JPWO2019172137A1 - Multi-layer film and its manufacturing method - Google Patents

Abstract

An object of the present invention is to provide a multilayer film having excellent transparency and excellent conductivity. The multi-layer film of the present invention is a multi-layer film including a base film and an easy-adhesion layer provided on the base film, and the easy-adhesion layer is a crosslinkable polymer and the crosslinkable property. It is composed of a cured product of a polymer composition containing a cross-linking agent capable of cross-linking a polymer and carbon nanotubes. The carbon nanotubes contain a single-layer carbon nanotube at a ratio of 50% or more and have a specific surface area of 1000 m2 / g. The above, and the average diameter (Av) and the diameter distribution (3σ) satisfy the relational expression: 0.60> 3σ / Av> 0.20.

Description

The present invention relates to a multilayer film and a method for producing the same.

Various optical films are used in various image display devices such as liquid crystal display devices, organic EL display devices, and plasma displays. Such an optical film is used by being bonded to an arbitrary member having various other functions such as a polarizer, a hard coat layer, an antireflection layer, an antistatic layer, an antiglare layer, and an antifouling layer. Therefore, such an optical film is required to adhere well to these members.

In response to such demands, there is a method of providing a layer (hereinafter, referred to as "easy-adhesive layer") capable of exhibiting excellent adhesiveness on the surface of an optical film by itself or by using it as a base of an adhesive. It has been used conventionally. For example, Patent Document 1 proposes a multi-layer film in which an easy-adhesive layer obtained by curing a predetermined composition is provided on a base film. Then, according to Patent Document 1, the above-mentioned multilayer film can be satisfactorily adhered to a member to be bonded.

International Publication No. 2015/098750

However, in the above-mentioned conventional multi-layer film, it has been required to improve the conductivity in order to prevent dust and the like from adhering to the easy-adhesion film side and to secure the handleability.
That is, there is room for further improvement in the above-mentioned conventional multi-layer film in that it enhances conductivity while ensuring the transparency required for an optical film.

Therefore, an object of the present invention is to provide a multilayer film having excellent transparency and excellent conductivity, and a method for producing the multilayer film.

The present inventor has conducted diligent studies for the purpose of solving the above problems. Then, the present inventor of the present invention can form the easy-adhesive layer by curing the polymer composition containing a predetermined component when producing the multi-layer film having the easy-adhesive layer on the base film. We have found that the transparency and conductivity of the film can be improved in a well-balanced manner, and completed the present invention.

That is, the present invention aims to advantageously solve the above problems, and the multilayer film of the present invention includes a base film and an easily adhesive layer provided on the base film. A multi-walled film, the easy-adhesion layer comprises a cured product of a polymer composition containing a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and carbon nanotubes, and the carbon nanotubes. Contains single-walled carbon nanotubes at a rate of 50% or more, has a specific surface area of 1000 m ² / g or more, and has a relational expression between the average diameter (Av) and the diameter distribution (3σ): 0.60> 3σ. It is characterized in that / Av> 0.20 is satisfied. As described above, it contains a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and single-walled carbon nanotubes at a ratio of 50% or more, has a specific surface area of 1000 m ² / g or more, and has an average. A relational expression between the diameter (Av) and the diameter distribution (3σ): An easy-adhesion layer formed by curing a polymer composition containing carbon nanotubes satisfying 0.60> 3σ / Av> 0.20 is formed on a substrate film. The multi-walled film prepared for the above is ensured excellent transparency and is also excellent in conductivity.
In the present invention, the "ratio" of single-walled carbon nanotubes contained in carbon nanotubes counts the number of single-walled carbon nanotubes out of 100 carbon nanotubes randomly selected using a transmission electron microscope (TEM). It can be obtained by.
Further, in the present invention, the "specific surface area" refers to the nitrogen adsorption specific surface area measured by the BET method.
In the present invention, the "diameter distribution (3σ)" refers to the sample standard deviation (σ) of the diameter of the carbon nanotube multiplied by 3. Further, in the present invention, the "average diameter of carbon nanotubes (Av)", "standard deviation of sample diameter of carbon nanotubes (σ)" and "average length of carbon nanotubes" are observed with a transmission electron microscope, respectively. Below, the diameter (outer diameter) and length of 100 randomly selected carbon nanotubes can be measured and determined.

Here, in the multilayer film of the present invention, the crosslinkable polymer may contain at least one selected from the group consisting of an acid structure-containing polyurethane, an acid structure-containing acrylic polymer, and an acid structure-containing polyester. preferable. If an easy-adhesive layer is formed using a polymer composition containing at least one of an acid structure-containing polyurethane, an acid structure-containing acrylic polymer, and an acid structure-containing polyester as a crosslinkable polymer, a multi-layer having an adhesive layer is provided. The transparency can be further improved while sufficiently ensuring the adhesiveness of the film.

In the multilayer film of the present invention, it is preferable that the base film contains at least one of an alicyclic structure-containing polymer and an acrylic polymer. If a base film containing an alicyclic structure-containing polymer and / or an acrylic polymer is used as a polymer component, low hygroscopicity and dimensional stability can be achieved while sufficiently ensuring excellent transparency of the multilayer film. And can increase the lightness.

Here, in the multilayer film of the present invention, it is preferable that the polymer composition contains the carbon nanotubes of 0.1 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the crosslinkable polymer. If the easy-adhesion layer is formed by using the polymer composition containing carbon nanotubes in an amount within the above range, the transparency of the multilayer film can be further enhanced and the conductivity can be further improved.

The present invention also aims to advantageously solve the above problems, and the method for producing a multi-walled film of the present invention is to crosslink a crosslinkable polymer and the polymer on a base film. It contains a cross-linking agent that can be crosslinked and single-walled carbon nanotubes at a ratio of 50% or more, has a specific surface area of 1000 m ² / g or more, and has an average diameter (Av) and a diameter distribution (3σ) relational expression: 0. Includes a step of supplying a polymer composition containing carbon nanotubes satisfying .60> 3σ / Av> 0.20, and a step of curing the polymer composition supplied on the base film. It is characterized by. If the easy-adhesion layer is formed on the base film through the above-mentioned steps, excellent transparency is ensured and a multi-layer film having excellent conductivity can be obtained.

Here, the method for producing a multilayer film of the present invention comprises an aqueous dispersion containing the crosslinkable polymer and water and the carbon nanotubes prior to the step of supplying the polymer composition onto the base film. , Dispersant, and an aqueous dispersion containing water and the cross-linking agent are mixed to prepare the polymer composition. If the easy-adhesion layer is formed by using the polymer composition prepared through the above steps, the aggregation of carbon nanotubes is suppressed, and the transparency and conductivity of the multi-walled film provided with the easy-adhesion layer are further improved. be able to.

In the method for producing a multilayer film of the present invention, it is preferable that the dispersant contains an anionic surfactant. When an anionic surfactant is used as the dispersant, the aggregation of carbon nanotubes can be further suppressed, and the transparency and conductivity of the multi-walled film provided with the easy-adhesion layer can be further improved.

According to the present invention, it is possible to provide a multilayer film having excellent transparency and also excellent conductivity, and a method for producing the multilayer film.

Hereinafter, embodiments of the present invention will be described in detail. The multilayer film of the present invention is not particularly limited, but can be used as an optical film such as a protective film, a retardation film, and an optical compensation film. Further, the multilayer film of the present invention can be produced by using the method for producing a multilayer film of the present invention. Then, the multilayer film of the present invention can be used for various purposes as a laminated body by laminating it with an arbitrary member, for example.

(Multi-layer film)
The multilayer film of the present invention includes a base film and easy-adhesion layers provided on one or both sides of the base film. The easy-adhesion layer is usually provided directly on the surface of the base film without interposing another layer (that is, the easy-adhesion layer is usually provided adjacent to the base film). Further, the film of the present invention may include a layer (other layers) other than the base film and the easy-adhesion layer.
The easy-adhesion layer of the multilayer film of the present invention contains a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and single-walled carbon nanotubes at a ratio of 50% or more, and has a specific surface area of 1000 m. ^{A polymer composition containing carbon nanotubes which are 2} / g or more and whose average diameter (Av) and diameter distribution (3σ) satisfy the relational expression: 0.60> 3σ / Av> 0.20 is cured. It is characterized by being a cured product.
Since the multilayer film of the present invention forms an easy-adhesion layer by curing a polymer composition containing the above-mentioned predetermined components, it has excellent transparency and conductivity.

<Base film>
The base film is not particularly limited, but a film made of resin (resin film) can be used. Here, the resin constituting the base film contains a polymer component, and may optionally contain a component other than the polymer component (arbitrary component).

