TWI740935B - Adhesive sheet - Google Patents

Abstract

The adhesive sheet of the present invention relates to a substrate and an adhesive layer formed of an adhesive composition that are laminated in order, and the adhesive layer is formed of a material containing carbon nanotubes, and A structure in which conductive layers having a plurality of gaps are laminated, and the adhesive force measured by sticking the surface of the conductive layer side to the to-be-adhered body is 4.5 N/25 mm or more.

Description

Adhesive sheet

The present invention relates to adhesive sheets.

In the past, the grounding mark for pasting conductive electronic parts can be used for electronic devices such as computers and communication equipment, electromagnetic shielding materials such as storage containers, grounding wires such as electrical parts, and ignition prevention materials caused by sparks generated from static electricity. .

As the specific structure of the grounding mark for pasting electronic parts, on the adhesive layer made of adhesive composition, to impart anti-static property and conductivity, disperse metals such as copper powder, silver powder, nickel powder, and aluminum powder can be used. The composition of conductive materials such as powder.

Various grounding marks for pasting electronic parts have been proposed.

For example, Patent Document 1 discloses that a conductive adhesive layer composed of a conductive adhesive composed of a conductive adhesive dispersed with one or more conductive substances selected from carbon nanotubes and carbon micro coils is provided on a conductive support layer. material.

In addition, Patent Document 2 describes that a network-shaped metal vapor-deposited film is provided on one side of a resin film, and the metal vapor-deposited film is provided with dispersed metal particles. Conductive adhesive tape for conductive adhesive layer made of conductive adhesive.

〔Advanced Technical Documents〕 〔Patent Documents〕

[Patent Document 1] JP 2001-172582 A

[Patent Document 2] JP 11-323275 A

However, in the conductive composite material described in Patent Document 1, when a large amount of conductive substance is added to the adhesive layer, the adhesive force of the adhesive layer tends to decrease. On the other hand, in order to increase the adhesive force, when the content of conductive material particles in the adhesive layer is reduced, the conductivity tends to decrease. Therefore, the high adhesion and high conductivity of the adhesive layer are in a trade-off relationship.

In addition, since the conductive adhesive tape described in Patent Document 2 can obtain sufficient conductivity, the metal particles added to the adhesive composition must be in sufficient contact with the metal vapor deposition layer. However, in this conductive adhesive tape, the metal vapor-deposition layer forms a network, so the contact accuracy between the metal particles and the metal vapor-deposition layer becomes low. Therefore, in order to obtain sufficient conductivity, a large amount of metal particles must be added to the adhesive composition, and it is difficult to have both adhesiveness and conductivity. In addition, the surface of the metal vapor-deposited layer may be oxidized to form an oxide film. When the oxide film is formed, the adhesive strength or conductivity is reduced, and the color tone of the conductive adhesive tape is changed in appearance.

The present invention is to provide excellent adhesion while having The purpose is to have an adhesive sheet with low surface resistivity, excellent conductivity, and good discoloration resistance.

The inventors have found that the adhesive layer is formed of a material containing carbon nanotubes, and an adhesive sheet with a conductive layer with a plurality of gaps can solve the above-mentioned problem.

That is, the present invention relates to the following [1] to [9].

[1] An adhesive sheet characterized by being laminated in the order of a substrate and an adhesive layer formed of an adhesive composition, and on the adhesive layer, a material made of carbon nanotubes The structure is formed and laminated with conductive layers having a plurality of gaps, and the adhesive force measured by sticking the surface of the conductive layer side to the to-be-adhered body is 4.5N/25mm or more.

[2] The adhesive sheet as described in [1] above, wherein the plurality of gaps in the conductive layer have a structure for forming the adhesive layer.

[3] The adhesive sheet as described in [1] or [2] above, wherein the surface of the conductive layer has a structure in which carbon nanotubes are arranged preferentially in one direction.

[4] The adhesive sheet as described in any one of [1] to [3] above, wherein the conductive layer is a layer formed by a plurality of carbon nanotubes assembled by a fibrous material.

[5] The adhesive sheet as described in [4] above, wherein the thickness of the fibrous material is 1 to 300 μm on average.

[6] The adhesive sheet as described in any one of [1] to [5] above, wherein the total light transmittance of the conductive layer is 70 to 100%.

[7] The adhesive sheet according to any one of [1] to [6] above, wherein the acid value of the adhesive composition is 6.0 mgKOH/g or more.

[8] The adhesive sheet as described in any one of [1] to [7] above, wherein the substrate has a surface that can be printed or printed on the side opposite to the side of the adhesive layer of the substrate.

[9] The adhesive sheet described in any one of [1] to [8] above is used as a grounding mark for attaching electronic parts.

While the adhesive sheet of the present invention has excellent adhesive force, its surface resistivity is low, electrical conductivity is excellent, and discoloration resistance is also good.

1, 2‧‧‧Adhesive sheet

3‧‧‧Grounding mark for pasting electronic parts

11‧‧‧Substrate

12, 12a‧‧‧Adhesive layer

13‧‧‧Conductive layer

13a‧‧‧Gap

15‧‧‧Electronic parts (grounded objects)

16‧‧‧Cabinet (grounding point)

[FIG. 1] A schematic cross-sectional view showing an example of the structure of the adhesive sheet of the present invention.

[Fig. 2] shows a schematic cross-sectional view of an example of the use state of the adhesive sheet of the present invention.

[The form of implementing the invention]

In this manual, the so-called "mass average molecular weight (Mw)" It is a value in terms of polystyrene measured by a gel permeation chromatography (GPC) method, and is specifically a value measured according to the method described in the Examples.

In addition, for example, "(meth)acrylic acid" means using both "acrylic acid" and "methacrylic acid". The same is true for other similar terms.

〔Adhesive sheet〕

The adhesive sheet of the present invention is laminated in the order of a substrate and an adhesive layer formed of an adhesive composition, and further, on the aforementioned adhesive layer, has a material formed of a carbon nanotube-containing test tube, and has plural The conductive layer of each gap is laminated.

Fig. 1 is a schematic cross-sectional view showing an example of the structure of the adhesive sheet of the present invention.

The adhesive sheet 1 shown in FIG. 1(a) has a structure in which a substrate 11, an adhesive layer 12, and a conductive layer 13 are laminated in this order. As shown in FIG. 1(a), the conductive layer 13 is a layer having a plurality of gaps 13a.

For the adhesive sheet of one aspect of the present invention, the adhesive sheet 1 shown in FIG. 1(a) may be completely unfilled in the gap 13a, but the adhesive sheet 2 shown in FIG. 1(b) is Among the plurality of gaps 13 a of the conductive layer 13, a part of the adhesive layer 12 is filled, and it is preferable to have a configuration that forms the adhesive layer 12 a.

If it is the structure of the adhesive sheet 2 as shown in Fig. 1(b), the adhesion area between the adherend and the adhesive layer is large, and higher adhesive force can be expressed. In addition, since the conductive layer 13 has a structure in which the adhesive layer 12 is embedded, the conductive layer 13 is provided to make the adhesive As the sheet thickness decreases and increases.

And, it can be the adhesive sheet 1 as shown in Figure 1(a), or as shown in Figure 2. For the adhesion to the object, the adhesive will be adhered from the side of the substrate 11 by the pressure A part of the layer 12 enters into the plurality of gaps 13a of the conductive layer, and after further contacting the object, it can be bonded to the object.

Therefore, even with the structure of the adhesive sheet 1 as shown in FIG. 1(a), high adhesive force can be exhibited when it is attached to the body.

Furthermore, as the structure of the adhesive sheet of the present invention, it is not particularly limited as long as it has a structure in which a substrate, an adhesive layer, and a conductive layer are laminated in this order. For example, it may be formed on the conductive layer 13. The composition of the peeling sheet is further laminated.

The peeling sheet is capable of being peeled off and pasted to the adhesive layer 12a formed in the plurality of gaps 13a having the conductive layer 13 and the conductive layer 13, and has the function of protecting the adhesive layer 12a formed in the conductive layer 13 and the gap 13a .

In addition, in the adhesive sheet 1 shown in FIG. 1(a) and the adhesive sheet 2 shown in FIG. 1(b), although the adhesive layer 12 is directly laminated on the substrate 11, it is an aspect of the present invention The adhesive sheet can also be a configuration in which a primer layer is provided between the substrate 11 and the adhesive layer 12 from the viewpoint of improving the adhesion between the substrate 11 and the adhesive layer 12.

Hereinafter, each structure of the adhesive sheet of the present invention will be described.

<Substrate>

As the substrate with the adhesive sheet of the present invention, it can be appropriately selected from various materials in the range that can achieve the effects of the present invention and according to the application. Composition of the substrate.

As a specific substrate, for example, a conductive substrate composed of a conductive material such as a metal can be used, or an insulating substrate composed of a self-insulating material can also be used.

Furthermore, the substrate used in one aspect of the present invention may further contain an ultraviolet absorber, a light stabilizer, an antioxidant, an anti-charge agent, a slip agent, an anti-blocking agent, a coloring agent, and the like.

In addition, the substrate used in one aspect of the present invention may be a single-layer substrate, or a plurality of substrates laminated with two or more different layers.

The adhesive sheet of the present invention has a structure in which a conductive layer 13 formed of a material containing a carbon nanotube with conductivity is laminated on the adhesive layer. Therefore, as a substrate, an edge substrate can be used. The adhesive surface of the body can exhibit excellent anti-charge and electrical conductivity.

Examples of insulating substrates include paper substrates such as high-quality paper, coated paper, coated paper, cellophane, impregnated paper, and dust-free paper; laminated paper substrates in which thermoplastic resins such as polyethylene are laminated on these paper substrates. Material; Porous substrates such as non-woven fabrics; Synthetic paper composed of polyethylene resin, polypropylene resin, polyester resin, etc.; Containing polyolefin resins selected from polyethylene resins, polypropylene resins, and polybutylene terephthalic acid Plastic film of one or more resins including polyester resins such as ethylene glycol ester resin, polyethylene terephthalate resin, acetate resin, ABS resin, polystyrene resin, and chlorinated vinyl resin Or flakes and so on.

