding of the present invention, and are not intended to limit the present invention. Therefore, the various embodiments disclosed in the above embodiments are intended to encompass all design changes and equivalents of the technical scope of the invention.

For example, the peeling sheets 12a, 12b in the adhesive sheet 1 can be omitted. Any one.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the scope of the invention is not limited to the embodiments.

[Example 1]

1. Preparation of (meth) acrylate copolymer

The (meth) acrylate polymer (A) was prepared by copolymerizing 60 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of methyl methacrylate, and 20 parts by mass of 2-hydroxyethyl acrylate. The molecular weight of the (meth) acrylate polymer (A) was measured by the method described later, and the weight average molecular weight (Mw) was 600,000.

2. Preparation of adhesive composition

100 parts by mass of the (meth) acrylate polymer (A) obtained in the above Process 1 (solid content conversion value; the same applies hereinafter), 3-mercaptopropyltrimethoxy which is a decane-based decane coupling agent (B) Co-condensation product of decane and methyltriethoxy decane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-41-1810", oligomer type, thiol equivalent: 450 g/mol) 0.05 0.2 parts by mass of trimethylolpropane-modified toluene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate L") as a crosslinking agent (C), mixed and thoroughly stirred, and The coating solution of the adhesive composition having a solid content concentration of 38% by mass was obtained by diluting with methyl ethyl ketone.

In the above, the respective components (solid content conversion values) of the adhesive composition when the (meth) acrylate polymer (A) is 100 parts by mass (solid content conversion value) are shown in Table 1. The details of the abbreviations and the like described in Table 1 are as follows.

[(Meth)acrylate polymer (A)]

2EHA: 2-ethylhexyl acrylate

MMA: Methyl methacrylate

HEA: 2-hydroxyethyl acrylate

[Centane coupling agent (B) having a mercapto group]

X-41-1810: a cocondensate of 3-mercaptopropyltrimethoxydecane and methyltriethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-41-1810"), Polymer type, thiol equivalent: 450g/mole)

KBM-803: 3-mercaptopropyltrimethoxydecane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-803", low molecular weight, thiol equivalent: 196.4 g/mole)

[Other decane coupling agents]

KBM-403: 3-glycidyloxypropyltrimethoxydecane (manufactured by Shin-Etsu Silicone Co., Ltd., trade name "KBM-403", low molecular type)

KBE-9007: 3-isocyanate propyl triethoxy decane (manufactured by Shin-Etsu Silicone Co., Ltd., trade name "KBE-9007", low molecular type)

3. Manufacture of adhesive sheets

A peeling treatment of a heavy release type release sheet (manufactured by LINTEC Corporation, trade name "SP-PET382150", thickness: 38 μm) obtained by peeling one surface of a polyethylene terephthalate film with an anthrone-based release agent On the surface, the coating solution of the adhesive composition obtained in the above Process 2 was applied by a knife coater, and then heat-treated at 90 ° C for 1 minute to form a coating layer (thickness: 25 μm). Similarly, a light-peelable release sheet obtained by peeling one surface of a polyethylene terephthalate film with an anthrone-based release agent The coating solution of the adhesive composition obtained in the above process 2 was applied onto the release-treated surface (manufactured by LINTEC Corporation, product name "SP-PET382120") by a knife coater, and then heat-treated at 90 ° C. A coating layer (thickness: 25 μm) was formed in 1 minute.

Then, the heavy release release sheet with the coating layer obtained in the above and the light release release sheet with the coating layer obtained above are bonded together so that the two coating layers are in contact with each other, and After aging for 7 days under conditions of 23 ° C and 50% RH, an adhesive sheet composed of a heavy release type release sheet/adhesive layer (thickness: 50 μm) / light release type release sheet was produced.

[Examples 2 to 10, Comparative Examples 1 to 10]

In the same manner as in Example 1, except that the type and ratio of the decane coupling agent (the decane coupling agent (B) having a mercapto group and the other decane coupling agent) and the ratio of the crosslinking agent (C) were changed as shown in Table 1. Make adhesive sheets. Further, for Comparative Examples 7 to 10, N,N-bis(2-ethylhexyl)-(4 or 5)-methyl-1H-benzotriazole-1-methylamine (trade name, manufactured by BASF Corporation) "IRGMET 39") was incorporated as a rust inhibitor in the adhesive composition in the proportions shown in Table 1.

Here, the weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement).

<Measurement conditions>

‧GPC measuring device: manufactured by TOSOH CORPORATION, HLC-8020

‧GPC column (passed in the following order): TOSOH CORPORATION

TSK guard column HXL-H

TSK gel GMHXL (×2)

TSK gel G2000HXL

‧ Determination of solvent: tetrahydrofuran

‧Measurement temperature: 40 ° C

[Test Example 1] (Measurement of gel fraction)

The adhesive sheets obtained in the examples and the comparative examples were cut into a size of 80 mm × 80 mm, and the adhesive layer was wrapped in a polyester mesh (mesh size 200), and the mass was weighed by a precision balance, minus The quality of the above-mentioned net alone is used to calculate the quality of the adhesive itself. Set the quality at this time to M1.

Next, the adhesive wrapped in the above polyester web was immersed in ethyl acetate at room temperature (23 ° C) for 24 hours. Thereafter, the adhesive was taken out, air-dried for 24 hours in an environment of a temperature of 23 ° C and a relative humidity of 50%, and dried in an oven at 80 ° C for 12 hours. After drying, the quality of the adhesive itself is calculated by weighing the mass by a precision balance and subtracting the individual mass of the above net. Set the quality at this time to M2. The gel fraction (%) is represented by (M2/M1) × 100. The results are shown in Table 2.