<< Polymer component >>
The polymer component contained in the resin constituting the base film is not particularly limited, but has low moisture absorption, dimensional stability, while sufficiently ensuring excellent transparency of the multi-layer film provided with the base film. From the viewpoint of enhancing lightness, alicyclic structure-containing polymer and acrylic polymer are preferable, and alicyclic structure-containing polymer is more preferable. As the polymer component, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

[Alicyclic structure-containing polymer]
The alicyclic structure-containing polymer is a polymer containing a repeating unit having an alicyclic structure. As the alicyclic structure-containing polymer, either a polymer having an alicyclic structure in the main chain or a polymer having an alicyclic structure in the side chain can be used, but the base film can be used. From the viewpoint of exhibiting excellent mechanical strength and heat resistance in the provided multi-layer film, a polymer having an alicyclic structure in the main chain is preferable. As the alicyclic structure-containing polymer, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

-Alicyclic structure-
Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure. Among them, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is more preferable, from the viewpoint of exerting excellent mechanical strength and heat resistance on the multilayer film.

Here, the number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, and 30 or less per alicyclic structure. The number is preferably 20 or less, and more preferably 15 or less. When the number of carbon atoms constituting the alicyclic structure is within the above range, the multi-layer film provided with the base film exhibits excellent mechanical strength and heat resistance while ensuring the moldability of the base film. be able to.

Further, the ratio of the repeating units having an alicyclic structure in the alicyclic structure-containing polymer is more than 50% by mass, assuming that all the repeating units constituting the alicyclic structure-containing polymer are 100% by mass. It is preferably 55% by mass or more, more preferably 70% by mass or more, particularly preferably 90% by mass or more, and 100% by mass or less. When the ratio of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer is more than 50% by mass, it is possible to improve the heat resistance while increasing the transparency of the multilayer film provided with the base film. it can.

-Specific example of alicyclic structure-containing polymer-
Specific examples of the alicyclic structure-containing polymer include norbornene-based polymers, monocyclic cyclic olefin-based polymers, cyclic conjugated diene-based polymers, and vinyl alicyclic hydrocarbon-based polymers. Among these, the norbornene-based polymer is preferable from the viewpoint of ensuring the moldability of the base film and exhibiting excellent transparency in the multilayer film provided with the base film.

Examples of the norbornene-based polymer include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and an arbitrary monomer, or a hydride thereof; Examples thereof include an addition polymer of a monomer having a norbornene structure, an addition copolymer of a monomer having a norbornene structure and an arbitrary monomer, or a hydride thereof. Among these, norbornene from the viewpoint of imparting excellent transparency, heat resistance, low moisture absorption, dimensional stability, and lightness to the multi-layer film provided with the base film while ensuring the moldability of the base film. A hydride of a ring-opening polymer of a monomer having a structure and a hydride of a ring-opening copolymer of a monomer having a norbornene structure and an arbitrary monomer are preferable.

Examples of the monomer having a norbornene structure include bicyclo [2.2.1] hept-2-ene (trivial name: norbornene) and tricyclo [4.3.0.1 ^2,5 ] deca-3,7. -Diene (trivial name: dicyclopentadiene), 7,8-benzotricyclo [4.3.0.1 ^2,5 ] deca-3-ene (trivial name: methanotetrahydrofluorene), tetracyclo [4.4. 0.1 ^2,5 . 1 ^7,10 ] Dodeca-3-ene (trivial name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent on the ring) can be mentioned. Here, examples of the substituent on the ring of these compounds include an alkyl group, an alkylene group, and a polar group. Examples of the polar group include a hetero atom and a group containing a hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom. Examples of the group containing a hetero atom include a carboxyl group, a carbonyloxycarbonyl group (carboxylic acid anhydride group), an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group and a sulfonic acid. The group and the like can be mentioned. A plurality of these substituents may be attached to the ring, the same or different from each other. Further, as the monomer having a norbornene structure, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The arbitrary monomer capable of ring-opening copolymerization or addition copolymerization with the above-mentioned monomer having a norbornene structure is not particularly limited, and for example, those listed in International Publication No. 2015/098750 may be used. it can.

The monocyclic cyclic olefin polymer, cyclic conjugated diene polymer, and vinyl alicyclic hydrocarbon polymer are not particularly limited, and those listed in International Publication No. 2015/098750 are used, for example. be able to.

-Method of preparing alicyclic structure-containing polymer-
The method for preparing the alicyclic structure-containing polymer is not particularly limited, and a known method can be used. For example, a polymer having a norbornene structure can be prepared by ring-opening polymerization or addition polymerization of a monomer composition containing at least the above-mentioned monomer having a norbornene structure and optionally hydrogenating. ..

[Acrylic polymer]
The acrylic polymer is a polymer containing at least one of a repeating unit derived from (meth) acrylic acid and a repeating unit derived from a (meth) acrylic acid derivative. The acrylic polymer may optionally contain repeating units derived from monomers (other monomers) other than (meth) acrylic acid and (meth) acrylic acid derivatives.
In the present invention, "(meth) acrylic" means acrylic and / or methacrylic.

-(Meta) acrylic acid and (meth) acrylic acid derivatives-
Here, examples of the (meth) acrylic acid include acrylic acid and methacrylic acid.
Moreover, as a (meth) acrylic acid derivative, for example, (meth) acrylic acid ester can be mentioned. Examples of the (meth) acrylic acid ester include a monofunctional (meth) acrylic acid ester and a polyfunctional (meth) acrylic acid ester.

Examples of the monofunctional (meth) acrylic acid ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, sec-butyl acrylate, and acrylic. Acrylic acid esters such as t-butyl acid, n-hexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl acrylate; methyl methacrylate, methacrylic Ethyl acetate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate , Methacrylic acid esters such as 2-ethylhexyl methacrylate, n-decyl methacrylate, n-dodecyl methacrylate; One of these may be used alone, or two or more thereof may be used in combination at any ratio.

Examples of the polyfunctional (meth) acrylic acid ester include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloxypropyl methacrylate, and tetraethylenedimethacrylate. Acrylate, polyethylene glycol # 400 diacrylate, tricyclodecanedimethanol di (meth) acrylate, dipentaerythritol hexaacrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol diacrylate hydroxypivalate, 1,9 -Nonandiol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropantri (meth) acrylate, ditrimethylolpropanetetraacrylate, dipropylene glycol diacrylate, tri. Examples thereof include propylene glycol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol dimethacrylate, and ethoxylated bisphenol A dimethacrylate. One of these may be used alone, or two or more thereof may be used in combination at any ratio.
In the present invention, "(meth) acrylate" means acrylate or methacrylate.

The ratio of the repeating units derived from the (meth) acrylic acid ester in the acrylic polymer is preferably more than 50% by mass, with 100% by mass of all the repeating units constituting the acrylic polymer. It is more preferably 7% by mass or more, further preferably 70% by mass or more, particularly preferably 90% by mass or more, and 100% by mass or less.

-Other monomers-
The other monomer is not particularly limited, and any monomer copolymerizable with the (meth) acrylic acid and the (meth) acrylic acid derivative can be used. For example, examples of other monomers include alkenyl aromatic monomers, conjugated diene monomers, unconjugated diene monomers, and vinyl cyanide monomers described in JP-A-2015-024511. Examples thereof include α, β-ethylenically unsaturated carboxylic acid amide monomer, carboxylic acid unsaturated alcohol ester, and olefin monomer. One of these may be used alone, or two or more thereof may be used in combination at any ratio.

-Method of preparing acrylic polymer-
The method for preparing the acrylic polymer is not particularly limited, and a known method can be used. For example, as an acrylic polymer containing a repeating unit derived from a polyfunctional (meth) acrylic acid ester, a monomer composition containing a polyfunctional (meth) acrylic acid ester is used, and a known photopolymerization initiator is used. It can be prepared by addition polymerization.

<< Any component >>
In addition to the above-mentioned polymer components, the resin constituting the base film may optionally contain, for example, a colorant, a plasticizer, a fluorescent whitening agent, a dispersant, a heat stabilizer, a light stabilizer, and ultraviolet absorption. Additives such as agents, anti-static agents, antioxidants, lubricants, surfactants and the like can be mentioned. One of these components may be used alone, or two or more thereof may be used in combination at any ratio.
The components other than the above-mentioned polymer components contained in the resin constituting the base film are preferably 0% by mass or more and 20% by mass or less, and more preferably 0% by mass or more and 10% by mass or less. preferable.

<< Structure of base film >>
The base film may be a film having a single-layer structure composed of only one layer, or a film having a multi-layer structure composed of two or more layers. When the base film has a multi-layer structure, the resins used for forming each layer may be the same or different.

<< Properties of base film >>
Here, the total light transmittance of the base film is preferably 85% or more, more preferably 90% or more, and more preferably 95% or more, from the viewpoint of exhibiting good transparency in the multilayer film. It is more preferable to have.
Further, the haze of the base film is preferably 0.3% or less, and more preferably 0.2% or less, from the viewpoint of causing the multilayer film to exhibit good transparency.
In the present invention, the "total light transmittance" and "haze" of the base film are measured in the same manner as the "total light transmittance" and "haze" of the multilayer film described in the examples of the present specification. can do.

The thickness of the base film is preferably 5 μm or more, more preferably 20 μm or more, preferably 500 μm or less, and more preferably 300 μm or less.