In addition, the plastic film or sheet may be unstretched, and may also be stretched in a uniaxial or biaxial direction such as longitudinal or transverse.

In addition, the plastic film or sheet may be a single-layer film or sheet, or a multi-layer film or sheet of a laminate of two or more layers.

As the conductive substrate, for example, metal foil, metal vapor-deposited plastic film or sheet in which metal is vapor-deposited on the above-mentioned plastic film or sheet, metal fiber woven fabric or metal fiber non-woven fabric, metal-coated fiber woven fabric, or metal Coated fiber non-woven fabric, carbon fiber woven fabric or carbon fiber non-woven fabric, etc.

In addition, as the metal constituting the above-mentioned conductive substrate, for example, a single metal such as platinum, gold, silver, copper, palladium, tungsten, aluminum, nickel, chromium, iron, magnesium, zinc, tin, or a combination of two or more kinds Alloys of metals.

As these substrates, plastic films or sheets with hard coating on the surface, or plastic films or sheets that can be printed or printed on the surface can be used.

Furthermore, as a substrate used in one aspect of the present invention, a substrate with a surface that can be printed or printed (hereinafter also referred to as "printing surface") on the side opposite to the side of the adhesive layer is preferred. A plastic film or sheet with a printing surface is better.

By using a substrate with a printing surface, the manufacturing number information of electronic parts can be printed or printed on the printing surface, which is helpful for the management of electronic parts.

As a method of forming the printing surface, a method of forming a printing coating formed of a composition for forming a printing printing coating film containing a resin component on the surface of a substrate can be cited.

Moreover, when a substrate made of a forming material that can form a surface that can be printed or printed is used, the surface of the substrate does not need to be printed or printed A cover film, but from the viewpoint of improving the printability of printing, it can also be formed as a printing cover film.

Examples of the resin component contained in the composition for forming a printing cover film include acrylic resins, styrene resins, polyester urethane resins, polyester resins, and polyurethane resins. Resins, polyol resins, polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives, acetate derivatives, polyvinyl chloride resins, polyimide resins, latex resins, etc.

In addition, the composition for forming a printing coat film may further contain pigments, colorants, shock-absorbing agents, plasticizers, surfactants, dispersants, freeze-melt stabilizers, neutralizers, tackifiers, wetting agents, and antiseptics. General-purpose additives such as foaming agents, lubricants, rust inhibitors, electrification inhibitors, preservatives, antioxidants, and ultraviolet absorbers.

The thickness of the printing coat film is preferably 10 to 600 nm, more preferably 30 to 200 nm.

In addition, when the substrate used in one aspect of the present invention is a plastic film or sheet, from the viewpoint of improving the adhesion between the substrate and the adhesive layer, the surface of the plastic film or sheet is applied as necessary Surface treatment such as oxidation method or embossing method is preferable.

The oxidation method is not particularly limited, and examples include corona discharge treatment, plasma treatment, chromic acid oxidation (wet), flame treatment, hot air treatment, and ozone. Ultraviolet radiation treatment, etc.

Moreover, it does not specifically limit as a roughening method, For example, a sandblasting method, a solvent processing method, etc. are mentioned.

Although these surface treatments can be appropriately selected according to the type of substrate, the corona discharge treatment method is preferred from the viewpoint of the effect of improving the adhesion to the adhesive layer and the operability.

The thickness of the substrate can be appropriately adjusted according to the application. From the viewpoint of ease of handling, it is preferably 10 to 250 μm, more preferably 15 to 200 μm, and more preferably 20 to 150 μm.

<Adhesive layer>

The adhesive layer with the adhesive sheet of the present invention is a layer formed of an adhesive composition.

The thickness of the adhesive layer can be appropriately adjusted according to the application, etc., but is preferably 1 to 100 μm, more preferably 3 to 60 μm, and more preferably 5 to 40 μm.

If the thickness of the adhesive layer is 1μm or more, it can be rated as having good adhesion to the object.

On the other hand, when the thickness of the adhesive layer is 100 μm or less, it is advantageous in terms of productivity and becomes an adhesive sheet that is easy to handle.

For one aspect of the present invention, the acid value of the adhesive composition as the material for forming the adhesive layer is preferably 6.0 mgKOH/g or more, more preferably 30 mgKOH/g or more, and more preferably 50 mgKOH/g or more .

If the acid value of the adhesive composition is 6.0 mgKOH/g or more, the adhesive layer formed of the adhesive composition tends to exhibit high adhesive force, so it is preferable. In addition, even if the thickness of the formed adhesive layer is reduced, high adhesive force can be expressed. Moreover, even if the adhesive agent that supplements the adhesive force is not used or the amount of the adhesive agent is reduced, the high adhesive force can be expressed while reducing the viscosity. The compounding amount of the adhesion-imparting agent can suppress external leakage caused by the adhesion-imparting agent for the formed adhesive layer and prevent the contamination of the object to be adhered.

Moreover, as the acid value of the adhesive composition, although there is no upper limit, it is preferably 100 mgKOH/g or less, more preferably 90 mgKOH/g or less, and more preferably 85 mgKOH/g or less.

In this specification, the acid value of the adhesive composition mentioned above is the value measured by the method described in the examples.

And, for example, as described in Patent Document 2, an adhesive sheet having an adhesive layer in which metal particles are dispersed, if the acid value of the adhesive composition forming the adhesive layer is high, the dispersed metal particles will oxidize, causing the adhesive The layer is easily discolored, which is problematic from the viewpoint of discoloration resistance.

For an adhesive sheet with an adhesive layer with dispersed metal particles or an adhesive sheet with a metal layer on the surface of the adhesive layer, if the acid value of the adhesive composition of the material forming the adhesive layer becomes low, it must be included in the Types of resin components or additives in the adhesive composition. However, an adhesive layer formed of an adhesive composition with a low acid value tends to have a low adhesive force.

On the other hand, in the adhesive sheet of the present invention, a conductive layer formed of a carbon nanotube that is not easily oxidized is laminated on the adhesive layer, and it is difficult to cause discoloration of the adhesive layer in contact with the conductive layer.

Therefore, the adhesive layer with the adhesive sheet of the present invention is not limited in the selection of the forming material, and an adhesive composition with a high acid value can also be selected. The result can be an adhesive sheet with high adhesion.

In addition, with the present invention, since an adhesive composition with excellent adhesiveness and high acid value can be used, even if the thickness of the formed adhesive layer is reduced, it can be expressed Now high adhesion.

The adhesive composition of the forming material of the adhesive layer preferably contains a resin component. According to the type of the main resin used, it may further contain an adhesive imparting agent, a crosslinking agent, a hardening accelerator, and other additives other than these. , And can also contain carbon nanomaterials.

Hereinafter, each component contained in the adhesive composition of the forming material of the adhesive layer will be described.

〔Resin composition〕

In the present invention, the term "resin component" means a resin having a predetermined repeating unit and having a mass average molecular weight (Mw) of 10,000 or more.

The content of the resin contained in the adhesive composition is generally 40-100% by mass, preferably 45-99.9% by mass, more preferably, relative to the total amount (100% by mass) of the active ingredients in the adhesive composition It is 50 to 99.5% by mass, more preferably 60 to 99.0% by mass, and still more preferably 70 to 98.0% by mass.

The mass average molecular weight (Mw) of the resin component is preferably 10,000 to 200 from the viewpoint of preparing an adhesive composition with good adhesiveness and from the viewpoint of the material for forming the adhesive layer that easily enters the gap of the conductive layer. Million, more preferably 20,000 to 1.5 million, more preferably 30,000 to 1.3 million.

Examples of the resin component include acrylic resins; rubber-based resins such as natural rubber, styrene-based resins, and polyisobutylene-based resins; silicon-based resins such as silylated urethane resins; polysiloxane-based resins; Urethane resin; polyester resin, etc.

Among them, the resin component is also selected from acrylic resin, polyiso One or more types of butene-based resins, urethane-based resins, and silicated urethane resins are preferred.

The preferred acrylic resins, polyisobutylene resins, urethane resins, and silicated urethane resins as the resin components are described below.

(Acrylic resin)

As the acrylic resin used in one aspect of the present invention, for example, a polymer containing a structural unit derived from an alkyl (meth)acrylate having a linear or branched alkyl group, and a polymer containing a cyclic Structure (meth)acrylic acid ester constitutes a polymer, etc.

In addition, when these polymers are copolymers, the form of copolymerization is not particularly limited, and they may be any of block copolymers, random copolymers, and graft copolymers.

The mass average molecular weight (Mw) of the acrylic resin is preferably 250,000 to 1.5 million, more preferably 350,000 to 1.3 million, more preferably 450,000 to 1.1 million, and still more preferably 650,000 to 1.05 million.

As an aspect of the present invention, the acrylic resin used has a structure containing an alkyl (meth)acrylate (p1') derived from an alkyl group (hereinafter also referred to as "monomer (p1')") The acrylic polymer of the unit (p1) is preferred, and the acrylic polymer of the structural unit (p2) derived from the functional group-containing monomer (hereinafter also referred to as "monomer (p2')") is further contained together with the structural unit (p1) Copolymers are preferred.

As the alkyl carbon number of the monomer (p1'), from the viewpoint of improving the adhesive force of the adhesive sheet, it is preferably 1-20, more preferably 1-16, more preferably 1-12, and further Preferably it is 1-8.

In addition, the alkyl group of the monomer (p1') may be a straight chain alkyl group or a branched chain alkyl group.

Specific monomers (p1') include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and n-butyl (meth)acrylate. , Isobutyl (meth) acrylate and other butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobutyl (meth) acrylate, etc. Octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, etc.

In addition, these monomers (p1') can be used alone or in combination of two or more kinds.

