Laminated film

Abstract

This laminated film comprises a resin layer on at least one surface of a resin base material. If M represents the peak intensity of fragments of positive ions showing a maximum intensity as detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, and T represents the sum of the peak intensity of positive ions of an alkali metal element and the peak intensity of positive ions of an alkaline earth metal element, T / M is 0.001-0.100. The tape peeling strength of the laminated film is at most 2.0 N / 19 mm.　Provided is a laminated film that inhibits deterioration in element performance when used as a process film for an electronic component such as a multilayer ceramic capacitor or for a component member of a battery.

Description

Laminated Film

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

[0002] Plastic films are widely used as substrate films in many applications, such as magnetic recording materials, packaging materials, etc., due to their excellent mechanical properties, electrical properties, dimensional stability, transparency, and chemical resistance. Furthermore, plastic films having a resin layer with excellent release properties on at least one outermost surface are often used as process films (hereinafter sometimes referred to as release films), such as protective films for adhesive layers in adhesive products, and carrier films in the production and processing of components for electronic components and batteries.

[0003] The resin layer of such casting films is generally formed by coating with paint, but the organic solvents contained in the paint pose a problem in terms of environmental impact. In light of this background, in recent years, in order to reduce environmental impact and improve the working environment, the use of organic solvents has been reduced and water-based paints using water as the main solvent or dispersion medium have become more widespread. For example, a film in which a layer containing a silicone compound is provided using a water-based paint (Patent Document 1) has been studied, and a casting film in which a long-chain alkyl resin that does not contain a silicone compound is used as a mold release agent in the resin layer in order to eliminate problems caused by silicone compounds, such as cissing of the coating liquid and pinholes (Patent Document 2) has been studied.

[0004] Multilayer ceramic capacitors, a type of electronic component, are small but have a wide capacitance range, and are used in a variety of electrical circuits for purposes such as noise removal and power supply voltage smoothing, making them an essential core component for increasing the functionality of mobile phones and automobiles.The manufacturing process for multilayer ceramic capacitors involves applying a dielectric ceramic slurry onto a release film, drying it, and then peeling off the layer formed by the slurry (surface layer) from the release film.

[0005] Furthermore, in recent years, research and development of all-solid-state batteries has been actively conducted as next-generation batteries that can achieve both safety and battery performance, and it is known that in all-solid-state batteries that use an oxide-based solid electrolyte, which is particularly stable in the atmosphere and resistant to heat, it is possible to increase ionic conductivity by making the internal structure of the element a laminated structure similar to that of a multilayer ceramic capacitor (Patent Document 3). A laminated all-solid-state battery that uses an oxide-based solid electrolyte can be manufactured by the same process as a multilayer ceramic capacitor, in which a solid electrolyte slurry is applied to a release film and dried to form a surface layer, and then the surface layer is peeled off from the release film to form a solid electrolyte layer.

[0006] In the above-mentioned multilayer electronic components, particularly in the multilayer ceramic capacitor, alkaline earth metal oxides such as SrO and CaO and Na are contained in the barium titanate dielectric. ２ O.K. ２ It is known that when alkali metal oxides such as O are present as impurities, they have a significant effect on the sintering state of barium titanate and, in turn, on its electrical properties (Patent Document 4).

[0007] Furthermore, in order to improve the lamination accuracy of the components in the laminated electronic components, the surface layer of the release film that comes into contact with each layer of the components of the electronic components is required to be smooth, and in particular, to have few protrusions (Patent Documents 5 and 6).

[0008] Japanese Patent Application Laid-Open No. 2010-195014 International Publication No. 2020 / 017289 Japanese Patent Application Laid-Open No. 2016-1600 Japanese Patent Application Laid-Open No. 8-191031 Japanese Patent Application Laid-Open No. 2022-174071 Japanese Patent Application Laid-Open No. 2021-24175

[0009] As a result of intensive research, the present inventors have found that when a laminate film having a resin layer formed with a water-based paint is used as a release film, alkali metal elements or alkaline earth metal elements contained in the surface of the laminate film migrate to the surface layer through the resin layer, thereby degrading the performance of components of electronic components and batteries. Furthermore, with the recent trend toward miniaturization and higher performance of electronic components and components, the thickness of each layer of dielectrics and solid electrolytes tends to decrease, and it has also been found that when the surface layer is thinner, the influence of impurities becomes more pronounced.

[0010] On the other hand, as a result of the inventors' investigation into the surface shape of the laminated film, they found that, although adjusting the maximum surface roughness Rt described in Patent Document 5 and the maximum protrusion height P described in Patent Document 6 have a certain effect in controlling the surface shape of the constituent members of electronic components, they are not suitable for controlling the peel force of the surface layer.