<< Manufacturing method of base film >>
The method for producing the base film is not particularly limited, and known methods such as a cast molding method, an extrusion molding method, and an inflation molding method can be used. Further, the base film may be an unstretched film that has not been stretched, or may be a stretched film that has been stretched.
Further, in order to make good adhesion between the base film and the easy-adhesion layer described later, it is preferable to perform a modification treatment on the surface of the base film. Examples of the surface modification treatment for the base film include energy ray irradiation treatment and chemical treatment.
Examples of the energy ray irradiation treatment include corona discharge treatment, plasma treatment, electron beam irradiation treatment, and ultraviolet irradiation treatment. Among these, the corona discharge treatment and the plasma treatment are preferable, and the corona discharge treatment is more preferable, from the viewpoint of processing efficiency and the like.
Examples of the chemical treatment include a saponification treatment, a treatment of immersing in an aqueous oxidizing agent solution (for example, potassium dichromate solution, concentrated sulfuric acid), and then washing with water.

<Easy adhesive layer>
The easy-adhesion layer is a layer made of a cured product of a predetermined polymer composition. By forming an easy-adhesive layer made of a cured product of a predetermined polymer composition on the above-mentioned base film to form a multi-layer film, the resulting multi-layer film is conductive while ensuring excellent transparency. Can be improved.

<< Polymer composition >>
As described above, the polymer composition contains at least a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and carbon nanotubes having predetermined properties. Moreover, the polymer composition may contain a solvent such as water. Furthermore, the polymer composition may contain components (other components) other than the crosslinkable polymer, the crosslinking agent, the carbon nanotubes, and the solvent.

[Crosslinkable polymer]
The crosslinkable polymer is not particularly limited as long as it is a polymer capable of forming a crosslinked structure by reacting with a crosslinking agent described later. That is, the crosslinkable polymer is a polymer having a site capable of reacting with the crosslinking agent, and as such a crosslinkable polymer, a polymer containing an acid structure (acid structure-containing polymer) is preferable. Here, examples of the acid structure include acidic groups such as a hydroxyl group (-OH), a carboxyl group (-COOH), and a sulfonic acid group (-SO ₃ H), and a carboxyl group is preferable. The acid structure-containing polymer may have one kind of acid structure or may have two or more kinds of acid structures in an arbitrary ratio.

In the polymer composition containing water as a solvent, the polymer containing the acid structure described above may have a small amount of a surfactant capable of assisting the dispersion of the acid structure-containing polymer (or the polymer composition may be used. Even if it does not contain a surfactant), it can be in the form of particles in the composition and can be dispersed well. As described above, the fact that the acid structure-containing polymer particles can be dispersed and stabilized in water without a surfactant is said to be the "self-emulsifying type" of the acid structure-containing polymer.
By using the polymer containing the above-mentioned acid structure, it is expected that the water resistance of the double glazing film provided with the easy-adhesion layer will be improved, and the amount of the surfactant can be reduced. The transparency can be further improved while improving the adhesiveness of the obtained multilayer film.

The acid structure-containing polymer is not particularly limited, but from the viewpoint of further improving the transparency while sufficiently ensuring the adhesiveness of the multi-layer film provided with the easy-adhesion layer, the acid structure-containing polyurethane and the acid structure. The acrylic polymer contained and the polyester containing an acid structure are preferable. As the crosslinkable polymer such as an acid structure-containing polymer, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio. For example, as the crosslinkable polymer, a composite of two or more kinds of polymers (resins) (for example, a carboxyl group-containing polyester resin acrylic resin composite) may be used.

[Polyurethane containing acid structure]
The acid structure-containing polyurethane is a polymer having a urethane bond (-NHCOO-) in the main chain and containing an acid structure in the main chain and / or the side chain.
As the acid structure-containing polyurethane, a carboxyl group-containing polyurethane is preferable. Examples of the carboxyl group-containing polyurethane include (i) a compound having two or more hydroxyl groups in one molecule, (ii) a compound having two or more isocyanate groups in one molecule, and (iii) one molecule. A polymer obtained by reacting a compound having two or more hydroxyl groups and a carboxyl group can be used.

-(I) A compound having two or more hydroxyl groups in one molecule-
(I) As the compound having two or more hydroxyl groups in one molecule, for example, a known polyol described in International Publication No. 2015/098750 can be used. (I) As the compound having two or more hydroxyl groups in one molecule, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio. As the compound (i) having two or more hydroxyl groups in one molecule, a polyester polyol or a polyether polyol can be preferably used.

Here, examples of the polyester polyol include those obtained by polycondensing a polyvalent carboxylic acid or an anhydride thereof and a polyol (excluding the polyester polyol) under the condition of excess hydroxyl group.
Examples of the polyvalent carboxylic acid that can be used for preparing the polyester polyol include dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid; trimellitic acid. Such as tricarboxylic acid. One of these may be used alone, or two or more thereof may be used in combination at any ratio.
Examples of the polyol that can be used for preparing the polyester polyol include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, and 1,4-. Butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexaneglycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclode Examples thereof include candimethanol, 1,4-cyclohexanedimethanol, 2,2-dimethylpropanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octamethylenediol, glycerin and trimethylolpropane. One of these may be used alone, or two or more thereof may be used in combination at any ratio.

Specific examples of the polyester polyol include a condensate of ethylene glycol and adipic acid, a condensate of 1,4-butanediol and adipic acid, a condensate of 1,6-hexanediol and adipic acid, and 1,6. -Examples include a condensate of hexanediol, propylene glycol and adipic acid.
The polyester polyol also contains a polylactone diol obtained by ring-opening polymerization of a lactone using glycol as an initiator.

Examples of the polyether polyol include the alkylene oxide adduct of the polyol described above as "a polyol that can be used for preparing a polyester polyol"; a ring-opening copolymer of an alkylene oxide and a cyclic ether (such as tetrahydrofuran); polyethylene glycol, polypropylene glycol, and ethylene. Glycol-propylene glycol copolymers, 1,4-butanediol copolymers; glycols such as glycols, polytetramethylene glycols, polyhexamethylene glycols, and polyoctamethylene glycols; and the like. Further specific examples of the polyether polyol include poly (oxypropylene ether) polyol, poly (oxyethylene-propylene ether) polyol and the like.

-(Ii) A compound having two or more isocyanate groups in one molecule-
(Ii) Examples of the compound having two or more isocyanate groups in one molecule include an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, and an aromatic polyisocyanate. (Ii) As the compound having two or more isocyanate groups in one molecule, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The aliphatic polyisocyanate compound is preferably an aliphatic diisocyanate having 1 to 12 carbon atoms, and examples thereof include hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, and hexane diisocyanate (HDI).
As the alicyclic polyisocyanate compound, an alicyclic diisocyanate having 4 to 18 carbon atoms is preferable, and for example, 1,4-cyclohexanediisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI). Can be mentioned.
Examples of the aromatic polyisocyanate include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate.

-(Iii) A compound having two or more hydroxyl groups and carboxyl groups in one molecule-
(Iii) Examples of the compound having two or more hydroxyl groups and carboxyl groups in one molecule include dimethylol alkanoic acid. As the compound having two or more hydroxyl groups and a carboxyl group in (iii) one molecule, one kind may be used alone, or two or more kinds may be used in combination at an arbitrary ratio.
Examples of dimethylol alkanoic acid include dimethylol acetic acid, dimethylol propionic acid, and dimethylol butyric acid.

-Method of preparing acid structure-containing polyurethane-
The method for preparing the acid structure-containing polyurethane is not particularly limited, and a known method can be used. For example, the above-mentioned compound (i), compound (ii), and compound (iii) can be prepared by polycondensation by a known method.
In addition, a polar group (amino group, epoxy group, etc.) other than the above-mentioned acid structure may be introduced into the acid structure-containing polyurethane by a known method in order to improve the reactivity with the cross-linking agent described later.

[Acid structure-containing acrylic polymer]
The acid structure-containing acrylic polymer is a polymer containing at least one of a repeating unit derived from (meth) acrylic acid and a repeating unit derived from a (meth) acrylic acid derivative while containing the above-mentioned acid structure. The acid structure-containing acrylic polymer may optionally contain repeating units derived from monomers (other monomers) other than (meth) acrylic acid and (meth) acrylic acid derivatives.

Here, the (meth) acrylic acid and the (meth) acrylic acid derivative that can be used for preparing the acid structure-containing acrylic polymer, and other monomers are those described above in the section of "Acrylic polymer". Can be used.
Further, the acid structure may be a repeating unit acid structure (carboxyl group) derived from (meth) acrylic acid, and a monomer having an acid structure other than (meth) acrylic acid (other acid structure-containing singles). It may have an acid structure derived from (dimer). Furthermore, the acid structure may be introduced by any denaturing reaction. The other acid structure-containing monomer is not particularly limited as long as it is copolymerizable with (meth) acrylic acid and / or a (meth) acrylic acid derivative and has an acid structure. Known monomers can be used.

Examples of the acid structure-containing acrylic polymer include a copolymer of (meth) acrylic acid ester and (meth) acrylic acid, and a copolymer of (meth) acrylic acid ester and other acid structure-containing monomers. Examples thereof include polymers, (meth) acrylic acid esters, (meth) acrylic acid, and copolymers of other acid structure-containing monomers.
The ratio of the repeating units derived from the (meth) acrylic acid ester in these acid structure-containing acrylic polymers is more than 50% by mass, assuming that all the repeating units constituting the acid structure-containing acrylic polymer are 100% by mass. It is preferably 55% by mass or more, more preferably 70% by mass or more, particularly preferably 80% by mass or more, and preferably 99% by mass or less.