Among them, from the viewpoint of becoming an adhesive composition with good adhesive properties, as the monomer (p1'), butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are already contained. Those are preferred, and those containing n-butyl (meth)acrylate are preferred.

The content of the constituent unit (p1) is preferably 40 to 99.9% by mass, more preferably 50 to 99.5% by mass, and still more preferably 60 to 99.0 by mass relative to the total constituent unit (100% by mass) of the acrylic resin % Is more preferably 70-98.0% by mass, and still more preferably 80-95.0% by mass.

The "functional group" possessed by the monomer (p2') means that it reacts with the crosslinking agent of any additive mentioned later, and has a starting point for crosslinking. Functional group or functional group that promotes crosslinking.

Specific examples of the functional group include a hydroxyl group, a carboxyl group, an amino group, and an epoxy group.

The monomer (p2') includes, for example, a monomer containing a hydroxyl group, a monomer containing a carboxyl group, a monomer containing an amine group, and a monomer containing an epoxy group.

These monomers (p2') can be used alone or in combination of two or more kinds.

Among these, as the monomer (p2'), from the viewpoint of becoming an adhesive composition with excellent adhesive properties, it is preferable to have a monomer containing a hydroxyl group and a monomer containing a carboxyl group, which can be increased From the viewpoint of the acid value of the adhesive composition and the adhesive composition that further improves the adhesive properties, a monomer containing a carboxyl group is preferred.

Furthermore, for the present invention, in order to impart conductivity, it is not necessary to disperse metal powder in the adhesive layer or to contact the adhesive layer with a layer formed of metal.

Therefore, it is also possible to use an acrylic resin which is a cause of an increase in the acid value of the adhesive composition and has a constitutional unit derived from a monomer containing a carboxyl group. By using the acrylic resin, the adhesiveness of the adhesive composition can be further improved.

Examples of monomers containing hydroxyl groups include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy Hydroxyalkyl (meth)acrylates such as butyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.; vinyl alcohol, alkene Unsaturated alcohols such as propyl alcohol, etc.

Examples of monomers containing carboxyl groups include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; and ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid and citraconic acid. Acid and its anhydrate, 2-carboxyethyl methacrylate, etc.

The content of the constituent unit (p2) is preferably 0.1 to 30% by mass, more preferably 0.2 to 25% by mass, and more preferably 0.5 to 20% by mass relative to the total constituent unit (100% by mass) of the acrylic resin. More preferably, it is 1.0-15 mass %.

In addition, the acrylic resin used in one aspect of the present invention may have other monomers derived from monomers (p1') and (p2') (p3 ') (hereinafter also referred to as "monomer (p3')") acrylic copolymer of the structural unit (p3).

The monomer (p3') may be a monomer that can be copolymerized with the monomers (p1') and (p2'), for example, acrylomorpholine, styrene, α-methylstyrene, Vinyl monomers such as vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide.

The content of the constituent unit (p3) is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, and more preferably 0 to 10% by mass relative to the total constituent unit (100% by mass) of the acrylic resin.

(Polyisobutylene resin)

As the polyisobutylene resin used in one aspect of the present invention (with Hereinafter, it is also referred to as "PIB-based resin"), which is a resin having a polyisobutylene skeleton in the main chain or side chain, specifically, a resin having the following structural unit (a).

As the mass average molecular weight (Mw) of the PIB-based resin, from the point of view that it becomes an adhesive composition with good adhesiveness, and from the point of view that a part of the adhesive composition and the adhesive layer can easily enter due to the gap of the conductive layer, It is preferably more than 20,000, more preferably 30,000 to 1 million, more preferably 50,000 to 800,000, and still more preferably 70,000 to 600,000.

If the mass average molecular weight of the PIB-based resin is 20,000 or more, sufficient cohesive force of the adhesive composition can be obtained, and the adhesive force can be sufficiently improved. On the other hand, if the mass average molecular weight of the PIB-based resin is 1 million or less, the adhesive composition obtained and a part of the adhesive layer formed by the adhesive composition will easily enter the gap of the conductive layer.

Examples of PIB-based resins include polyisobutylene which is a homopolymer of isobutylene, copolymers of isobutylene and isoprene, copolymers of isobutylene and n-butene, copolymers of isobutylene and butadiene, and copolymers of these The material is brominated or chlorinated and other halogenated butyl rubber.

In addition, when the PIB-based resin is a copolymer, the structural unit composed of isobutylene is the one with the largest content among all the structural units.

The content of the constituent unit made of isobutylene is preferably 80-100% by mass, more preferably 90-100% by mass, and more preferably 95~ 100% by mass.

These PIB-based resins may be used alone or in combination of two or more kinds.

In addition, from the viewpoint of improving the durability and weather resistance of the formed adhesive layer, it has a dense molecular structure during polymerization and contains constituent units derived from isobutylene that does not have polymerizable double bonds in the main chain and side chains. PIB resin is preferred.

As the content of the structural unit derived from isobutylene having no polymerizable double bond in the main chain and side chain, the total structural unit (100% by mass) of the PIB-based resin is preferably 80-100% by mass, more preferably 90 ~100% by mass, more preferably 95-100% by mass, and still more preferably 100% by mass.

As a method of synthesizing PIB-based resins, for example, a method of polymerizing monomer components such as isobutylene in the presence of Lewis acid catalysts such as aluminum chloride and boron trifluoride can be cited.

Moreover, when using a PIB-based resin, it is preferable to use a PIB-based resin with a high mass average molecular weight and a PIB-based resin with a low mass average molecular weight in combination.

More specifically, PIB-based resin (a1) (hereinafter also referred to as "PIB-based resin (a1)") with a mass average molecular weight of 270,000 to 600,000 and PIB-based resin with a mass average molecular weight of 50,000 to 250,000 can be used in combination. (a2) (hereinafter also referred to as "PIB-based resin (a2)") is preferred.

By using PIB-based resin (a1) with a high mass average molecular weight, the durability and durability of the adhesive layer formed from the resulting adhesive composition can be improved. Weather resistance, while also improving adhesion.

In addition, by using PIB-based resin (a2) with a low mass average molecular weight, it is compatible with PIB-based resin (a1), can moderately plasticize PIB-based resin (a1), and improve the adhesion of the adhesive layer. Body wettability, and improve adhesion properties, flexibility, etc.

As the mass average molecular weight (Mw) of the PIB-based resin (a1), it is preferably from 270,000 to 600,000, more preferably from 290,000 to 480,000, more preferably from 310,000 to 450,000, and further preferably from 320,000 to 320,000. 400000.

If the mass average molecular weight of the PIB-based resin (a1) is 270,000 or more, the cohesive force of the adhesive composition can be sufficiently improved, and the adhesive force can also be improved. In addition, it can solve the worries about the pollution of the body being implanted.

On the other hand, if the mass average molecular weight of the PIB-based resin (a1) is less than 600,000, the cohesive force of the adhesive composition becomes excessively high, and the disadvantages such as decrease in flexibility or fluidity can be avoided. The adhesive layer of the obtained adhesive composition has good wetting of the adherend. In addition, when the adhesive composition is prepared, the solubility to the solvent can be improved. Moreover, the obtained adhesive composition and a part of the adhesive layer formed by the adhesive composition easily enter the gap of the conductive layer.

The mass average molecular weight (Mw) of the PIB-based resin (a2) is preferably 50,000-250,000, more preferably 80,000-230,000, more preferably 140,000-220,000, and further preferably 180,000-210,000 .

If the mass average molecular weight of the PIB-based resin (a2) is 50,000 or more, the PIB-based resin (a2) is separated as a low-molecular component for the adhesive layer formed of the adhesive composition to prevent contamination of the body. Harmful. In addition, the amount of outgassing at high temperatures can also be reduced.

On the other hand, when the mass average molecular weight of the PIB-based resin (a2) is 250,000 or less, the PIB-based resin (a1) can be sufficiently plasticized, and the wetting with the object can be made good.

In addition, the above-mentioned PIB-based resins (a1) and (a2) can be used alone or in combination of two or more kinds.

For the total amount of PIB resin (100% by mass), the total content of PIB resin (a1) and (a2) is preferably 70-100% by mass, more preferably 85-100% by mass, and more preferably 95 to 100% by mass, more preferably 100% by mass.

For 100 parts by mass of PIB-based resin (a1), the content of PIB-based resin (a2) is preferably 5 to 55 parts by mass, more preferably 6 to 40 parts by mass, more preferably 7 to 30 parts by mass, and furthermore It is preferably 8 to 20 parts by mass.

If the content of the PIB-based resin (a2) is 5 parts by mass or more, the PIB-based resin (a1) can be sufficiently plasticized, and the adhesive layer formed by the obtained adhesive composition can be adhered to The wetting becomes good and the adhesion can be improved.

In addition, when the content of the PIB-based resin (a2) is 55 parts by mass or less, the cohesive force can be sufficiently increased, so that the formed adhesive layer can be imparted with excellent adhesion, retention, and durability.

(Urethane resin)

As one aspect of the urethane resin used in the present invention, if at least one of the main chain and the side chain has one or more urethane bonds There is no particular limitation on the polymer with the urea bond.

As a specific urethane-based resin, for example, a urethane-based prepolymer (U1) obtained by reacting a polyol and a polyvalent isocyanate compound, or the urethane-based prepolymer (U1), the urethane-based polymer (U2) obtained by further using a chain extender to carry out a chain extension reaction, etc.

As the mass average molecular weight (Mw) of the urethane-based resin, from the viewpoint of becoming an adhesive composition with good adhesion and the viewpoint of easily entering a part of the adhesive composition and the adhesive layer in the gap of the conductive layer, It is preferably 10,000 to 200,000, more preferably 12,000 to 150,000, more preferably 15,000 to 100,000, and still more preferably 20,000 to 70,000.

Examples of the polyol used as the raw material of the urethane-based prepolymer (U1) include polyols such as alkylene glycol, polyether polyol, polyester polyol, and polycarbonate polyol. The compound is not particularly limited as long as it is a polyol, and it may be a bifunctional diol or a trifunctional triol.