[0011] Therefore, in order to solve the above-mentioned drawbacks, an object of the present invention is to provide a laminated film that, when used as a process film in the manufacture of components for electronic components such as multilayer ceramic capacitors and batteries, suppresses deterioration in the performance of these components.

[0012] In order to solve the above problems, the first laminate film of the present invention and the second laminate film of the present invention have the following configuration.

[0013] The first laminate film of the present invention has a resin layer on at least one surface of a resin substrate, and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity of the positive ion fragment exhibiting the maximum intensity detected is defined as M, and the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the positive ion peak intensity of the alkaline earth metal element is defined as T, where M is the peak intensity of the positive ion fragment exhibiting the maximum intensity, and T is the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the positive ion peak intensity of the alkaline earth metal element. The laminate film has a tape peel strength of 2.0 N / 19 mm or less.

[0014] The second laminate film of the present invention has a resin layer on at least one surface of a resin substrate, and the ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－and a ratio (Fh / Fb) of a total peak intensity Fh of the fragments derived from the resin substrate to a total peak intensity Fb of the fragments derived from the resin substrate is 1.000 or more and 100.000 or less.

[0015] More specifically, the present invention has the following configurations: [1] A laminate film having a resin layer on at least one surface of a resin substrate, wherein, when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity of the positive ion fragment exhibiting the maximum intensity is M and the sum of the peak intensities of the positive ions of alkali metal elements and the positive ions of alkaline earth metal elements is T, where T / M is 0.001 or more and 0.100 or less, and the tape peeling force is 2.0 N / 19 mm or less. [2] The ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ [3] The laminate film according to [1], wherein the ratio (Fh / Fb) of the total peak intensity Fh of the fragments derived from the resin substrate to the total peak intensity Fb of the fragments derived from the resin substrate is 1.000 or more and 100.000 or less. [4] The laminate film according to [1], wherein the resin substrate has a resin layer on at least one surface thereof, the ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－A laminate film having a ratio (Fh / Fb) of the total peak intensity Fh of fragments derived from the resin substrate to the total peak intensity Fb of fragments derived from the resin substrate of 1.000 or more and 100.000 or less. [4] The laminate film according to [3], wherein T / M is 0.001 or more and 0.100 or less, where M is the peak intensity of the positive ion fragment with the maximum intensity detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, and T is the sum of the peak intensities of the peak intensities of the positive ions of alkali metal elements and the positive ions of alkaline earth metal elements. [5] The laminate film according to [3] or [4], wherein the tape peel strength of the resin layer is 2.0 N / 19 mm or less. [6] The laminate film according to any one of [1] to [5], wherein K / M is 0.001 or more and 0.050 or less, where K is the peak intensity of the positive ions of potassium detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry. [7] The laminate film according to any one of [1] to [6], wherein the resin layer has sea-island domains in an elastic modulus image taken by an atomic force microscope (AFM), and the major axis Da of the island portions in the sea-island domains is 0.05 μm or more and 10 μm or less. [8] The laminate film according to [7], wherein, when the minor axis Db of the island portions in the sea-island domains is taken as Db, the ratio Da / Db is 1.1 or more. [9] The laminate film according to any one of [1] to [8], wherein, when the peak intensity of a positive ion fragment derived from polydimethylsiloxane detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry is taken as Si, the ratio Si / M is less than 0.010.

[10] The laminate film according to any one of [1] to [9], wherein the laminate film contains at least one of a biomass raw material and a recycled raw material.

[11] The laminate film according to any one of [1] to

[10] , wherein, in an X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge of the resin layer measured by a partial electron yield method, when the angle between the incident X-ray and the resin layer surface is θ and the spectral intensity at 293.5 eV is I(θ), I(15°) - I(90°) ≧ 0.50 is satisfied.

[12] The laminate film according to any one of [1] to

[11] , wherein the resin layer contains a long-chain alkyl resin and a melamine resin.

[13] The laminate film according to

[12] , wherein the long-chain alkyl resin is a block copolymer having an acrylic backbone.

[14] The laminate film according to any one of [1] to

[13] , wherein the resin layer further contains an acrylic resin and / or a polyester resin having an acid value of 5 mgKOH / g or more.

[15] The laminate film according to any one of [1] to

[14] , which is used in the production of components for electronic components or batteries.