-Method of preparing acid structure-containing acrylic polymer-
The method for preparing the acid structure-containing acrylic polymer is not particularly limited, and a known method can be used. For example, it can be prepared by addition polymerization of the monomer composition containing the above-mentioned monomer.
A polar group (amino group, epoxy group, etc.) other than the above-mentioned acid structure is introduced into the acid structure-containing acrylic polymer by a known method in order to improve the reactivity with the cross-linking agent described later. May be good.

[Polyester containing acid structure]
The acid structure-containing polyester is a polymer having an ester bond (-CO-O-) in the main chain and containing an acid structure in the main chain and / or the side chain.
As the acid structure-containing polypolyester, for example, a polymer obtained by reacting a polyol with a polybasic acid can be used. This polymer can have a carboxyl group that is not consumed and remains unreacted as an acid structure after the reaction between the polyol and the polybasic acid is completed. The acid structure may be introduced by reacting a third component having an acid structure together in the reaction of the polyol and the polybasic acid. Furthermore, the acid structure may be introduced by any denaturing reaction. As the above-mentioned polyol, polybasic acid, and third component having an acid structure, known ones can be used.

-Method of preparing polyester containing acid structure-
The method for preparing the acid structure-containing polyester is not particularly limited, and a known method can be used. For example, it can be prepared by polycondensing a polyol, a polybasic acid, and, if necessary, a third component having an acid structure by a known method.
In addition, a polar group (amino group, epoxy group, etc.) other than the above-mentioned acid structure may be introduced into the acid structure-containing polyester by a known method in order to improve the reactivity with the cross-linking agent described later.

-Specific examples of acid structure-containing polyester-
Examples of commercially available products containing acid structure include "Nichigo Polyester (registered trademark) (Nichigo Polyester W-0030, Nichigo Polyester W-0005S30WO, Nichigo Polyester WR-961, etc.)" series (Nippon Synthetic). (Made by Chemicals), "Pesresin A (Pesresin A-210, Pessresin A-520, Pessresin A-684G, Pessresin A-695GE, etc.)" series (manufactured by Takamatsu Yushi Co., Ltd.), "Byronal (registered trademark)" series (Toyobo Co., Ltd.) (Made) and so on.

[Characteristics of crosslinkable polymer]
The acid value of the crosslinkable polymer is preferably 2 mgKOH / g or more, more preferably 5 mgKOH / g or more, preferably 250 mgKOH / g or less, and more preferably 150 mgKOH / g or less. .. When the acid value of the acid structure-containing polyurethane is 2 mgKOH / g or more, the dispersibility of the acid structure-containing polyurethane in water can be sufficiently ensured. On the other hand, when the acid value of the acid structure-containing polyurethane is 250 mgKOH / g or less, the water resistance of the multilayer film provided with the easy-adhesion layer can be improved.
In the present invention, the "acid value" of the crosslinkable polymer can be measured according to JIS K 0070: 1992.

Here, the acid structure-containing polymer as the crosslinkable polymer is preferably neutralized with an organic base described later in the polymer composition. That is, the polymer composition preferably contains an acid structure-containing polymer neutralized with an organic base. If the acid structure of the acid structure-containing polymer is neutralized by an organic base, the adhesiveness of the multilayer film can be improved. In addition, the multilayer film can sufficiently exhibit its transparency even after being exposed to a high temperature.

Further, the crosslinkable polymer can be present in an arbitrary state in the polymer composition. For example, the crosslinkable polymer may be dispersed in the form of particles in a solvent, or may be dissolved in the solvent, but the solvent may be used. It is preferable that the particles are dispersed inside. When the crosslinkable polymer particles are dispersed in the solvent, the average particle size of the crosslinkable polymer particles is 0.01 μm or more from the viewpoint of further improving the transparency of the multi-layer film provided with the easy-adhesion layer. It is preferably 4 μm or less.
In the present invention, as the "average particle size", a particle size in which the particle size distribution is measured by a laser diffraction method and the cumulative volume calculated from the small diameter side in the measured particle size distribution is 50% is adopted.

[Crosslinking agent]
The cross-linking agent is not particularly limited as long as it can cure the polymer composition by cross-linking the above-mentioned cross-linking polymer. By cross-linking the cross-linking polymer with a cross-linking agent, it is possible to improve the mechanical strength, adhesiveness and moisture heat resistance of the obtained multi-layer film having an easy-adhesion layer. Then, the cross-linking agent usually reacts with a reactive group (such as the acid structure described above) of the cross-linking polymer to form a cross-linked structure.

Here, as the cross-linking agent, a compound having two or more functional groups capable of forming a bond by reacting with the reactive groups of the cross-linking polymer can be used. As the cross-linking agent, it is preferable to use a compound having two or more functional groups in one molecule capable of reacting with the carboxyl group of the cross-linking polymer or its anhydride group to form a bond.
Examples of the "functional group capable of forming a bond by reacting with the carboxyl group of the crosslinkable polymer or its anhydride group" include an epoxy group, a carbodiimide group, an oxazoline group and an isocyanate group. The cross-linking agent may have only one kind of these functional groups, or may have two or more kinds of these functional groups. Among these functional groups, an epoxy group is preferable from the viewpoint of improving the adhesiveness of the multi-layer film provided with the easy-adhesion layer.

The cross-linking agent is not particularly limited, but is an epoxy-based cross-linking agent (a compound having two or more epoxy groups in one molecule) and a carbodiimide-based cross-linking agent (a compound having two or more carbodiimide groups in one molecule). ), An oxazoline-based cross-linking agent (a compound having two or more oxazoline groups in one molecule), and an isocyanate-based cross-linking agent (a compound having two or more isocyanate groups in one molecule). As the cross-linking agent, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

Here, as the above-mentioned epoxy-based cross-linking agent, carbodiimide-based cross-linking agent, oxazoline-based cross-linking agent, and isocyanate-based cross-linking agent, International Publication No. 2015/098750, "epoxy compound", "carbodiimide compound", "oxazoline compound" , The ones listed as "isocyanate compounds" can be used respectively. Among these cross-linking agents, an epoxy-based cross-linking agent is preferable from the viewpoint of improving the adhesiveness of the multilayer film provided with the easy-adhesive layer.

[Epoxy cross-linking agent]
Preferable examples of the epoxy-based cross-linking agent include a compound obtained by an etherification reaction of polyols and epichlorohydrin, and a compound obtained by an esterification reaction of a dicarboxylic acid and epichlorohydrin.
Examples of polyols used for preparing epoxy-based cross-linking agents include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexaneglycol, and neo. Examples thereof include pentyl glycol, glycerin (glycerol), polyglycerin (polyglycerol), trimethylolpropane, pentaerythritol and sorbitol. One of these may be used alone, or two or more thereof may be used in combination at any ratio.
Examples of the dicarboxylic acid used in the preparation of the epoxy-based cross-linking agent include phthalic acid, terephthalic acid, oxalic acid, and adipic acid. One of these may be used alone, or two or more thereof may be used in combination at any ratio.
In the reaction of epichlorohydrin with polyols, usually 2 mol of epichlorohydrin is reacted with 1 mol of polyols. Further, in the reaction of dicarboxylic acid and epichlorohydrin, usually, 2 mol of epichlorohydrin is reacted with 1 mol of dicarboxylic acid.

More specifically, examples of epoxy-based cross-linking agents include ethylene glycol diglycidyl ether, glycerol polyglycidyl ether, 1,4-bis (2', 3'-epoxypropyloxy) butane, 1,3,5-tri. Glycidyl isocyanurate, 1,3-dicrysidyl-5- (γ-acetoxy-β-oxypropyl) isosinurate, sorbitol polyglycidyl ethers, polyglycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, diglycerol polyglycidyl ethers , 1,3,5-triglycidyl (2-hydroxyethyl) isocyanurate, glycerol polyglycerol ethers, trimethylolpropane polyglycidyl ethers and the like.
Further, to give a suitable example of an epoxy-based cross-linking agent as a commercially available product, "Denacol (registered trademark) series" manufactured by Nagase ChemteX Corporation (Denacol EX-313, EX-521, EX-614B, EX-313, EX) -810) and the like.
As the epoxy-based cross-linking agent, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

[Amount of cross-linking agent]
Here, the polymer composition preferably contains 1 part by mass or more of the cross-linking agent, more preferably 3 parts by mass or more, and further preferably 7 parts by mass or more per 100 parts by mass of the crosslinkable polymer. It is particularly preferably contained in an amount of 10 parts by mass or more, preferably 200 parts by mass or less, more preferably 100 parts by mass or less, further preferably 60 parts by mass or less, and particularly preferably 30 parts by mass or less. When the blending amount of the cross-linking agent in the polymer composition is within the above-mentioned range, the cross-linking reaction is allowed to proceed satisfactorily to enhance the adhesiveness of the multi-layer film provided with the easy-adhesive layer and to improve the mechanical strength. Can be done.