Among these polyols, diols are preferred from the viewpoints of availability and reactivity.

As the diol, for example, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7- Alkane diols such as heptane diol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and other alkane diols, polyethylene glycol, polypropylene glycol, polybutylene glycol and other polyalkylene glycols, polytetramethylene glycol Such as polyoxyalkylene glycol and so on. And these diols can be used individually or in combination of 2 or more types.

Among these glycols, when further reacting with a chain extender, from the viewpoint of inhibiting gelation during the reaction, glycols with a mass average molecular weight of 1,000 to 3,000 are preferred.

Examples of the polyvalent isocyanate compound used as a raw material of the urethane-based prepolymer (U1) include aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate.

Examples of aromatic polyisocyanates include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-phenylene diisocyanate Toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3 ,5-Triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4',4"-triphenylmethane triisocyanate, 1,4-tetramethylxylene Diisocyanate, 1,3-tetramethylxylene diisocyanate, etc.

Examples of aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate , 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, etc.

Examples of alicyclic polyisocyanates include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI), 1,3-cyclopentane diisocyanate, and 1,3-cyclohexane Diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate Esters, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanate methyl)cyclohexane, etc.

In addition, these polyvalent isocyanate compounds may be trimethylolpropane addition modifiers of the above-mentioned polyisocyanates, burette-type modifiers that react with water, or isocyanurate-type modifiers containing isocyanurate rings. Sex body.

Among these polyvalent isocyanate compounds, from the viewpoint of obtaining urethane polymers with excellent adhesive properties, they are selected from 4,4'-diphenylmethane diisocyanate (MDI), 2,4- Xylene diisocyanate (2,4-TDI), 2,6-tylene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), 3-isocyanate methyl-3,5,5- Trimethylcyclohexyl isocyanate (IPDI) and one or more of these modified products are preferred, and from the viewpoint of weather resistance, one or more selected from HMDI, IPDI, and these modified products are preferred.

The isocyanate group content (NCO%) in the urethane-based prepolymer (U1) is measured in accordance with JIS K 1603, preferably 0.5-12% by mass, more preferably 1-4% by mass .

As the chain extender, a compound having at least one of two hydroxyl groups and an amino group or a compound having at least one of three hydroxyl groups and an amino group is preferred.

The compound having at least one of two hydroxyl groups and an amino group is preferably at least one compound selected from the group consisting of aliphatic diols, aliphatic diamines, alkanolamines, bisphenols, and aromatic diamines.

As aliphatic diols, for example, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,3- 7-heptane two Alkane diols such as alcohols, alkane diols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol.

As aliphatic diamine, ethylene diamine, 1, 3- propane diamine, 1, 4- butane diamine, 1, 5- pentane diamine, 1, 6-hexane diamine, etc. are mentioned, for example.

Examples of alkanolamines include monoethanolamine, monopropanolamine, and isopropanolamine.

As bisphenol, bisphenol A etc. are mentioned, for example.

Examples of aromatic diamines include diphenylmethane diamine, xylene diamine, xylene diamine, and the like.

Examples of compounds having at least one of three or more hydroxyl groups and amino groups include polyols such as trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol, 1-amino-2,3-propane Diol, 1-methylamino-2,3-propanediol, N-(2-hydroxypropylethanolamine) and other amino alcohols, ethylene oxide or propylene oxide of tetramethylxylene diamine Additives, etc.

(Silylated urethane resin)

As the silylated urethane resin used in one aspect of the present invention, the main chain of a urethane resin having a urethane bond and/or a urea bond in the main chain or side chain A resin having a hydrolyzable silicon group represented by the following general formula (1) is preferred at both ends.

In addition, as the main chain of the silicated urethane resin, those having the same structure as the above-mentioned urethane resin can be cited.

In the above general formula (1), X ¹ and X ^{2 are} each independently a hydroxyl group or an optionally substituted alkoxy group, and R ¹ is an optionally substituted alkyl group with 1 to 20 carbon atoms. The alkyl group may be linear or branched.

Examples of substituents when X ¹ , X ² , and R ¹ may have a substituent include a halogen atom, a hydroxyl group, a cyano group, a nitro group, and an amino group.

Since the silylated urethane resin has a hydrolyzable silyl group represented by the above general formula (1) at both ends of the main chain, it can be formed by the hydrolysis, dehydration and condensation of silylated urethane resins. Effectively form a three-dimensional network structure, which can improve adhesion.

In general formula (1), ^{the carbon number of the alkyl group represented by R 1 is} preferably 1-12, more preferably 1-5, and more preferably 1-3 from the viewpoint of improving adhesion.

Moreover, in the general formula (1), when X ¹ and X ² are alkoxy groups, the carbon number of the alkoxy group is preferably 1 to 12, more preferably 1 to 5 from the standpoint of improving adhesion. More preferably, it is 1~3.

The mass average molecular weight (Mw) of the silicified urethane resin is derived from the viewpoint that it becomes an adhesive composition with good adhesion, and the viewpoint that it is easy to enter the adhesive composition and part of the adhesive layer in the gap of the conductive layer In view, it is preferably 1,000 to 300,000, more preferably 5,000 to 200,000, more preferably 10,000 to 150,000, and still more preferably 20,000 to 100,000.

〔Adhesive imparting agent〕

The adhesive composition used in one aspect of the present invention may further contain an adhesive imparting agent from the viewpoint of further improving adhesiveness.

In addition, for the present invention, the so-called "adhesive imparting agent" is a compound in the field of oligomers whose mass average molecular weight (Mw) is less than 10,000 that can be mixed with the above-mentioned resin component and has an improved adhesive performance of the resin component.

Examples of the adhesion-imparting agent include rosin resins, rosin phenol resins and their ester compounds; hydrogenated rosin resins obtained by hydrogenating these rosin resins; terpene resins, terpene phenol resins, and aromatic modified resins. Terpene-based resins such as terpene-based resins; hydrogenated terpene-based resins obtained by hydrogenating these terpene-based resins; pentene, isoprene, piperine, and 1.3-pentadiene produced by thermal decomposition of naphtha C5 series petroleum resin obtained by copolymerization of other C5 fractions and hydrogenated petroleum resin of the C5 series petroleum resin; indene, vinyl toluene, α-methylstyrene, β-methylbenzene produced by thermal decomposition of naphtha C9 petroleum resin obtained by copolymerization of C9 fractions such as ethylene and hydrogenated petroleum resin of the C9 petroleum resin.

From the viewpoint of improving the adhesive force, the softening point of the adhesion imparting agent is preferably 60 to 170°C, more preferably 75 to 150°C, more preferably 85 to 140°C, and further preferably 90 to 130°C.

And the value of the softening point of the adhesion imparting agent is a value measured in accordance with JIS K 2531.

When the adhesive composition used in one aspect of the present invention contains an adhesive imparting agent, the content of the adhesive imparting agent is The total amount (100% by mass) of the composition is preferably 1-60% by mass, more preferably 5-50% by mass, and more preferably 10-30% by mass.

Moreover, the more the content of the adhesive imparting agent, the better the adhesive properties of the resulting adhesive composition. On the other hand, the smaller the content of the adhesion-imparting agent, the formed adhesive layer can suppress the leakage caused by the adhesion-imparting agent and prevent the contamination of the adherend.

In addition, when using resin components other than the silylated urethane resin, the content of the adhesion imparting agent is preferably 5-60 parts by mass relative to 100 parts by mass of the resin component contained in the adhesive composition. It is more preferably 10 to 50 parts by mass, more preferably 13 to 40 parts by mass, and still more preferably 15 to 30 parts by mass.

If the content is 5 parts by mass or more, the adhesive force of the obtained adhesive composition can be further improved. Moreover, if the content is 60 parts by mass or less, sufficient flexibility can be imparted to the adhesive layer formed of the adhesive composition obtained.

When a silicified urethane resin is used as a resin component, the content of the adhesion imparting agent is improved by the adhesive force for 100 parts by mass of the silicified urethane resin contained in the adhesive composition From a viewpoint, it is preferably 10 to 250 parts by mass, more preferably 40 to 200 parts by mass, more preferably 70 to 150 parts by mass, and still more preferably 90 to 110 parts by mass.

〔Crosslinking agent〕

As the resin component, a resin component having a functional group (for example, propylene having a structural unit (p2) derived from a functional group-containing monomer (p2') is used In the case of acid-based resins, etc., from the viewpoint of improving the adhesive strength, it is preferable to further add a cross-linking agent to the adhesive composition.

The crosslinking agent is one that reacts with the functional group of the resin component to crosslink the resins.

Examples of the crosslinking agent include isocyanate-based crosslinking agents such as xylene diisocyanate, hexamethylene diisocyanate, and these adducts; epoxy-based crosslinking agents such as ethylene glycol glycidyl ether; 1-(2-Methyl)-aziridine] triazine triazine and other aziridine-based cross-linking agents; chelating system cross-linking agents such as aluminum chelate, etc. These crosslinking agents can be used individually or in combination of 2 or more types. Among them, the isocyanate-based crosslinking agent is preferred from the viewpoints of increasing the cohesive force and improving the adhesive strength and the ease of availability.

When the adhesive composition used in one aspect of the present invention contains a crosslinking agent, the content of the crosslinking agent can be appropriately adjusted by the number of functional groups having the resin component, but from the viewpoint of promoting the crosslinking reaction, For 100 parts by mass of the resin component contained in the adhesive composition, it is preferably 0.01-10 parts by mass, more preferably 0.03-7 parts by mass, and more preferably 0.05-4 parts by mass.

〔Curing accelerator〕

As the resin component, when using a silicified urethane resin, from the viewpoint of promoting the cross-linking reaction between the silicon groups of the silicated urethane resin and improving the adhesion, the silicidation is added at the same time. Urethane resin and hardening accelerator are preferred.

