TWI643745B - Laminated film and manufacturing method thereof - Google Patents

Abstract

The present invention provides a laminated film and a method for manufacturing the same. The laminated film has excellent adhesiveness and alkali-resistant adhesiveness between a resin layer system and a thermoplastic resin film, and is particularly suitable for coatings containing CNTs and dispersants dispersed in an aqueous solvent. In the case of a CNT dispersion, the CNT dispersion can be uniformly applied.

The present invention includes the following configurations. That is, a laminated film is provided on at least one side of a thermoplastic resin film with a resin layer (X) formed of a coating composition containing inorganic particles (A) and a polyester resin (B) having a hydrophilic functional group. The laminated film, wherein the content of the inorganic particles (A) in the coating composition is 50% to 90% by mass based on the total amount of the coating composition, and the content of the polyester resin (B) having a hydrophilic functional group is relative to the coating The composition is all 10% by mass to 50% by mass, and satisfies the following (1) to (4).

(1) The surface roughness Ra (centerline average roughness) of the resin layer (X) is 5.0 nm or more and 30.0 nm or less.

(2) The average primary particle diameter of the inorganic particles (A) is 15 nm to 80 nm.

(3) The water contact angle of the resin layer (X) is 75 ° or less.

(4) The haze of the laminated film is 3.0% or less.

Description

Laminated film and manufacturing method thereof

The present invention relates to a laminated film having a resin layer laminated on a thermoplastic resin film, especially on a polyester film, and a method for manufacturing the same. More specifically, it relates to a laminate of a resin layer having excellent adhesion to a thermoplastic resin film, moisture and heat resistance, and alkali resistance, and exhibiting excellent coating properties when coating a carbon nanotube (CNT) dispersion. Thin film and its manufacturing method.

In recent years, due to the popularity of touch panels, the use of metals such as indium tin oxide (ITO), silver, or CNTs with conductive functions has been actively developed. Among them, since CNTs are stable to heat or chemicals, and can be dispersed in water or various solvents by using a dispersant, they are actively being studied as coating materials. In order to utilize the characteristics of CNTs through coating, it is necessary to form a conductive network using CNTs on a substrate. Therefore, excellent coatability is not required in the case where coating cissing and uneven coating of a coating solution (CNT dispersion) containing CNTs are not generated on a substrate. In addition, in terms of characteristics required for a conductive film, it is necessary to have adhesiveness between a thermoplastic resin film as a base material and a conductive layer and moisture and heat resistance. Therefore, in order to produce a thin film having excellent conductivity due to CNTs, it is necessary to have an undercoat layer that is superior in coating properties to a CNT dispersion and excellent in adhesion to a thermoplastic resin film. For example, Patent Document 1 describes A method for manufacturing a conductive film capable of achieving both coatability and conductivity by applying a CNT dispersion liquid containing CNT and a surfactant to a film, and washing and removing the remaining dispersant with water. In addition, Patent Document 2 describes a transparent substrate with a transparent antistatic film, which is composed of a conductive silica particle and an adhesive resin, and further includes colloidal silica. Furthermore, Patent Documents 3 and 4 describe a porous film containing a large number of inorganic particles. Patent Document 5 describes a biaxially stretched polyester film laminated with an antireflection layer containing an inorganic component and an organic component.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-149516

[Patent Document 2] Japanese Patent Laid-Open No. 2009-203282

[Patent Document 3] Japanese Patent Application Publication No. 2012-167181

[Patent Document 4] Japanese Patent Laid-Open No. 2013-136216

[Patent Document 5] Japanese Patent Laid-Open No. 2012-153057

However, Patent Literature 1 does not describe the heat-resistant stability and the moisture-heat resistant stability. Furthermore, the step of rinsing with water has a large impact on the environment and may become a major obstacle to mass productivity. In Patent Document 2, since the conductive fine particles, the adhesive resin, and the colloidal silica are contained in the same film, there is no description about the coatability of the conductive coating. Patent Documents 3 and 4 disclose a porous membrane containing a large amount of inorganic particles . However, although there is a related disclosure of the reflection characteristics and a disclosure of a porous film for a dye-sensitized solar cell adjacent to the conductive layer, there is no disclosure that if the coating property and adhesiveness to the adjacent conductive layer occur, influences. Furthermore, even in Patent Document 5, although an anti-reflection layer including an inorganic component and an organic component is described, it is produced by vapor deposition or CVD, and there is no description about the coating property of the conductive layer.

The present invention relates to a laminated film having a resin layer having excellent adhesiveness with a thermoplastic resin film, moisture and heat resistance, and alkali resistance. In particular, the present invention relates to a laminated film having a resin layer having excellent uniform coating properties when a CNT dispersion dispersed in an aqueous solvent is applied.

The present invention includes the following configurations. That is, 1. A laminated film comprising, on at least one side of a thermoplastic resin film, a resin layer (X) formed of a coating composition containing inorganic particles (A) and a polyester resin (B) having a hydrophilic functional group. ), Wherein the content of the inorganic particles (A) in the coating composition is 50% by mass or more and 90% by mass or less based on the total amount of the coating composition, and the content of the polyester resin (B) having a hydrophilic functional group is relatively All coating compositions are 10% by mass to 50% by mass, and satisfy the following (1) to (4): (1) Surface roughness Ra (centerline average roughness) of the resin layer (X) is 5.0 Above nm and below 30.0 nm; (2) The average primary particle diameter of the inorganic particles (A) is above 15 nm and below 80 nm; (3) The water contact angle of the resin layer (X) is below 75 °; (4) The haze of the laminated film is 3.0% or less; 2. The laminated film according to 1., wherein the surface potential of the resin layer (X) is greater than or equal to -50 mV and lower than or equal to -10 mV; 3. Such as 1. or 2 The laminated film according to claim 1, wherein the inorganic particle (A) has a hydroxyl-containing acrylic resin (D) on its surface; 4. The laminated film according to any one of 1. to 3., wherein the inorganic particle (A) is Colloidal silica; 5. The laminated film according to any one of 1. to 4, wherein the coating composition contains sugar alcohol (C), and its content is 5 mass% or more and 20 mass% or less relative to the coating composition; 6. The laminated film according to any one of 1. to 5, wherein the polyester resin (B) having a hydrophilic functional group is formed by polymerizing the polyester resin (B) with a hydrophilic functional group. The raw materials of the ester resin are all 1 to 25 mol% of a dicarboxylic acid having a sulfonate group and an ester-forming derivative thereof, and / or a polycarboxylic acid having 3 or more carboxylate groups, and A polyester resin produced from a raw material of an ester-forming derivative thereof; 7. The laminated film according to any one of 1. to 6., which is used as a primer film for conductive coating; 8. A method for manufacturing a laminated film, which is a method for manufacturing a laminated film in which a resin layer (X) is provided on at least one side of a thermoplastic resin film and satisfies the following conditions (1) to (4), which comprises the following steps: After coating a coating composition on at least one side of a thermoplastic resin film, a resin layer (X) is formed by heating and stretching. The coating composition contains inorganic particles (A) and a polyester resin having a hydrophilic functional group ( B), wherein the content of the inorganic particles (A) in the coating composition is all relative to the coating composition 50% by mass or more and 90% by mass or less, the content of the polyester resin (B) having a hydrophilic functional group is 10% by mass or more and 50% by mass or less based on the entire coating composition, (1) the surface of the resin layer (X) is rough Degree Ra (centerline average roughness) is 5.0 nm to 30.0 nm; (2) The average primary particle diameter of the inorganic particles (A) is 15 nm to 80 nm; (3) The water contact angle of the resin layer (X) is 75 ° or less; (4) The haze of the laminated film is 3.0% or less; 9. The manufacturing method of the laminated film according to 8., wherein the surface potential of the resin layer (X) is more than -50mV and less than -10mV; 10. The method for producing a laminated film according to 8. or 9, wherein the inorganic particles (A) have a hydroxyl-containing acrylic resin (D) on the surface; 11. The method according to any one of 8. to 10. The method for producing a laminated film, wherein the coating composition contains sugar alcohol (C), and its content is 5 mass% or more and 20 mass% or less based on the coating composition.

The laminated film of the present invention relates to a laminated film having a resin layer having excellent adhesion to a thermoplastic resin film, and particularly when coating a CNT dispersion dispersed in an aqueous solvent, exhibiting excellent coatability.

[Form of Implementing Invention]

Hereinafter, the laminated film which has the resin layer (X) formed from the coating composition containing the inorganic particle (A) and the polyester resin (B) which has a hydrophilic functional group in this invention is demonstrated in detail.

(1) Resin layer (X) and laminated film

The surface roughness Ra (centerline average roughness) of the resin layer (X) of the present invention needs to be 5.0 nm or more and 30.0 nm or less. When the surface roughness Ra (centerline average roughness) is 5.0 nm or more, a resin formed from a coating composition containing inorganic particles (A) and a polyester resin (B) having a hydrophilic functional group can be used. Since the surface area of the layer (X) becomes large, when the CNT dispersion described later is applied, the wet spreading area can be increased to exhibit uniform coatability. In addition, when the surface roughness Ra (center line average roughness) of the resin layer (X) is 5.0 nm or more, a CNT dispersant can be adsorbed between the spaces between the inorganic particles (A) to exhibit good coatability. On the other hand, by setting the surface roughness Ra (center line average roughness) of the resin layer (X) to 30.0 nm or less, the resin layer (X) can be maintained uniformly without peeling off when coating the CNT dispersion. Coating properties. On the other hand, when the surface roughness Ra (average roughness of the center line) of the resin layer (X) is greater than 30.0 nm, the resin layer (X) will be peeled off when the CNT dispersion is applied, and the transparency of the film will be deteriorated. The haze of the laminated film will deteriorate (increase).