[carbon nanotube]
Carbon nanotubes are components that can mainly contribute to improving the conductivity of a multi-walled film having an easy-adhesion layer.

[Ratio of single-walled carbon nanotubes]
Here, the carbon nanotubes include single-walled carbon nanotubes and multi-walled carbon nanotubes. Among these, in the present invention, it is essential to use single-walled carbon nanotubes. By using the single-walled carbon nanotubes, the size of the dispersed particles of the dispersion can be reduced, and the transparency of the multi-walled film provided with the easy-adhesion layer can be ensured.
In the present invention, the carbon nanotubes contained in the polymer composition need to contain single-walled carbon nanotubes in a proportion of 50% or more and 100%, and contain single-walled carbon nanotubes in a proportion of 70% or more. It is more preferable to contain single-walled carbon nanotubes in a proportion of 80% or more, further preferably to contain single-walled carbon nanotubes in a proportion of 85% or more, and a single-walled in a proportion of 90% by mass or more. It is particularly preferable to contain carbon nanotubes. When carbon nanotubes having a ratio of single-walled carbon nanotubes of less than 50% are used, not only the conductivity of the multi-walled film provided with the easy-adhesion layer cannot be ensured, but also the transparency is lowered.

〔Specific surface area〕
Here, the carbon nanotubes need to have a specific surface area of 1000 m ² / g or more, ^{preferably 2500 m 2} / g or less, and ^{more preferably 2000 m 2} / g or less. If the specific surface area of the carbon nanotubes ^{is less than 1000 m 2} / g, the multi-walled carbon nanotubes, amorphous carbon, and metal impurities increase, and the transparency of the multi-walled film provided with the easy-adhesion layer cannot be ensured. In addition, the amount of defects (repellling unevenness) of the multilayer film provided with the easy-adhesion layer increases. On the other hand, when the specific surface area of the carbon nanotubes is 2500 m ² / g or less, there are few structural defects of the carbon nanotubes, so that the conductivity of the multi-walled film provided with the easy-adhesion layer can be further improved.

[Average diameter (AV) and diameter distribution (3σ)]
Further, the carbon nanotubes need to have a ratio (3σ / Av) of the diameter distribution (3σ) to the average diameter (Av) of more than 0.20, preferably 0.30 or more, preferably 0.40. More preferably, it is more preferably 0.49 or more, particularly preferably 0.50 or more, it is necessary to be less than 0.60, and it is 0.58 or less. preferable. If the 3σ / Av of the carbon nanotubes is out of the above range, the conductivity of the multi-walled film provided with the easy-adhesion layer is lowered.
The average diameter (Av) of the carbon nanotubes is preferably 0.5 nm or more, more preferably 1 nm or more, and more preferably 15 nm, from the viewpoint of further improving the conductivity of the multi-walled film provided with the easy-adhesion layer. It is preferably less than or equal to, and more preferably 10 nm or less.
The average diameter (Av) and standard deviation (σ) of the carbon nanotubes may be adjusted by changing the manufacturing method and manufacturing conditions of the carbon nanotubes, or a plurality of types of carbon nanotubes obtained by different manufacturing methods may be combined. It may be adjusted by.

-G / D ratio-
The G / D ratio of the carbon nanotubes used in the present invention, that is, the ratio of the G-band peak intensity to the D-band peak intensity in the Raman spectrum is preferably 10 or less, and preferably 4 or less. When the G / D ratio is 10 or less, there are many structural defects of carbon nanotubes and the number of bending points increases. Therefore, the bundle structure of carbon nanotubes can be loosened to reduce the dispersed particle size, and the amount of defects due to coarse particles (repelling). It is possible to reduce unevenness).
The G / D ratio is an index generally used for evaluating the quality of CNTs. The Raman spectra of CNT measured by Raman spectroscopy system, the vibration mode is observed, called G band (1600 cm ^-1 vicinity) and D-band (1350 cm around ^-1). The G band is a vibration mode derived from the hexagonal lattice structure of graphite, which is the cylindrical surface of CNT, and the D band is a vibration mode derived from an amorphous portion. The lower limit of the G / D ratio is not particularly limited, but is preferably 1.0 or more. When the G / D ratio is 1.0 or more, the conductivity of the multi-layer film provided with the easy-adhesion layer can be sufficiently ensured.

[How to prepare carbon nanotubes]
The carbon nanotubes having the above-mentioned properties are, for example, supplied by a chemical vapor deposition method (CVD method) by supplying a raw material compound and a carrier gas onto a substrate having a catalyst layer for producing carbon nanotubes on the surface. A method of dramatically improving the catalytic activity of a catalyst layer by allowing a trace amount of an oxidizing agent (catalyst activator) to be present in the system when synthesizing carbon nanotubes (Super Growth Method; International Publication No. 2006/011655). (See No.) can be used. In the following, the carbon nanotubes obtained by the super growth method may be referred to as "SGCNT".

[Amount of carbon nanotubes]
Here, the polymer composition preferably contains 0.1 part by mass or more of carbon nanotubes, more preferably 0.4 parts by mass or more, and 0.8 parts by mass or more per 100 parts by mass of the crosslinkable polymer. It is more preferably contained, more preferably 1.2 parts by mass or more, preferably 5.0 parts by mass or less, and more preferably 3.0 parts by mass or less. When the blending amount of carbon nanotubes in the polymer composition is 0.1 parts by mass or more per 100 parts by mass of the crosslinkable polymer, the conductivity of the multi-walled film provided with the easy-adhesive layer can be further improved. When the amount is 5.0 parts by mass or less, the transparency of the multi-walled film provided with the easy-adhesion layer can be further enhanced.

[solvent]
The solvent that the polymer composition can contain is not particularly limited, but water and a water-soluble solvent can be preferably mentioned. Here, examples of the water-soluble solvent include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether and the like. Above all, it is preferable to use water as the solvent. Further, as the solvent, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.
The amount of the solvent contained in the polymer composition can be appropriately adjusted so that the viscosity of the polymer composition is in a range suitable for coating, for example. When the polymer composition contains a solvent, the solid content concentration of the polymer composition is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1% by mass or more, and 15% by mass. % Or less, more preferably 10% by mass or less. When the solid content concentration of the polymer composition is within the above range, the handleability and coatability of the polymer composition can be ensured.

[Other ingredients]
In addition to the above-mentioned crosslinkable monomer, crosslinker, organic base, carbon nanotube, and solvent, the polymer composition may contain the dispersant and organic base described below, and known curing accelerators. , Hardening aids, heat-resistant stabilizers, weather-resistant stabilizers, leveling agents, antioxidants, anti-static agents, slip agents, anti-blocking agents, anti-fog agents, lubricants, dyes, pigments, natural oils, synthetic oils, waxes, etc. Can be mentioned. One of these may be used alone, or two or more thereof may be used in combination at any ratio.

[Dispersant]
The dispersant contained in the polymer composition is used, for example, when preparing a dispersion liquid of carbon nanotubes prior to the preparation of the polymer composition, and specifically, "method for producing a multi-walled film". Examples thereof include surfactants and polysaccharides described later in.

[Organic base]
The polyurethane composition preferably contains an organic base, particularly when the crosslinkable polymer contains an acid structure-containing polymer. The organic base is a component that functions as a neutralizing agent that neutralizes the acid structure of the acid structure-containing polymer. Then, the organic base can contribute to the improvement of the adhesiveness of the multi-layer film provided with the easy-adhesion layer by neutralizing the acid structure of the acid structure-containing polymer.

-Non-volatile-
Here, the organic base is preferably non-volatile. In the present invention, the fact that the organic base is "nonvolatile" means that the organic base does not vaporize under the conditions of 1 atm and less than 100 ° C. In other words, it can be said that the non-volatile organic base is an organic base having a melting point of less than 100 ° C. but a boiling point of 100 ° C. or higher, or an organic base having a melting point of 100 ° C. or higher. By using a non-volatile organic base, it is possible to improve the adhesive layer of the multilayer film provided with the easy-adhesive layer.
Here, the melting point of the organic base is, for example, preferably 110 ° C. or higher, more preferably 130 ° C. or higher, and further preferably 140 ° C. or higher. The melting point of the organic base is not particularly limited, but is usually 250 ° C. or lower.
The boiling point of the organic base is, for example, more preferably 120 ° C. or higher, and further preferably 150 ° C. or higher. When the boiling point of the organic base is 100 ° C. or higher, the adhesive layer of the multilayer film provided with the easy-adhesive layer can be further improved. The upper limit of the boiling point of the organic base is not particularly limited, but is usually 300 ° C. or lower.