As a hardening accelerator, the capacity is changed by the control of the cross-linking density From the standpoint of improving adhesion and cohesiveness, it is preferable to select at least one selected from the group consisting of aluminum-based catalysts, titanium-based catalysts, zirconium-based catalysts, and boron trifluoride-based catalysts.

As the aluminum-based catalyst, aluminum alkoxide, aluminum chelate, and aluminum (III) chloride are preferred. As the titanium-based catalyst, titanium alkoxide, titanium chelate, and titanium (IV) chloride are preferred. As the zirconium-based catalyst, zirconium alkoxide, zirconium chelate, and zirconium (IV) chloride are preferred. As the boron trifluoride catalyst, the amine complex or alcohol complex of boron trifluoride is preferred.

When the adhesive composition used in one aspect of the present invention contains a hardening accelerator, the content of the hardening accelerator is, from the viewpoint of hardening promotion, for the silicified urethane carboxylic acid contained in the adhesive composition For 100 parts by mass of the ester resin, it is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 8 parts by mass, and still more preferably 0.03 to 5 parts by mass.

〔Carbon Nanomaterials〕

The adhesive composition used in one aspect of the present invention may further contain carbon nanomaterials from the viewpoint of obtaining an adhesive sheet with further reduced surface resistivity.

Although the carbon nanomaterial used in the present invention is composed of a material containing graphite flakes with a six-membered ring arrangement structure as the main structure, the graphite structure may also contain elements other than carbon such as boron or nitrogen. The rice material can also be in the form of enclosing other substances, and the carbon nano material can also be in the form of being modified into other conductive substances.

Examples of carbon nanomaterials include carbon nanotubes, Carbon nanofiber, carbon nanohorn, carbon nanoketone, fullerene, etc.

These carbon nanomaterials may be used alone or in combination of two or more kinds.

Among them, as carbon nanomaterials, carbon nanotubes are also preferred.

The applicable carbon nanotubes are the same as the carbon nanotubes used as the conductive layer forming material described later.

In addition, carbon nanomaterials are based on the viewpoint that the carbon nanomaterials are kept close to each other in the adhesive layer and the surface resistivity of the adhesive layer is effectively reduced. It is better to mix with resin components in the form.

As a solvent of this dispersion liquid, water or an organic solvent can be mentioned.

As a method of preparing a dispersion liquid containing carbon nanomaterials, for example, a method of adding carbon nanomaterials to the above-mentioned solvent, imparting vibrations by ultrasound or the like, and dispersing the carbon nanomaterials in the solvent can be cited.

When the adhesive composition used in one aspect of the present invention contains a carbon nanomaterial, the content of the carbon nanomaterial is preferably 0.01 for 100 parts by mass of the resin component contained in the adhesive composition ~15 parts by mass, more preferably 0.05-10 parts by mass, more preferably 0.1-5 parts by mass, still more preferably 0.3-2 parts by mass.

If the content of the carbon nanomaterial is 0.01 parts by mass or more, the surface resistivity of the adhesive layer formed from the obtained adhesive composition can be reduced more efficiently.

On the other hand, if the content of the carbon nanomaterial is 15 parts by mass or less, the adhesive properties of the resulting adhesive composition can be maintained well.

〔Other additives〕

The adhesive composition used in one aspect of the present invention may further contain other additives within a range that does not impair the effects of the present invention.

As other additives, for example, antioxidants, ultraviolet absorbers, light stabilizers, resin stabilizers, fillers, pigments, extenders, infrared absorbers, near-infrared absorbers, and antiseptics can be cited. Antifungal agents, rust inhibitors, plasticizers, high boiling point solvents, etc.

These additives can be used individually or in combination of 2 or more types.

The content of each of these additives is preferably 0-10 parts by mass, more preferably 0-8 parts by mass, and more preferably 0-5 parts by mass for 100 parts by mass of the resin component contained in the adhesive composition.

<Conductive layer>

The conductive layer of the adhesive sheet of the present invention is formed of a material containing a carbon nanotube and has a layer with a plurality of gaps.

The so-called "carbon nano test tube" used in the present invention is a carbon structure having a structure in which a graphite (black lead) sheet with a six-membered carbon ring structure as the main structure is enclosed into a cylindrical shape, and the macro form is a needle-like material , But the micro form refers to a carbon polyhedron in the shape of a hollow cylinder and conductive.

In addition, the density of carbon nanotubes is lower than that of conductive metals.

Since the adhesive sheet of the present invention uses a carbon nanotube as a conductive material, it can achieve lighter weight compared with conventional adhesive sheets using metal.

And, in the material forming the conductive layer, carbon can be added at the same time Nano test tube with various additives.

The content of the carbon nanotube contained in the conductive layer is preferably 80-100% by mass, more preferably 90-100% by mass, more preferably 90-100% by mass for the total amount (100% by mass) of the conductive layer 95 to 100% by mass, more preferably 98 to 100% by mass.

For example, as described in Patent Document 1, a grounding label having an adhesive layer in which a conductive substance is dispersed has a problem of decreased adhesion due to the presence of the conductive substance.

On the other hand, the adhesive sheet of the present invention is based on the pressure when sticking to the body, and because part of the adhesive layer is interposed between the plurality of gaps of the conductive layer and the body to be adhered, it can maintain good adhesion in a well-balanced manner. Power and conductivity, especially can play the role of grounding label.

For one aspect of the present invention, the total light transmittance of the conductive layer is preferably 70% to 98%, more preferably 75% to 97%, and more preferably 80% to 95%.

In this specification, the total light transmittance means a value measured in accordance with JIS K7361, and more specifically, a value measured in accordance with the method described in the examples.

The value of the total light transmittance of the conductive layer indirectly indicates the gap ratio of the conductive layer, and it can be judged that the larger the value, the greater the gap ratio.

Therefore, if the total light transmittance is more than 70%, the area occupied by the carbon nanotube per unit area of the conductive layer will be reduced, so it becomes a conductive layer that forms multiple gaps. As a result, when adhering to the object, the adhesive layer and the object are adhered through the gap, so a conductive layer that forms multiple gaps is used When it is time, it can become an adhesive sheet that improves the adhesive force.

On the other hand, if the total light transmittance is 98% or less, it can be an adhesive sheet with excellent conductivity.

In one aspect of the present invention, as the mass increase by the lamination of the conductive layer calculated by the following formula (F1), it is preferably 5.0 g/m ² or less, more preferably 3.0 g/m ² or less, It is more preferably 1.0 g/m ² or less, and still more preferably 0.5 g/m ² or less.

Formula (F1): [The increase in the mass of the lamination of the conductive layer] = ([The mass of the adhesive sheet]-[The mass of the standard adhesive sheet]) × 100

In addition, in the above formula (F1), "the quality of the adhesive sheet" and "the quality of the standard adhesive sheet" represent the quality of the slice of the target "adhesive sheet" and "standard adhesive sheet" cut into 100mm×100mm squares. .

For one aspect of the present invention, as the increase in the thickness of the lamination of the conductive layer calculated by the following formula (F2), it is preferably less than 10.0 μm, more preferably less than 5.0 μm, and still more preferably It is less than 2.0μm.

Formula (F2): [The increase in the thickness of the laminate by the conductive layer] = [The thickness of the adhesive sheet]-[The thickness of the standard adhesive sheet]

In addition, the "standard adhesive sheet" in the above formulas (F1) and (F2) means an adhesive sheet produced by the same method as the target adhesive sheet, except that it does not have a conductive layer. In other words, the "adhesive sheet" in the above formulas (F1) and (F2) is constituted by removing the conductive layer as a "standard adhesive sheet". And, for the specific aspect, it is based on the description of the embodiment.

For one aspect of the present invention, it is preferable to have a structure in which carbon nanotubes are arranged preferentially in one direction on the surface of the conductive layer.

In the surface of the conductive layer with such a structure, since a plurality of gaps exist without deviation, it can become an adhesive sheet with uniform and excellent adhesive force for the entire adhesive surface.

In this specification, the so-called "carbon nanotubes are aligned preferentially in one direction" means that the carbon nanotubes are aligned slightly parallel to one direction on the surface of the conductive layer. For example, the long axis of a carbon nanotube is equivalent to a line in a direction in the surface of the conductive layer that is slightly parallel.

In addition, the so-called "priority alignment" state means that the alignment state is the mainstream. For example, as mentioned above, when the long axis of the carbon nanotube is slightly parallel to a direction (P) on the surface of the conductive layer as the mainstream, the long axis of a part of the carbon nanotube on the surface of the conductive layer can be aligned with the conductive layer. In the layer surface, one direction (P) does not appear to be aligned in a slightly parallel state.

Moreover, as mentioned above, the “conductive layer with a structure in which carbon nanotubes are arranged preferentially in one direction in the surface” can be easily formed through the following steps (1) to (2), for example.

‧Step (1): Use the chemical vapor growth method (CVD method) to fabricate the tube cluster of carbon nanotubes on a substrate such as a silicon wafer coated with a catalyst on the surface.

‧Step (2): Twist the end of the tube bundle of the carbon nano test tube obtained in step (1), pull it out in one direction, and pull it away from the substrate to obtain a thin carbon nano test tube sheet.

For step (1), as a specific procedure of the CVD method, a substrate such as a silicon wafer coated with a catalyst on the surface is set in a CVD furnace, and carbon such as _{methane (CH 4} ) or acetylene (C ₂ H _{2) is supplied at about 800 ℃} The method of raw material gas can be exemplified.

By this method, on the substrate of the catalyst, the horizontal plane of the substrate, such as the tube cluster of the carbon nanotubes that grow in the vertical direction, can be formed.

For step (1), the tube cluster height of the formed carbon nanotube test tube is preferably 20-2000 μm, more preferably 50-1500 μm, and more preferably 100-1000 μm.

For step (2), twist the end of the tube cluster of the carbon nano test tube aligned in the vertical direction on the horizontal plane of the substrate, and pull it out in one direction with tweezers. By pulling it away from the substrate, a thin sheet can be obtained. Shaped carbon nano test tube flakes.

