Laminated film

Abstract

The present invention provides a laminated film that has, on at least one surface of a thermoplastic resin base material, a resin layer X containing an antistatic agent and that satisfies all of the following (1) to (3). (1) The ratio (N / C) between elemental nitrogen and elemental carbon of the resin layer X, as calculated by a high-resolution rutherford backscattering spectroscopy (HR-RBS) measurement, and the average content ratio between nitrogen atoms and carbon atoms per 1 nm, as calculated on the basis of the thickness (nm) of the resin layer X, are each not less than 0.0030 [nm-1]. (2) The surface resistivity of the resin layer X is not more than 1.0×1010 Ω / □. (3) The surface free energy of the resin layer X is not less than 20.0 mN / m, but less than 30.0 mN / m.　Provided is a laminated film that is excellent in releasability and antistatic properties of a surface layer and that can contribute to an improvement in performance of an electronic component or a battery without contamination by silicone and without loss of an antistatic material.

Description

Laminated Film

[0001] The present invention relates to a laminate film having a resin layer on at least one surface of a substrate film.

[0002] Plastic films have excellent properties such as mechanical properties, electrical properties, dimensional stability, transparency, and chemical resistance, and are therefore widely used as substrate films in many applications such as magnetic recording materials and packaging materials. These plastic films are generally used in the form of laminated films in which a coating material is applied to the surface and cured to provide a functional resin layer on the surface.

[0003] In particular, when used as a processing film for the manufacture of electronic components, a coating material such as a ceramic slurry (hereinafter referred to as a surface layer) is applied to the resin layer of a polyester film, dried, and then the surface layer is peeled off from the polyester film. In this surface layer peeling process, a film with excellent releasability is required from the viewpoint of processability, and films containing a silicone compound and an amino resin in the resin layer are commonly used (Patent Document 1). However, when these silicone compounds are contained in the resin layer, the surface free energy of the resin layer is reduced, which may result in poor applicability of a coating material such as a ceramic slurry.

[0004] Furthermore, with the recent trend toward smaller electronic devices and higher performance, there is a demand for high-quality release films with fewer foreign particles and defects. For example, studies have been conducted to suppress the adhesion of foreign particles and peeling electrification by adding antistatic materials to release films (Patent Document 2).

[0005] Meanwhile, as a silicone-free release agent (hereinafter referred to as a non-silicone release agent) that has excellent applicability for coatings such as ceramic slurries, a technology has been investigated that combines a long-chain alkyl group-containing resin, an olefin resin, a fluorine compound, or a wax-based compound, particularly a long-chain alkyl group-containing resin, with an amino resin capable of forming a dense crosslinked film and an antistatic agent (Patent Document 3). Furthermore, a release film that exhibits stable antistatic properties and excellent release properties by using a carbon-based antistatic agent such as carbon nanofiber has also been investigated (Patent Document 4). Furthermore, to solve the poor compatibility between polythiophene-based antistatic agents and silicone-based release agents, a release layer has been formed on a substrate film, followed by a release layer on or on the other side of the antistatic layer (Patent Document 5). Furthermore, in order to obtain a release film that does not generate peeling static and has excellent release properties, a release film in which a release layer is formed on one side of a polyester film and an antistatic layer on the other side has been investigated (Patent Document 6). On the other hand, Patent Document 7 proposes an antistatic film having a conductive layer on at least one side of a thermoplastic resin film, the conductive layer containing carbon nanotubes (A), a carbon nanotube dispersant (B), a binder resin (C), and an acrylic resin (D) having an alkyl chain with 12 or more carbon atoms, as a film that has antistatic properties and antifouling properties that allow the adhesive layer attached thereto to be easily wiped off.

[0006] JP 2017-105092 A JP 2020-023690 A JP 2019-131826 A JP 2007-190717 A International Publication No. 2016 / 133092 JP 2000-158611 A JP 2010-072423 A

[0007] As a result of the inventors' investigation of the above-mentioned technology, it was found that when the formulations of Patent Documents 1 and 2, which use a silicone compound as a release agent, are used as a processing film for manufacturing electronic components, the silicone compound may cause problems such as repelling or pinholes in the process of coating a surface layer such as a ceramic slurry on a resin layer of a polyester film, drying it, and then peeling the dried surface layer from the polyester film. Furthermore, even if no major problems arise in the coating process, it was found that the silicone compound may migrate to the surface layer side when the surface layer is peeled from the polyester film, and residues may remain on the surface even after firing the ceramic slurry, which may adversely affect the performance of the electronic components.

[0008] In the formulation of Patent Document 3, which avoids contamination by silicone compounds by using a non-silicone release agent, sufficient resistance values ​​could not be obtained, as the antistatic properties depended on humidity, etc. Furthermore, when an amino resin was used in combination with an electronic conductive antistatic agent that is not affected by humidity, deterioration of the antistatic properties, resulting in insufficient resistance values, was confirmed.

[0009] In the formulation of Patent Document 4, which uses carbon nanofibers as an antistatic material, good antistatic properties are obtained, but the cross-linking of the resin layer is not sufficiently high, resulting in a high peeling force of the surface layer of the ceramic slurry, etc. As a result, the surface layer may be ruptured during the process of peeling the surface layer from the polyester film, and further, the carbon nanofibers may fall off and be transferred to the surface layer, adversely affecting the performance of electronic components.

[0010] In Patent Document 5, in which an antistatic layer is formed on a base film and then a release layer is formed on or on the other side of the antistatic layer, multiple coating and drying processes are required, resulting in productivity and cost issues. Furthermore, in the formulation of Patent Document 6, in which a release layer is formed on one side of a polyester film and an antistatic layer is formed on the other side, sufficient antistatic effect may not be obtained when peeling off the ceramic slurry. Furthermore, as a result of the inventors' investigation of the technology described in Patent Document 7, it was found that with "antifouling properties that allow the attached adhesive layer to be easily wiped off," peeling off the surface layer from a polyester film, which is the target of the present application, was sometimes difficult.

[0011] In recent years, the use of release films has been investigated in the vapor deposition process in lithium-ion battery manufacturing and in the coating and transfer process of electrolytes and electrodes in all-solid-state battery manufacturing. However, the release layer must be heat-resistant, solvent-resistant, and antistatic in harsh environments such as vacuum and bone-dry conditions.

[0012] Therefore, an object of the present invention is to provide a laminate film that has excellent release properties and antistatic properties for the surface layer, and that can contribute to improving the performance of electronic components and batteries, without contamination by silicone or shedding of the antistatic material. Furthermore, the laminate film of the present invention is excellent in productivity and cost because it is processed using a resin composition containing a release agent and an antistatic agent in a single coating and drying process.

[0013] In order to solve the above problems, the present invention has the following configuration: [1] A laminate film having a resin layer X containing an antistatic agent on at least one surface of a thermoplastic resin substrate film, the laminate film satisfying all of the following (1) to (3): (1) The average content ratio of nitrogen atoms to carbon atoms per 1 nm calculated from the ratio (N / C) of nitrogen elements to carbon elements calculated by measuring the resin layer X using a high-resolution Rutherford backscattering spectroscopy (HR-RBS method) and the thickness (nm) of the resin layer X is 0.0030 [nm －１ (2) The surface resistivity of the resin layer X is 1.0×10 １０Ω / □ or less. (3) The surface free energy of the resin layer X is 20.0 mN / m or more and less than 30.0 mN / m. [2] A laminate film having a resin layer X containing an antistatic agent on at least one surface of a thermoplastic resin substrate film, wherein the resin layer X contains a long-chain alkyl resin, a melamine compound, and an acrylic resin. [3] The laminate film according to [1] or [2], wherein the antistatic agent contained in the resin layer X is a conductive carbon material. [4] The laminate film according to [3], wherein the antistatic agent contained in the resin layer X is carbon nanotubes. [5] The laminate film according to any one of [1] to [4], wherein, when the surface of the resin layer X is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K)[-] of the peak intensity (P) of a fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at the maximum intensity is less than 0.01. [6] The laminate film according to any one of [1] to [5], wherein the resin layer X contains a long-chain alkyl resin as a release agent, and the long-chain alkyl resin has an exothermic peak temperature (Tc) of 30° C. or more and 90° C. or less when heated from 25° C. to 200° C. at a rate of 20° C. / min in a differential scanning calorimeter (DSC) and then cooled from 200° C. to −50° C. at a rate of 20° C. / min in a temperature-lowering process. [7] The laminate film according to [6], wherein the resin layer X contains a long-chain alkyl resin and a melamine compound, and also contains at least one resin selected from the group consisting of an acrylic resin, a polyester resin, an epoxy resin, and a urethane resin. [8] The laminate film according to any one of [1] to [7], wherein the X-ray absorption near edge structure (XANES) spectrum at the carbon K-absorption edge of the resin layer X measured by a partial electron yield method satisfies I(15°)-I(90°)≧0.10, where θ is the angle between incident X-rays and the X-plane of the resin layer X and I(θ) is the spectral intensity at 293.5 eV. [9] The laminate film according to any one of [2] and [5] to [8], wherein the long-chain alkyl resin is a block copolymer.

[10] The laminate film according to any one of [1] to [9], wherein the thermoplastic resin substrate film is a polyester film containing at least one of a biomass raw material and a recycled raw material.

[11] A resin layer Y is provided on the surface opposite to the resin layer X, and the surface resistivity is 1.0 × 10 on both surfaces. １０

[12] The laminate film according to

[11] , wherein the resin layer Y contains carbon nanotubes.

[13] The laminate film according to [1], wherein the laminate film is used in a manufacturing process of an electronic component or a battery component.

[0014] According to the present invention, by achieving both easy releasability and antistatic properties in the resin layer provided on the laminate film, the processability in the step of peeling off the surface layer is improved, and a releaseable laminate film is provided that is free from silicone contamination and antistatic agent detachment, thereby contributing to improved performance of electronic components and batteries.

[0015] In the first embodiment of the laminated film of the present invention, the resin layer X containing an antistatic agent must satisfy all of the following requirements (1) to (3).

[0016] Regarding the first embodiment, the meaning of each characteristic and an example of a control method will be described first. (1) The ratio of nitrogen atoms to carbon atoms (N / C) calculated by measuring the resin layer X using a high-resolution Rutherford backscattering spectroscopy (HR-RBS) method and the average content ratio of nitrogen atoms to carbon atoms per 1 nm calculated from the thickness (nm) of the resin layer X are 0.0030 [nm －１ (2) The surface resistivity of the resin layer X is 1.0×10 or more. １０ (3) The surface free energy of the resin layer X is 20.0 mN / m or more and less than 30.0 mN / m.

[0017] The first requirement for the resin layer X contained in the laminate film of the present invention is that the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X, calculated from the ratio of nitrogen atoms to carbon atoms (N / C) calculated by high-resolution Rutherford backscattering spectroscopy (HR-RBS) measurement and the thickness (nm) of the resin layer X, is 0.0030 [nm －１ ] or more.

[0018] Here, we will explain the atomic weights calculated by high-resolution Rutherford backscattering spectroscopy (HR-RBS). There are many methods for quantifying the bonding state and hardness of the resin layer surface in laminate films. Examples include vibrational spectroscopy using infrared spectroscopy and indentation hardness analysis using nanoindentation. However, these methods make it difficult to separate the polyester film portion, which corresponds to the substrate, from the resin layer. This makes it difficult to accurately grasp the properties of the resin layer while minimizing the influence of the polyester film portion. However, HR-RBS allows for a more accurate understanding of the properties of the resin layer. When the measurement sample is a laminate film with a resin layer on one side of a polyester film, HR-RBS involves irradiating He ions from the surface of the resin layer toward the substrate layer, and analyzing the energy of the He ions scattered backward, i.e., from the substrate layer toward the substrate layer surface, to obtain surface structural information. This method can provide elemental, depth, and concentration information on the resin layer surface. Because this method is surface-sensitive, it allows for effective and highly accurate analysis of the properties of layers formed on the surface, such as resin layers.

[0019] Specifically, the information that can be obtained by the HR-RBS method is the ion intensity (i.e., the number) of ions scattered with a specific energy, where the energy corresponds to elemental information and the ion intensity corresponds to the abundance of each element. Since the ion intensity is a value that varies depending on the measurement conditions, it is actually converted into the relative quantity of the element of interest.

[0020] The inventors have investigated numerical values ​​characterizing the surface characteristics of resin layers made of non-silicone materials and found that by controlling the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X, calculated from the ratio of nitrogen atoms to carbon atoms (N / C) and the thickness (nm) of the resin layer X, within a preferred range, it is possible to suppress the detachment of antistatic agents in resin layers using non-silicone release agents. Because nitrogen atoms are abundant at reaction sites of organic compounds, they are thought to be an index that effectively characterizes film properties. However, because the absolute number of each element fluctuates depending on the thickness of the resin layer, it is necessary to convert them to numerical values ​​per unit thickness in order to more accurately represent the properties of the resin layer.