In addition, the water contact angle of the resin layer (X) of the present invention needs to be 75 ° or less. When the water contact angle of the resin layer (X) is 75 ° or less, when the CNT dispersion described later is coated on the resin layer (X), the resin layer (X) can synthesize the surface roughness Ra (centerline average roughness). As a result, the CNT dispersion is uniformly coated without occurrence of coating cissing and uneven coating. The resin layer (X) has a small water contact angle (close to 0 °), although it can be suppressed In the case of coating cissing and uneven coating, the water contact angle of the resin layer (X) is preferably greater than 25 ° for the following reasons. When the water contact angle of the resin layer (X) is more than 25 °, for example, even under high temperature and high humidity such as 60 ° C and 90% RH, the swelling of the resin layer (X) and the moisture-heat resistance due to moisture absorption can be suppressed reduce. In addition, even in the evaluation of the alkali resistance adhesion, it is possible to suppress the penetration of the lye to the resin layer (X) and to suppress the decrease in adhesion. The water contact angle of the resin layer (X) is more preferably from 50 ° to 70 °. The water contact angle of the resin layer (X) becomes smaller when the content of the inorganic particles (A) in the coating composition forming the resin layer (X) is increased to increase the surface area of the resin layer (X). In addition, as the copolymerization amount of the hydrophilic functional group contained in the polyester resin (B) having a hydrophilic functional group increases, it decreases. Therefore, the water contact angle of the resin layer (X) depends on the content of the inorganic particles (A), the copolymerization amount of the hydrophilic functional groups contained in the polyester resin (B) having a hydrophilic functional group, and the hydrophilic functions. Base type, and adjust appropriately.

Moreover, the haze of the laminated film of the present invention needs to be 3.0% or less. The resin layer (X) of the present invention is formed of a coating composition containing an extremely large amount of inorganic particles (A) in an amount of 50 to 90% by mass based on the entire coating composition. When the inorganic particles (A) in the resin layer (X) agglomerate or the resin layer (X) is unevenly coated or cracked, the transparency of the film is deteriorated (haze increases). In addition, when the inorganic particles (A) in the resin layer (X) are aggregated or coating unevenness or cracking occurs in the resin layer (X), good coatability cannot be exhibited. Therefore, by setting the haze of the laminated film to 3.0% or less, the above-mentioned effects of the present invention can be exhibited in the resin layer (X). In addition, when the haze of the laminated film is 3.0% or less, when it is used as a primer film for conductive coating, it can be applied to applications requiring transparency such as a touch panel and electronic paper.

The conductive coating in the present invention refers to a conductive paint containing a conductive material such as CNT, a dispersant, and a solvent on a substrate such as a film. When the obtained conductive coating substrate is, for example, a thin film, it can be used as a conductive film and used as an electrode of a touch panel or electronic paper as described above. The characteristics required for a conductive film include: conductivity, transparency, adhesion between a film as a substrate and a conductive layer, and moisture and heat resistance. In the present invention, the undercoat film for conductive coating refers to a base film on which a conductive paint is applied in order to obtain a conductive film. As the characteristics required for the base coating film for conductive coating, the adhesion between the thermoplastic resin film and the resin layer as the base material, the resistance to moisture and heat, the control of water contact angle, and low haze are required. In addition, when a conductive film is subjected to an etching process, an undercoat film for conductive coating is required to have alkali resistance.

In addition, the coatability of a conductive paint is also required in the base coating film for conductive coating. For example, when a conductive coating is coated on the surface of a general thermoplastic resin film (such as a polyethylene terephthalate film), the conductive coating may be cracked or unevenly coated on the thermoplastic resin film. When the conductive paint cannot be applied uniformly, the conductivity of the conductive coating layer is reduced. In addition, although the purpose of dispersing conductive materials such as CNTs in coating materials is to include dispersants in conductive coating materials, dispersants are usually insulating materials. Therefore, when conductive coating materials are not uniformly coated, The conductivity of the conductive coating layer may be reduced. The laminated film of the present invention has a resin layer (X) having excellent coatability on a thermoplastic resin film, which can suppress cracking of the conductive paint and uneven coating, and form a uniform conductive coating layer. Therefore, the laminated film of the present invention satisfies the above-mentioned conductivity Characteristics required for primer coatings for adhesive coatings. Therefore, the laminated film of the present invention can be suitably used as a primer film for conductive coating.

Furthermore, it is preferable that the resin layer (X) of the laminated film of the present invention has a surface solar potential of -50 mV or more and -10 mV or less. When the surface potential of the resin layer (X) is lower than -10 mV, the surface of the resin layer (X) can be made polar, and the cracking and uneven application of the conductive paint can be suppressed to form a uniform conductive coating layer. On the other hand, when the surface sunk potential is equal to or greater than -50 mV, adhesion to the thermoplastic resin film as a substrate and the resin layer (X) and moisture-heat resistance can be imparted.

The method for adjusting the surface potential of the resin layer (X) to be -50 mV or more and -10 mV or less is not particularly limited. Methods for adjusting the surface potential of the surface include, for example, performing a corona treatment, a plasma treatment, a discharge treatment, a physical treatment such as a flame treatment, and a chemical treatment such as an acid treatment or an alkali treatment on the resin layer (X). Introducing an anionic functional group such as a carboxyl group or a hydroxyl group on the surface of the resin layer (X); or using inorganic particles (AD) having a hydroxyl group-containing acrylic resin (D) described later on part or all of the surface as the resin layer ( X) Inorganic particles (A) and the like. Method for using inorganic particles (AD) having a hydroxyl group-containing acrylic resin (D) described later on part or all of its surface as the inorganic particles (A) contained in the resin layer (X), and the resin layer (X The method of performing a discharge treatment such as a corona treatment and a plasma treatment is preferred because it is easy to adjust the surface solar potential to -50mV or more and -10mV or less.

(2) Inorganic particles (A)

The laminated film of the present invention is contained in the coating composition forming the resin layer (X), and must contain 50% by mass or more of the entire coating composition. 90% by mass or less of inorganic particles (A). The so-called inorganic particles in the present invention are particles composed of a compound having a covalent bond among compounds other than organic compounds and having a molecule containing two or more kinds of atoms as the smallest unit. Therefore, in the present invention, the metal oxide particles are included in the inorganic particles, but the metal particles are not included. By including the inorganic particles (A) in the above-mentioned range in the coating composition forming the resin layer (X), the resin layer (X) can obtain good coatability. The composition of the inorganic particles (A) usable in the present invention includes, for example, silica, colloidal silica, alumina, cerium oxide, kaolin, talc, mica, calcium carbonate, barium sulfate, carbon black, zeolite, and oxidation. Fine particles of titanium and various metal oxides are preferred. In particular, from the viewpoint of dispersibility to the polyester resin (B) having a hydrophilic functional group, particle hardness, heat resistance, and alkali resistance, inorganic colloid particles are preferred, and colloidal silica is particularly preferred. . Furthermore, it is preferable that an -SiOH group or -OH- ion is present on the surface of colloidal silicon oxide, and an electric double layer is formed in a negatively charged state. For example, the "SNOWTEX (registered trademark)" series made by Nissan Chemical Industry Co., Ltd. and the "Cataloid (registered trademark)" series made by Nissan Chemical Industry Co., Ltd. are applicable. When the colloidal silica is used as the inorganic particles (A), the inorganic particles (A) can be well dispersed in the resin layer (X), and the surface roughness Ra of the resin layer (X) can be made 30.0 nm or less.

The average primary particle diameter of the inorganic particles (A) needs to be 15 nm to 80 nm. When the average primary particle diameter of the inorganic particles (A) is less than 15 nm, the surface of the resin layer (X) is too smooth, and when the CNT dispersion described later is applied, good coatability cannot be exhibited. In addition, if the average primary particle diameter of the inorganic particles (A) exceeds 80 nm, uneven coating or cracks may occur in the resin layer (X). As a result, the transparency and coating properties of the film are deteriorated. The average primary particle diameter in the present invention means a particle diameter obtained by a measurement method described later.

The content of the inorganic particles (A) in the coating composition of the present invention is required to be 50% by mass or more and 90% by mass or less with respect to the entire coating composition. When the content of the inorganic particles (A) is less than 50% by mass, the resin layer (X) cannot be satisfactorily coated with the CNT dispersion. This reason is inferred that if the content of the inorganic particles is small, as described above, when the CNT dispersion is coated on the resin layer (X), the CNT dispersant is adsorbed between the spaces between the inorganic particles (A). Dispersion becomes worse. On the other hand, when the content of the inorganic particles (A) exceeds 90% by mass, the film-forming property of the resin layer (X) cannot be maintained. It is preferably 70% by mass or more and 80% by mass or less. When the content of the inorganic particles (A) in the coating composition of the present invention is within the above range, adhesion to the resin layer (X) and the thermoplastic resin film, moisture and heat resistance, and alkali resistance can be imparted.