In addition, the carbon nanotube sheet is obtained by pulling it out in one direction, so it has a structure that preferentially arranges the carbon nanotube tube in one direction on the surface.

Furthermore, for one aspect of the present invention, the conductive layer is preferably a layer formed by aggregating a plurality of fibers of carbon nanotubes.

When the conductive layer is formed by such a fibrous material, the area occupied by the carbon nanotube per unit area is reduced, so it becomes a conductive layer that forms a large number of gaps. When adhering to the adherend, the adhesive layer adheres to the adherend through the gap. Therefore, when a conductive layer that forms a large number of gaps is used, it can be an adhesive sheet that further improves the adhesion.

The average thickness of the fibrous material assembled by the carbon nanotubes constituting the conductive layer is preferably 1 to 300 μm, more preferably 3 to 150 μm, more preferably 5 to 100 μm, and still more preferably 7 to 50 μm .

In addition, in this specification, the "thickness of the fibrous material" means the diameter (or the major diameter) of the outer circumference of the fibrous material.

In addition, the value of "the average thickness of the fibrous material" means measuring the thickness of ten arbitrarily selected fibrous materials, and the average value of these ten fibers can be regarded as the "average of the thickness of the fibrous material".

And, as the above-mentioned "the conductive layer formed by the fibrous material assembled by a plurality of carbon nanotubes" is, for the flaky carbon nanotube sheet obtained through the above step (2), by binding (bundling) processing, can be easily formed.

The "bundling process" in this manual refers to the process of forming a bundle of a plurality of carbon nanotubes that are close together. By applying this binding treatment, the above-mentioned fibrous material can be easily formed.

As a specific method of bundling treatment, a method of exposing the flaky carbon nanotube sheet obtained in the above step (2) to the vapor of a liquid substance at room temperature can be mentioned.

Examples of liquid substances at room temperature used in the bundling treatment include water; alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone and methyl ethyl ketone; and esters such as ethyl acetate.

These can be used individually or in combination of 2 or more types.

In addition, after exposing the flaky carbon nanotube sheet obtained in the above step (2) to the substance particles (aerosol) that are liquid at room temperature, the binding process may also be applied.

When the liquid material particles are bound at room temperature, the average particle size of the particles is preferably 5nm~200μm, more preferably 7.5nm~ 100μm, more preferably 10nm-50μm.

In addition, the above-mentioned "conductive layer formed by fibrous materials assembled by a plurality of carbon nanotubes" means that the sheet-like conductive layer obtained in the above step (2) is used as a twisted yarn, and a plurality of the yarns are arranged The material can also be easily formed into flakes.

For one aspect of the present invention, the conductive layer may be a single layer, or a plurality of layers laminated with two or more layers. In addition, the above-mentioned bundling treatment can also be performed on a plurality of layers in which two or more flaky carbon nanotube sheets are laminated.

The thickness of the conductive layer can be appropriately adjusted according to the application, etc., and is preferably 0.01 to 100 μm, more preferably 0.05 to 75 μm.

<Peeling Sheet>

The adhesive sheet of the present invention may also be a structure in which a release sheet is further laminated on the conductive layer.

As the peeling sheet, a peeling sheet subjected to double-sided peeling treatment, or a single-sided peeling processed peeling sheet, etc. are used, and a peeling sheet in which a release agent is applied to a base material for the peeling sheet can be exemplified.

Examples of the substrate for the release sheet include paper substrates such as cellophane, coated paper, and high-quality paper, laminated paper in which thermoplastic resins such as polyethylene are laminated on these paper substrates, or polyethylene terephthalic acid Polyester resin films such as ethylene glycol ester resins, polybutylene terephthalate resins, polyethylene naphthalate resins, and plastic films such as polyolefin resin films such as polypropylene resins and polyethylene resins, etc. .

As the release agent, for example, polysiloxane resin, olefin Rubber elastomers such as hydrocarbon resins, isoprene resins, butadiene resins, long-chain alkyl resins, alkyd resins, fluorine resins, etc.

In addition, when the adhesive sheet of the present invention is used as an earth label when a part of a hard disk drive (HDD) is to be adhered, it is better to use a non-silicone-based resin as a release agent.

The thickness of the peeling sheet can be adjusted appropriately according to the application, etc., preferably 10~200μm, more preferably 25~150μm.

<primer layer>

In the adhesive sheet of the present invention, from the viewpoint of improving the adhesion between the substrate and the adhesive layer, a primer layer can be further provided between the substrate and the adhesive layer.

The primer layer may be formed of a composition for forming a primer layer containing a resin component.

Examples of the resin component include acrylic resins, acrylic modified polyolefin resins, chlorinated polyolefin resins, chlorinated vinyl-vinyl acetate copolymers, urethane resins, polyester resins, and polyamides. Resin, rubber-based resin, etc.

In addition, the composition for forming a primer layer may further contain general additives such as fillers, plasticizers, crosslinking agents, tackifiers, antioxidants, and ultraviolet absorbers.

The thickness of the primer layer is preferably 10 to 2000 nm, more preferably 20 to 1000 nm, and more preferably 30 to 500 nm.

〔Method of manufacturing adhesive sheet〕

Next, the manufacturing method of the adhesive sheet of the present invention will be explained.

The method for producing the adhesive sheet of the present invention is not particularly limited. For example, an adhesive composition containing resin components and other components is directly coated on one surface of the substrate to form a coating film, and the coating film is formed by heating and drying After the adhesive layer is formed, a method of laminating a separately produced conductive layer on the formed adhesive layer can be exemplified.

In addition, as another method of manufacturing the adhesive sheet of the present invention, a solution of the adhesive composition is directly applied to one surface of the substrate to form a coating film, and then a conductive layer sheet is laminated on the coating film, and the conductive layer is laminated on the conductive layer. In the state of a layer, a method of forming an adhesive layer after heating and drying the coating film is also possible.

Furthermore, after forming an adhesive layer on the release-treated surface of a separately prepared release sheet, by transferring the adhesive layer to one surface of the substrate, an adhesive layer can be formed on the substrate.

In addition, the adhesive composition has good coating properties on the substrate or the release sheet surface and improved workability, and is in the form of a solution of the adhesive composition after being diluted with water or an organic solvent. good.

Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol, etc. .

In addition, these organic solvents can be used directly in the organic solvent used in the synthesis of the resin component, or other organic solvents used in the synthesis of the resin component can be used in order to uniformly apply the adhesive solution.

The solid content concentration of the solution of the adhesive composition is preferably 5 to 60% by mass, more preferably 10 to 45% by mass, and more preferably 15 to 30% by mass.

Examples of coating methods for the adhesive composition include spin coating, spray coating, bar coating, knife coating, roll coating, knife coating, die coating, and gravure coating. Law and so on.

〔Various properties of adhesive sheet〕

For the adhesive sheet of one aspect of the present invention, the adhesive force measured as the surface of the conductive layer side adhered to the body is 4.5N/25mm or more, preferably 6.0N/25mm or more, more preferably 8.0N/ 25mm or more, more preferably 10.0N/25mm or more, still more preferably 50N/25mm or less, more preferably 40N/25mm or less.

In addition, in this specification, the value of the above-mentioned adhesive force means the value measured by the method described in the examples.

After placing the adhesive sheet of one aspect of the present invention in an environment of 23°C and 50%RH (relative humidity) for 1 week, it is preferable to measure the surface resistivity of the exposed adhesive layer and the conductive layer side surface 1.0×10 ⁺⁴ Ω/□ or ^{less, more preferably 8.0×10 +3} Ω/□ or less, more preferably 5.0×10 ⁺³ Ω/□ or less, still more preferably 1.0×10 ⁺³ Ω/□ the following.

In addition, in this specification, the value of the surface resistivity of the adhesive sheet represents the value measured by the method described in the examples.

The total light transmittance of the adhesive sheet as one aspect of the present invention is preferably 60 to 98%, more preferably 65 to 97%, and more preferably 70 to 95%.

And, for this specification, the value of the total light transmittance of the adhesive sheet The value measured in accordance with JIS K7361 for the pressure-sensitive adhesive sheet formed by removing the peeling sheet and sticking to the body to be adhered specifically represents the value measured by the method described in the examples.

As a conductive material, the adhesive sheet of the present invention uses carbon nanotubes, so weight reduction can be achieved.

For a laminate made up of a substrate with the adhesive sheet of the present invention, an adhesive layer, and a conductive layer, as the mass ^{per area of 1 m 2 of the adhered surface adhered to the adhered side of the laminate, it is preferably} 8~150g/m ² , more preferably 10~120g/m ² , more preferably 15~100g/m ² .

In addition, the adhesive sheet of the present invention, as a conductive material, can exhibit excellent conductivity even if no metal material is used. Therefore, the choice of materials for the adhesive composition forming the adhesive layer is wide, and it can also be used with excellent adhesiveness. And an adhesive composition with a high acid value. As a result, the adhesive sheet can be thinned.

When the adhesive sheet of the present invention is used for applications that require thinning, the total thickness of the adhesive sheet during the pasting of the adherend is preferably 120 μm or less, more preferably 100 μm or less, and more preferably 85 μm or less.

And, "the total thickness of the adhesive sheet when it is pasted on the object" means the total thickness of the adhesive sheet that is the composition of removing the release sheet and sticking to the object.

〔Use of adhesive sheet〕

The adhesive sheet of one aspect of the present invention can be used as an electromagnetic shielding material, electrical parts, etc. for electronic equipment such as computers and communication equipment, or storage containers, for example. Grounding marks for bonding electronic parts used for bonding of grounding wires, fire prevention materials, etc.; adhesive sheets for the protection, holding, or transportation of electrodes, conductive materials, and electronic parts; adhesive sheets or structural members for protection of optical parts; Adhesive sheet for protecting against electrification; Adhesive sheet for dust removal; Printed logo; Adhesive tape for sealing; Adhesive tape for fixing; Adhesive tape for airtight; Adhesive sheet for protection of components of buildings or conveying machinery; Designed It is used as an adhesive sheet.