[0021] The average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X, calculated from the ratio of nitrogen atoms to carbon atoms (N / C) and the thickness (nm) of the resin layer X, is 0.0030 [nm －１ By setting the thickness to be equal to or greater than this, the crosslinking density of the resin layer X is improved, and when a coating agent such as a ceramic slurry is applied, the penetration of the binder component contained in the slurry into the resin layer X is suppressed, thereby enabling easy peeling when peeling off the surface layer. Furthermore, since the antistatic agent is held inside the resin layer X, it is possible to suppress the antistatic agent from falling off.

[0022] The average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X is 0.0030 [nm －１ ], for example, the releasability may be insufficient when peeling off the surface layer, or the antistatic agent may fall off from the resin layer X. From the above viewpoint, in the laminated film of the present invention, the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X is 0.0050 [nm －１ ] or more, and －１ On the other hand, the upper limit of the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X is not particularly limited, but when the resin layer X is made of an organic compound, it is preferably about 0.1000 [nm －１ ] is the practical upper limit, and from the viewpoint of feasibility, it is preferably 0.0200 [nm －１The details of the measurement of the ratio of nitrogen atoms to carbon atoms (N / C) by the HR-RBS method will be described later.

[0023] In the laminate film of the present invention, the ratio of nitrogen atoms to carbon atoms (N / C) calculated by the HR-RBS method and the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness in the resin layer X can be controlled not only by adjusting the amounts of the components constituting the resin layer X, but also by several factors, such as the crosslinking state of the resin layer X, adjustment of film density due to the progress of drying when the resin layer X is formed by a wet coating method, and an in-line coating method in which the resin layer X is applied during the polyester film production process. A preferred composition of the resin layer X constituting the laminate film of the present invention and a preferred method for producing the laminate film will be described later.

[0024] The second requirement for the resin layer X contained in the laminated film of the present invention is that the surface resistivity is 1.0 × 10 １０ The surface resistivity must be 1.0 x 10 Ω / □ or less. １０ When the surface resistivity is 1.0×10 Ω / □ or less, adhesion of foreign matter due to film charging and peeling charging of the surface layer can be suppressed. ９ Ω / □ or less is preferable, and 1.0×10 ８ The lower limit is not particularly limited, but it is preferably 1.0 × 10 Ω / □, which is the lower limit of a general antistatic agent. ２ The surface resistivity can be controlled within the above range by, for example, adjusting the amount of an antistatic agent or a release agent to fall within the preferred ranges described below, or by using a carbon-based antistatic agent.

[0025] A third requirement for the resin layer X contained in the laminate film of the present invention is that the surface free energy must be 20.0 mN / m or more and less than 30.0 mN / m. By setting the surface free energy within this range, a surface layer such as a ceramic slurry can be applied to the resin layer X of the laminate film without repelling, and easy peeling can be achieved in the surface layer peeling step.

[0026] The surface free energy of the resin layer X in the present invention is preferably 22.0 mN / m or more and less than 28.0 mN / m, and more preferably 24.0 mN / m or more and less than 26.0 mN / m.

[0027] If the surface free energy of the resin layer X is less than 20.0 mN / m, coating repelling may occur in the step of applying the surface layer, resulting in a decrease in yield, or a large amount of release agent may be required, resulting in transfer of the release agent or antistatic agent from the resin layer X and adversely affecting the performance of the electronic component. On the other hand, if the surface free energy of the resin layer X is 30.0 mN / m or more, heavy peeling may occur in the step of peeling the surface layer, resulting in rupture of the surface layer.

[0028] In order to control the surface free energy of the resin layer X within the above-described preferred range, for example, a method of controlling the surface free energy of the resin layer X to be I(15°)−I(90°)≧0.10 in a XANES spectrum described later, where θ is the angle formed between the incident X-ray and the resin layer X surface and I(θ) is the spectral intensity at 293.5 eV, or a method of using a preferred material described later as a release agent can be used.

[0029] On the other hand, a second embodiment of the laminate film of the present invention is a laminate film having a resin layer X containing an antistatic agent on at least one surface of a thermoplastic resin substrate film, and it is necessary that the resin layer X contains a long-chain alkyl resin, a melamine compound, and an acrylic resin.

[0030] By adopting such a configuration, the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness of the resin layer X, the surface resistivity, and the surface free energy, which are calculated from the ratio of nitrogen atoms to carbon atoms (N / C) calculated by the high-resolution Rutherford backscattering spectroscopy (HR-RBS) measurement and the thickness (nm) of the resin layer X, can be sufficiently satisfied, and therefore the effects of the present invention, such as easy peelability of the resin layer, antistatic properties, processability in the step of peeling the surface layer, and suppression of silicone contamination and shedding of the antistatic agent, can be simultaneously achieved. Preferred materials for use in the laminate film of the present invention will be described later.

[0031] <Substrate Film, Polyester Film> The laminate film of the present invention has a resin layer X on at least one surface of the substrate film. The substrate film in the laminate film of the present invention will be described in detail below. There are no particular restrictions on the type of substrate film, but polyester films are preferably used from the viewpoints of heat resistance and cost (hereinafter, polyester films used as substrate films may be referred to as "substrate film" or "substrate"). A polyester film refers to a film containing polyester as the main component, and the "main component" refers to a component contained in an amount of more than 50 parts by mass when the total resin constituting the film is taken as 100 parts by mass.

[0032] In the present invention, the substrate film may contain particles. When particles are contained, the content of particles is preferably 3.0 parts by mass or less based on the entire substrate film. By setting the particle content within the above range, a laminate film with excellent transparency can be obtained.

[0033] The polyester used in the base film of the laminated film of the present invention will be described below. First, polyester is a general term for polymers having an ester bond in the main chain, and polyesters containing at least one component selected from ethylene terephthalate, propylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene-2,6-naphthalate, ethylene-α,β-bis(2-chlorophenoxy)ethane-4,4′-dicarboxylate, etc. are preferably used.

[0034] The polyester film using the above polyester is preferably a biaxially oriented polyester film. A biaxially oriented polyester film is a polyester film oriented in two perpendicular directions, which exhibits a biaxially oriented pattern in wide-angle X-ray diffraction. A biaxially oriented polyester film is generally obtained by stretching an unstretched polyester sheet or film by approximately 2.5 to 5.0 times in both the longitudinal direction and the width direction perpendicular to the longitudinal direction, followed by heat treatment to complete the crystal orientation. Biaxially oriented polyester films have sufficient thermal stability, particularly dimensional stability and mechanical strength, and also have good flatness.

[0035] In addition, various additives such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, nucleating agents, etc. may be added to the polyester film to the extent that they do not deteriorate its properties.

[0036] The thickness of the polyester film is not particularly limited and may be appropriately selected depending on the application and type, but is usually preferably 10 to 500 μm, more preferably 15 to 250 μm, and even more preferably 20 to 200 μm in terms of mechanical strength, handleability, etc. The polyester film may be any of a single-layer film, a composite film obtained by coextrusion, and a film obtained by laminating obtained films by various methods.

[0037] The polyester film used as the substrate film of the laminated film of the present invention preferably contains at least one of biomass raw materials and recycled raw materials from the viewpoint of reducing environmental impact. Here, biomass refers to organic compounds derived from plants that are photosynthesized from carbon dioxide and water. When biomass is burned, it usually becomes carbon dioxide and water again, so biomass can be used as so-called carbon-neutral renewable energy. Furthermore, biomass raw materials refer to polyesters containing structural units derived from biomass.

[0038] When the ratio of plant-derived carbon atoms to the total carbon atoms is taken as the biomass degree, for example, in an ethylene terephthalate unit, if only the ethylene glycol component is entirely plant-derived, the biomass degree is theoretically 20%. To increase the biomass degree beyond that, the terephthalic acid must also be plant-derived, which would have a greater effect in reducing the environmental load but would increase production costs. The ethylene glycol component and the terephthalic acid component may be a combination of petroleum-derived components and plant-derived components.

[0039] The lower limit of the biomass degree of the polyester constituting the film is preferably 5%, more preferably 10%, and even more preferably 13%, from the viewpoint of realizing an environmental load reduction effect. A biomass degree of 5% or more can be expected to have an environmental load reduction effect. On the other hand, when only considering the reduction of the environmental load, the higher the upper limit of the biomass degree, the better, with 100% being the upper limit. However, from the viewpoint of achieving both production costs and a reduction of the environmental load, a biomass degree of 20% or less is practically preferable.

[0040] As a known method for analyzing the presence or absence of biomass raw materials, for example, the carbon isotope ( １４ C).

[0041] Recycled raw materials are raw materials that are recovered and reused from polyesters that have been converted into chemical products once or multiple times. Examples of recycled raw materials for the laminate film of the present invention include uncoated portions at both widthwise ends cut and removed during the production process of the laminate film of the present invention, recovered products of other polyester films, and polyester products distributed in forms other than films, such as PET bottles. When producing the laminate film of the present invention, the proportion of recycled raw materials per 100 parts by mass of polyester raw materials (recycle rate) is preferably 90 parts by mass or less. Limiting the use of recycled raw materials to 90 parts by mass or less reduces the amount of highly crystalline polyesters that have been converted into chemical products, thereby reducing the deterioration of thermal properties and transparency, and coloration of the resulting laminate film.

[0042] <Resin Layer X> The laminate film of the present invention has a resin layer X on at least one surface of the substrate film from the viewpoint of achieving both excellent releasability and antistatic properties.

[0043] In order to prevent contamination by silicone, the resin layer X in the laminate film of the present invention preferably has a ratio (P / K)[-] of the peak intensity (P) of a fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at the maximum intensity in time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS) of less than 0.01.

[0044] When the peak intensity ratio (P / K) [-] in time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS) is in the above-mentioned preferred range, the resin layer X contains few components derived from polydimethylsiloxane, so that when the laminated film of the present invention is used as a process film for manufacturing electronic components, the silicone compound derived from polydimethylsiloxane is unlikely to migrate (transfer) to the product side, and problems such as defective elements in the electronic components are not caused. From the viewpoint of feasibility, a ratio of less than 0.001 (the lower limit of measurement) is even more preferable.

[0045] The method for making the P / K of the resin layer X of the laminated film of the present invention fall within the above range is not particularly limited, but for example, a method using a release agent that does not contain silicone can be mentioned.

[0046] In the laminate film of the present invention, in the X-ray absorption fine structure (XAFS) spectrum measured by partial electron yield spectroscopy for the resin layer X, the X-ray absorption near edge structure (XANES) spectrum at the carbon K-absorption edge preferably satisfies I(15°)-I(90°)≧0.10, where θ is the angle between the incident X-ray and the resin layer X-plane and I(θ) is the spectral intensity at 293.5 eV. I(15°)-I(90°) being less than 0.10 indicates that the spectral intensity does not change with the angle θ between the incident X-ray and the resin layer X-plane, i.e., the X-ray irradiation direction, and indicates that there is no anisotropy in the orientation of the long-chain alkyl groups. On the other hand, when the resin layer X satisfies I(15°)-I(90°)≧0.10, it means that there is a bias in the orientation direction of the long-chain alkyl groups in the resin layer X, specifically that orientation in the vertical direction is promoted. This makes it difficult for surface layer components such as ceramic slurry to penetrate into the resin layer X, thereby improving the peelability of the surface layer. From the above perspective, I(15°)-I(90°)≧0.30 is more preferable, and I(15°)-I(90°)≧0.50 is even more preferable. By setting I(15°)-I(90°) within the above-mentioned preferred range, it is possible to improve the peel strength of the surface layer. Note that, as a method for achieving I(15°)-I(90°)≧0.10, an embodiment in which the resin layer X contains a release agent (A) and adjusting the type and amount thereof can be mentioned. On the other hand, the upper limit of I(15°)-I(90°) is not particularly limited, but the upper limit achievable from practical materials and processes is generally 10.00 or less, preferably 1.00 or less. Details of the release agent (A) will be described later.

[0047] <Resin Layer Y> The laminate film of the present invention can be provided with a resin layer Y on the side opposite to the resin layer X. By making the resin layer Y a layer containing an antistatic agent, it becomes possible to further suppress peel electrification when peeling a surface layer such as a ceramic slurry from the resin layer X.

[0048] The surface resistivity of the resin layer Y is 1.0×10 １０ It is preferable that the surface resistivity is 1.0×10 Ω / □ or less. １０When the surface resistivity is 1.0×10 Ω / □ or less, adhesion of foreign matter due to film charging and charging when peeling the surface layer from the resin layer X can be suppressed. ８ Ω / □ or less is preferable, and 1.0×10 ７ The lower limit is not particularly limited, but it is preferably 1.0 × 10 Ω / □, which is the lower limit of a general antistatic agent. ２ The surface resistivity can be controlled within the above range by, for example, adjusting the amount of antistatic agent added to fall within the preferred range described below, or by using a carbon-based antistatic agent.

[0049] <Coating Composition> A preferred coating composition for forming the resin layer of the laminated film of the present invention will be described below.