[Test Example 2] (Measurement of adhesion)

The light release release sheet was peeled off from the adhesive sheets obtained in the examples and the comparative examples, and the exposed adhesive layer was attached to a polyethylene terephthalate (PET) film having an easy adhesion layer (TOYOBO CO.). An easy-to-adhere layer of the product name "PET A4300", thickness: 100 μm, manufactured by LTD., to obtain a laminate of a heavy release release sheet/adhesive layer/PET film. The obtained laminate was cut into a width of 25 mm and a length of 100 mm, and this was used as a sample.

The peel-off release sheet was peeled off from the above sample under the environment of 23 ° C and 50% RH, and the exposed adhesive layer was attached to soda lime glass (Nippon) After being manufactured by Sheet Glass Co., Ltd., the autoclave made of KURIHARA CORPORATION was pressurized at 0.5 MPa and 50 ° C for 20 minutes. Thereafter, the mixture was allowed to stand under the conditions of 23 ° C and 50% RH for 24 hours, and then the adhesion was measured under the conditions of a peeling speed of 300 mm/min and a peeling angle of 180 degrees using a tensile tester (TENSILON, manufactured by ORIENTEC Co., LTD.). Force (N/25mm). The conditions other than those described herein were measured in accordance with JIS Z 0237:2009. The results are shown in Table 2.

[Test Example 3] (Evaluation of migration prevention effect)

(1) Manufacturing of wiring board

A copper-clad laminate (manufactured by NIKKAN INDUSTRIES Co., Ltd., product name "NIKAFLEX") laminated with a copper foil (thickness: 18 μm) and a polyethylene terephthalate film (thickness: 50 μm) On the foil surface, an etch resist pattern is printed by screen printing. Thereafter, the comb-shaped electrode is formed by etching to remove the unnecessary copper foil. The line width of each electrode was 300 μm, and the gap between the electrodes was 50 μm.

(2) Evaluation of migration prevention effect

The light release release sheet was peeled off from the adhesive sheets obtained in the examples and the comparative examples, and the exposed adhesive layer was attached to a polyethylene terephthalate (PET) film having an easy adhesion layer (TOYOBO CO.). An easy-to-adhere layer of the product name "PET A4300", thickness: 100 μm, manufactured by LTD., to obtain a laminate of a heavy release release sheet/adhesive layer/PET film. Next, the heavy release type release sheet was peeled off from the laminated body, and the exposed adhesive layer was attached to the above-mentioned comb-shaped electrode, and this was used as a sample.

The sample was allowed to stand under humid heat conditions of 85 ° C and 85% RH, and a voltage of 5 V was applied between the electrodes in this state to carry out a migration test. Starting from the test After 8 hours, 24 hours, and 48 hours, the comb-shaped electrode was observed with an optical microscope (magnification: 10 times), and the migration prevention effect was evaluated based on the evaluation criteria shown below. The results are shown in Table 2.

◎: Dissolution of the electrode (positive electrode) and formation of dendrite crystals in the electrode (negative electrode) were not observed at all.

○: Dissolution was observed only at the end of the electrode (positive electrode), and no branch crystal was observed in the electrode (negative electrode).

×: Dissolution of the electrode (positive electrode) and formation of dendrite crystals in the electrode (negative electrode) were observed.

In addition, the reference image of the above evaluation criteria is shown in FIG.

As is clear from Table 2, the adhesive sheet obtained in the examples can effectively prevent and suppress migration, and is excellent in the migration prevention effect.

[Industrial availability]

The migration preventing agent, the adhesive, and the adhesive sheet of the present invention can be suitably used, for example, in a capacitive touch panel using a copper electrode or a silver electrode.

1‧‧‧Adhesive film

11‧‧‧Adhesive layer

12a, 12b‧‧‧ peeling film

Claims (10)

A migration preventing agent characterized by containing a decane coupling agent having a mercapto group. The migration preventing agent according to claim 1, wherein the decane coupling agent is a fluorenyl group-containing oligomer-type decane coupling agent. The migration preventing agent according to claim 1, wherein the sulfhydryl equivalent of the organic hydrazine compound constituting the decane coupling agent is 100 g/mole or more and 1000 g/mole or less. An adhesive comprising: an adhesive composition comprising the migration preventing agent according to claim 1 of the patent application scope. The adhesive according to claim 4, wherein the adhesive composition comprises: a (meth) acrylate polymer (A); and a decane coupling agent having a mercapto group as the migration preventing agent (B) . The adhesive agent according to claim 5, wherein the (meth) acrylate polymer (A) contains 3% by mass or more and 35% by mass or less of a hydroxyl group-containing monomer as a single constituting the polymer. Body unit. The adhesive according to claim 5, wherein the adhesive composition further contains a crosslinking agent (C). The adhesive according to claim 5, wherein the content of the decane coupling agent (B) having a mercapto group in the adhesive composition is relative to the (meth)acrylate polymer (A) 100. The mass part is 0.01 parts by mass or more and 5 parts by mass or less. An adhesive sheet comprising: two release sheets; The adhesive layer is sandwiched by the release sheet in contact with the release surface of the two release sheets, and the pressure-sensitive adhesive layer is composed of the adhesive according to any one of claims 4 to 8. The adhesive sheet according to claim 9, wherein the adhesive layer is disposed on the touch panel in contact with the electrode.