Further, it is more preferable that the inorganic particles (A) are inorganic particles (AD) having a part or all of the surface having a hydroxyl group-containing acrylic resin (D) described later. (Of course, the resin layer containing inorganic particles (AD) contains Inorganic particles (A) and acrylic resin (D)). When the resin layer (X) contains the inorganic particles (AD), when the resin layer is formed using the resin composition, aggregation of the inorganic particles (A) during drying can be suppressed, and transparency can be further improved. In addition, when the resin layer (X) contains the inorganic particles (AD), the surface potential of the resin layer (X) can be adjusted to be -50 mV or more and -10 mV or less, thereby preventing formation of cracks and uneven coating of the conductive paint. A uniform conductive coating layer, and the adhesiveness between the thermoplastic resin film as the base material and the conductive layer (X) and the wet heat resistance are improved.

Here, in the present invention, the inorganic particle (A) having the acrylic resin (D) on the surface means that the acrylic resin (D) is adsorbed / adhered to a part or the entire surface of the inorganic particle (A).

The method for producing the inorganic particles (AD) is not particularly limited, and examples thereof include a method of surface-treating the inorganic particles (A) with an acrylic resin (D). Specifically, the following methods (i) to (iv) are exemplified. method. Furthermore, in the present invention, the surface treatment refers to a treatment in which all or a part of the surface of the inorganic particles (A) is adsorbed / adhered to the acrylic resin (D).

(i) A method in which a mixture in which inorganic particles (A) and an acrylic resin (D) are mixed in advance is added to a solvent and dispersed.

(ii) A method in which inorganic particles (A) and acrylic resin (D) are sequentially added to a solvent and dispersed.

(iii) A method of dispersing the inorganic particles (A) and the acrylic resin (D) in a solvent in advance, and mixing the obtained dispersion.

(iv) A method of adding an acrylic resin (D) to the obtained dispersion after dispersing the inorganic particles (A) in a solvent.

The effect of the purpose can be obtained by any of these methods.

Moreover, the dispersing device can be used: dissolver, high-speed mixer, homogenizer, Mida, ball mill, roll mill, sand mill, paint agitator, SC mill, ring mill, pin mill, etc.

Further, the dispersion method uses the above-mentioned device to rotate the rotating shaft at a peripheral speed of 5 to 15 m / sec. The rotation time is 5 to 10 hours. When dispersing, it is more preferable to use dispersing beads such as glass beads from the viewpoint of improving dispersibility. The size of the beads is preferably 0.05 to 0.5 mm, more preferably 0.08 to 0.5 mm, and particularly preferably 0.08 to 0.2 mm.

The methods of mixing and stirring are shaking the container by hand, or using a magnetic stirrer or stirring blade to perform ultrasonic irradiation and vibration dispersion.

The presence or absence of adsorption or adhesion of the acrylic resin (D) on all or part of the surface of the inorganic particles (A) can be confirmed by the following analysis method. An object to be measured (for example, a resin composition containing inorganic particles (A)) is centrifuged in a Hitachi tabletop ultracentrifuge (manufactured by Hitachi Koki Co., Ltd .: CS150NX) (rotation speed: 3.000 rpm, separation time: 30 minutes) ), After the inorganic particles (A) (and the acrylic resin (D) adsorbed on the surface of the inorganic particles (A)) are allowed to settle, the supernatant is removed, and the precipitate is concentrated and dried. X-ray photoelectron spectroscopy (XPS) was used to analyze the concentrated and dried sediment to confirm whether the surface of the inorganic particles (A) had the acrylic resin (D). When the surface of the inorganic particles (A) is 100% by mass relative to the total of the inorganic particles (A), when the presence of the acrylic resin (D) is confirmed to be 1% by mass or more, the surface of the metal oxide particles (A) is considered to be adsorbed. / Those with acrylic resin (D) attached.

(3) Polyester resin with hydrophilic functional group (B)

In the present invention, the polyester resin (B) having a hydrophilic functional group means a polyester resin having a hydrophilic functional group on a terminal or side chain of the polyester resin. By using a polyester resin having a hydrophilic functional group, the hydrophilicity of the polyester resin can be improved, and the solubility or dispersibility to an aqueous solvent can be improved. Examples of the hydrophilic functional group include a sulfonate group and a carboxylate group. In order for the polyester resin (B) to contain a hydrophilic functional group, a dicarboxylic acid having a sulfonate group, a diol, and an ester-forming derivative thereof (a compound containing a sulfonate group), or Polycarboxylic acids and esters thereof Formable derivatives (compounds containing a trivalent or higher polycarboxylic acid salt group) and the like are used as raw materials for polyester resins.

The sulfonate-containing compound system can be used, for example, sulfophthalic acid, 5-sulfoisophthalic acid, 5-sodium sulfoisophthalic acid, 4-sulfoisophthalic acid, and alkali metal salts thereof. , Alkaline earth metal salts and ammonium salts, but not limited to these.

Examples of compounds containing trivalent or higher polycarboxylic acid salt groups include, for example, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tris Carboxylic acids, trimesic acid, 1,2,3,4-butanetetracarboxylic acid, 1,2,3,4-pentanetetracarboxylic acid and alkali metal salts, alkaline earth metal salts and ammonium salts thereof, But it is not limited to these.

The carboxylic acid component constituting the polyester resin may be an aromatic, aliphatic, or alicyclic dicarboxylic acid or a trivalent or higher polycarboxylic acid. As the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, phthalic acid, 2,5-dimethylphthalic acid, 5-sodium sulfoisophthalic acid, and 1,4-naphthalenedicarboxylic acid can be used. And such ester-forming derivatives.

The content of the polyester resin (B) having a hydrophilic functional group in the coating composition of the present invention is necessary to be 10% by mass or more and 50% by mass or less with respect to the entire coating composition. When the content of the polyester resin (B) having a hydrophilic functional group is less than 10% by mass, good CNT coating properties cannot be obtained. This reason is inferred that if the content of the polyester resin (B) is small, the film-forming property when the resin layer (X) containing a large amount of inorganic particles (A) is formed is reduced, and cracks occur not only in the resin layer (X). When the CNT dispersion is coated on the resin layer (X), the inorganic particles (A) are also peeled off and fall off from the resin layer (X). On the other hand, a polyester resin (B) having a hydrophilic functional group Even if it exceeds 50% by mass, the same good CNT coating properties cannot be obtained. This reasoning is inferred that if the content of the polyester resin (B) is too large, the content of the inorganic particles (A) in the resin layer (X) will be relatively reduced, and most of the inorganic particles (A) will be buried in the hydrophilic function. In the base polyester resin (B), the effect of the inorganic particles (A) as described above cannot be exhibited. The content of the polyester resin (B) having a hydrophilic functional group in the coating composition is preferably 15% by mass or more and 30% by mass or less. When the content of the inorganic particles (A) in the coating composition of the present invention is within the above range, adhesion to the resin layer (X) and the thermoplastic resin film, moisture and heat resistance, and alkali resistance can be imparted.

When the raw material components of the polyester resin constituting the polyester resin (B) containing a hydrophilic functional group are all 100 mol%, a sulfonic acid group or a trivalent or higher polycarboxylic acid group as a hydrophilic functional group is included. The compound is preferably 1 to 25 mole%. When the compound containing a sulfonate group or a trivalent or more polyvalent carboxylate group as a hydrophilic functional group is 1 mol% or more, hydrophilicity can be imparted not only to the polyester resin (B) containing a hydrophilic functional group. , And can be dissolved or dispersed in aqueous solvents. When the compound containing a sulfonate group or a trivalent or higher polyvalent carboxylate group as a hydrophilic functional group is 25 mol% or less, the polyester resin (B) containing the hydrophilic functional group can be stably used. Manufactured by copolymerization.

Polyester resin diol components can be used: ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butane Alcohol and neopentyl glycol.

The polyester resin (B) having a hydrophilic functional group can be produced, for example, as follows. For example, it can be produced by a method of converting a dicarboxylic acid component and a diol component to a polycarboxylic acid group containing a sulfonate group or a trivalent or more polyvalent carboxylate group. A method in which the compound is produced by a polycondensation reaction after the first step of the esterification reaction or transesterification reaction; or the first step of the esterification reaction or transesterification reaction of a dicarboxylic acid component and a diol component After the step, a method of adding a compound containing a sulfonate group or a trivalent or higher polyvalent carboxylate group, and a method for producing the polycondensation reaction with the reaction product in the first step, and the like are performed. In this case, the reaction catalyst system may be, for example, an alkali metal, an alkaline earth metal, manganese, cobalt, zinc, antimony, germanium, or a titanium compound.

The polyester resin (B) having a hydrophilic functional group obtained by the above-mentioned production method is dispersed or dissolved in a solvent to form a coating composition. Examples of the method of dispersing or dissolving in an aqueous solvent include a method of dissolving or dispersing the polyester resin (B) in an aqueous solution of an alkaline compound such as ammonia, sodium hydroxide, potassium hydroxide, and various amines while stirring. . In this case, a water-soluble organic solvent such as methanol, ethanol, isopropanol, butylcellulose, and ethylcellulose can be used in combination.