[0050] <Release Agent (A)> Examples of release agents that can be used in the first embodiment of the resin layer X of the laminate film of the present invention include long-chain alkyl group-containing resins, olefin resins, fluorine compounds, and wax-based compounds. Among these, long-chain alkyl group-containing resins are preferred because they can exhibit good releasability. On the other hand, from the viewpoint of adjusting the nitrogen atom to carbon atom ratio (N / C) of the resin layer X of the laminate film of the present invention, calculated by the HR-RBS method, and the average nitrogen atom to carbon atom content ratio per nm of thickness in the resin layer X, within preferred ranges, it is preferable for the release agent to contain a reactive functional group as a side chain in addition to the long-chain alkyl group. That is, a particularly preferred form of the release agent of the present invention is a copolymer resin having a long-chain alkyl group and a reactive functional group. Examples of reactive functional groups include hydroxyl groups, carboxyl groups, amino groups, glycidyl groups, isocyanate groups, vinyl groups, acrylic groups, and methacrylic groups. However, from the viewpoint of compatibility with water, a preferred solvent described below, a hydroxyl group is particularly preferred.

[0051] In the laminate film of the present invention, from the viewpoint of allowing the resin layer X to function as a release layer, the resin layer X preferably contains a long-chain alkyl resin as a release agent, and the long-chain alkyl resin preferably has an exothermic peak temperature (Tc) of 30°C or higher and 90°C or lower during the temperature decrease process when heated from 25°C to 200°C at 20°C / min using a differential scanning calorimeter (DSC) and then cooled from 200°C to -50°C at 20°C / min. The exothermic peak temperature (Tc) is more preferably 35°C or higher and 80°C or lower, and even more preferably 40°C or higher and 70°C or lower. By having an exothermic peak temperature Tc of 30°C or higher and 90°C or lower, the long-chain alkyl group of the release agent is more likely to be vertically oriented, the surface free energy of the resin layer X can be controlled within a preferred range, and good coatability and easy releasability of the surface layer are exhibited.

[0052] In a second embodiment of the resin layer X of the laminated film of the present invention, the resin layer X contains a long-chain alkyl resin as a release agent (A).

[0053] Commercially available long-chain alkyl group-containing compounds may be used. Specifically, the "Ashio Resin" (registered trademark) series, which are long-chain alkyl compounds manufactured by Asio Sangyo Co., Ltd., the "Peiroil" (registered trademark) series, which are long-chain alkyl compounds manufactured by Lion Specialty Chemicals, and the Resem series, which are aqueous dispersions of long-chain alkyl compounds manufactured by Chukyo Yushi Co., Ltd., can be used. The release agent preferably has an alkyl group having 12 or more carbon atoms, and more preferably has an alkyl group having 16 or more carbon atoms. By making the carbon number of the alkyl group 12 or more, hydrophobicity is enhanced, and the release agent can exhibit sufficient release performance. There is no particular upper limit on the number of carbon atoms in the alkyl group, but a carbon number of 25 or less is preferred because it is easy to manufacture.

[0054] The presence or absence of alkyl groups having 12 or more carbon atoms can also be evaluated from the laminate film, for example, by using the intensity of signals corresponding to alkyl groups obtained by TOF-SIMS (TOF-SIMS: time-of-flight secondary ion mass spectrometry). In this case, by combining the cutting method using ion sputtering, it is possible to perform continuous measurements in the depth direction (thickness direction), and the distribution state of alkyl group-containing compounds can also be evaluated.

[0055] It is more preferable that the release agent (A) is a block copolymer comprising units having an alkyl group. When the release agent is a block copolymer comprising units having an alkyl group, the alkyl groups are more easily oriented, the surface free energy of the resin layer X can be controlled within a preferred range, and good coatability and easy releasability of the surface layer are achieved. The method for producing the block copolymer is not particularly limited as long as it is a living radical polymerization method other than atom transfer radical polymerization (ATRP method). Various polymerization methods can be used, such as reversible addition-fragmentation chain transfer polymerization (RAFT method), polymerization using an organotellurium compound (TERP method), polymerization using an organoantimony compound (SBRP method), polymerization using an organobismuth compound (BIRP method), and living radical polymerization methods with an exchange chain mechanism such as iodine transfer polymerization, as well as the nitroxy radical method (NMP method). Among these, the RAFT method and the NMP method are preferred from the viewpoints of polymerization controllability and ease of implementation.

[0056] <Binder Resin (B)> In the first embodiment of the resin layer X in the laminated film of the present invention, the binder resin (B) forming the resin layer X has an average content ratio of nitrogen atoms to carbon atoms per 1 nm, which is a parameter corresponding to the crosslinking density of the resin layer X, of 0.0030 [nm －１Any resin can be used as long as it satisfies the above requirement. As such a resin, it is preferable to use at least one selected from the group consisting of acrylic resins, epoxy resins, and urethane resins. However, from the viewpoint of adjusting the crosslinking density of the resin layer X and the ease of introducing reactive functional groups, it is more preferable to use an acrylic resin. Examples of reactive functional groups include hydroxyl groups, carboxyl groups, amino groups, glycidyl groups, isocyanate groups, vinyl groups, acrylic groups, and methacrylic groups. However, from the viewpoint of adjusting the crosslinking density of the resin layer X, it is preferable for the resin to have a hydroxyl group or a carboxyl group, and a copolymerized acrylic resin having both a hydroxyl group and a carboxyl group is particularly preferable.

[0057] In a second embodiment of the resin layer X of the laminated film of the present invention, the resin layer X contains an acrylic resin as the binder resin (B).

[0058] The acrylic resin that can be used as the binder resin (B) is not particularly limited, and examples of the constituent monomer components include alkyl acrylate, alkyl methacrylate (the alkyl group can be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, a phenyl group, a benzyl group, a phenylethyl group, etc.), hydroxy group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, N-methyl acrylate, N-methyl meth ... Amide group-containing monomers such as ethyl acrylamide, N-methyl methacrylamide, N-methylolacrylamide, N-methylol methacrylamide, N,N-dimethylolacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, and N-phenyl acrylamide; amino group-containing monomers such as N,N-diethylaminoethyl acrylate and N,N-diethylaminoethyl methacrylate; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; and monomers containing a carboxyl group or a salt thereof such as acrylic acid, methacrylic acid, and salts thereof (lithium salt, sodium salt, potassium salt, etc.). These monomers may be polymerized alone or in combination with other types of monomers for copolymerization.

[0059] The glass transition point (Tg) of the acrylic resin used as the binder resin (B) of the laminated film of the present invention is not particularly limited, but is preferably 0 to 90°C, more preferably 10 to 80°C. By using an acrylic resin with a Tg of 0°C or higher, releasability is maintained even under high temperature and high humidity conditions. Conversely, by using an acrylic resin with a Tg of 90°C or lower, the occurrence of cracks during stretching in the preferred production method described below can be reduced. Furthermore, the weight average molecular weight of the acrylic resin is preferably 100,000 or higher, more preferably 300,000 or higher, from the viewpoint of achieving both film-forming properties and releasability.

[0060] Preferred acrylic resins for use in the laminated film of the present invention include copolymers containing hydroxyalkyl acrylate, acrylamide, N-methylolacrylamide, glycidyl methacrylate, and acrylic acid, and particularly preferred are copolymers containing 2-hydroxyethyl acrylate and acrylic acid.

[0061] Other examples of epoxy resins that can be used as the binder resin (B) include sorbitol polyglycidyl ether-based crosslinking agents, polyglycerol polyglycidyl ether-based crosslinking agents, diglycerol polyglycidyl ether-based crosslinking agents, and polyethylene glycol diglycidyl ether-based crosslinking agents. As the epoxy resin, commercially available epoxy resins may be used. For example, epoxy compounds "Denacol" (registered trademark) EX-611, EX-614, EX-614B, EX-512, EX-521, EX-421, EX-313, EX-810, EX-830, EX-850, etc., manufactured by Nagase Chemtec Corporation; diepoxy / polyepoxy compounds (SR-EG, SR-8EG, SR-GLG, etc.) manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.; and epoxy crosslinking agents "EPICLON" (registered trademark) EM-85-75W or CR-5L, manufactured by Dainippon Ink Mfg. Co., Ltd., can be suitably used. Among these, water-soluble epoxy resins are preferably used.

[0062] The urethane resin used as the binder resin (B) in the laminated film of the present invention is preferably a resin obtained by reacting a polyhydroxy compound with a polyisocyanate compound by a known urethane resin polymerization method such as emulsion polymerization or suspension polymerization.

[0063] Examples of polyhydroxy compounds include polyethylene glycol, polypropylene glycol, polyethylene-propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexamethylene adipate, polyhexamethylene sebacate, polytetramethylene adipate, polytetramethylene sebacate, trimethylolpropane, trimethylolethane, pentaerythritol, polycarbonate diol, and glycerin.

[0064] Examples of polyisocyanate compounds that can be used include hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, an adduct of tolylene diisocyanate and trimethylenepropane, and an adduct of hexamethylene diisocyanate and trimethylolethane.

[0065] <Crosslinking Agent (C)> In the first embodiment of the resin layer X in the laminate film of the present invention, it is particularly preferable for the resin layer X to contain a crosslinking agent (C), particularly from the viewpoint of sufficiently promoting the crosslinking reaction of the resin layer X and adjusting the nitrogen atom to carbon atom ratio (N / C) calculated by HR-RBS and the average nitrogen atom to carbon atom content ratio per 1 nm of thickness in the resin layer X. Examples of the crosslinking agent (C) include melamine compounds, carbodiimide compounds, isocyanate compounds, and oxazoline compounds. Among these, melamine compounds have a large amount of reactive functional groups per unit molecular weight and form dense crosslinks upon high-temperature heating. When the laminate film is used as a release film, this allows for easy peeling of a surface layer such as a ceramic slurry from the laminate film, and prevents the antistatic agent from falling off.

[0066] Examples of melamine compounds that can be used as the crosslinking agent (C) include melamine, methylolated melamine derivatives obtained by condensing melamine with formaldehyde, compounds obtained by reacting methylolated melamine with a lower alcohol to partially or completely etherify the melamine, and mixtures thereof. The melamine compound may be a condensate of a monomer or a dimer or higher polymer, or a mixture thereof. Examples of lower alcohols that can be used for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. The functional group in the melamine compound is an imino group, a methylol group, or an alkoxymethyl group such as a methoxymethyl group or a butoxymethyl group, per molecule. Examples include imino-type methylated melamine resins, methylol-type melamine resins, methylol-type methylated melamine resins, and fully alkylated methylated melamine resins. Among these, methylolated melamine resins are the most preferred.

[0067] In a second embodiment of the resin layer X of the laminated film of the present invention, the resin layer X contains a melamine compound as the crosslinking agent (C).

[0068] However, when an electron-conductive antistatic agent, such as a thiophene-based material, is selected as the antistatic agent contained in the resin layer X and / or resin layer Y of the laminate film of the present invention, the unshared electrons of the N element of the amino resin may be donated to the electron-conductive antistatic material, resulting in the disappearance of holes, which are positively charged simple substances, and an increase in the surface specific resistance. Therefore, when a thiophene-based material is used as the antistatic agent, it is preferable to select a carbodiimide compound, an isocyanate compound, or an oxazoline compound as the crosslinking agent (C). That is, one preferred embodiment of the present invention is a configuration in which the crosslinking agent (C) is at least one compound selected from the group consisting of a carbodiimide compound, an isocyanate compound, and an oxazoline compound, and the antistatic agent (D) described below are both contained.

[0069] The carbodiimide compound usable as the crosslinking agent (C) is a compound having one or more carbodiimide groups or tautomeric cyanamide groups as functional groups in the molecule. Specific examples of such carbodiimide compounds include dicyclohexylmethanecarbodiimide, dicyclohexylcarbodiimide, tetramethylxylylenecarbodiimide, and urea-modified carbodiimide, and these can be used alone or in combination.

[0070] Furthermore, examples of isocyanate compounds that can be used as the crosslinking agent (C) include tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, meta-xylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanatehexane, an adduct of tolylene diisocyanate and hexanetriol, an adduct of tolylene diisocyanate and trimethylolpropane, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-bitrylene-4,4' diisocyanate, 3,3' dimethyldiphenylmethane-4,4'-diisocyanate, and meta-phenylene diisocyanate.

[0071] Furthermore, since isocyanate groups readily react with water, in terms of the pot life of the coating material, it is preferable to use blocked isocyanate compounds in which the isocyanate groups are masked with a blocking agent, etc. In this case, when heat is applied in the drying step after the resin composition for forming the resin layer is applied to the polyester film, the blocking agent dissociates, exposing the isocyanate groups, and causing the crosslinking reaction to proceed.

[0072] The oxazoline compound that can be used as the crosslinking agent (C) has an oxazoline group as a functional group therein, and is preferably an oxazoline group-containing copolymer obtained by copolymerizing at least one monomer containing an oxazoline group and at least one other monomer.