-Specific examples of non-volatile organic bases-
Here, examples of the non-volatile organic base include 2-amino-2-methyl-1-propanol (AMP), triethanolamine, triisopropanolamine (TIPA), monoethanolamine, diethanolamine, and tri [(2-2-). Hydroxy) -1-propyl] amine, 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-hydroxymethyl-1,3-propane potassium hydroxide, zinc ammonium complex, copper Ammonium complex, silver ammonium complex, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-amino Propyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) urea, 3-ureidopropyltrimethoxysilane, 3-aminopropyl-tris (2-methoxy-ethoxy-ethoxy) ) Silane, N-methyl-3-aminopropyltrimethoxycarboxylic acid dihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipate dihydrazide, sebatic acid dihydrazide, dodecanedioic acid dihydrazide, isoftal acid dihydrazide, terephthalate dihydrazide Kinolin, picolin, pyridine, morpholine, piperazine, cyclohexylamine, hexamethylenediamine, N, N-dimethylformamide, ethylenediamine, diethylenetriamine, tetraethylenepentamine, pentaethylenepentamine, N, N-diethylmethanolamine, N, N- Dimethylethanolamine, aminoethylethanolamine, N-methyl-NN-diethanolamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazin, 2-methylpiperazin, 2,5-dimethylpiperazine, isophoronediamine , 4,4'-Dicyclohexylmethanediamine, 3,3'-dimethyl-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, aminoethylethanolamine, aminopropylethanolamine, aminohexylethanolamine, Aminoethylpropanolamine, aminopropylpropanolamine, aminohexylpropanolamine, diethylenetriamine, dipropylenetri Aimidazole, 1- (2-aminoethyl) -2-methylimidazole, 1- (2-aminoethyl) -2-ethylimidazole, 2-aminoimidazole sulfate, 2- (2-aminoethyl) -benzoimidazole, pyrazole , 5-Aminopyrazole, 1-Methyl-5-Aminopyrazole, 1-Isopropyl-5-Aminopyrazole, 1-benzyl-5-Aminopyrazole, 1,3-dimethyl-5-Aminopyrazole, 1-Isopropyl-3- Methyl-5-aminopyrazole, 1-benzyl-3-methyl-5-aminopyrazole, 1-methyl-4-chloro-5-aminopyrazole, 1-methyl-4-acino-5-aminopyrazole, 1-isopropyl- Examples thereof include 4-chloro-5-aminopyrazole, 3-methyl-4-chloro-5-aminopyrazole, and 1-benzyl-4-chloro-5-aminopyrazole. One of these may be used alone, or two or more thereof may be used in combination at any ratio.

Among these, a non-volatile amine compound such as adipic acid dihydrazide is preferable from the viewpoint of further improving the adhesive layer of the multi-layer film provided with the easy-adhesive layer.

-Amount of organic base compounded-
Here, the polymer composition preferably contains 0.5 parts by mass or more of an organic base per 100 parts by mass of the crosslinkable polymer (particularly, an acid structure-containing polymer), and more preferably 1 part by mass or more. It is preferable that it contains 2 parts by mass or more, more preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 10 parts by mass or less. When the blending amount of the organic base in the polymer composition is 0.5 parts by mass or more per 100 parts by mass of the crosslinkable polymer, the adhesiveness of the multilayer film provided with the easy-adhesive layer can be improved. If the amount is less than a part by mass, when the multilayer film is used by adhering it to a polarizer made of polyvinyl alcohol, it is possible to prevent color loss of the polarizer.

[Method for preparing polymer composition]
The method for preparing the polymer composition is not particularly limited and can be obtained by mixing the above-mentioned components, but it is preferably prepared by the method described later in "Method for producing a multilayer film".

<< Properties of Easy Adhesive Layer >>
An easy-adhesion layer can be obtained by curing the above-mentioned polymer composition by, for example, the method described in the "method for producing a multilayer film" of the present invention described later. Here, the easy-adhesive layer, which is a cured product of the polymer composition, contains components derived from the components contained in the polymer composition. For example, in one aspect of the present invention, the easy-adhesive layer contains at least a crosslinkable polymer crosslinked by a crosslinking agent and single-walled carbon nanotubes at a ratio of 50% or more, and has a specific surface area of 1000 m ² / g or more. And includes carbon nanotubes in which the average diameter (Av) and the diameter distribution (3σ) satisfy the relational expression: 0.60> 3σ / Av> 0.20.

Here, the thickness of the easy-adhesive layer (when the multilayer film has easy-adhesive layers on both sides, the thickness of each easy-adhesive layer) is preferably 0.005 μm or more, and preferably 0.01 μm or more. Is more preferable, 0.03 μm or more is further preferable, 10 μm or less is preferable, 5 μm or less is more preferable, and 3 μm or less is further preferable. When the thickness of the easy-adhesion layer is within the above-mentioned range, the easy-adhesion layer can be sufficiently adhered to the base film, and the warp of the multilayer film including the easy-adhesion layer can be suppressed.

<Other layers>
Examples of the layer that the multilayer film of the present invention can provide other than the above-mentioned base film and the easy-adhesion layer include an antireflection layer, a hard coat layer, an antistatic layer, an antiglare layer, an antifouling layer, and a separator film. Be done. In the multilayer film of the present invention, these other layers are usually provided on the surface opposite to the surface on which the easy-adhesion layer is provided.

(Manufacturing method of double glazing)
Then, by the production method of the present invention in which the above-mentioned polymer composition is cured, a multilayer film provided with an easy-adhesion layer can be produced. Specifically, the method for producing a multilayer film of the present invention includes a step (supply step) of supplying the above-mentioned polymer composition on the above-mentioned base film and the above-mentioned polymer supplied on the base film. It includes a step of curing the composition (curing step). The multi-layer film of the present invention contains a crosslinkable polymer and an aqueous dispersion containing water (an aqueous dispersion of the crosslinkable polymer) before the feeding step, and a single-layer carbon nanotube at a ratio of 50% or more. Carbon nanotubes containing, the specific surface area is 1000 m ² / g or more, and the average diameter (Av) and the diameter distribution (3σ) satisfy the relational expression: 0.60> 3σ / Av> 0.20, dispersion. The step (composition preparation step) of preparing a polymer composition by mixing an agent, an aqueous dispersion containing water (an aqueous dispersion of carbon nanotubes) and a cross-linking agent capable of cross-linking a cross-linking polymer is included. Is preferable. Further, the method for producing a multilayer film of the present invention may include steps (other steps) other than the above-mentioned composition preparation step, supply step and curing step.

<Composition preparation process>
As the polymer composition to be supplied onto the base film in the feeding step, it is preferable to separately prepare an aqueous dispersion of the crosslinkable polymer and an aqueous dispersion of carbon nanotubes, and prepare them together. By preparing the polymer composition in this way, it is possible to suppress the aggregation of carbon nanotubes and further improve the transparency and conductivity of the multilayer film provided with the easy-adhesion layer.
Both the aqueous dispersion of the crosslinkable polymer and the aqueous dispersion of the carbon nanotubes can be prepared by a known method. When an acid structure-containing polymer such as an acid structure-containing polyurethane is used as the crosslinkable polymer, the aqueous dispersion of the acid structure-containing polymer contains the above-mentioned organic base in addition to the acid structure-containing polymer and water. Is preferable.

As the dispersant that can be contained in the aqueous dispersion of carbon nanotubes, for example, a known dispersant that can assist the dispersion of carbon nanotubes can be used, and examples thereof include surfactants and polysaccharides. Among these, a surfactant is more preferable, and an anionic surfactant is further preferable, from the viewpoint of further improving the transparency and conductivity of the multilayer film provided with the easy-adhesion layer. As the anionic surfactant, sodium dodecyl sulfate, sodium deoxycholate, sodium cholic acid, sodium dodecylbenzenesulfonate, sodium dodecyldiphenyloxide disulfonate and the like can be used.
As the dispersant, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The aqueous dispersion of carbon nanotubes preferably contains 10 parts by mass or more of a dispersant, more preferably 100 parts by mass or more, and preferably 1500 parts by mass or less, preferably 1000 parts by mass, per 100 parts by mass of carbon nanotubes. It is more preferably contained in an amount of parts or less, more preferably 500 parts by mass or less, and particularly preferably 300 parts by mass or less. When the amount of the dispersant in the aqueous dispersion is 10 parts by mass or more per 100 parts by mass of the carbon nanotubes, the aggregation of the carbon nanotubes is sufficiently suppressed and the transparency and conductivity of the multi-walled film provided with the easy-adhesion layer are provided. If it is 1500 parts by mass or less, the conductivity of the multi-walled film can be sufficiently ensured.

<Supply process>
The method for supplying the polymer composition onto the base film is not particularly limited, but it is preferable to use a coating method. Specific coating methods include, for example, wire bar coating method, dip method, spray method, spin coating method, roll coating method, gravure coating method, air knife coating method, curtain coating method, slide coating method, and extrusion coating method. And so on.

<Curing process>
The method for curing the polymer composition on the base film is not particularly limited. For example, when the polymer composition contains a solvent, it is preferable to heat the crosslinkable polymer under conditions in which the solvent can be removed while crosslinking the crosslinkable polymer with a crosslinking agent. The heating conditions are not particularly limited, but for example, the heating temperature can be 70 ° C. or higher and 90 ° C. or lower, and the heating time can be 1 minute or longer and 30 minutes or shorter.