(4) Sugar alcohol (C)

The sugar in the present invention is a general term for a carbohydrate having a carbon atom of 3 or more as shown by the molecular formula C _m H _n O _p (m, n, p is an integer of 3 or more, and n is a multiple of p). Those with carbonyl groups such as aldehyde or ketone. The sugar alcohol (C) in the present invention is an alcohol having one or more hydroxyl groups obtained by reducing the carbonyl group of the sugar molecule shown above. Furthermore, in a sugar molecule having two or more carbonyl groups, at least one carbonyl group is reduced, and as long as it has one or more hydroxyl groups, even if other carbonyl groups are not reduced and remain, it is equivalent to the sugar alcohol in the present invention.

The sugar alcohol (C) usable in the present invention is not particularly limited to a chain structure or a cyclic structure, but the one having a boiling point of a monomer of 170 ° C or higher Better. By using a monomer having a boiling point of 170 ° C or higher, the film forming property of the resin layer (X) can be improved during the process of forming the resin layer (X) on the laminated film, the occurrence of cracks can be suppressed, and the increase in the haze value can be suppressed. . In particular, in the following line coating method, when the resin layer (X) is formed, if a sugar alcohol having a boiling point of 170 ° C or higher is used, the film-forming property of the resin layer (X) is improved, and the occurrence of cracks is greatly suppressed. . The in-line coating method is a method in which coating is performed in a step of manufacturing a thermoplastic resin film. After the coating composition is applied to a thermoplastic resin film, when the thermoplastic resin film is uniaxially or biaxially stretched, fluidity can be imparted to the coating composition. Therefore, when stretched, the film forming property of the resin layer (X) is increased. Raise and greatly suppress the occurrence of cracks. However, in the in-line coating method, after the coating composition is applied to the thermoplastic resin film, the stretching step and the heat treatment step are performed at a high temperature. When the boiling point of the sugar alcohol (C) is low, the sugar alcohol (C) evaporates during the stretching step and the heat treatment step, and the smoothness of the resin layer (X) is deteriorated, or the sugar alcohol (X) in the resin layer (X) is deteriorated. C) When the content is reduced. By setting the boiling point of the sugar alcohol (C) within the above range, it is possible to stably exist in the resin layer (X) not only when the solvent of the coating composition is dried, but also when the heat treatment is performed when the crystalline orientation of the thermoplastic resin film is completed. The water contact angle after the resin layer (X) is formed is set to 75 ° or less. Specific examples of the sugar alcohol (C) include glycerol, butaerythritol, threitol, arabinitol, xylitol, ribitol, iditol, galactitol, glucositol, and mannose. Alcohol, heptyl alcohol, perseitol, and inositol. These may be used singly or as a mixture of two or more. Among these, glycerol, xylitol, glucosyl alcohol, mannitol, and butaerythritol are preferable because they are easily obtained industrially.

The content of sugar alcohol (C) in the coating composition of the present invention It is preferable that 100% by mass of the coating composition be 5 to 20% by mass. When the content of the sugar alcohol (C) is 5 mass% or more, in the process of forming the resin layer (X) on the laminated film, not only the occurrence of cracking of the resin layer (X) and the rise of the haze value can be suppressed, but also the resin can be reduced. Layer (X) water contact angle. In addition, by setting the content of the sugar alcohol (C) to 20% by mass or less, it is possible to impart adhesiveness to the thermoplastic resin film and the resin layer (X) and moisture and heat resistance.

(5) Acrylic resin containing hydroxyl group (D)

The acrylic resin (D) having a hydroxyl group contained in the resin layer of the present invention is not particularly limited if a hydroxyl group is introduced into a side chain or a terminal of a general acrylic resin, but the resin layer (X) is formed by using a resin composition. The point that the aggregation of the inorganic particles (A) during the drying process is suppressed to improve the transparency, and that the water contact angle of the resin layer (X) is 75 ° C. or lower are particularly preferable for the structure described later.

That is, a resin having a monomer unit (d1) represented by formula (1), a monomer unit (d2) represented by formula (2), and a monomer unit (d3) represented by formula (3) is preferred. .

(In the formula (1), the R ₁ group represents a hydroxyl group, a hydrogen atom, or a methyl group, and n represents an integer of 9 to 34.)

(In formula (2), the R ₂ group represents a hydroxyl group, a hydrogen atom, or a methyl group. And the R ₄ group represents a group containing two or more saturated carbocyclic rings.)

(In the formula (3), the R ₃ group represents a hydroxyl group, a hydrogen atom, or a methyl group. Also, the R ₅ group represents a hydroxyl group, a carboxyl group, a tertiary amine group, a quaternary ammonium salt group, a sulfonic acid group, or a phosphate group.)

Here, the acrylic resin (D) in the present invention is preferably a resin having a monomer unit (d1) represented by the formula (1).

When an acrylic resin having a monomer unit of n and less than 9 in the formula (1) is used, the dispersibility of the inorganic particles (A) in an aqueous solvent (the explanation of the aqueous solvent is described later) becomes unstable. As described later, in the present invention, a resin composition containing at least inorganic particles (A), a polyester resin (B) having a hydrophilic functional group, and an aqueous solvent is applied to a polyester film as a substrate, and It is preferable to dry it to form a resin layer. Therefore, if an acrylic tree having monomer units in which n in the formula (1) is less than 9 is used In the case of grease, the inorganic particles (A) may aggregate or settle in the resin composition, or the inorganic particles (A) may aggregate during the drying step. As a result, there may be a case where a laminated film with good transparency cannot be obtained, or the adhesion of CNTs may be deteriorated. On the other hand, since an acrylic resin having a monomer unit in which n in Formula (1) exceeds 34 has a significantly low solubility in an aqueous solvent, it is easy to cause aggregation of the acrylic resin in the aqueous solvent. Since the aggregate is larger than the wavelength of visible light, there is a case where a multilayer film having good transparency or coating properties of CNTs may be deteriorated.

In order that the acrylic resin (D) in the present invention has a monomer unit (d1) represented by the formula (1), the (meth) acrylate monomer (d1 ') represented by the following formula (4) is used as It is preferred that the raw materials are used and polymerized.

The (meth) acrylic acid ester monomer (d1 ′) is preferably a (meth) acrylic acid ester monomer represented by an integer of 9 to 34 in formula (4), and an integer of 11 to 32 The (meth) acrylate monomer shown is more preferable, and the (meth) acrylate monomer shown by the integer of 13-30 is more preferable.

The (meth) acrylic acid ester monomer (d1 ') is not particularly limited as long as it is a (meth) acrylic acid ester monomer in which n in the formula (4) is 9 or more and 34 or less. Specific examples include: Decyl acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, 1-methyltridecyl (meth) acrylate, Hexadecyl (meth) acrylate , Octadecyl (meth) acrylate, eicosyl (meth) acrylate, behenyl (meth) acrylate, tetracosyl (meth) acrylate, thirty Alkyl esters and the like are particularly preferably dodecyl (meth) acrylate and tridecyl (meth) acrylate. These may be used singly or as a mixture of two or more.

The acrylic resin (D) in the present invention is preferably a resin having a monomer unit (d2) represented by the above formula (2).

In formula (2), if an acrylic resin having a monomer unit containing only one saturated carbon ring is used, the function as teric hindrance is insufficient, and inorganic particles (A) are present in the resin composition. Agglomeration or sedimentation, or agglomeration of the inorganic particles (A) in the drying step.

Since this aggregate is larger than the wavelength of visible light, the coating property and adhesiveness of a laminated film or CNT with good transparency may not be obtained.

In order that the acrylic resin (D) in the present invention has a monomer unit (d2) represented by the formula (2), the (meth) acrylic acid ester monomer (d2 ') represented by the following formula (5) is used The raw materials are preferably used and polymerized.

Examples of the (meth) acrylic acid ester monomer (d2 ') represented by the formula (5) include a cross-linked condensation ring structure (a structure in which two or more rings each share two atoms and are bonded), Spiral compounds (having a structure that shares one carbon atom and two cyclic structures are combined) and other cyclic structures, specifically, compounds with bicyclic, tricyclic, and tetracyclic compounds, among which From the viewpoint of compatibility with the binder, a (meth) acrylate containing a bicyclic group is preferred.

Examples of the bicyclic group-containing (meth) acrylic acid esters include isopropyl (meth) acrylate, ethyl (meth) acrylate, dicyclopentyl (meth) acrylate, and dicyclo (meth) acrylate. Pentene ester, adamantane (meth) acrylate, dimethyladamantyl (meth) acrylate, and the like are particularly preferably isoamyl (meth) acrylate.

The acrylic resin (D) in the present invention is preferably a resin having a monomer (d3) represented by the formula (3).

For example, when an acrylic resin having a monomer unit of any of the R ₅ group in formula (3) without a hydroxyl group, a carboxyl group, a tertiary amine group, a quaternary ammonium group, a sulfonic acid group, or a phosphate group is used, the acrylic resin and The compatibility of the aqueous solvent may be insufficient. In the resin composition, an acrylic resin may be precipitated, or the inorganic particles (A) may be aggregated or settled, or the inorganic particles (A) may be aggregated during the drying step.