Moreover, the adhesive sheet of the present invention not only has excellent adhesion, but also has excellent conductivity with low surface resistivity and good discoloration resistance.

Therefore, the adhesive sheet of the present invention can be used as a grounding mark for pasting electronic parts.

Fig. 2 shows an exemplary cross-sectional schematic diagram of a usage state of using the adhesive sheet of the present invention as a grounding mark for pasting electronic parts (hereinafter also simply referred to as "grounding label").

FIG. 2 shows the ground tag 3 of the present invention, which is used by pasting the electronic component 15 of the conductor of the earth object and the chassis 16 of the grounding place. The electrostatic gas charged on the electronic component 15 of the grounded object is used to discharge the chassis 16 at the grounding position through the conductive layer 13, and the charged electrostatic gas can be removed from the electronic component 15.

Moreover, as shown in FIG. 2, after the grounding label 3 is pasted, there is an adhesive layer 12 on the plurality of gaps 13 a with the conductive layer 13, which is in contact with the electronic component 15 and the housing 16 of the body. Therefore, the ground tag 3 is connected to the electronic component 15 and the housing 16 with sufficient holding force.

Use the grounding label of the present invention to stick hard disk drives (HDD) When the parts are used, the content of polysiloxane compounds in each layer (base material, adhesive layer, peeling sheet, primer layer, etc.) constituting the grounding label is less than the equivalent of silicon atoms. It is preferably 0.1% by mass, preferably less than 0.01% by mass, and even more preferably if it is not detected. In addition, the content of polysiloxane compounds can be calculated by fluorescent X-ray analysis.

When a polysiloxane compound is contained in each layer constituting the ground label, the polysiloxane compound is gradually vaporized, and is accumulated on The surface of the electrical contact part, etc., form a tiny polysilicon oxide layer.

The accumulation of the polysilicon oxide layer also becomes the cause of poor conductivity of electrical parts, especially when the polysilicon oxide layer is also accumulated on the surface of the head or disk in the HDD, it is easy to cause the hard disk to read or fill. bad.

Therefore, when the grounding tag of the present invention is used for sticking parts in HDD, the content of the polysiloxane compound in each layer constituting the grounding tag is preferably a very small amount.

[Example]

Hereinafter, the present invention will be described in more detail with examples, but the present invention is not limited by these examples. In addition, the measurement methods of various physical properties in this example are as follows.

(1) Mass average molecular weight (Mw)

Measure with the following equipment and conditions, and then convert to standard polystyrene The value obtained.

Device name: "HLC-8220GPC" (manufactured by Tosoh Corporation)

Column: Connected by "TSKgelGMHXL", "TSKgelGMHXL" and "TSKgel2000HXL" (all manufactured by Tosoh Corporation) in order

Developing solvent: tetrahydrofuran

Injection volume: 80μl

Measuring temperature: 40℃

Flow rate: 1.0mL/min

Detector: differential refractometer

(2) Acid value of adhesive composition

Accurately weigh out and take 0.3 g (solid content) of the adhesive layer formed of the target adhesive composition, add toluene, and prepare a solution of the adhesive composition with a solid content concentration of 1% by mass.

Next, for the prepared solution of the adhesive composition, as an indicator, 2-3 drops of phenolphthalein alcohol solution are added, and then titrated with 0.1N potassium hydroxide alcohol solution. The end point is when the solution turns red, and the acid value (mgKOH/g) of the target adhesive composition is calculated from the titration amount and the mass of the sample at that time.

(3) Mass increase by the lamination of conductive layer

Except that the conductive layer is not provided, the In the same way, a standard adhesive sheet composed of a base material/adhesive layer/release sheet was additionally manufactured.

The target adhesive sheet composed of substrate/adhesive layer/conductive layer/release sheet and the above-mentioned standard adhesive sheet were each cut into a square of 100 mm×100 mm, and the mass was measured.

And by the following formula (F1), the mass increase by the conductive layer (unit: g/m ² ) is calculated.

Formula (F1): [The increase in the mass of the lamination of the conductive layer] = ([The mass of the adhesive sheet]-[The mass of the standard adhesive sheet]) × 100

(4) Increase the thickness of the laminate by the conductive layer

Except that the conductive layer is not provided, a standard adhesive sheet composed of a base material/adhesive layer/release sheet is manufactured by the same method as the target adhesive sheet.

The thickness of the target adhesive sheet composed of the substrate/adhesive layer/conductive layer/release sheet and the thickness of the above-mentioned standard adhesive sheet are used with a constant pressure thickness tester (the product name of Tektronix Co., Ltd. "PG20J") Perform the measurement.

On the above, the increase in thickness by the lamination of the conductive layer is calculated by the following formula (F2).

Formula (F2): [The increase in the thickness of the laminate by the conductive layer] = [The thickness of the adhesive sheet]-[The thickness of the standard adhesive sheet]

(5) The average thickness of the assembled fibrous material in plural carbon nanotubes

The conductive layer composed of carbon nanotubes (hereinafter also referred to as "CNTs") before the adhesive layer is laminated is observed with an optical microscope, and the fibrous objects composed of the plurality of CNTs forming the conductive layer are randomly collected Take out 10 pieces. The average value was calculated after measuring the thickness of each of the 10 extracted fibrous materials.

(6) Total light transmittance of conductive layer or adhesive sheet

Using a haze meter (product name "NDH2000" manufactured by Nippon Denshoku Kogyo Co., Ltd.), in accordance with JIS K7361, measure the total light transmittance of the conductive layer and the adhesive sheet.

In addition, the total light transmittance of the adhesive sheet is removed from the release sheet, and a laminate composed of the base material/adhesive layer/conductive layer (in Comparative Example 1, the laminate composed of the base material/adhesive layer) is used as Test the test piece.

(7) Adhesion of the adhesive sheet

Cut the target adhesive sheet into a size of 5mm×300mm as a test piece. Under an environment of 23°C and 50%RH (relative humidity), the peeling sheet is removed from the test piece, and the surface of the exposed conductive layer is pasted on The stainless steel plate (SUS304, 360 grinded) to be attached to the body is allowed to stand for 24 hours in the same environment.

After standing for 24 hours, the adhesive force of the target adhesive sheet was measured by the 180° pull-off method based on JIS Z0237:2000 at a stretching speed of 300 mm/min.

(8) Surface resistivity of adhesive sheet

Cut the target adhesive sheet into a size of 20mm×40mm as a test piece, and let it stand for 1 week in an environment of 23°C and 50%RH (relative humidity).

After standing, using a low resistivity meter (product name "Loresta GP MCP-T610" manufactured by Mitsubishi Chemical Analytical Instruments Co., Ltd.) in accordance with JIS-K7194, when the peeling sheet is removed from the test piece, it is important to reveal the adhesive layer and The surface resistivity of the conductive layer side surface was measured. The surface resistivity was measured three times, and the average value was used as the surface resistivity of the target adhesive sheet.

(9) Discoloration resistance of the adhesive sheet

Cut the target adhesive sheet into a size of 20 mm × 40 mm as a test piece, and let it stand still for 1 week in an environment of 60°C. After standing still, the discoloration of the conductive layer was visually observed, and the discoloration resistance of the adhesive sheet was evaluated according to the following criteria.

A: No discoloration and excellent discoloration resistance.

F: Discoloration is seen, and the discoloration resistance is deteriorated.

Manufacturing examples 1~6

Add resin components and various additives of the type and mixing amount (solid content ratio) shown in Table 1, add ethyl acetate or toluene as a dilution solvent, and stir to prepare each adhesive composition with the solid content concentration shown in Table 1. (I)~(VI). In addition, the measurement results of the acid values of the adhesive compositions (I) to (VI) are also shown in Table 1.

Used in the preparation of adhesive compositions (I) ~ (VI) as shown in Table 1 The details of the contained resin components and various additives are shown below.

<Resin composition>

‧Acrylic resin (1): Contains an acrylic copolymer with constituent units derived from n-butyl acrylate (BA) and acrylic acid (AAc) (BA/AAc=90.0/10.0 (mass ratio), Mw=600,000) ), an ethyl acetate solution with a solid content of 33.6 mass%.

‧Acrylic resin (2): Contains those derived from n-butyl acrylate (BA), methacrylate (MA), acrylomorpholine (ACMO), and 2-hydroxyethyl acrylate (HEA) The constitutional unit of acrylic copolymer (BA/MA/ACMO/HEA=80.0/5.0/14.0/1.0 (mass ratio), Mw=1 million), an ethyl acetate solution with a solid content of 30% by mass.

‧Acrylic resin (3): Contains those derived from n-butyl acrylate (BA), meth methacrylate (MMA), vinyl acetate (VAc), and 2-hydroxyethyl acrylate (HEA) Acrylic copolymer of constituent unit (BA/MMA/VAc/HEA=80.0/10.0/9.0/1.0 (mass ratio), Mw=1 million), an ethyl acetate solution with a solid content of 15% by mass.

‧PIB-based resin (1): Polyisobutylene-based resin with Mw of 340,000 (product name "Oppanol B50" manufactured by BASF).

‧PIB-based resin (2): Polyisobutylene-based resin with Mw of 200,000 (product name "Oppanol B30" manufactured by BASF).

‧ Urethane resin: Containing silicified urethane resin (polyoxy Trimethylene glycol/N-aminoethyl-γ-aminopropylmethyldimethoxysilane/methacrylate=96.0/2.5/1.5 (mass ratio), Mw=50,000), solid content Ethyl acetate solution with a concentration of 70% by mass.

<Various additives>

‧Crosslinking agent (1): Tosoh Co., Ltd. product name "CoronateL", isocyanate-based crosslinking agent, solid content concentration = 75% by mass.

‧Crosslinking agent (2): Product name "TakenateD-110N" manufactured by Mitsui Chemicals Co., Ltd., isocyanate-based crosslinking agent, solid content concentration = 75% by mass.