<Other processes>
The method for producing a multilayer film of the present invention may include a step of subjecting the surface of the easy-adhesion layer obtained through the above-mentioned curing step to a hydrophilic surface treatment. By performing the hydrophilic surface treatment, the adhesiveness of the multi-layer film provided with the easy-adhesion layer can be sufficiently improved. Examples of the hydrophilized surface treatment include corona discharge treatment, plasma treatment, saponification treatment, and ultraviolet irradiation treatment described in International Publication No. 2015/098750.
Further, the method for producing a multilayer film of the present invention may include a step of providing the above-mentioned other layer on the surface of the base film opposite to the surface of the base film provided with the easy-adhesive layer.

(Laminated body)
The multi-layer film of the present invention described above can be bonded to another member and used as a laminate including the multi-layer film and the other member. Hereinafter, a case where the multilayer film of the present invention is bonded to a polarizer and used as a polarizing plate will be described as an example.

<Polarizer>
The polarizing plate includes a polarizing element and the multilayer film of the present invention. Then, in the polarizer and the multilayer film of the present invention, for example, the polarizer and the multilayer film may be directly adhered to each other only through the easy-adhesive layer of the multilayer film, or the polarizer and the multilayer film may be directly adhered to each other. , It may be adhered through a layer (adhesive layer) composed of an easy-adhesive layer and an adhesive. Further, the polarizing plate may be provided with a multilayer film on one surface of the polarizer, or may be provided with a multilayer film on both sides.

<< Polarizer >>
The polarizer is not particularly limited, and a known polarizer can be used. As the polarizer, for example, a polarizer containing polyvinyl alcohol is preferable. The polarizer containing polyvinyl alcohol may be produced, for example, by adsorbing iodine or a dichroic dye on a polyvinyl alcohol film and then uniaxially stretching it in a boric acid bath, or iodine or dichroism on a polyvinyl alcohol film. It may be produced by adsorbing and stretching a color dye, and further modifying a part of polyvinyl alcohol units in the molecular chain to polyvinylene units.
Further, as the polarizer, for example, a polarizing element having a function of separating polarized light into reflected light and transmitted light, such as a grid polarizer, a multilayer polarizer, and a cholesteric liquid crystal polarizer, may be used.
The degree of polarization of the polarizer is preferably 98% or more, more preferably 99% or more. The thickness of the polarizer is preferably 5 μm or more and 80 μm or less.

<< Adhesive layer >>
As described above, the multilayer film may be adhered to the polarizer only through the easy-adhesive layer, or may be adhered to the polarizer via the easy-adhesive layer and the adhesive layer. In this case, the easy-adhesion layer of the multilayer film functions as a base for the adhesive layer. The adhesive for forming the adhesive layer is not particularly limited, and for example, a known adhesive described in International Publication No. 2015/098750 can be used.
The thickness of the adhesive layer is preferably 0.05 μm or more, preferably 0.1 μm or more, preferably 5 μm or less, and more preferably 1 μm or less.

<< Manufacturing method of polarizing plate >>
There is no limitation on the method of bonding the multilayer film and the polarizer. For example, after applying an adhesive to one surface of a polarizer to form an adhesive layer, a roll laminator is used to separate the polarizer and the multilayer film, and the adhesive layer of the polarizer and the multilayer film easily. A method in which the adhesive layer is attached so as to be in contact with the adhesive layer and dried or irradiated with light such as ultraviolet rays is preferable.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the following description, "%" and "part" representing quantities are based on mass unless otherwise specified.
Then, in the present invention, the transparency, conductivity, adhesiveness, and amount of defects of the multilayer film were evaluated according to the following criteria.

<Transparency>
The total light transmittance and haze of the multilayer film were measured using a "turbidity meter NDH-300A" manufactured by Nippon Denshoku Kogyo Co., Ltd. in accordance with JIS K7361-1: 1997 and JIS K7136: 2000. The larger the total light transmittance value and the smaller the haze value, the better the transparency of the multilayer film.
<Conductivity>
Using a high resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., product name "Hiresta (registered trademark) -UX MCP-HT800"), the surface resistance (Ω) at any three points on the easy-adhesion layer side of the multi-layer film. / □) was measured, and the average value of these was taken as the surface resistance of the multilayer film. The smaller the surface resistance value, the better the conductivity of the multilayer film.
<Adhesiveness (cutter peeling test after moist heat)>
The surface of the easy-adhesion layer of the multilayer film produced in each Example and Comparative Example and one side of the polarizer produced in Production Example 3 were bonded together with a roll laminator using the adhesive produced in Production Example 4. .. Further, a protective film (triacetyl cellulose film manufactured by Konica Minolta, trade name "KC4UYW", thickness: 40 μm) is attached to the other side of the polarizing element by using the adhesive produced in Production Example 4 to obtain polarized light. Manufactured a board.
Next, a surface of the multilayer film of the polarizing plate opposite to the easy-adhesion layer and a glass substrate were bonded to each other via an adhesive sheet (“LUCIACS CS9621T” manufactured by Nitto Denko Corporation) to prepare a sample.
The obtained sample was allowed to stand in a constant temperature and humidity chamber at 60 ° C. and 90% RH for 200 hours. Then, a notch was made from the end and surface of the sample taken out from the constant temperature and humidity chamber with a cutter. Then, the polarizing plate of the sample was pulled to attempt peeling. When peeling occurred between the multilayer film and the glass substrate, the easy-adhesive layer and the adhesive had sufficient adhesive strength, and the adhesiveness was evaluated as "good". Further, when peeling occurred between the polarizer and the multilayer film, the adhesive strength of the easy-adhesive layer and the adhesive was insufficient, and the adhesiveness was evaluated as "poor".
<Defect amount (repellency unevenness)>
The produced multilayer film was irradiated with a video light VLG-301 manufactured by LPL. The reflected light of this film was visually observed from an angle, and the number of spots having a diameter of 0.5 mm or more and transparently shining in a substantially circular shape was counted as unevenness and converted to the number per ^{1 m 2.}

(Production Example 1-1: Preparation of base film (I))
Pellets of a resin containing an alicyclic structure-containing polymer as a polymer component (“ZEONOR® 1430” manufactured by Nippon Zeon Co., Ltd., glass transition temperature: 135 ° C.) were pelleted using a hot air dryer in which air was circulated. It was dried at 70 ° C. for 2 hours. The dried resin was extruded and molded by using a T-die film melt-extrusion molding machine having a resin melt-kneader equipped with a screw having a diameter of 65 mm under the conditions of a molten resin temperature of 270 ° C. and a width of a T-die of 500 mm. Next, the obtained molded body was subjected to corona discharge treatment under the conditions of an output of 300 W, an electrode length of 240 mm, a work electrode distance of 3.0 mm, and a transport speed of 4 m / min using a corona treatment device (manufactured by Kasuga Electric Co., Ltd.). The base film (I) (thickness: 100 μmm, length: 1000 m) was used.
(Production Example 1-2: Preparation of base film (II))
It consists of 90.0 parts of ditrimethylolpropane tetraacrylate ("NK ester AD-TMP," manufactured by Shin-Nakamura Chemical Co., Ltd.), 10.0 parts of photoinitiator ("Irgacure 907", manufactured by Ciba Geigy), and 900.0 parts of butyl acetate. The mixture was uniformly stirred and mixed, and then filtered through a 1 μm filter to prepare an ultraviolet curable resin solution.
The obtained ultraviolet curable resin solution was applied to both sides of the base film (I) prepared in Production Example 1-1 using a gravure coater so that the dry film thickness was 2 μm, and 5 at 80 ° C. Allowed to dry for minutes. Then, ultraviolet irradiation (integrated light intensity: 400 mJ / cm ² ) was carried out using an ultra-high pressure mercury lamp to obtain a base film (II). The base film (II) has a layer of an acrylic polymer on the outermost surface.
(Production Example 2-1: Synthesis of carbon nanotubes)
Carbon nanotubes (SGCNT (I)) were obtained by using the above-mentioned super growth method. Specifically, SGCNT (I) was grown under the following conditions.
Carbon compound as raw material compound: ethylene; supply rate 50 sccm
Atmosphere (carrier gas): Helium, hydrogen mixed gas; Supply speed 1000 sccm
Catalyst activator: Water vapor addition amount; 300ppm
Catalyst layer: Iron thin film (thickness 1 nm)
Substrate: Silicon wafer The obtained SGCNT (I) has a BET specific surface area of 1,050 m ² / g and a G / D ratio of 3.0, and is characterized by single-walled carbon nanotubes in measurement with a Raman spectrophotometer. A spectrum of radial breathing mode (RBM) was observed in the low frequency region of 100 to 300 cm ^-1. In addition, as a result of randomly observing 100 SGCNTs using a transmission electron microscope, the ratio of single-walled carbon nanotubes was 90%, the average diameter (Av) was 3.3 nm, and the diameter distribution (3σ) was 1.9 nm. 3, σ / Av was 0.58.
(Production Example 2-2: Synthesis of carbon nanotubes)
SGCNT (II) was produced under the same conditions as in Production Example 2-2 except that an iron thin film (thickness 1.5 nm) was used as the catalyst layer. The obtained SGCNT (II) has a BET specific surface area of 1,020 m ² / g and a G / D ratio of 2.3, and has a BET specific surface area of 1,020 m 2 / g and a G / D ratio of 2.3. Radial breathing mode (RBM) spectra were observed in the low frequency region of 300 cm ^-1. In addition, as a result of randomly observing 100 SGCNTs using a transmission electron microscope, the ratio of single-walled carbon nanotubes was 75%, the average diameter (Av) was 4.9 nm, and the diameter distribution (3σ) was 2.4 nm. 3, σ / Av was 0.49.
(Manufacturing Example 3: Fabrication of Polarizer)
A polyvinyl alcohol film having a thickness of 80 μm was dyed in a 0.3% aqueous iodine solution. Then, it was stretched up to 5 times in a 4% aqueous boric acid solution and a 2% aqueous potassium iodide solution, and then dried at 50 ° C. for 4 minutes to obtain a polarizer.
(Manufacturing example 4: Preparation of adhesive)
Gocefymer (registered trademark) Z410 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., polyvinyl alcohol containing an acetoacetyl group) was diluted with water to a solid content of 3% to obtain an adhesive.