[0073] Examples of monomers containing an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline, and these may be used alone or in combination. Of these, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

[0074] In the oxazoline compound, at least one other monomer used for the monomer containing an oxazoline group is a monomer copolymerizable with the monomer containing an oxazoline group, and examples thereof include acrylic acid esters or methacrylic acid esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid; acrylonitrile; and methacrylonitrile. Any unsaturated nitriles, unsaturated amides such as acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, vinyl esters such as vinyl acetate and vinyl propionate, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, olefins such as ethylene and propylene, halogen-containing α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride, and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene, and the like can be used alone or in combination of two or more thereof.

[0075] <Antistatic Agent (D)> The laminate film of the present invention must contain an antistatic agent (D) as a component of the resin layer X and / or the resin layer Y. The type of antistatic agent (D) is not particularly limited, and for example, conductive carbon materials such as carbon nanotubes (hereinafter referred to as CNT), polymer materials having a conductive structure typified by polythiophene structures, acidic polymers in a free acid state, and the like can be used alone or in combination. In the present invention, from the viewpoint of achieving both antistatic properties and releasability, it is more preferable to use a conductive carbon material, and CNT is particularly preferable.

[0076] A particularly preferred embodiment of the resin layer X and / or resin layer Y of the laminate film of the present invention comprises a long-chain alkyl group-containing resin as the release agent (A), an acrylic resin as the binder resin (B), a melamine compound as the crosslinking agent (C), and CNT as the antistatic agent (D). An even more preferred embodiment comprises a long-chain alkyl group-containing resin that is a block copolymer as the release agent (A), a copolymerized acrylic resin having both hydroxyl and carboxyl groups as the binder resin (B), a melamine compound as the crosslinking agent (C), and CNT as the antistatic agent (D). This combination allows for the achievement of both releasability and antistatic properties while adjusting the nitrogen to carbon atom ratio (N / C) calculated by HR-RBS and the average nitrogen to carbon atom content ratio per nanometer of thickness in the resin layer X.

[0077] In the present invention, CNT refers to a seamless tube in which a honeycomb-structured graphene sheet composed only of carbon atoms is rolled into a cylindrical shape. A single-walled CNT is one in which the graphene sheet is essentially rolled into one layer, a double-walled CNT is one in which the graphene sheet is rolled into two layers, and a multi-walled CNT is one in which the graphene sheet is rolled into three or more layers. The CNT used in the present invention is preferably a straight or bent single-walled CNT, a straight or bent double-walled CNT, a straight or bent multi-walled CNT, or a combination thereof.

[0078] The honeycomb structure refers to a network structure mainly consisting of six-membered rings, but due to the structure of CNTs, the bent parts of the tube or the closed parts of the cross section may have ring structures other than six-membered rings, such as five-membered rings or seven-membered rings.

[0079] Among the above CNTs, the CNTs used in the present invention are preferably straight or bent single-walled CNTs and straight and / or bent double-walled CNTs from the viewpoint of electrical conductivity. Single-walled CNTs and double-walled CNTs are excellent in terms of dispersibility in solvents, durability, and production costs. On the other hand, multi-walled CNTs with three or more walls are excellent in dispersibility and production costs, but may not provide sufficient electrical conductivity.

[0080] Furthermore, the CNTs used in the present invention preferably have a diameter of 1 nm or more. Furthermore, the diameter of the CNTs is preferably 50 nm or less, more preferably 10 nm or less. When the upper diameter limit is within the above preferred range, the CNTs are less likely to form a multilayer structure of three or more layers, the conductive paths are less likely to diverge between layers, and conductivity can be increased. Furthermore, a large amount of CNTs is not required, and the CNTs do not fall off from the resin layer X and / or the resin layer Y. Therefore, they are not transferred to the surface layer of the ceramic slurry or the like, and the device performance is not degraded. A small amount can achieve sufficient antistatic properties. On the other hand, CNTs with a diameter lower limit within the above preferred range are easy to manufacture and readily available.

[0081] The aspect ratio of the CNT used in the present invention is preferably 100 or more. Furthermore, the aspect ratio of the CNT is preferably 5,000 or less. By setting the aspect ratio of the CNT within the above range, the antistatic properties of the resin layer X and / or the resin layer Y can be improved. When the aspect ratio of the CNT is set within the above range, when the inline coating method described below is used to form the resin layer X and / or the resin layer Y, the CNT are appropriately loosened during the stretching process, and the conductive paths between the CNT are not broken, and a network with sufficient gaps between the CNTs can be formed. When such a network structure is formed, good antistatic properties can be exhibited.

[0082] The aspect ratio is the length (nm) of a CNT divided by the diameter (nm) of the CNT (CNT length (nm) / CNT diameter (nm)).

[0083] CNTs with these properties can be obtained by known manufacturing methods such as chemical vapor deposition, catalytic vapor phase growth, arc discharge, and laser evaporation. When producing CNTs, fullerenes, graphite, and amorphous carbon are simultaneously produced as by-products, and catalytic metals such as nickel, iron, cobalt, and yttrium also remain. Therefore, it is preferable to remove these impurities and purify the CNTs. To remove impurities, ultrasonic dispersion treatment, along with acid treatment using nitric acid, sulfuric acid, etc., is effective, and the combined use of separation using a filter is even more preferable for improving purity.

[0084] Single-walled CNTs and double-walled CNTs are generally thinner than multi-walled CNTs, and if uniformly dispersed, they can ensure a greater number of conductive paths per unit volume, resulting in high conductivity. However, depending on the manufacturing method, a large amount of semiconducting CNTs may be produced as a by-product. In such cases, it becomes necessary to selectively manufacture or sort conductive CNTs. Multi-walled CNTs generally exhibit conductivity, but if the number of walls is too large, the number of conductive paths per unit weight decreases. Therefore, even when multi-walled CNTs are used, their CNT diameter is preferably 50 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less. Furthermore, when single-walled CNTs or double-walled CNTs are used, due to their structure, a diameter of 20 nm or less, more preferably 10 nm or less, is preferred from the perspective of antistatic properties.

[0085] When a polythiophene compound is used as the antistatic agent (D), for example, a compound having a structure in which the 3- and 4-positions of the thiophene ring are substituted can be used. Furthermore, a compound in which oxygen atoms are bonded to the 3- and 4-carbon atoms of the thiophene ring can be preferably used. Compounds in which a hydrogen atom or a carbon atom is directly bonded to the carbon atom may not easily render the coating liquid water-soluble. The above compounds can be produced by, for example, the methods disclosed in JP-A-2000-6324, EP-A-602713, and U.S. Pat. No. 5,391,472, but other methods may also be used.

[0086] For example, 3,4-ethylenedioxythiophene is obtained using an alkali metal salt of 3,4-dihydroxythiophene-2,5-dicarboxy ester as a starting material, and then potassium peroxodisulfate, iron sulfate, and the previously obtained 3,4-ethylenedioxythiophene are introduced into an aqueous polystyrene sulfonic acid solution and reacted to obtain a composition in which a polythiophene such as poly(3,4-ethylenedioxythiophene) is complexed with an acidic polymer such as polystyrene sulfonic acid.

[0087] Furthermore, an aqueous coating composition containing poly-3,4-ethylenedioxythiophene and polystyrene sulfonic acid, such as that sold by H. C. Starck (Germany) as Baytron P, can be used.

[0088] On the other hand, examples of acidic polymers in the free acid state include polymeric carboxylic acids, polymeric sulfonic acids, and polyvinyl sulfonic acids. Examples of polymeric carboxylic acids include polyacrylic acid, polymethacrylic acid, and polymaleic acid. Examples of polymeric sulfonic acids include polystyrene sulfonic acid, with polystyrene sulfonic acid being particularly preferred in terms of antistatic properties. The free acid may be in the form of a partially neutralized salt. It may also be used in the form of a copolymer with other copolymerizable monomers, such as acrylic acid esters, methacrylic acid esters, and styrene. The molecular weight of the polymeric carboxylic acid or polymeric sulfonic acid is not particularly limited. However, from the viewpoint of coating stability and antistatic properties, the weight-average molecular weight is preferably 1,000 to 1,000,000, and more preferably 5,000 to 150,000. Alkali salts such as lithium salts and sodium salts, or ammonium salts, may also be included as long as they do not impair the properties of the invention. Neutralized salts of polyanions are also believed to function as dopants. This is because polystyrene sulfonic acid and ammonium salts, which function as very strong acids, shift the equilibrium to the acidic side as the equilibrium reaction progresses after neutralization.

[0089] The preferred contents of the release agent (A), binder resin (B), crosslinking agent (C) and antistatic agent (D) in the resin composition for forming the resin layer X of the laminated film of the present invention are as follows.

[0090] <Content Ratio of Each Resin Composition in Resin Layer X> In the resin composition for forming the resin layer X of the present invention, there is a preferred content of the release agent (A). Specifically, when the total of the release agent (A), binder resin (B), and crosslinking agent (C) is 100 parts by mass, the content of the release agent (A) is preferably 10 parts by mass or more and 50 parts by mass or less, more preferably 20 parts by mass or more and 40 parts by mass or less, and even more preferably 35 parts by mass or less. When the content of the release agent (A) is 10 parts by mass or more, good releasability of the surface layer is exhibited. On the other hand, when the content of the release agent (A) is 50 parts by mass or less, when used as a release film, the detachment of the release agent (A) from the laminate film is reduced, and contamination by the release agent (A) can be suppressed. Furthermore, when the amount of the release agent (A) is 50 parts by mass or less, the reduction in the effect of the antistatic agent (D) due to the excessive presence of the release agent (A) on the surface can be suppressed.

[0091] There is also a preferred range for the content of the crosslinking agent (C). Specifically, when the total of the release agent (A), binder resin (B), and crosslinking agent (C) is 100 parts by mass, the content of the crosslinking agent (C) is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and particularly preferably 60 parts by mass or more. By using the crosslinking agent (C) in the above-described range, it becomes easier to control the ratio of nitrogen atoms to carbon atoms (N / C) calculated by the HR-RBS method and the average content ratio of nitrogen atoms to carbon atoms per nm thickness in the resin layer X within preferred ranges, thereby improving the releasability of various adherends. Meanwhile, the upper limit of the content depends on the amounts of the release agent (A) and binder resin (B), but is 90 parts by mass, preferably 85 parts by mass, and more preferably 75 parts by mass.

[0092] On the other hand, the blending ratio of the binder resin (B) can be adjusted so that the aforementioned release agent (A) and crosslinking agent (C) are contained in a preferable amount. However, if the binder resin (B) is less than 5 parts by mass when the total of the release agent (A), binder resin (B), and crosslinking agent (C) is 100 parts by mass, it becomes difficult to support the resin layer X, which may lead to the resin layer X falling off or deterioration in quality.

[0093] The content of the antistatic agent (D) in the resin layer X used in the present invention is preferably 0.05 parts by mass or more and 20.0 parts by mass or less, when the total of the release agent (A), binder resin (B), and crosslinking agent (C) is 100 parts by mass. It is more preferably 0.5 parts by mass or more and 15 parts by mass or less, and even more preferably 1.0 part by mass or more and 10.0 parts by mass or less. Within the above preferred range, the resin layer X has sufficient antistatic performance, while the cohesive force due to the intermolecular force between the antistatic agents (D) is not too high, and the dispersibility of the antistatic agent (D) is not reduced. Therefore, the uniformity of the resin layer X is maintained, the surface layer is less likely to peel off easily, and deterioration of performance due to the antistatic agent (D) falling off when used as an electronic component can be effectively prevented.

[0094] <Content ratio of each resin composition in resin layer Y> In the laminate film of the present invention, a resin layer Y can be provided on the surface opposite to the resin layer X. The resin layer Y preferably contains a binder resin (B), a crosslinking agent (C), and an antistatic agent (D), and may also contain a release agent (A).

[0095] The content of the binder resin (B) in the resin layer Y is preferably 5 parts by mass or more and 100 parts by mass or less, preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 80 parts by mass or less, when the total of the release agent (A), the binder resin (B), and the crosslinking agent (C) is taken as 100 parts by mass. When the content of the binder resin (B) in the resin layer Y is within the above-mentioned preferred range, it is possible to effectively prevent the failure to obtain antistatic performance due to poor film formation.

[0096] The content of the crosslinking agent (C) in the resin layer Y is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and particularly preferably 50 parts by mass or more, when the total of the release agent (A), the binder resin (B), and the crosslinking agent (C) is taken as 100 parts by mass. When the crosslinking agent (C) satisfies the above content, it is possible to suppress the antistatic agent (D) from falling off.

[0097] The content of the antistatic agent (D) in the resin layer Y is preferably 0.05 parts by mass or more and 900 parts by mass or less, more preferably 0.5 parts by mass or more and 700 parts by mass or less, and even more preferably 1.0 part by mass or more and 500 parts by mass or less, when the total of the release agent (A), the binder resin (B), and the crosslinking agent (C) is taken as 100 parts by mass. By setting the content of the antistatic agent (D) within the above range, it is possible to impart antistatic properties to the resin layer Y.