‧Adhesion imparting agent (1): Product name "KE-359" manufactured by Arakawa Chemical Industry Co., Ltd., rosin-based resin, softening point=94~104℃.

‧Adhesion imparting agent (2): manufactured by Arakawa Chemical Industry Co., Ltd., product name "AlconP-125", hydrogenated petroleum resin, softening point = 125°C.

‧Adhesive agent (3): Product name "YSPolystarNH125" manufactured by Yasuhara Chemical Co., Ltd., terpene phenol resin, softening point: 130°C.

‧Hardening accelerator: Product name "OrgaticsTC-100" manufactured by Matsumoto Fine Chemical Co., Ltd., titanium chelating system catalyst.

‧CNT: Cylindrical multi-layer carbon nanotubes under the product name "NC7000" manufactured by Nanosyl.

Example 1 (1) The formation of carbon nanotube clusters

A thermal CVD (Chemical Vapor Deposition) device equipped with 3 furnaces using argon as the carrier gas and acetylene as the carbon source is used to form carbon nanotube clusters on silicon wafers by the catalytic chemical vapor growth method . In addition, the height of the carbon nanotube cluster is 300μm.

(2) Production of single-layer CNT sheet

Twist the end of the carbon nanotube cluster formed in (1) above and pull it out with tweezers to produce a flake-shaped CNT sheet (x).

And attach the CNT sheet (x) to the metal mesh (opening size: 700μm×600μm, line width: 40μm, thickness: 50μm).

On the CNT sheet (x) attached to the metal mesh, after spraying isopropanol through the sprayer, in the CNT sheet (x), the area that is not connected with the patterned ridge structure of the metal mesh is processed Bundle processing.

Through the above process, a sheet-like single-layer CNT sheet subjected to bundling treatment is obtained.

In addition, the obtained single-layer CNT sheet is formed by a plurality of CNT aggregated fibrous materials, has a plurality of gaps, and has a structure in which CNTs in the surface are arranged preferentially in one direction.

(3) Production of adhesive sheet

On one surface of a polyethylene terephthalate (PET) film with a thickness of 50 μm on the substrate, the adhesive composition (I) prepared in Production Example 1 was coated to form a coating film, and the coating After the cloth film is dried, an adhesive layer with a thickness of 25 μm is formed.

On the surface of the formed adhesive layer, as a conductive layer, the single-layer CNT sheet formed in the above (2) and subjected to the bundling treatment is pressed and bonded, and the surface of the conductive layer is further shown The peeling sheet was attached to the peeling surface of a PET film with a thickness of 38 μm, which was peeled off by polysiloxane, to produce an adhesive sheet (a).

Furthermore, it was confirmed that a part of the adhesive layer was filled in the plurality of gaps with the conductive layer to form the adhesive layer.

Example 2

In the same manner as in the above (2) of Example 1, two CNT sheets (x) were produced each. The two CNT sheets (x) produced were stacked on the above-mentioned metal mesh and adhered.

Next, in the same manner as in the above-mentioned (2) of Example 1, the binding process was performed in a state where two CNT sheets (x) were stacked to obtain a two-layer CNT sheet.

In addition, the obtained two-layer CNT sheet is formed by aggregating a plurality of CNT fibers, has a plurality of gaps, and has a structure that preferentially arranges the CNTs on the surface in one direction.

Regarding the above (3) of Example 1, except that the two-layer CNT sheet was used as the conductive layer, an adhesive sheet (b) was produced in the same manner as in Example 1.

Example 3

In the same manner as in the above-mentioned (2) of Example 1, 3 CNT sheets (x) were produced each. On the metal mesh, the three CNT sheets (x) produced were stacked and adhered.

Next, in the same manner as in the above-mentioned (2) of Example 1, the binding process was performed in a state where three CNT sheets (x) were stacked to obtain a three-layer CNT sheet.

In addition, the obtained three-layer CNT sheet is formed by a plurality of CNT aggregated fibrous materials, has a plurality of gaps, and has a structure in which CNTs are arranged preferentially in one direction on the surface.

For the above (3) of Example 1, as the conductive layer, the three layers are used Except for the CNT sheet, an adhesive sheet (c) was produced in the same manner as in Example 1.

Example 4

Regarding the above (3) of Example 1, except that the adhesive composition (II) prepared in Production Example 2 was used to form an adhesive layer, an adhesive sheet (d) was produced in the same manner as in Example 1.

Example 5

Regarding the above (3) of Example 1, an adhesive sheet (e) was produced in the same manner as in Example 1, except that the adhesive composition (III) prepared in Production Example 3 was used to form an adhesive layer.

Example 6

Regarding the above (3) of Example 1, an adhesive sheet (f) was produced in the same manner as in Example 1, except that the adhesive composition (IV) prepared in Production Example 4 was used to form an adhesive layer.

Example 7

Regarding the above (3) of Example 1, an adhesive sheet (g) was produced in the same manner as in Example 1, except that the adhesive composition (V) prepared in Production Example 5 was used to form an adhesive layer.

Example 8

For the above (3) of Example 1, the one prepared in Manufacturing Example 6 was used Except that the adhesive composition (VI) formed an adhesive layer, an adhesive sheet (h) was produced in the same manner as in Example 1.

Example 9

Twist a part of the end of the carbon nanotube bundle formed by the same method as in Example 1 above (1), and pull out a carbon nanotube sheet with a width of 5mm (hereinafter also referred to as "CNT sheet (y)) "). The CNT sheet (y) is passed through a metal wheel with a diameter of 5mm, and the CNT sheet (y) is bundled. The bundled CNT sheet (y) and a rubber ring (inner diameter: 3cm, outer diameter: 4cm, cross-sectional shape: round ) Contact with the inner surface of the rubber ring, and rotate the rubber ring in the circumferential direction of the rubber ring to make the bundled sheet slide on the rubber ring. The friction generated by this sliding causes the bundled CNT sheet (y) to be kneaded into a yarn. In this state, the yarn formed by twisting the CNT sheet (y) is wound on a spool. In addition, the step of winding the yarn from the carbon nanotube cluster is continuously performed.

Next, take the base material for forming the adhesive layer obtained by the same method as in the above (3) of Example 1, with the adhesive layer facing outward, and roll it up on the outer surface of a 3cm diameter rubber roller without creases. And fixed.

The yarn formed by twisting the CNT sheet (y) is attached to the vicinity of the end of the adhesive layer wound by the rubber drum, and the yarn is repeatedly ejected while slowly moving at a constant speed in a direction parallel to the rotation axis of the rubber drum. While drawing the yarn spirally at equal intervals, wind it up on a rubber drum with an adhesive layer fixed on the outer surface. After the yarn is wound on the rubber drum, cut off the base material and the yarn of each section of the yarn being wound in parallel with the rotation axis of the rubber drum The adhesive layer is taken out of the base material wound on the rubber roller, and on the surface of the adhesive layer formed on the base material, a conductive layer with yarns made of CNTs aligned at equal intervals is further formed. In addition, the average thickness of the yarn composed of CNTs is 10 μm, and the average interval between the yarns is 0.5 mm.

And, on the surface on which the conductive layer was formed, the release-treated surface of a PET film with a thickness of 38 μm of the release sheet was attached to the release-treated surface of the silicone release-treated to obtain an adhesive sheet (i).

Comparative example 1

Except that the conductive layer was not provided, an adhesive sheet (j) was produced in the same manner as in Example 1.

Comparative example 2

The copper mesh (network pattern: square grid shape, area per gap: 0.4mm ² , network thickness: 8 μm) formed by etching copper with a thickness of 20 μm was used as the conductive layer, and the same as in Example 1, Make an adhesive sheet (k).

The results of measurement or evaluation of the adhesive sheets (a) to (k) and the conductive layer with each adhesive sheet produced in the Examples and Comparative Examples are shown in Table 2.

It can be seen from Table 2 that while the adhesive sheets (a) to (i) produced in Examples 1-9 have excellent adhesion, they also have excellent conductivity with low surface resistivity and good discoloration resistance.

On the other hand, in the adhesive sheet (j) produced in Comparative Example 1, the surface resistivity has exceeded the high surface resistivity result of the upper limit of the range that can be measured by the low resistivity meter used.

In addition, in the adhesive sheet (k) produced in Comparative Example 2, the copper mesh of the conductive layer was easily oxidized, resulting in a decrease in adhesive force, and at the same time, discoloration of the copper mesh was observed, which was a result of the deterioration of the discoloration resistance.

Claims (9)

An adhesive sheet characterized by being laminated in the order of a substrate and an adhesive layer formed of an adhesive composition, and on the adhesive layer, the adhesive layer is formed of a material containing carbon nanotubes, and The structure of laminating conductive layers with a plurality of gaps, and the adhesive force measured by sticking the surface of the conductive layer side to the to-be-adhered body is 4.5N/25mm or more. For the surface of the conductive layer, there are carbon nanotubes in one The direction presents a structure of priority. The adhesive sheet according to claim 1, wherein the plurality of gaps of the conductive layer have a structure for forming the adhesive layer. The adhesive sheet of claim 1 or 2, wherein the conductive layer is a layer formed by a plurality of carbon nanotubes assembled by fibrous materials. Such as the adhesive sheet of claim 3, wherein the thickness of the aforementioned fibrous material is 1 to 300 μm on average. Such as the adhesive sheet of claim 1 or 2, wherein the total light transmittance of the aforementioned conductive layer is 70-100%. The adhesive sheet of claim 1 or 2, wherein the acid value of the adhesive composition is 6.0 mgKOH/g or more. The adhesive sheet of claim 1 or 2, wherein the substrate has a surface that can be printed on the side opposite to the side of the adhesive layer of the substrate. Such as the adhesive sheet of claim 7, wherein the aforementioned printing is printing. Such as the adhesive sheet of claim 1 or 2, it is used as a grounding mark for pasting electronic parts.

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