Since this aggregate is larger than the wavelength of visible light, the coating property and adhesiveness of a laminated film or CNT with good transparency may not be obtained.

In order that the acrylic resin (D) in the present invention has a monomer unit (d3) represented by the following formula (6), it is a (meth) acrylate monomer (d3 ') represented by the following formula (6) ) Is preferably used as a raw material and polymerized.

The (meth) acrylate monomer (d3 ') represented by the formula (6) is exemplified by the following compounds.

Examples of the (meth) acrylate monosystem having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2,3-dihydroxybutyl (meth) acrylate. Esters, 4-hydroxybutyl (meth) acrylate, poly (ethylene) glycol mono (meth) acrylate, etc., and monoesters of (meth) acrylic acid; or the monoesters and ε-caprolactone Among the compounds subjected to ring-opening polymerization, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are particularly preferred.

Mono- (meth) acrylic acid ester systems having a carboxyl group can be exemplified by α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid, or (meth) Semi-esterified products of hydroxyalkyl acrylate and acid anhydride are particularly preferred, such as acrylic acid and methacrylic acid.

Examples of single systems containing tertiary amino groups include: N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N N, N-Dialkylaminoalkyl (meth) acrylate such as, N-dimethylaminopropyl (meth) acrylate; N, N-dimethylaminoethyl (methyl) ) N, N-dioxane of acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, etc. Aminoaminoalkyl (meth) acrylamide and the like are particularly preferably N, N-dimethylaminoethyl (meth) acrylate.

The single system containing a quaternary ammonium group is preferably a quaternizing agent such as epihalohydrin, halotoluene, haloalkane, etc., in the above-mentioned tertiary amine group-containing monomer. Specific examples include: 2- (Methacryloxy) ethyltrimethylammonium (Meth) acrylic acid chloride, chloride, 2- (methacryloxy) ethyltrimethylammonium bromide, 2- (methacryloxy) ethyltrimethylammonium dimethyl phosphate, etc. Oxyalkyltrialkylammonium salts; (meth) acrylfluorenyl groups of methacrylfluorenylaminopropyltrimethylammonium chloride, methacrylfluorenylaminopropyltrimethylammonium bromide, etc. Aminoalkyltrialkylammonium salts; tetraalkyl (meth) acrylates such as tetrabutylammonium (meth) acrylate; trialkylbenzylammoniums such as trimethylbenzylammonium (meth) acrylate ( Meth) acrylate and the like are particularly preferably 2- (methacryloxy) ethyltrimethylammonium chloride.

Examples of the sulfonic acid-containing single system include (meth) acrylamide-alkanesulfonic acid such as butylacrylamidesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, or the like, or 2 -A sulfoalkyl (meth) acrylate and the like, such as a sulfoethyl (meth) acrylate, and particularly preferably a 2-sulfoethyl (meth) acrylate.

Examples of the phosphoric acid group-containing acrylic single system include acidic (meth) acrylic acid phosphoroethoxyethyl and the like, and especially acidic (meth) acrylic acid phosphoroethoxyethyl is preferred.

(6) Thermoplastic resin film

The thermoplastic resin film used in the laminated film of the present invention is a film formed of a thermoplastic resin. It is a general name for a film which is melted or softened by heat, and is not particularly limited. Examples of thermoplastic resins include polyolefin resins such as polyester resins, polypropylene resins, and polyethylene films; acrylic resins such as polylactic acid resins, polycarbonate resins, polymethacrylate resins, or polystyrene resins. Polyamide resins such as nylon resins; polyvinyl chloride resins, polyurethane resins, fluorine-containing resins, polystyrene resins, etc. The thermoplastic resin used in the thermoplastic resin film can be a single polymer or It may be a copolymer. Also, plural resins can be used.

Representative examples of these thermoplastic resin films include polyolefin films such as polyester films, polypropylene films, and polyethylene films; polylactic acid films, polycarbonate films, polymethacrylate films, or polystyrene films, etc. Acrylic resins; polyamide films such as nylon; polyvinyl chloride films, polyurethane films, fluorine-containing films, and polyphenylene sulfide films.

Among these, polyester films, polypropylene films, and polyamide films are preferred from the viewpoints of mechanical characteristics, dimensional stability, and transparency, and also from the viewpoints of mechanical characteristics and versatility. Polyester film is particularly preferred.

Therefore, in the present invention, a polyester resin constituting a polyester film that is particularly suitable as a thermoplastic resin will be described in detail below.

First of all, polyester is a general term for a polymer that uses an ester bond as the main binding chain of the main chain. It can be selected from ethylene terephthalate, propylene terephthalate, and ethylene 2,6-naphthalate. Ester, Butyl terephthalate, Propylene 2,6-naphthalene dicarboxylate, and Ethyl-α, β-bis (2-chlorophenoxy) ethane-4,4'-dicarboxylic acid ester, etc. One of at least one of the constituents is the main constituent. These constituents may be used alone or in combination of two or more of them. However, it is particularly preferable to use ethylene terephthalate when judging the quality, economics, etc. among them. That is, in the present invention, the thermoplastic resin used in the thermoplastic resin film is preferably ethylene terephthalate. When heat or shrinkage stress is applied to the thermoplastic resin film, polyethylene 2,6-naphthalene dicarboxylate, which is excellent in heat resistance and rigidity, is particularly preferred. Such gathering The ester may further include a part of other dicarboxylic acid components and diol components, and it is preferable to include 20 mol% or less.

The limiting viscosity (measured in o-chlorophenol at 25 ° C) of the polyester resin forming the thermoplastic resin film of the laminated film of the present invention is preferably 0.4 to 1.2 dl / g, and more preferably 0.5 to 0.8 dl / g. Those within the scope are preferred embodiments of the present invention.

The polyester film using the above-mentioned polyester is preferably biaxially oriented. Biaxially oriented polyester film is generally stretched about 2.5 to 5 times each in the length direction and the width direction perpendicular to the length direction of an unstretched polyester sheet or film, and then heat-treated Those who have completed the crystal orientation show the biaxial orientation pattern by wide-angle X-ray diffraction. When the thermoplastic resin film does not have a biaxial orientation, the thermal stability of the conductive film, especially the dimensional stability, insufficient mechanical strength, or poor flatness are not good.

In addition, various additives such as antioxidants, heat-resistant stabilizers, weather-resistant stabilizers, ultraviolet absorbers, organic easy-lubricants, pigments, dyes, organic or Inorganic particles, fillers, antistatic agents and nucleating agents.

There is no particular limitation on the thickness of the thermoplastic resin film, and it is appropriately selected depending on the application and type, but from the viewpoint of mechanical strength and operability, it is generally preferably 10 to 500 μm, more preferably 38 to 250 μm, and most preferably 75 to 150 μm. good. In addition, the thermoplastic resin film may be a composite film using coextrusion, or a film in which the obtained film is bonded by various methods.

(7) Formation method of resin layer (X)

In the present invention, a coating composition containing the inorganic particles (A), a polyester resin (B) having a hydrophilic functional group, and additives and a solvent as necessary is coated on a thermoplastic resin film, and the solvent is dried as necessary. Thus, a composition layer can be formed on a thermoplastic resin film. As the inorganic particles (A), it is preferable to use inorganic particles (AD) having an acrylic resin (D) in part or on the entire surface of the inorganic particles (A).

In the present invention, the solvent is preferably one using an aqueous solvent. This is because by using an aqueous solvent, rapid evaporation of the solvent in the drying step can be suppressed, and not only a uniform resin layer can be formed, but also excellent in terms of environmental burden.

Here, the aqueous solvent refers to water or alcohols such as methanol, ethanol, isopropanol, butanol; ketones such as acetone, methyl ethyl ketone, and the like; ethylene glycol, diethylene glycol, and propylene glycol Ethylene glycol and other organic solvents which are soluble in water are mixed in any ratio. This is because by using an aqueous solvent, rapid evaporation of the solvent in the drying step can be suppressed, and not only a uniform resin layer can be formed, but also excellent in terms of environmental burden.

The coating method of the coating composition on the thermoplastic resin film may be any of an on-line coating method and an off-line coating method, and an on-line coating method is preferred.

The line coating method refers to a method of coating in a step of manufacturing a thermoplastic resin film. Specifically, it refers to coating at any stage from melt-extrusion of a thermoplastic resin to heat treatment and winding after biaxial stretching. Generally, it is substantially obtained by quenching after melt-extrusion. Unstretched (unoriented) thermoplastic resin film (A Film), then uniaxially stretched (uniaxially oriented) thermoplastic resin film (B film) stretched in the lengthwise direction, or biaxially stretched (biaxially oriented) thermoplastic resin film ( C film).

In the present invention, it is preferable to apply a coating composition to any of the above-mentioned A film, B film, or C film of a thermoplastic resin film before the crystal orientation is completed, and then uniaxially or biaxially stretch the thermoplastic resin film. A method of performing a heat treatment at a temperature higher than the boiling point of a solvent to orient the crystal of the thermoplastic resin film and to provide a composition layer. According to this method, the film formation of the thermoplastic resin film and the coating and drying of the coating composition (that is, the formation of the composition layer) can be performed at the same time, which is advantageous to the manufacturing cost. In addition, it is easy to make the thickness of the resin layer thinner by stretching after coating.