[0098] Furthermore, when the resin layer Y contains the release agent (A), the content thereof is preferably 50 parts by mass or less, and more preferably 30 parts by mass or less, when the total of the release agent (A), the binder resin (B), and the crosslinking agent (C) is taken as 100 parts by mass. By setting the content of the release agent (A) within the above range, it is possible to impart releasability to the resin layer Y without impairing the antistatic properties of the resin layer Y.

[0099] The resin composition for forming the resin layer X and / or the resin layer Y of the laminate film of the present invention may contain a particulate component in addition to the release agent (A), the binder resin (B), the crosslinking agent (C), and the antistatic agent (D). In particular, when the resin layer X and / or the resin layer Y of the laminate film of the present invention contains the release agent (A), if the film surface is smooth, the slipperiness is enhanced, unlike conventional films. In the laminate film of the present invention, if the slipperiness is so high that the winding property is deteriorated, by including such a particulate component in the resin composition for forming the resin layer X and / or the resin layer Y, protrusions can be formed on the surface of the resin layer X and / or the resin layer Y, improving transportability.

[0100] Particulate components suitable for use in the laminated film of the present invention include oxide fine particles of elements located on and to the left of the diagonal line connecting boron (B), silicon (Si), arsenic (As), tellurium (Te), and astatine (At). Examples of such particulate components include SiO ２ , TiO ２ , ZrO ２ , ZnO, CeO ２ , SnO ２ , Sb ２ O ５ , indium-doped tin oxide (ITO), phosphorus-doped tin oxide (PTO), Y ２ O ３ , La ２ O ３ , Al ２ O ３ These particle components may be used singly or in combination of two or more. From the viewpoint of dispersion stability and refractive index, SiO ２ , TiO ２ , ZrO ２ is particularly preferred.

[0101] The particle components used in the resin layer X and / or resin layer Y of the laminate film of the present invention preferably have a number-average particle diameter of 3 nm to 500 nm, more preferably 20 nm to 400 nm, and even more preferably 40 nm to 300 nm. Here, the number-average particle diameter refers to the particle diameter determined using a transmission electron microscope (TEM). Specifically, the outer diameters of 10 particles present in a screen are measured at a magnification of 500,000 times, and this is repeated for a total of 100 fields of view to determine the outer diameters of 100 particles. Here, the outer diameter refers to the maximum diameter of the particle (i.e., the longest diameter of the particle, i.e., the longest diameter among the particles). This also applies to particles with internal cavities. When the number-average particle diameter of the particle component is 3 nm or more, van der Waals forces between particles are suppressed, tending to reduce particle aggregation. On the other hand, when the number-average particle diameter of the particle component is 500 nm or less, particle shedding from the resin layer X and / or resin layer Y can be reduced.

[0102] The method for producing the particle component is not particularly limited, and examples thereof include a method of surface treating the particle component with an acrylic resin, and specific examples include the following methods (i) to (iv). In the present invention, surface treatment refers to a treatment in which an acrylic resin is adsorbed and attached to all or part of the surface of the particle component. The desired effect can be achieved by any of the following methods (i) to (iv). (i) A method in which a mixture of a particle component and an acrylic resin is mixed in advance, added to a solvent, and then dispersed. (ii) A method in which the particle component and the acrylic resin are added in order to a solvent and dispersed. (iii) A method in which the particle component and the acrylic resin are dispersed in a solvent in advance, and the resulting dispersion is mixed. (iv) A method in which the particle component is dispersed in a solvent, and then the acrylic resin is added to the resulting dispersion.

[0103] Dispersion equipment that can be used includes dissolvers, high-speed mixers, homomixers, meaders, ball mills, roll mills, sand mills, paint shakers, SC mills, annular mills, and pin mills. Suitable conditions for using the above equipment include a peripheral rotation speed of the rotating shaft of 5 to 15 m / s and a rotation time of 5 to 10 hours. Furthermore, in order to enhance dispersibility, it is more preferable to use dispersion beads such as glass beads during dispersion. The diameter of the dispersion beads is preferably 0.05 to 0.5 mm, more preferably 0.08 to 0.5 mm, and even more preferably 0.08 to 0.2 mm. Mixing and stirring can be performed by shaking the container by hand, using a magnetic stirrer or stirring blade, ultrasonic irradiation, vibration dispersion, or the like.

[0104] The content of the particle component in the resin layer X and / or the resin layer Y is preferably 0.5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total of the release agent (A), the binder resin (B), and the crosslinking agent (C). It is more preferably 1 part by mass or more and 7 parts by mass or less, and even more preferably 2 parts by mass or more and 5 parts by mass or less. By setting the content of the particle component to 0.5 parts by mass or more and 10 parts by mass or less, relative to the total of the release agent (A), the binder resin (B), and the crosslinking agent (C), it is possible to impart a suitable surface shape to the resin layer X and / or the resin layer Y without impairing the film-forming properties of the resin layer X and / or the resin layer Y. As a result, it is possible to fully exhibit the desired transportability.

[0105] Furthermore, the resin layer X and / or resin layer Y of the laminate film of the present invention may contain a crosslinking catalyst. The inclusion of a crosslinking catalyst allows the crosslinking reaction between the binder resin (B) and the crosslinking agent (C) to proceed efficiently during heat treatment, increasing the nitrogen to carbon ratio (N / C) calculated by HR-RBS measurement and the average nitrogen to carbon atom content ratio per nanometer, calculated from the thickness (nm) of the resin layer X and / or resin layer Y. In other words, the degree of crosslinking of the resin layer X and / or resin layer Y is increased. As a result, when a surface layer is applied to the resin layer X and / or resin layer Y, penetration of the surface layer into the resin layer X and / or resin layer Y is more unlikely, making it easier to improve the peelability of the surface layer. Examples of crosslinking catalysts that can be used include acidic catalysts such as p-toluenesulfonic acid and dodecylbenzenesulfonic acid, and amine salt catalysts.

[0106] When preparing a resin composition, a solvent or dispersion medium (hereinafter simply referred to as "solvent") may be included. That is, various components may be dissolved or dispersed in a solvent to form a resin composition, which may then be applied to a polyester substrate. When such a method is employed, a film having a resin layer laminated thereon can be obtained by drying the solvent after application and heating.

[0107] In the laminate film of the present invention, it is preferable to use an aqueous solvent as the solvent. Here, the aqueous solvent refers to a mixture of water or water and a water-soluble organic solvent, such as alcohols (e.g., methanol, ethanol, isopropyl alcohol, butanol), ketones (e.g., acetone, methyl ethyl ketone), or glycols (e.g., ethylene glycol, diethylene glycol, propylene glycol), in any ratio. The use of an aqueous solvent not only prevents the solvent from rapidly evaporating during the heating step, allowing for the formation of a uniform resin layer X and / or resin layer Y, but also provides an advantage in terms of environmental impact.

[0108] The resin composition for forming the resin layer in the laminate film of the present invention can be prepared by mixing and stirring a water-dispersed or water-soluble release agent (A), a binder resin (B), a crosslinking agent (C), an antistatic agent (D), and an aqueous solvent in any order at a desired weight ratio. Next, various additives such as a lubricant, inorganic particles, organic particles, a surfactant, an antioxidant, and a thermal initiator can be added as needed, in any order, as long as they do not deteriorate the properties of the resin layer X and / or resin layer Y formed from the resin composition. Examples of methods for mixing and stirring include shaking the container by hand, stirring with a magnetic stirrer or stirring blade, ultrasonic irradiation, vibration dispersion, and the like.

[0109] <Manufacturing Method> In the laminate film of the present invention, the resin layer X and / or resin layer Y can be provided on at least one side of the base film by either an in-line coating method or an off-coating method, but the in-line coating method is preferred. The in-line coating method is a method in which coating is performed within the polyester film manufacturing process. Specifically, it refers to a method in which coating is performed at any stage from melt extrusion of a polyester resin to biaxially stretching, heat treatment, and winding up. Typically, coating is performed on any of the following films: an unstretched (unoriented) polyester film (A film) in a substantially amorphous state obtained by melt extrusion and quenching, a uniaxially stretched (uniaxially oriented) polyester film (B film) that has been subsequently stretched in the longitudinal direction, or a biaxially stretched (biaxially oriented) polyester film (C film) that has been further stretched in the width direction and has not yet been heat-treated.

[0110] On the other hand, the offline coating method is a method in which the above-mentioned A film is stretched uniaxially or biaxially, and heat-treated to complete the crystal orientation of the polyester film, and then a resin composition is applied to the resulting film (C film) in a process separate from the film-forming process.

[0111] In the present invention, it is preferable to produce the laminate film by an in-line coating method. By producing the laminate film by the in-line coating method, not only can the laminate film be produced at lower cost than, for example, forming the resin layer X and / or the resin layer Y on a biaxially stretched PET film by off-coating, but also, by subjecting the laminate film to a high-temperature heat treatment of 200°C or higher, which is essentially impossible by off-coating, the dense crosslinking of the resin layer X and / or the resin layer Y can be promoted, and when a coating agent such as a ceramic slurry is applied, the penetration of the binder component contained in the slurry into the resin layer X and / or the resin layer Y can be suppressed, thereby enabling easy peeling when peeling off the surface layer. Furthermore, the dense crosslinking keeps the antistatic agent inside the resin layer X and / or the resin layer Y, thereby suppressing the antistatic agent from falling off. In particular, from the viewpoints of production cost, dimensional stability after heat treatment, heat shrinkage properties, and the density of resin layer X and / or resin layer Y, it is preferable to produce the polyester film by a production method in which a coating composition is applied to at least one surface of the polyester film before the crystal orientation is completed, the polyester film is stretched in at least one direction, and then heat-treated to complete the crystal orientation of the polyester film.

[0112] <Coating Method> The resin composition can be applied to the polyester film by any known coating method, such as bar coating, reverse coating, gravure coating, die coating, blade coating, etc. Here, the adhesion between the polyester film and the resin layer X and / or the resin layer Y will be described.

[0113] When resin layer X and / or resin layer Y are provided on a polyester film by a conventional off-coating method, if resin layer X and / or resin layer Y contain a release agent, the low surface energy of resin layer X and / or resin layer Y has poor adhesion to the film, which can lead to problems such as the resin layer being scraped off when the film roll is rewound, resulting in a deterioration in peel strength. However, when resin layer X and / or resin layer Y are laminated by an in-line coating method, applying a coating composition to the polyester film before completion of crystal orientation allows a very small amount of coating composition to penetrate into the polyester film, thereby imparting adhesion between resin layer X and / or resin layer Y and the thermoplastic resin substrate. As a result, excellent peel strength can be achieved.

[0114] <Method for forming resin layer X and / or resin layer Y> In the present invention, it is preferable to form the resin layer X and / or resin layer Y by applying a coating composition to at least one surface of a polyester film and then drying it. In the present invention, when a solvent is contained in the coating composition, it is preferable to use an aqueous solvent as the solvent. By using an aqueous solvent, it is possible to suppress rapid evaporation of the solvent during the drying step, and not only can a uniform and high-quality resin layer X and / or resin layer Y be formed, but it is also excellent in terms of environmental impact.

[0115] Here, the aqueous solvent refers to water or a mixture of water and a water-soluble organic solvent, such as an alcohol such as methanol, ethanol, isopropyl alcohol, or butanol, a ketone such as acetone or methyl ethyl ketone, or a glycol such as ethylene glycol, diethylene glycol, or propylene glycol, in any ratio that does not cause phase separation.

[0116] As mentioned above, the coating method of the coating composition on the film is preferably the in-line coating method. Specifically, it refers to a method of coating at any stage from melt-extrusion of the polyester resin to biaxially stretched, heat-treated and wound up, and is usually coated on any of the following films: a substantially amorphous unstretched (unoriented) film (A film) obtained by melt-extrusion and rapid cooling, a uniaxially stretched (uniaxially oriented) film (B film) that has been subsequently stretched in the longitudinal or width direction, or a biaxially stretched (biaxially oriented) film (C film) that has been further stretched in the width direction or longitudinal direction and has not yet been heat-treated.

[0117] In the present invention, it is preferable to employ a method in which a coating composition is applied to either the above-mentioned A film or B film before the crystal orientation is complete, and then the film is stretched uniaxially or biaxially and heat-treated at a temperature higher than the boiling point of the solvent to complete the crystal orientation of the film and provide resin layer X and / or resin layer Y. This method has the advantage of being low in manufacturing costs because film formation and the application and drying of the coating composition (i.e., formation of resin layer X and / or resin layer Y) can be carried out simultaneously, and it also makes it easy to ensure the aforementioned substrate adhesion.

[0118] Among these, the method of applying the coating composition to a film (film B) uniaxially stretched in the longitudinal direction, followed by stretching in the width direction and heat treatment is superior. This is because, compared to the method of applying the coating composition to an unstretched film and then biaxially stretching, this method requires one less stretching step, making it less likely for defects or cracks to occur in the resin layer X and / or resin layer Y due to stretching, and making it possible to form a resin layer X and / or resin layer Y with excellent smoothness. Furthermore, as mentioned above, applying the coating composition to a film before completion of crystal orientation can impart adhesion between the resin layer X and / or resin layer Y and the polyester film.