(Example 1)
<Preparation of aqueous dispersion of acid structure-containing polyurethane>
As an aqueous dispersion of an acid structure-containing polyurethane, an aqueous dispersion of a polyether polyurethane (“Superflex (registered trademark) 870” manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was prepared.
<Preparation of water dispersion of carbon nanotubes>
90 mg of SGCNT (I) of Production Example 2-1 was added to 90 mL of a 1% aqueous sodium dodecyl sulfate solution, and treated 20 times using a jet mill (“JN-20” manufactured by Joko Co., Ltd.) to eliminate SGCNT (I). An aqueous dispersion containing 1% was obtained. The obtained aqueous dispersion contained 1000 parts of sodium dodecyl sulfate per 100 parts of SGCNT.
<Preparation of polymer composition>
To 7.0 g of the above-mentioned aqueous dispersion of acid structure-containing polyurethane, 0.04 g of adipic acid dihydrazide (melting point: 180 ° C.) as a non-volatile organic base (2 parts of adipate dihydrazide per 100 parts of acid structure-containing polyurethane) was added. 0.3 g of glycerol polyglycidyl ether (“Denacol EX-313” manufactured by Nagase ChemteX Corporation) as an epoxy-based cross-linking agent (15 parts of glycerol polyglycidyl ether per 100 parts of acid structure-containing polyurethane) and water dispersion of the above-mentioned carbon nanotubes. A polymer composition was prepared by adding 34 g of a liquid (1.7 parts of carbon nanotubes per 100 parts of polyurethane containing an acid structure) and 39 g of water.
<Making a multi-layer film>
The above-mentioned polymer composition was applied to one side of the base film (I) of Production Example 1-1 using a bar coater. The polymer composition on the base film (I) was cured by drying at 80 ° C. for 10 minutes to obtain a multi-layer film having an easily adhesive layer on the base film (I). The obtained multi-layer film was used to evaluate transparency, conductivity, defect amount, and adhesiveness. The results are shown in Table 1.

(Example 2)
When preparing the polymer composition, instead of the aqueous dispersion of the acid structure-containing polyurethane, the aqueous dispersion of the acid structure-containing polyester resin acrylic resin composite (“Pesresin A-684G” manufactured by Takamatsu Oil & Fat Co., Ltd., a carboxyl group as the acid structure was used. In the production of the multilayer film, the base film (II) of Production Example 1-2 was used instead of the base film (I) of Production Example 1-1. Other than that, an aqueous dispersion of carbon nanotubes, a polymer composition, a multi-layer film, and a polarizing plate were prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

(Example 3)
In preparing the polymer composition, an aqueous dispersion of an acid structure-containing polyester (“Byronal MD-1480” manufactured by Toyobo Co., Ltd.) was used instead of the aqueous dispersion of the acid structure-containing polyurethane. Other than that, an aqueous dispersion of carbon nanotubes, a polymer composition, a multi-layer film, and a polarizing plate were prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

(Example 4)
In preparing the polymer composition, SGCNT (II) of Production Example 2-2 was used instead of SGCNT (I) of Production Example 2-1. Other than that, an aqueous dispersion of acid structure-containing polyurethane, an aqueous dispersion of carbon nanotubes, a polymer composition, a multilayer film, and a polarizing plate were prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

(Comparative Example 1)
In the preparation of the aqueous dispersion of carbon nanotubes, instead of SGCNT (I) of Production Example 2-1 single-walled carbon nanotubes (“HiPco®” manufactured by NanoIntegras Inc., BET specific surface area 790 m ² / g, G / D ratio: 11, ratio of single-walled carbon nanotubes: 100%, average diameter (Av): 1.1 nm, diameter distribution (3σ): 0.2 nm, 3σ / Av: 0.18) were used. Other than that, an aqueous dispersion of acid structure-containing polyurethane, an aqueous dispersion of carbon nanotubes, a polymer composition, a multilayer film, and a polarizing plate were prepared in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

(Comparative Example 2)
When preparing the aqueous dispersion of carbon nanotubes, instead of SGCNT (I) of Production Example 2-1 the multi-walled carbon nanotubes (“NC7000” manufactured by Nanocil, BET specific surface area: 260 m ² / g, G / D ratio: 0. 6.6, the ratio of single-walled carbon nanotubes: 0%, average diameter (Av): 9.3 nm, diameter distribution (3σ): 2.6 nm, 3σ / Av: 0.28) was used. Other than that, an aqueous dispersion of acid structure-containing polyurethane, an aqueous dispersion of carbon nanotubes, a polymer composition, a multilayer film, and a polarizing plate were prepared in the same manner as in Example 1, and various evaluations were performed. The surface resistance (conductivity) could not be measured because it exceeded the measurement upper limit of the high resistivity meter. The results other than conductivity are shown in Table 1.

From Table 1, a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and single-walled carbon nanotubes at a ratio of 50% or more are contained, the specific surface area is 1000 m ² / g or more, and the average is An easy-adhesion layer is formed on a base film using a polymer composition containing carbon nanotubes in which the diameter (Av) and the diameter distribution (3σ) satisfy the relational expression: 0.60> 3σ / Av> 0.20. In Examples 1 to 4 formed, it is possible to obtain a multi-walled film having excellent transparency and conductivity and a small amount of defects, and further, in a polarizing plate using the multi-walled film, the multi-walled film and a polarizer are obtained. It can be seen that can be adhered well.
On the other hand, in ^{Comparative Example 1 using carbon nanotubes having a specific surface area of less than 1000 m 2} / g and 3σ / Av of 0.20 or less, the conductivity of the obtained multi-walled film is lowered and the amount of defects is reduced. It can be seen that it increases.
On the other hand, in Comparative Example 2 using carbon nanotubes in which the ratio of the single-walled carbon nanotubes is less than 50% and the specific surface area is ^{less than 1000 m 2} / g, the transparency and conductivity of the obtained multi-walled film are lowered. It can also be seen that the amount of defects increases.

According to the present invention, it is possible to provide a multilayer film having excellent transparency and also excellent conductivity, and a method for producing the multilayer film.

Claims (7)

A multi-layer film including a base film and an easily adhesive layer provided on the base film.
The easy-adhesive layer comprises a cured product of a polymer composition containing a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and carbon nanotubes.
The carbon nanotubes contain single-walled carbon nanotubes at a ratio of 50% or more, have a specific surface area of 1000 m ² / g or more, and have an average diameter (Av) and a diameter distribution (3σ) relational expression: 0. A multi-walled film satisfying 60> 3σ / Av> 0.20. The multilayer film according to claim 1, wherein the crosslinkable polymer contains at least one selected from the group consisting of an acid structure-containing polyurethane, an acid structure-containing acrylic polymer, and an acid structure-containing polyester. The multilayer film according to claim 1 or 2, wherein the base film contains at least one of an alicyclic structure-containing polymer and an acrylic polymer. The multilayer film according to any one of claims 1 to 3, wherein the polymer composition contains the carbon nanotubes of 0.1 part by mass or more and 5.0 parts by mass or less per 100 parts by mass of the crosslinkable polymer. .. The base film contains a crosslinkable polymer, a crosslinking agent capable of crosslinking the crosslinkable polymer, and single-walled carbon nanotubes at a ratio of 50% or ^{more, and has a specific surface area of 1000 m 2} / g or more. Then, a step of supplying a polymer composition containing carbon nanotubes in which the average diameter (Av) and the diameter distribution (3σ) satisfy the relational expression: 0.60> 3σ / Av> 0.20, and
A step of curing the polymer composition supplied on the base film and
A method for producing a multi-layer film, including. Prior to the step of supplying the polymer composition onto the base film,
The step of preparing the polymer composition by mixing the crosslinkable polymer and the aqueous dispersion containing water, the aqueous dispersion containing the carbon nanotubes, the dispersant, and water, and the crosslinker. The method for producing a multilayer film according to claim 5. The method for producing a multilayer film according to claim 6, wherein the dispersant contains an anionic surfactant.