Among them, a method in which a coating composition is applied to a film (B film) which is uniaxially stretched in the longitudinal direction and then stretched in the width direction to perform a heat treatment is excellent. This is because, compared with the method of applying biaxial stretching after coating an unstretched film, there is one less stretching step, so defects and cracks in the resin layer caused by stretching are less likely to occur, and transparency can be formed. And the reason for the smooth resin layer.

On the other hand, the off-line coating method refers to the step of forming a film with the film after uniaxial or biaxial stretching of the above-mentioned A film and performing heat treatment to complete the crystalline orientation of the thermoplastic resin film, or on the A film. Method for applying coating composition in different steps.

In view of the various advantages mentioned above, the resin layer in the present invention is preferably provided by an in-line coating method.

Therefore, the most preferable method for forming the resin layer in the present invention is a method in which an aqueous coating composition using an aqueous solvent is applied to a thermoplastic resin film by an in-line coating method and dried. The method of coating the coating composition on the B film after uniaxial stretching is preferred. The solid content concentration of the coating composition is preferably 5% by weight or less. By setting the solid content concentration to 5% by weight or less, good coating properties can be imparted to the coating composition, and a laminated film provided with a transparent and uniform resin layer (X) having a haze of 3.0% or less can be produced.

(8) Adjustment method of coating composition using aqueous solvent

A coating composition using an aqueous solvent can be obtained by mixing each of the substances (A), (B), (C), and (D) having water-dispersible or water-soluble properties with an aqueous solvent in any order and in a desired manner. The solid content weight ratio is prepared by mixing and stirring.

As described above, the content of the inorganic particles (A) in the coating composition is required to be 50% by mass or more and 90% by mass or less with respect to the resin composition. The mixing and stirring methods can be performed by manually shaking the container, or using a magnetic stirrer or a stirring paddle for ultrasonic irradiation and vibration dispersion.

To the extent that the characteristics of the resin layer (X) provided by the coating composition are not deteriorated, various additives such as a cross-linking agent, an easy lubricant, inorganic particles, organic particles, a surfactant, or an antioxidant may be added as necessary.

(9) Coating method

The coating method of the coating composition to the thermoplastic resin film can be a conventional coating method, such as a bar coating method, a reverse coating method, and a gravure Any method such as a coating method, a die coating method, and a doctor blade coating method.

(10) Manufacturing method of laminated film

Next, as for the manufacturing method of the laminated film of this invention, when using a polyethylene terephthalate (it abbreviates to PET below) as a thermoplastic resin film, it demonstrates as an example, Of course, it is not limited to this. First, the pellets of PET are sufficiently vacuum-dried, and then supplied to an extruder, and melt-extruded in a sheet shape at about 280 ° C. to be cooled and solidified to produce an unstretched (unoriented) PET film (A film). This film was stretched 2.5 to 5.0 times in the lengthwise direction by a roller heated to 80 to 120 ° C to obtain a uniaxially oriented PET film (B film). On one side of the B film, the coating composition of the present invention prepared to a predetermined concentration was applied. In this case, a surface treatment such as a corona discharge treatment may be performed on the coating surface of the PET film before coating. By performing a surface treatment such as corona discharge treatment, the coating composition can improve the wettability of the PET film, prevent cracking of the coating composition, and achieve a uniform coating thickness.

After coating, the end portion of the PET film was held with a clip and led to a heat treatment zone (preheating zone) at 80 to 130 ° C to dry the solvent of the coating composition. After drying, it is stretched 1.1 to 5.0 times in the width direction. Next, it leads to a heat treatment zone (heat-fixed zone) of 160 to 240 ° C, and performs a heat treatment for 1 to 30 seconds to complete the crystal orientation.

(Method for measuring characteristics and method for evaluating effects)

The measurement method of the characteristics of this invention and the evaluation method of an effect are as follows.

(1) Measurement of total light transmittance / haze

Prepare 3 (3) 5 cm square laminated film samples on each side. Then, the sample was left at 23 ° C and 50% relative humidity for 40 hours. Will each try A turbidimeter "NDH5000" manufactured by Nippon Denshoku Industries Co., Ltd. was used. The total light transmittance was measured in accordance with JIS "Test Method for Total Light Transmittance of Plastic Transparent Materials" (K7361-1, published in 1997). The method and the measurement of the haze are carried out in accordance with the method of JIS "Method for Obtaining the Haze of Transparent Materials". The values of the total light transmittance and haze of 3 points (3) were averaged, respectively, and the values of the total light transmittance and haze of the laminated film were made.

(2) Measurement of average primary particle diameter of inorganic particles (A)

First, the collodion glue (low nitrocellulose with a concentration of 2% by mass) was dropped into a pure water surface, and the collodion film spread on the water surface was adhered to a nickel 400 grid as a supporting film. Next, the inorganic particles dispersed in the solvent were dropped on a grid, and the solvent was dried to prepare a measurement sample. The obtained sample for measurement was observed at 10,000 to 1 million times using a TEM (transmission electron microscope: H7100FA type manufactured by Hitachi, Ltd.) to obtain a 10-point photograph of the entire inorganic particle. For the 10 points (10 pieces) of inorganic particles, the longest long side of each particle (diameter if it is a sphere) was read, and the measured values at 10 points were averaged to make the average primary particle diameter of the inorganic particles.

(3) Measurement of surface roughness Ra (center line average roughness) of the resin layer

First, the resin layer (X) of the laminated film was measured using a scanning probe microscope (Shimadzu, Japan, SPM9600). The cantilever system uses a non-contact mode high-resonance-frequency type probe (NANOSENSORS), model PPP-NCHR. The scanning speed is 0.5 Hz and the number of pixels is 512 × 512 in a field of 1 μm × 1 μm. Next, the obtained data was calculated and processed in accordance with JIS B0601 (2001) of the JIS standard to obtain a surface roughness Ra (centerline average roughness).

(4) Measurement of water contact angle of resin layer

First, the laminated film was left for 24 hours in an environment of a room temperature of 23 ° C and a relative humidity of 65%. Then, under the same environment, the contact angle of pure water with respect to the resin layer was measured by a contact angle meter CA-D type (manufactured by Kyowa Interface Science Co., Ltd.) at 5 points each. The maximum and minimum values of the measured values at 5 points are removed, and the average value of the measured values at the remaining 3 points is taken as the water contact angle of the resin layer.

(5) Adhesiveness assessment

On the resin layer (X) side of the laminated film, a 25 × 5 cut of 5 × 5 was made at a cutting interval of 2 mm in accordance with JIS 5600-5-6 (established in 1999). Next, on the part where the cut is marked, use 18mm CELLOTAPE (registered trademark) (product number: CT-18S) of NICHIBAN to make the cut visible, and wipe the CELLOTAPE (registered trademark) firmly with your fingers. Then, CELLOTAPE (registered trademark) was instantly torn away from the resin layer at an angle of about 60 °. Calculate the number of peeled meshes. In addition, even if only a part of the grid is peeled off, it is calculated as 1 grid. The number of evaluations was 5 times, and the average value was obtained. The evaluation criteria are as follows. The evaluation criteria "B" or more was judged as good adhesion.

A: The peeling number of the grid is 0 grid

B: The number of peelings of the grid exceeds 0 grid and 3 grids or less

C: The number of peelings of the grid exceeds 3 grids and 5 grids or less

D: The number of peeling of the grid exceeds 5 grids.

(6) Evaluation of moisture and heat resistance

In the same manner as in the above (5), the laminated film was left to stand in a constant temperature and humidity layer (LU-113 made by ESPEC (stock)) set at 60 ° C and 90% RH. Keep it for 10 days (240 hours). After 10 days had elapsed, the sample was taken out of the constant temperature and humidity layer, and allowed to stand for 1 hour in a normal state (23 ° C, relative humidity 50%). After standing still, the adhesiveness evaluation was performed in the same manner as in (5). The evaluation criteria were the same as (5), and the evaluation criteria "B" or more were judged as good adhesion.

A: The peeling number of the grid is 0 grid

B: The number of peelings of the grid exceeds 0 grid and 3 grids or less

C: The number of peelings of the grid exceeds 3 grids and 5 grids or less

D: The number of peeling of the grid exceeds 5 grids.

(7) Evaluation of CNT coating properties

The CNT dispersion system is prepared as follows. First, 0.1 mg of CNT (linear double-layer CNT: manufactured by Science Laboratories, diameter 5 nm) and sodium carboxymethyl cellulose (Sigma-Aldrich Japan (stock)) as a CNT dispersant (hereinafter referred to as CMC-Na) ) 0.25mg and 249.65mg of water were fed into a 50mL test tube to prepare a CNT dispersion, and an ultrasonic crusher (VCX-502 made by Tokyo Physico Chemical Industries, Ltd .; output 250W, direct irradiation) was irradiated for 30 minutes, A uniform CNT dispersion was obtained (CNT concentration 0.04% by mass, CNT dispersant 0.10% by mass, (B) / (A) = 2.5).

Next, the obtained CNT dispersion was applied using a rod, and applied to the resin layer (X) of the laminated film so that the coating thickness became 6 to 10 μm. Next, the laminated film sample coated with the CNT dispersion was dried in a hot air oven "HIGH-TEMP-OVEN PHH-200" made by ESPEC (stock) set at 100 ° C (air flow meter "7"), An evaluation sample was obtained.