[0119] Therefore, a preferred method for forming resin layer X and / or resin layer Y in the present invention is to apply a coating composition using an aqueous solvent to a polyester film using an in-line coating method, followed by drying and heat treatment. A more preferred method is to in-line coat the coating composition on the uniaxially stretched B film. In the laminate film manufacturing method of the present invention, drying can be carried out at a temperature range of 80 to 130°C to complete removal of the solvent from the coating composition. Heat treatment can be carried out at a temperature range of 160 to 240°C to complete crystal orientation of the polyester film and complete thermal curing of the coating composition to complete the formation of resin layer X and / or resin layer Y. A temperature of 180 to 240°C is particularly preferred. Heat treatment temperatures below 160°C not only result in reduced performance of the polyester substrate film, such as a decrease in the heat resistance of the substrate, but also make it difficult to achieve dense crosslinking of resin layer X and / or resin layer Y, which can lead to poor releasability of the surface layer and / or removal of the antistatic agent.

[0120] Furthermore, the solids concentration of the coating composition is preferably 40 parts by mass or less. By setting the solids concentration to 40 parts by mass or less, good coatability can be imparted to the coating composition, and a laminate film having a uniform resin layer X and / or resin layer Y can be produced.

[0121] The solid content concentration represents the ratio of the mass of the coating composition obtained by subtracting the mass of the solvent from the mass of the coating composition (i.e., [solid content concentration] = [(mass of coating composition) - (mass of solvent)] / [mass of coating composition]).

[0122] <Method for producing laminated film> Next, the method for producing the laminated film of the present invention will be specifically described using an example in which the base film is a polyethylene terephthalate (PET) film, but the laminated film of the present invention is not limited to that obtained by this production method.

[0123] First, PET pellets are thoroughly vacuum-dried, then fed into an extruder, melt-extruded into a sheet at approximately 280°C, and cooled to solidify, producing an unstretched (unoriented) PET film (film A). This film A is stretched 2.5 to 5.0 times in the longitudinal direction using rolls heated to 80 to 120°C to obtain a uniaxially oriented PET film (film B). A coating composition prepared to a predetermined concentration is applied to one side of this film B. Prior to application, the surface of the PET film to be coated may be subjected to a surface treatment such as corona discharge treatment. Surface treatment such as corona discharge treatment improves the wettability of the resin composition to the PET film, prevents cissing of the resin composition, and achieves a uniform coating thickness.

[0124] After coating, the PET film is gripped by clips at its edges and guided to a heat treatment zone (preheating zone) at 80 to 130°C, where the solvent in the coating composition is dried and, after drying, stretched 1.1 to 5.0 times in the width direction. The film is then guided to a heating zone (heat treatment zone) at 150 to 250°C and heat-treated for 1 to 30 seconds to complete the crystal orientation and the formation of resin layer X and / or resin layer Y. This heating step (heat treatment step) is believed to promote crosslinking of resin layer X and / or resin layer Y. During this heating step (heat treatment step), a relaxation treatment of 3 to 15% may be performed in the width direction or longitudinal direction, as necessary. A laminate film can be obtained in this manner, and the resulting laminate film can also be wound into a film roll.

[0125] The laminate film of the present invention will be described in more detail below using examples, but the laminate film of the present invention is not limited to these examples.

[0126] <Methods for Measuring Characteristics and Evaluating Effects> The methods for measuring characteristics and evaluating effects in the present invention are as follows.

[0127] (1) The thicknesses dx and dy of the resin layer X and the resin layer Y are ４ and / or OsO ４The laminated film was then frozen and cut parallel to the film thickness direction to obtain 10 ultrathin section samples for resin layer cross-section observation. The cross section of each sample was observed at 10,000 to 1,000,000 magnifications using a TEM (transmission electron microscope: H7100FA type manufactured by Hitachi, Ltd.) to obtain cross-sectional photographs. The thickness of the resin layer was measured using the microscope's length measurement function from the cross-sectional photographs of the 10 samples, and the obtained measured values ​​were averaged to obtain the thickness dx of resin layer X of the laminated film and the thickness dy of resin layer Y.

[0128] (2) The ratio of nitrogen atoms to carbon atoms (N / C) calculated by high-resolution Rutherford backscattering spectroscopy (HR-RBS) and the average content ratio of nitrogen atoms to carbon atoms per 1 nm of thickness of the resin layer X. The Rutherford backscattering spectroscopy is an analytical technique for obtaining information about elements in a sample by irradiating a measurement sample with an ion beam and analyzing the energy of ions scattered backward (Rutherford scattering) upon collision with elements in the sample. Information obtained by analyzing the energy of scattered ions using the Rutherford backscattering spectroscopy includes information about the type and number of elements that collide in the sample, as well as relative information about their location (i.e., depth) based on the change in energy before collision with the element.

[0129] The measurement device used was a Pelletron 3SDH manufactured by National Electrostatics Corporation. The energy was 2,300 keV and the beam diameter was 2 mm. ４ He ＋＋ The ions were irradiated onto the sample at an incident angle of 75° to the sample surface, and the scattered ４ He ＋＋ Ions were detected at scattering angles of 160° and 146° using a polarized magnetic energy analyzer. Measurements were performed with a sample current of 7 nA, an irradiation dose of 40 μC, and an energy range of 200 to 1,000 keV. The obtained spectrum was subjected to simulation fitting to convert it into a depth profile, and the surface density [atoms / cm ２] was calculated. In order to reduce damage such as burn-in caused by the measurement, measurements were performed at 10 points while shifting the position, and the data obtained by integrating these measurements was used for analysis. First, the obtained data was analyzed and separated into data derived from the substrate and data derived from the resin layer X. Specifically, the nitrogen element (N), which is not contained in the substrate of the laminated polyester film of the example of the present invention, was used as an index, and the threshold at which the nitrogen element was no longer detected was set as the boundary between the substrate and the resin layer X, and separation analysis was performed based on relative position information. Next, the areal density [atoms / cm ] of the nitrogen element obtained from the resin layer was calculated. ２ ] was calculated by dividing the surface density of carbon atoms obtained from the resin layer [atoms / cm ２ The ratio of nitrogen atoms to carbon atoms (N / C) was calculated by dividing the ratio by the thickness of the resin layer X measured in (1) to obtain the average content ratio of nitrogen atoms to carbon atoms per 1 nm of the thickness of the resin layer X.

[0130] (3) Surface Resistivity Value The surface resistivity value was measured by preparing a laminate film to be measured, leaving it at a relative humidity of 23% and 25°C for 24 hours, and then measuring it in that atmosphere using a Digital Ultra-High Resistance / Micro Ampere Meter R8340A and a Resistivity Chamber 12702A (manufactured by Advantest Corporation, main electrode: Φ50 mm, counter electrode: Φ103 mm) after applying a voltage of 100 V for 10 seconds. The unit of surface resistivity is Ω / □. The surfaces of resin layer X and resin layer Y of the laminate film opposite to the base film were evaluated, and the average value of a total of 10 measurements was used as the surface resistivity value of the sample.

[0131] (4) Surface Free Energy First, the laminated film is left to stand for 24 hours in an atmosphere at room temperature of 23°C and a relative humidity of 65%. Then, in the same atmosphere, the contact angles of four solutions, namely, pure water, ethylene glycol, formamide, and diiodomethane, on the surface side of the resin layer X of the laminated film are measured at five points for each solution using a contact angle meter CA-D model (manufactured by Kyowa Interface Science Co., Ltd.). The average value of the three measured values ​​excluding the maximum and minimum values ​​of the five measured values ​​is taken as the contact angle of each solution.

[0132] Next, using the contact angles of the four types of solutions obtained, the "surface free energy of a solid (γ) is calculated as the dispersion force component (γＳ ｄ ), polar force component (γ Ｓ ｐ ), and the hydrogen bonding strength component (γ Ｓ ｈ The dispersion force, polar force, hydrogen bonding force, and surface energy, which is the sum of the dispersion force and polar force, are calculated by the geometric mean method based on the extended Fowkes equation (extended Fowkes equation).

[0133] The specific calculation method is shown below. The meaning of each symbol is explained below. γ Ｓ Ｌ When is the tension at the interface between a solid and a liquid, equation (i) holds.

[0134] gamma Ｓ Ｌ γ: Surface energy γ of resin layer X and the known solution shown in the table Ｓ γ: surface energy of resin layer X Ｌ : Surface energy of known solutions listed in the table γ Ｓ ｄ γ: dispersion force component of surface energy of resin layer X Ｓ ｐ γ: polar force component of surface energy of resin layer X Ｓ ｈ γ: hydrogen bonding force component of the surface energy of the resin layer X Ｌ ｄ : Dispersion force component of the surface energy of the known solution listed in the table γ Ｌ ｐ : Polar force component of the surface energy of the known solutions listed in the table γ Ｌ ｈ : Hydrogen bonding force component of the surface energy of the known solution listed in the table γ Ｓ Ｌ = γ Ｓ +γ Ｌ -2(γ Ｓ ｄ ・γ Ｌ ｄ ) １／２ -2(γ Ｓ ｐ ・γ Ｌ ｐ ) １／２ -2(γ Ｓ ｈ・γ Ｌ ｈ ) １／２ ... Formula (I).

[0135] Furthermore, the state when a droplet is in contact with a smooth solid surface at a contact angle (θ) is expressed by the following equation (Young's equation):

[0136] gamma Ｓ = γ Ｓ Ｌ +γ Ｌ cosθ... Formula (b).

[0137] Combining these formulas (a) and (b), the following formula is obtained:

[0138] (γ Ｓ ｄ ・γ Ｌ ｄ ) １／２ +(γ Ｓ ｐ ・γ Ｌ ｐ ) １／２ +(γ Ｓ ｈ ・γ Ｌ ｈ ) １／２ = γ Ｌ (1+cosθ) / 2... Formula (B).

[0139] In practice, the contact angle (θ) and the surface tension components (γ) of four types of solutions, namely water, ethylene glycol, formamide, and diiodomethane, were measured. Ｌ ｄ , γ Ｌ ｐ , γ Ｌ ｈ ) into equation (C) and solve the four simultaneous equations. As a result, the surface energy of the solid (γ), the dispersion force component (γ Ｓ ｄ ), polar force component (γ Ｓ ｐ ), and the hydrogen bonding strength component (γ Ｓ ｈ ) is calculated.

[0140] (5) Method for Analyzing the Composition of the Surface of Resin Layer X The composition of the surface of the resin layer X of the laminated film was analyzed using GCIB-TOF-SIMS (GCIB: gas cluster ion beam, TOF-SIMS: time-of-flight secondary ion mass spectrometry). The measurement conditions are as follows. In the chart obtained by the measurement, the peak intensity of the fragment detected at the maximum intensity was determined as K, the fragment derived from polydimethylsiloxane (SiCH ３ ＋ The peak intensity of the fragment ion (M / Z=43) was defined as P, and the ratio P / K was calculated. When P / K<0.1, it was determined that the resin layer X did not substantially contain a silicone compound. <Sputtering conditions> Ion source: Argon gas cluster ion beam <Detection conditions> Primary ions: Bi ３＋＋ (25 keV) Secondary ion polarity: Negative Mass range: m / z 0 to 1,000 Measurement range: 200 x 200 μm ２ .

[0141] (6) Exothermic Peak Temperature (Tc) During Temperature Decrease by Differential Scanning Calorimetry (DSC) 1 g of the release agent (A) or the resin layer X cut from the surface of the laminate film was placed in an aluminum cup with a diameter of 5 cm and dried in a hot air oven at 80°C for 24 hours to prepare a solid sample of the dried release agent (A) or resin layer X. 3 mg of the prepared solid sample was taken and measured using a differential scanning calorimeter (DSC6220, manufactured by Hitachi High-Tech Science Corporation). First, in a nitrogen atmosphere, the temperature was increased from 25°C to 200°C at a rate of 20°C / min and held at 200°C for 5 minutes. The temperature was then decreased to -50°C at a rate of 20°C / min, and the peak temperature of the curve obtained during this temperature decrease was measured. This measurement was performed three times, and the average value was taken as (Tc). In this case, two or more melting peak temperatures may be observed within the temperature range, or the melting peak temperature may be a peak temperature that can be observed on a multi-stage DSC chart called a shoulder (observed in a chart where two or more peaks overlap), but in the present invention, the peak temperature at which the absolute value of the heat quantity (unit: mW) on the vertical axis of the DSC chart is greatest is defined as (Tc).

[0142] (7) X-ray absorption near edge structure (XANES) spectrum The laminate film was polished on the side opposite to the resin layer X surface, and the thickness of the laminate film was adjusted to 10 μm. A measurement sample was cut out from the polished laminate film to a length of 12 mm and a width of 6 mm. Next, the resin layer X surface of the measurement sample was irradiated with X-rays, and the amount of absorption was measured to measure the X-ray absorption fine structure (XAFS) spectrum. The measurement conditions and analysis conditions were as follows.

[0143] Experimental facility: Ritsumeikan University SR Center Experimental station: BL11 Spectrometer: Grating spectrometer Absorption edge: Carbon K (284.2 eV) absorption edge E0: 287.319 eV Pre-edge range: -20 to 10 eV Normalization range: 15 to 70 eV Detection method: Partial electron yield method using multichannel plate measurement Horizontal axis correction: Π of highly oriented pyrolytic graphite ＊ In the XAFS spectrum, the peak was corrected to 255.5 eV. For the X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge, the angle between the incident X-ray and the longitudinal vector of the resin layer X-plane of the laminate film was defined as θ, and the spectral intensity at 293.5 eV obtained by the partial electron yield method was defined as I(θ). The spectral intensity I(15°) at θ = 15° minus the spectral intensity I(90°) at θ = 90° was defined as I(15°) - I(90°).

[0144] (8) Peeling Force of Surface Layer A laminated film was cut into a size of 20 mm wide and 70 mm long, and a ceramic slurry having the following composition was applied to the resin layer X of the laminated film of the present invention using an applicator with the longitudinal direction as the traveling direction to a final thickness of 2 μm, followed by drying at 100°C for 1 minute in a hot air oven to form a ceramic sheet (surface layer). Using a peeling device "VPA-2" manufactured by Kyowa Interface Science Co., Ltd. and a 1N load cell, the opposite surface of the surface layer was fixed to the measurement stage and a 90° peel test was performed with the longitudinal direction as the traveling direction at a peel speed of 300 mm / min.

[0145] The average peel force between 15 and 35 mm was calculated from the graph of peel force (N) vs. displacement (mm) obtained by the measurement. This measurement was carried out five times, and the average of three measurements, excluding the maximum and minimum values, was taken as the peel force of the laminated film and was evaluated as follows. A rating of A or higher was considered good, and B was considered to be at a level that was acceptable for practical use.

[0146] S: Less than 20 mN / cm A: 20 mN / cm or more and less than 40 mN / cm B: 40 mN / cm or more and less than 80 mN / cm C: 80 mN / cm or more <Preparation of ceramic slurry> BaTiO ３ (manufactured by Sakai Chemical Industry Co., Ltd.) 85 parts by mass; Polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd. "S-LEC (registered trademark)" BM-2) 15 parts by mass; Dioctyl phthalate (manufactured by Kanto Chemical Co., Ltd.) 5 parts by mass; Toluene 150 parts by mass; Ethanol (manufactured by Tokyo Chemical Industry Co., Ltd.) 150 parts by mass.

[0147] Zirconia balls (YTZ-1, manufactured by Nikkato Corporation) having a diameter of 1 mm were added in an amount 2.5 times the weight of the slurry solution, and the mixture was stirred at 55 rpm for 72 hours using a mix rotor (MIX ROTOR VNRC-5, manufactured by AS ONE).

[0148] (9) Charging Property When Peeling Off the Surface Layer The ceramic sheet-attached release film obtained in (8) above, in which a ceramic sheet layer (surface layer) was laminated on the surface layer side of the laminated film, was cut to a width of 20 mm and a length of 80 mm. Next, the surface layer was peeled off from the resin layer surface of the release film by the peeling test of (8) (peeling rate 300 mm / min). The electrostatic potential on the peeled ceramic sheet side was measured using a digital electrostatic potential meter (KSD-0103, manufactured by Kasuga Electric Co., Ltd.) in an atmosphere at 20°C and 50% RH, and the absolute value of the electrostatic potential was evaluated according to the following four criteria, with S representing very good, A representing good, and B representing a level that is acceptable for practical use.

[0149] S: ≦0.05 kV A: More than 0.05 kV and 0.20 kV or less B: More than 0.20 kV and 0.50 kV or less C: >0.50 kV (10) Evaluation of Antistatic Agent Drop-off The laminated film was cut into pieces of 110 mm by 110 mm, and the ceramic slurry prepared in (8) was applied to the resin layer X of the laminated film of the present invention using an applicator so as to have a final thickness of 5 μm. The ceramic slurry was then dried in a hot air oven at 100° C. for 1 minute to form a ceramic sheet (surface layer), and the surface resistivity (SR1) of the surface layer was measured by the method in (3).

[0150] One separator of an acrylic adhesive sheet ("OCA" (registered trademark) 8146-2) manufactured by 3M was peeled off and attached to the surface layer of the ceramic laminate sheet. The acrylic adhesive sheet was then peeled off from the laminate film, and the surface layer was transferred to the acrylic adhesive sheet. The surface resistivity (SR2) of the transferred surface layer was measured using the method described in (3), and the shedding of the antistatic agent was evaluated by (SR1) / (SR2), with A representing good and B representing a level that presents no practical problems. A: (SR1) / (SR2) less than 10 (no transfer) B: (SR1) / (SR2) 10 or more but less than 100 C: (SR1) / (SR2) 100 or more <Resins, etc. used in the production of laminated films> <Release Agent (A)> - Release Agent (A-1): Long-chain alkyl resin 1 200 parts by mass of xylene and 600 parts by mass of octadecyl isocyanate were added to a four-neck flask and heated with stirring. Once the xylene began to reflux, 100 parts by mass of polyvinyl alcohol with an average degree of polymerization of 500 and a degree of saponification of 88 mol% was added in small amounts at 10-minute intervals over approximately 2 hours. After the addition of the polyvinyl alcohol was completed, the mixture was refluxed for an additional 2 hours to complete the reaction. The reaction mixture was cooled to approximately 80°C and then added to methanol, causing the reaction product to precipitate as a white precipitate. This precipitate was then filtered off, and 140 parts of xylene was added and heated to completely dissolve the mixture. Thereafter, the procedure of adding methanol again to cause precipitation was repeated several times, and the precipitate was then washed with methanol and dried and pulverized to obtain a long-chain alkyl group-containing resin (A-1): a resin having a polymethylene main chain and an alkyl group with 18 carbon atoms in the side chain. This was diluted with water to make it 20 parts by mass.

[0151] Mold release agent (A-2): Long-chain alkyl resin 2 A 25 mL pressure-resistant glass polymerization ampoule was charged with methyl methacrylate (hereinafter, MMA) (manufactured by Kanto Chemical Co., Inc.), α,α'-azobisisobutyronitrile (hereinafter, AIBN) (manufactured by Kanto Chemical Co., Inc.) as a polymerization initiator, cumyl dithiobenzoate (hereinafter, CDB) as a RAFT agent, and toluene as a solvent in a weight ratio (g) of MMA / CDB / AIBN / toluene = 2.92 / 0.03 / 0.007 / 2.27. Next, the mixed solution in the ampoule was degassed twice by freeze-degassing, and then the ampoule was sealed and heated in a 100°C oil bath for 18 hours to obtain polymerization solution 1. Next, docosyl acrylate, AIBN as a polymerization initiator, and toluene as a solvent were added to the reaction solution in the ampoule in a weight ratio (g) of docosyl acrylate / AIBN / toluene = 1.37 / 0.003 / 1.3. After two cycles of freeze-degassing, the ampoule was sealed and heated at 100°C for 48 hours. Polymerization Solution 1 was then added dropwise to 20 times the mass of hexane, followed by stirring to precipitate a solid. The resulting solid was filtered and vacuum-dried overnight at 40°C to obtain a long-chain alkyl resin (A-2) having an alkyl group with 22 carbon atoms. The resulting long-chain alkyl resin (A-2) was emulsified as follows to obtain an aqueous resin emulsion. 375 g of water was placed in a 1 L homomixer, and 45 g of polyoxyethylene nonylphenyl ether, 30 g of polyoxyethylene polyoxypropylene glycol, 200 g of long-chain alkyl resin (A-2), and 150 g of toluene were added in that order, followed by heating to 70° C. and stirring to homogenize. This mixture was transferred to a pressure homogenizer and emulsified, and then the pressure was reduced while heating to distill off the toluene.

[0152] Release agent (A-3): Long-chain alkyl resin 3 A long-chain alkyl group-containing resin (A-3: having a polymethylene main chain and an alkyl group with 12 carbon atoms on the side chain) was obtained by synthesizing it in the same manner as for the long-chain alkyl group-containing resin (A-1), except that dodecyl isocyanate was used instead of octadecyl isocyanate.

[0153] Release agent (A-4): Long-chain alkyl resin 4 An aqueous coating liquid (A-4) was prepared by dissolving a long-chain alkyl group-containing acrylic resin having the following copolymer composition in water containing 5% by weight of isopropyl alcohol and 5% by weight of n-butyl cellosolve. The lauryl methacrylate had a long-chain alkyl chain with 12 carbon atoms.

[0154] <Copolymerization components> Lauryl methacrylate 70% by weight, methacrylic acid 25% by weight, 2-hydroxyethyl methacrylate 5% by weight.

[0155] Release agent (A-5): Silicone-based release agent 100 parts by mass of a thermosetting silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KS-847H") and 1 part by mass of a catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., product name "CAT-PL-50T") were diluted with toluene to obtain a solution with a solids concentration of 1.5 parts by mass.

[0156] <Binder Resin (B)> Binder Resin (B-1): Acrylic Resin (Hydroxyl Group-Containing) Methyl methacrylate (α), ethyl acrylate (β), 2-hydroxyethyl acrylate (γ), and acrylonitrile (δ) were charged into a stainless steel reaction vessel in a mass ratio of (α) / (β) / (γ) / (δ) = 60 / 32 / 6 / 2, and 2 parts by mass of sodium dodecylbenzenesulfonate as an emulsifier was added per 100 parts by mass of (α) to (δ) combined, followed by stirring to prepare Mixed Solution 1. Next, a reaction apparatus equipped with a stirrer, reflux condenser, thermometer, and dropping funnel was prepared. 60 parts by mass of the above Mixed Solution 1, 200 parts by mass of isopropyl alcohol, and 5 parts by mass of potassium persulfate as a polymerization initiator were charged into the reaction apparatus and heated to 60°C to prepare Mixed Solution 2. Mixed Solution 2 was maintained at 60°C for 20 minutes. Next, a mixed solution 3 consisting of 40 parts by weight of mixed solution 1, 50 parts by weight of isopropyl alcohol, and 5 parts by weight of potassium persulfate was prepared. Subsequently, mixed solution 3 was added dropwise to mixed solution 2 over 2 hours using a dropping funnel to prepare mixed solution 4. Thereafter, mixed solution 4 was heated to 60 ° C and maintained for 2 hours. The obtained mixed solution 4 was cooled to 50 ° C or below and then transferred to a container equipped with a stirrer and pressure reducing equipment. 60 parts by weight of 25% aqueous ammonia and 900 parts by weight of pure water were added thereto, and isopropyl alcohol and unreacted monomers were recovered under reduced pressure while heating to 60 ° C., and an acrylic resin (B-1) dispersed in pure water was obtained.

[0157] Binder resin (B-2): Acrylic resin (containing hydroxyl and carboxyl groups) Acrylic resin (B-2) was obtained in the same manner as for binder resin (B-1), except that the starting materials charged into a stainless steel reaction vessel were methyl methacrylate (α), ethyl acrylate (β), 2-hydroxyethyl acrylate (γ), and acrylonitrile (δ) / acrylic acid (ε) in a ratio of (α) / (β) / (γ) / (δ) / (ε) = 55 / 32 / 6 / 2 / 5 (mass ratio) so that the total was 100 parts by mass.

[0158] Binder resin (B-3): Polyester resin A water dispersion of thermosetting polyester resin (Z-836, manufactured by GOO Chemical Industry Co., Ltd., solid content concentration 15% by weight) was used.

[0159] <Crosslinking Agent (C)> Crosslinking agent (C-1): Melamine resin (methylol melamine) "Nicalac" (registered trademark) MW-035 (solid content concentration 70 mass %, solvent: water) manufactured by Sanwa Chemical Co., Ltd. was used.

[0160] Crosslinking agent (C-2): Carbodiimide compound "Carbodilite" (registered trademark) V-04 (solid content concentration 40% by mass, solvent: water) manufactured by Nisshinbo Chemical Inc. was used.

[0161] <Antistatic Agent (D)> Antistatic Agent (D-1): CNT Aqueous Dispersion 1 A CNT aqueous dispersion was prepared by placing 1.0 mg of straight double-walled CNT (manufactured by Science Laboratories, Inc., diameter 5 nm, aspect ratio 3000) as the CNT, 3.0 mg of carboxymethyl cellulose sodium (Sigma-Aldrich Japan K.K.) (hereinafter, CMC-Na) as a CNT dispersant, and 666 mg of water into a sample tube, and the resulting dispersion was irradiated with ultrasound for 30 minutes using an ultrasonic crusher (VCX-502 manufactured by Tokyo Rikakiki Co., Ltd., output 250 W, direct irradiation), to obtain a CNT aqueous dispersion (D-1) (CNT concentration 0.15 wt %, CNT dispersant 0.45 wt %, CNT dispersant / CNT = 3.0) consisting of uniform CNT and CNT dispersant.