The obtained laminated film samples were evaluated visually for the presence or absence of coating cracking, uneven coating, and the total light transmittance calculated from the three-point average value obtained in (1), and A4 size (210mm × 300mm) The laminated film samples were randomly measured for total light transmittance at 10 points and evaluated. The evaluation criterion was evaluated as "Good" CNT coating property.

A: The total light transmittance of any one of the 10 points measured at random is less than 0.7% of the average value of the 3 points obtained from (1).

B: The total light transmittance of any one of the 10 points measured at random is a difference of 0.7% or more and less than 1.0% with respect to the average of the 3 points obtained from (1).

C: The total light transmittance at any one of the 10 points measured at random has a difference of 1.0% or more from the average value of the 3 points obtained from (1).

D: Cracking of coating and uneven coating were clearly confirmed with the naked eye.

(8) Evaluation of alkali resistance

Five (5) 5 cm square laminated film samples were prepared. Next, each sample was immersed in a 3% by mass sodium hydroxide aqueous solution adjusted to 50 ° C. for 5 minutes. Then, the sample taken out from the sodium hydroxide aqueous solution was washed with running water for 5 minutes. After washing with water, it was left to dry in a normal state (23 ° C, relative humidity 50%) for 24 hours. After standing still, the adhesiveness was evaluated in the same manner as in (5). The evaluation criteria were the same as (5), and the evaluation criteria "B" or more were judged to be good alkali resistance.

A: The peeling number of the grid is 0 grid

B: The number of peelings of the grid exceeds 0 grid and 3 grids or less

C: The number of peelings of the grid exceeds 3 grids and 5 grids or less

D: The number of peeling of the grid exceeds 5 grids.

(8) Measurement of the surface potential of the resin layer (X)

First, a laminated film was sampled at a size of 3 cm × 1 cm suitable for measuring the size of a solid surface, and the measurement surface became the surface of the resin layer (X) of the laminated film. The sample was mounted on a solar potentiometer (Otsuka Electronics). (ELSZ-1000 manufactured by Co., Ltd., using a flat surface cell) and water as a solvent (temperature: 25 ° C, refractive index: 1.3328, viscosity: 0.8878 (cP), dielectric constant: 78.3) were measured three times. The three-time average of the values calculated from the Smoluchowski equation was used as the value of the sun potential.

[Example]

The present invention is further described in detail based on examples. However, the present invention is not limited to the following examples.

(Example 1)

The coating composition was adjusted as follows.

Inorganic particles (A1):

‧ Colloidal silicon oxide "SNOWTEX OL" (average primary particle size 45nm; manufactured by Nissan Chemical Industries, Ltd.)

Polyester resin (B) with hydrophilic functional group:

First, 50 parts by mass of terephthalic acid, 50 parts by mass of isophthalic acid, 50 parts by mass of ethylene glycol, and 30 parts by mass of neopentyl glycol, 0.3 parts by mass of antimony trioxide as a polymerization catalyst, and 0.3 parts by mass of zinc acetate Portions were added to the reactor flushed with nitrogen, and the polymerization reaction was performed at 190 to 220 ° C. under normal pressure for 12 hours while removing water to obtain a polyester diol. Next, 5 parts by mass of 5-sodium sulfoisophthalic acid and xylene as a solvent were added to the reactor in the obtained polyester diol, and the xylene was distilled off at 260 ° C under a reduced pressure of 0.2 mmHg. Polymerization was performed for 3 hours to obtain a hydrophilic functional group. Polyester resin (B). This polyester resin (B) was dissolved in an aqueous solvent containing ammonia and butyl cellulose.

Water-based solvent: pure water.

The above-mentioned (A1) and (B) are mixed so that the inorganic particles (A1) will be 50% by mass and the polyester resin (B) having a hydrophilic functional group will be 50% by mass with respect to the coating composition, and adjusted in pure water. The middle paint composition becomes paint 1 having a concentration of 1.5% by mass.

Next, PET granules (limiting viscosity 0.63 dl / g) containing substantially no particles were sufficiently vacuum-dried, then supplied to an extruder and melted at 285 ° C, extruded into a sheet shape by a T-shaped mouthpiece, and cast using static electricity. It is rolled into a mirror casting drum with a surface temperature of 25 ° C to cool and solidify. This unstretched film was heated to 90 ° C. and stretched 3.4 times in the longitudinal direction to prepare a uniaxially stretched film (B film). The film was subjected to a corona discharge treatment in the air.

Next, the coating material 1 was applied on the corona discharge-treated surface of the uniaxially stretched film using a coating bar. After coating both ends of the uniaxially stretched film in the width direction, hold it with a clip, lead it to the preheating zone, set the ambient temperature to 75 ° C, and then set the ambient temperature to 110 ° C using a radiant heater. Next, the ambient temperature was set at 90 ° C, and the coating composition was dried to form a composition layer. Next, it was continuously stretched 3.5 times in the width direction in a heating zone (stretching zone) at 120 ° C, and then a heat treatment was performed in a heat-treating zone (heat-fixing zone) at 230 ° C for 20 seconds to obtain a laminated film having a crystal orientation. In the obtained laminated film, the thickness of the PET film was 100 μm. The characteristics and the like of the obtained laminated film are shown in the table. It is excellent in transparency such as haze and total light transmittance, and is excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, and CNT coating property.

(Examples 2 to 4)

A laminated film was obtained in the same manner as in Example 1 except that the mass ratio of the inorganic particles (A) and the polyester resin (B) having a hydrophilic functional group in the coating composition was changed. The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Example 5)

Except that the inorganic particles (A) were changed to inorganic particles (A2): colloidal silica "SNOWTEX 50" (average primary particle diameter: 20 nm, manufactured by Nissan Chemical Co., Ltd.), a laminated layer was obtained in the same manner as in Example 2. film. The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Example 6)

Except that the inorganic particles (A) were changed to inorganic particles (A3): colloidal silica "Cataloid SI-80P" (average primary particle diameter of 80 nm, manufactured by Niwa Catalyst Co., Ltd.), it was the same as in Example 2. Method to obtain a laminated film. The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Examples 7 to 9)

In addition to the addition of D-glucositol (boiling point: 296 ° C, manufactured by Nacalai Tesque (Stock)) (C) as a sugar alcohol of the mass described in the table with respect to the coating composition as the inorganic particles (A) in the coating composition, Contains hydrophilic functions A laminated film was obtained in the same manner as in Example 2 except for the components other than the base polyester resin (B). The characteristics and the like of the obtained laminated film are shown in the table. Compared with Example 2, by adding D-glucosyl alcohol (C), although the surface roughness Ra and water contact angle of the resin layer (X) are low, the adhesiveness of the laminated film, moisture and heat resistance, and CNT coating property Each result of alkali resistance and alkali resistance was good.

(Example 10)

Except for the copolymerization of the polyester resin (B) having a hydrophilic functional group, 5-sodium sulfoisophthalic acid, which is a compound containing a sulfonic acid group having a hydrophilic functional group or a polycarboxylic acid group having a trivalent or higher value, is used. A laminated film was obtained in the same manner as in Example 2 except that the content was changed to 20 parts by mass. The characteristics and the like of the obtained laminated film are shown in the table. Compared with Example 2, the hydrophilicity of the polyester resin (B) having a hydrophilic functional group is improved, so the water contact angle is reduced, the adhesiveness of the laminated film, the heat and moisture resistance, the CNT coating property, and the alkali resistance are improved. Each result is good.

(Example 11)

Except changing the inorganic particles (A) to inorganic particles (A4): titanium oxide particles "NANOTEK" titanium oxide slurry (average primary particle diameter of 23 nm, manufactured by CI Chemical Co., Ltd.), the same method as in Example 2 was used, A laminated film was obtained. The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Example 12)

First, a general acrylic resin reaction tank equipped with a stirrer, a thermometer, and a reflux cooling pipe was fed with isopropyl alcohol 100 as a solvent. Parts, heated and stirred and maintained at 100 ° C.

At this time, 40 parts of undecyl methacrylate containing n = 19 as (meth) acrylate (d1 ') and two (meth) acrylate (d2') as drops were added dropwise over 3 hours. A mixture of 40 parts of cyclic isopropyl methacrylate and 20 parts of 2-hydroxyethyl acrylate as other (meth) acrylate (d3 ') having a hydroxyl group. Then, after the dropping was completed, the mixture was heated at 100 ° C. for 1 hour, and then an additional catalyst mixed solution containing 1 part of tert-butylperoxy-2-ethylhexanoate was fed. Then, it heated at 100 degreeC for 3 hours, and cooled, and obtained the acrylic resin (D). The structural formula of the obtained acrylic resin (D) is as follows. (However, the structural formula only indicates those having d1 ', d2', and d3 'in the chemical structure, and does not limit the order and value of each structural unit.)

‧Aqueous solvent: pure water.

‧Mixture of inorganic particles (A1D) and acrylic resin (D):

In an aqueous solvent, the inorganic particles (A1) and the acrylic resin (D) used in Example 1 were sequentially added and dispersed in the following manner to obtain a mixture of the inorganic particles (A1D) and the acrylic resin (D). (Method (ii) above). The addition ratio (mass ratio) of the inorganic particles (A1) to the acrylic resin (D) is (A1) / (D) = 45/10. The dispersion treatment was performed using a homogenizer, and was performed by rotating at a peripheral speed of 10 m / sec for 5 hours. And, in the finally obtained mixture, the mass ratio of the inorganic particles (A1D) to the acrylic resin (D) (A1D) / (D) = 45/10.