[0162] Antistatic agent (D-2): Polythiophene-based compound: 49 parts by mass of a 1% by mass aqueous solution of iron (III) sulfate, 8.8 parts by mass of 3,4-ethylenedioxythiophene (a thiophene compound), and 117 parts by mass of a 10.9% by mass aqueous solution of peroxodisulfuric acid were added to 1,887 parts by mass of an aqueous solution containing 20.8 parts by mass of polystyrene sulfonic acid, an acidic polymer compound. This mixture was stirred at 18°C ​​for 23 hours, and 154 parts by mass of a cation exchange resin ("Lewatit" (registered trademark) Monoplus S100H; manufactured by Lanxess) and 232 parts by mass of an anion exchange resin ("Lewatit" (registered trademark) Monoplus M800; manufactured by Lanxess) were added to the mixture. After stirring for 2 hours, the ion exchange resin was filtered off to obtain antistatic agent (D-2) (solids concentration: 1.3% by weight) consisting of a mixture of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonic acid.

[0163] Antistatic Agent (D-3): CNT Water Dispersion 2 CNT water dispersion 2 was prepared as follows.

[0164] First, 1.0 mg of CNT (double-walled CNT: manufactured by Science Laboratories, Inc., average diameter 5 nm), 1.0 mg of the CNT dispersant CMC-Na, and 248 mg of water were placed in a 50 mL sample tube to prepare a CNT aqueous dispersion, which was then irradiated with ultrasound for 30 minutes using an ultrasonic crusher (Tokyo Rikakiki Co., Ltd. VCX-502, output 250 W, direct irradiation) to obtain a uniform CNT aqueous dispersion (CNT concentration 0.40 wt %, CNT dispersant 0.40 wt %, (B) / (A) = 0.5).

[0165] Antistatic agent (D-4): Carbon nanofibers Carbon nanofibers having an average diameter of 15 nm and an average length of 1 μm (manufactured by JEMCO Co., Ltd., product name "CNF-T", tubular, dispersed in 3% by mass cyclohexanone) were used.

[0166] <Crosslinking catalyst> Catalyst 1: Dodecylbenzenesulfonic acid "NACURE" (registered trademark) 5528 from Kusumoto Chemicals Co., Ltd. (manufacturer: KING INDUSTRIES, NACURE DDBSA series: dodecylbenzenesulfonic acid catalyst (blocked acid catalyst)) was used.

[0167] Catalyst 2: Platinum catalyst A platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "CAT-PL-50T") was used.

[0168] Example 1 Resin composition for forming resin layer: A release agent (A-1), a binder resin (B-1), and a crosslinking agent (C-1) were mixed in a solids mass ratio of (A-1) / (B-1) / (C-1) = 25 / 30 / 45. Next, an antistatic agent (D-1) was added to a total of 100 parts by mass of the release agent (A-1), the binder resin (B-1), and the crosslinking agent (C-1) so that the solids content was 10 parts by mass, 5 parts by mass of catalyst 1 was added, and water was added according to the coating method and target thickness described below to adjust the solids concentration. Furthermore, to improve the coatability to polyester film, an acetylene diol surfactant ("Olfine" (registered trademark) EXP.4200 manufactured by Nissin Chemical Industry Co., Ltd.) was added in an amount of 0.1 parts by mass per 100 parts by mass of the mixed resin composition.

[0169] Polyester film: PET pellets (intrinsic viscosity 0.64 dl / g) containing two types of particles (4 parts by mass of silica particles with a primary particle size of 0.3 μm and 2 parts by mass of calcium carbonate particles with a primary particle size of 0.8 μm) were thoroughly vacuum-dried, fed into an extruder, melted at 280°C, extruded into a sheet from a T-shaped die, and wrapped around a mirror-finished casting drum at a surface temperature of 25°C using an electrostatic casting method, where the sheet was cooled and solidified to obtain an unstretched film (Film A). This unstretched film was then heated to 90°C and stretched 3.1 times in the longitudinal direction to obtain a uniaxially stretched film (Film B).

[0170] Laminated Film: After corona discharge treatment in air, the uniaxially stretched film was coated with a resin composition prepared by the method described above in the section on resin composition for forming the resin layer using a wire bar coater to a thickness of approximately 6 μm. The uniaxially stretched film coated with the resin composition was then clamped at both widthwise ends with clips and introduced into a tenter, where the solvent in the resin composition was dried in a preheating zone at an ambient temperature of 90-100°C. The film was then continuously stretched 3.6 times in the widthwise direction in a 100°C stretching zone, followed by heat treatment for 20 seconds in a 230°C heat treatment zone to form resin layer X. This was followed by a 5% relaxation treatment in the widthwise direction at the same temperature to obtain a laminated film with complete crystalline orientation of the polyester film. The properties of the resulting laminated film are shown in Tables 3 and 4.

[0171] Examples 2 to 7, Comparative Examples 1 to 3 Laminated films were obtained in the same manner as in Example 1, except that the formulation of the resin composition was changed as shown in Table 1. The properties of the obtained laminated films are shown in Tables 3 and 4.

[0172] Example 8 A laminated film was obtained using the resin composition of Example 1 in the following manner. A PET film "Lumirror" (registered trademark) T60 (substrate thickness: 50 μm) manufactured by Toray Industries, Inc. was used as the substrate. The resin composition was applied to the substrate using a wire bar. Next, to prevent deformation due to heat, a SUS plate film of the same shape as the film was placed on top, and the four sides were tightly held with double clips. After that, the film was dried and cured in a hot air oven at 230°C for 2 minutes to obtain a laminated film. The properties of the obtained laminated film are shown in Tables 3 and 4.

[0173] Comparative Example 4 A laminated film was prepared as follows.

[0174] First, binder resin (B-3) was added to antistatic agent (D-3), and the mixture was mixed and stirred for 15 minutes at 500 rpm using a magnetic stirrer to obtain a CNT dispersion. The composition weight ratio of antistatic agent (D-3), CNT dispersant, and binder resin (B-3) in the CNT dispersion (where the total weight of (D-3), CNT dispersant, and (B-3) is taken as 100% by weight) was as follows: (D-3) 4.0% by weight CNT dispersant 2.0% by weight (B-3) 94.0% by weight In this case, the weight ratio of CNT dispersant to (D-3) was 0.5.

[0175] Next, a long-chain alkyl group-containing acrylic resin (A-4) having the copolymerization composition shown below and the above-mentioned CNT dispersion were mixed so that [total weight of (D-3), CNT dispersant, and (B-3)] / [weight of (A-4)]=100 parts by weight / 10 parts by weight, thereby preparing a resin composition for coating.

[0176] Next, substantially particle-free PET pellets (intrinsic viscosity 0.63 dl / g) were thoroughly vacuum-dried, fed into an extruder, melted at 285°C, extruded into a sheet from a T-shaped die, and wrapped around a mirror-finished casting drum at a surface temperature of 25°C using an electrostatic casting method, where it was cooled and solidified. This unstretched film was heated to 90°C and stretched 3.4 times in the longitudinal direction to produce a uniaxially stretched film (Film B). This film was then subjected to a corona discharge treatment in air.

[0177] Next, the coating resin composition was applied to the corona discharge-treated surface of the uniaxially stretched film using a bar coater. The uniaxially stretched film coated with the coating resin composition was held at both widthwise ends with clips and introduced into a preheating zone, where the ambient temperature was adjusted to 75°C. Subsequently, the ambient temperature was adjusted to 110°C using a radiation heater, and then to 90°C, where the coating resin composition was dried. Subsequently, the film was continuously stretched 3.5 times in the widthwise direction in a heating zone (stretching zone) at 120°C, and then heat-treated for 20 seconds in a heat treatment zone (thermal setting zone) at 230°C, yielding a laminated film with complete crystal orientation.

[0178] Comparative Example 5 A laminated film was produced as follows. 100 parts by mass of silicone release agent (A-5) and 1 part by mass of catalyst 2 (platinum catalyst) were diluted with toluene to obtain a solution with a solids concentration of 1.5% by mass. Antistatic agent (D-4) was added to this solution so that its content in the total solids (antistatic release agent layer) was 5% by mass, thereby preparing a coating liquid. This coating liquid was then uniformly applied using a Meyer bar onto a 38 μm-thick polyethylene terephthalate (PET) film [manufactured by Mitsubishi Chemical Polyester Film Corporation, product name "T-100"] so that the thickness after drying would be 0.1 μm. This was then heated in a dryer at 130°C for 1 minute to form a resin layer, thereby producing a laminated film.

[0179] (Examples 9 and 10, Comparative Example 6) The resin compositions shown in Tables 1 and 2 were applied to each surface using a wire bar coater to a coating thickness of approximately 6 μm. Specifically, the surface of the uniaxially stretched film substrate opposite to the resin layer X was also subjected to a corona discharge treatment in air, and the resin composition for forming resin layer Y shown in Table 2 was applied to a coating thickness of approximately 6 μm using a wire bar coater. The resin layer Y was then formed simultaneously with the resin layer X by the same drying, stretching, and heat treatment as for the resin layer X. A laminate film was obtained in the same manner as in Example 1, except for this. The properties of the obtained laminate film are shown in Tables 3 and 4.

[0180] Examples 11 and 12: A laminated film was obtained in the same manner as in Example 3, except that PET pellets (Example 11) containing recycled materials in the proportions shown in Table 1 and a biomass material (Example 12) were used as the raw materials for the polyester film. The properties of the obtained laminated film are shown in Tables 2 and 3. The recycled material referred to here was the shredded uncoated portion removed during the polyester film production process in Examples 1 to 10, and was mixed with virgin materials for use in the production of the polyester film. The biomass material, on the other hand, was PET with a biomass content of 15%, in which some of the ethylene glycol units were derived from plants. Example 13: A laminated film was obtained in the same manner as in Example 10, except that PET pellets containing recycled materials in the proportions shown in Table 1 were used as the raw materials for the polyester film, as in Example 11.

[0181]

[0182]

[0183]

[0184]

[0185] The laminate film of the present invention has both easy releasability and antistatic properties for the resin layer, and therefore has excellent processability in the step of peeling off the surface layer, and is free from contamination by silicone and from shedding of the antistatic agent. Therefore, the laminate film of the present invention can be suitably used as a process film for the production of electronic component elements such as multilayer ceramic capacitors and inductors, and as a process film for the production of batteries such as lithium ion batteries and all-solid-state batteries.

Claims

1. A laminated film having a resin layer X containing an antistatic agent on at least one surface of a thermoplastic resin substrate film, wherein all of the following conditions (1) to (3) are met. (1) The ratio of nitrogen to carbon elements (N / C) calculated by high-resolution Rutherford backscattering (HR-RBS) measurement of the resin layer X, and the average content ratio of nitrogen atoms to carbon atoms per nm calculated from the thickness (nm) of the resin layer X, is 0.0030 [nm －１ That's all. (2) The surface resistivity of the resin layer X is 1.0 × 10⁸ Ω / □ or less. (3) The surface free energy of the resin layer X is 20.0 mN / m or more and less than 30.0 mN / m.

2. The laminated film according to claim 1, wherein the antistatic agent contained in the resin layer X is a conductive carbon material.

3. The laminated film according to claim 2, wherein the antistatic agent contained in the resin layer X is carbon nanotubes.

4. The laminated film according to claim 1, wherein, when the surface of the resin layer X is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K) [-] of the peak intensity (P) of the fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at maximum intensity is less than 0.

01.

5. The laminated film according to claim 1, wherein the resin layer X contains a long-chain alkyl resin as a release agent, and when the long-chain alkyl resin is heated from 25°C to 200°C at a rate of 20°C / min using a differential scanning calorimeter (DSC), and then cooled from 200°C to -50°C at a rate of 20°C / min, the exothermic peak temperature (Tc) during the cooling process is 30°C or higher and 90°C or lower.

6. The laminated film according to claim 5, wherein the resin layer X contains a long-chain alkyl resin and a melamine compound, and also contains at least one resin selected from the group consisting of acrylic resin, epoxy resin, and urethane resin.

7. The laminated film according to claim 1, wherein, for the resin layer X, the X-ray absorption fine structure (XAFS) spectrum measured by the partial electron yield method, specifically the X-ray absorption near-edge structure (XANES) spectrum of the carbon K absorption edge, satisfies the condition I(15°) - I(90°) ≥ 0.10, where θ is the angle between the incident X-ray and the resin layer plane, and I(θ) is the spectral intensity at 293.5 eV.

8. The laminated film according to claim 5, wherein the long-chain alkyl resin is a block copolymer.

9. The laminated film according to claim 1, wherein the thermoplastic resin substrate film is a polyester film containing at least one of biomass raw materials and recycled raw materials.

10. The laminated film according to claim 1, having a resin layer Y on the side opposite to the resin layer X, wherein the surface resistivity is 1.0 × 10⁸ Ω / □ or less on either side.

11. The laminated film according to claim 10, wherein the resin layer Y contains carbon nanotubes.

12. A laminated film according to any one of claims 1 to 11, used in the manufacturing process of an electronic component or a battery component.