The obtained inorganic particles (A1D) were centrifuged in a Hitachi tabletop ultracentrifuge (Hitachi Koki Co., Ltd .: CS150NX) (rotation speed 3,000 rpm, separation time 30 minutes), and the inorganic particles (A1) (and adsorbed on After the acrylic resin (D) on the surface of the inorganic particles (A1) has settled, the supernatant liquid is removed, and the precipitate is concentrated to dryness. As a result of X-ray photoelectron spectroscopy (XPS) analysis of the concentrated and dried sediment, it was confirmed that the acrylic resin (D) was present on the surface of the inorganic particles (A1). That is, the acrylic resin (D) was adsorbed / adhered to the surface of the inorganic particle (A1), and the obtained inorganic particle (A1D) was found to be equivalent to a particle having the acrylic resin (D) on the surface of the inorganic particle (A1).

Next, a laminated film was obtained in the same manner as in Example 3 except that the inorganic particles (A) in the coating composition were changed to inorganic particles (A1D). The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Example 13)

First, inorganic particles (A2D) were prepared by the same method as in Example 12 using the inorganic particles (A2) and acrylic resin (D) described in Example 5.

Next, a laminated film was obtained in the same manner as in Example 5 except that the inorganic particles (A) in the coating composition were changed to inorganic particles (A2D). The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Example 14)

First, inorganic particles (A3D) were prepared by the same method as in Example 12 using the inorganic particles (A3) and acrylic resin (D) described in Example 6.

Next, a laminated film was obtained in the same manner as in Example 6 except that the inorganic particles (A) in the coating composition were changed to inorganic particles (A3D). The characteristics and the like of the obtained laminated film are shown in the table. Its haze and total light transmittance are excellent in transparency, and are excellent in adhesion to a thermoplastic resin film, moisture and heat resistance, CNT coating properties, and alkali resistance.

(Comparative Examples 1, 2)

A laminated film was obtained in the same manner as in Example 1 except that the mass ratio of the inorganic particles (A) and the polyester resin (B) having a hydrophilic functional group in the coating composition was changed. The characteristics and the like of the obtained laminated film are shown in the table. In Comparative Example 1, since the amount of the inorganic particles (A) was small, the surface area of the resin layer (X) did not increase, and the coatability of the CNT dispersion was not good. In addition, in Comparative Example 2, the amount of the polyester resin (B) having a hydrophilic functional group was small, and the adhesion to the thermoplastic resin film and the alkali resistance were not good.

(Comparative example 3)

Except that the inorganic particles (A) were changed to colloidal silica "SNOWTEX XS" (average primary particle diameter 6 nm, manufactured by Nissan Chemical Co., Ltd.) (particles: X1), a laminated layer was obtained in the same manner as in Example 2. film. The characteristics and the like of the obtained laminated film are shown in the table. As the inorganic particles (A) contained in the resin layer (X) increase, the haze becomes 3.0% or more, and the surface roughness Ra is also low. The coating properties and alkali resistance of CNT dispersion are also not good.

(Comparative Example 4)

Except that the inorganic particles (A) were changed to colloidal silica "Spherical Slurry 140" (average primary particle diameter of 140 nm, manufactured by Niwa Catalyst Co., Ltd.) (particles: X2), the same method as in Example 2 was used. To obtain a laminated film. The characteristics and the like of the obtained laminated film are shown in the table. Since the average primary particle diameter of the inorganic particles (A) contained in the resin layer (X) is increased, the haze becomes 3.0% or more. In addition, the polyester resin (B) having a hydrophilic functional group has insufficient fixation of the inorganic particles (A) to the thermoplastic resin film, and has poor moist-heat adhesion and alkali resistance.

(Comparative example 5)

A polyester resin containing no hydrophilic functional group is produced by the following method. First, 50 parts by mass of terephthalic acid, 50 parts by mass of isophthalic acid, 50 parts by mass of ethylene glycol, 30 parts by mass of neopentyl glycol, and 0.3 parts by mass of antimony trioxide as a polymerization catalyst and 0.3 parts of zinc acetate The mass parts were put together in a reactor flushed with nitrogen, and while water was removed, a polymerization reaction was performed at 190 to 220 ° C. under normal pressure for 12 hours to obtain a polyester diol. Next, xylene as a solvent was fed into the reactor, and at the same time, xylene was distilled off at 260 ° C under a reduced pressure of 0.2 mmHg, and polymerization was performed for 3 hours to obtain a polyester resin. This polyester resin was dissolved in an ethanol solvent containing butyl cellulose. Otherwise, the same method as in Example 2 was used to obtain a laminated film. In the table, the content of the polyester resin having no hydrophilic functional group is described in the column of the polyester resin (B). The properties and the like of the obtained laminated film are shown in the table. Since a polyester resin having no hydrophilic functional group is used, the water contact angle is increased, and the coating property of CNT is not good.

(Comparative Example 6)

Except that the inorganic particles (A) were changed to styrene-based organic particles "SX8742 (B) -03" (average primary particle size: 30 nm, manufactured by JSR (JSR)) (particles: X3), they were the same as in Example 2. In this way, a laminated film is obtained. The characteristics and the like of the obtained laminated film are shown in the table. The organic particles contained in the resin layer (X) have low hydrophilicity, and have lower heat resistance and alkali resistance than inorganic particles. Therefore, the coating properties, wet heat resistance, and alkali resistance of CNTs are not good.

[Industrial availability]

Since it has excellent adhesion to thermoplastic resin films, moisture and heat resistance, and alkali resistance, and exhibits good coating properties to conductive materials such as CNTs, it can be used as a base for transparent conductive films for touch panels and electronic paper members. Coating used.

Claims (10)

A laminated film, which is a laminated film having a resin layer (X) formed of a coating composition containing inorganic particles (A) and a polyester resin (B) having a hydrophilic functional group on at least one side of a thermoplastic resin film, The content of the inorganic particles (A) in the coating composition is 50% by mass or more and 90% by mass or less relative to the total amount of the coating composition, and the content of the polyester resin (B) having a hydrophilic functional group is relative to the total amount of the coating composition. It is 10% by mass or more and 50% by mass or less, and satisfies the following (1) to (4): (1) the surface roughness Ra (centerline average roughness) of the resin layer (X) is 5.0 nm or more and 30.0 nm or less (2) The average primary particle diameter of the inorganic particles (A) is 15nm to 80nm; (3) The water contact angle of the resin layer (X) is 75 ° or less; (4) The haze of the laminated film is 3.0% or less , Wherein the surface potential of the resin layer (X) is more than -50mV and less than -10mV. The laminated film according to claim 1, wherein the inorganic particles (A) have a hydroxyl group-containing acrylic resin (D) on the surface thereof. The laminated film of claim 1 or 2, wherein the inorganic particles (A) are colloidal silica. For example, the laminated film of claim 1 or 2, wherein the coating composition contains sugar alcohol (C), and the content thereof is 5 mass% or more and 20 mass% or less based on the entire coating composition. The laminated film according to claim 1 or 2, wherein the polyester resin (B) having a hydrophilic functional group is composed of all the raw materials for the polyester resin constituting the polyester resin (B) containing a hydrophilic functional group. 1 to 25 mol% of a dicarboxylic acid and an ester-forming derivative thereof having a sulfonate group, and / or a polycarboxylic acid and an ester-forming derivative thereof having 3 or more carboxylate groups Polyester resin made from raw materials. The laminated film of claim 1 or 2 is used as a primer film for conductive coating. A manufacturing method of a laminated film, which is a manufacturing method of a laminated film in which a resin layer (X) is provided on at least one side of a thermoplastic resin film and satisfies the following conditions (1) to (4). After coating the coating composition on at least one side of the thermoplastic resin film, a resin layer (X) is formed by heating and stretching. The coating composition contains inorganic particles (A) and a polyester resin having a hydrophilic functional group. (B), wherein the content of the inorganic particles (A) in the coating composition is 50% by mass or more and 90% by mass or less with respect to the entire coating composition, and the content of the polyester resin (B) having a hydrophilic functional group is relative to All coating compositions are 10% by mass or more and 50% by mass or less, (1) the surface roughness Ra (centerline average roughness) of the resin layer (X) is 5.0 nm or more and 30.0 nm or less; (2) inorganic particles (A) The average primary particle diameter is 15nm to 80nm; (3) The water contact angle of the resin layer (X) is 75 ° or less; (4) The haze of the laminated film is 3.0% or less. For example, the method for manufacturing a laminated film according to claim 7, wherein the surface potential of the resin layer (X) is -50 mV or more and -10 mV or less. The method for manufacturing a laminated film according to claim 7 or 8, wherein the inorganic particles (A) have a hydroxyl group-containing acrylic resin (D) on a surface thereof. For example, the method for manufacturing a laminated film according to claim 7 or 8, wherein the coating composition contains sugar alcohol (C), and the content thereof is 5 mass% or more and 20 mass% or less with respect to the entire coating composition.