[16] A method for producing the laminate film according to any one of [1] to

[15] , comprising, in this order, a coating step of coating at least one surface of a polyester resin substrate sheet with a resin composition for forming the resin layer, the resin composition containing water as a main solvent; a stretching step of stretching the polyester resin substrate sheet in at least one axial direction after the resin composition has been applied; and a heat treatment step of heating the stretched polyester resin substrate sheet to form a resin layer.

[0016] According to the present invention, it is possible to provide a laminated film that, when used as a process film in manufacturing components of electronic components such as multilayer ceramic capacitors or laminated all-solid-state batteries with oxide-based solid electrolytes, can suppress deterioration in the performance of the components of the electronic components or batteries.

[0017] The laminate film of the present invention will be described in detail below. The laminate film of the present invention includes the first laminate film of the present invention and the second laminate film of the present invention. Hereinafter, unless otherwise specified, the term "laminated film of the present invention" refers to both.

[0018] The first laminate film of the present invention has a resin layer on at least one surface of a resin substrate, and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity of the positive ion fragment exhibiting the maximum intensity detected is defined as M, and the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the positive ion peak intensity of the alkaline earth metal element is defined as T, where M is the peak intensity of the positive ion fragment exhibiting the maximum intensity, and T is the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the positive ion peak intensity of the alkaline earth metal element. The laminate film has a tape peel strength of 2.0 N / 19 mm or less.

[0019] The second laminate film of the present invention has a resin layer on at least one surface of a resin substrate, and the ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ and a ratio (Fh / Fb) of a total peak intensity Fh of the fragments derived from the resin substrate to a total peak intensity Fb of the fragments derived from the resin substrate is 1.000 or more and 100.000 or less.

[0020] Time-of-flight secondary ion mass spectrometry (hereinafter sometimes referred to as TOF-SIMS) is an analytical technique that characterizes a solid surface by irradiating a solid sample with ions (primary ions), and then separating charged particles (secondary ions) from the surface by mass-to-charge ratio to characterize the surface. Because the majority of the secondary ions emitted are emitted from a single atomic or molecular layer on the solid surface, TOF-SIMS makes it possible to analyze an area several nanometers from the surface.

[0021] In addition to atomic secondary ions, TOF-SIMS can also measure and record secondary ions related to elements and molecular structures, such as fragment ions formed by bond cleavage in organic compounds, pseudo-molecular ions generated by hydrogen addition or desorption, metal cations, and oligomer ions that reflect information on average molecular weight.

[0022] As a result of extensive research, the present inventors have found that, when the peak intensity of the positive ion fragment exhibiting the maximum intensity detected when the resin layer surface of a laminate film is analyzed by TOF-SIMS is M, and the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the peak intensity of the positive ion peak intensity of the alkaline earth metal element is T, if T / M falls outside a certain range, problems will arise in the components of electronic components or batteries when such a laminate film is used as a release film for producing these components.

[0023] Here, the problems that occur in the components will be specifically explained using the example of a multilayer ceramic capacitor, which is an electronic component, and a dielectric slurry, which is a component. It has been discovered that in the process of applying a dielectric slurry for manufacturing a component of an electronic component to a laminate film, drying it, and then peeling the surface layer from the laminate film, alkali metals and alkaline earth metals present on the surface of the laminate film are transferred to the surface layer, thereby affecting the electrical properties of the multilayer ceramic capacitor, specifically reducing the capacitance and breakdown voltage of the multilayer ceramic capacitor.

[0024] The surface layer is a layer formed by applying and drying a dielectric slurry, and when the laminated film is used as a release film when manufacturing components for electronic components or batteries, these components correspond to the surface layer.

[0025] In addition, in order to stabilize the resin in water, a method is used in which the resin surface is modified with a surfactant (emulsifier) ​​that has both hydrophilic and hydrophobic groups in its molecule to emulsify the resin. Emulsifiers are broadly divided into ionic surfactants (anionic, cationic, amphoteric) and nonionic surfactants, of which anionic and nonionic surfactants are generally used as emulsifiers, and anionic surfactants, which have particularly excellent emulsifying properties, are frequently used as emulsifiers.

[0026] Anionic surfactants are surfactants that dissociate into hydrophilic negative ions when dissolved in water. Alkali metal ions such as sodium ions and potassium ions are often used as counter ions to neutralize anionic surfactants. The inventors' investigations revealed that when a laminate film having a resin layer formed on its surface using a resin emulsified with an anionic surfactant is used as a release film for manufacturing components for electronic components or batteries, the alkali metal ions contained in the release film are transferred to the surface layer (i.e., the layer of the component for the electronic component or battery), which can adversely affect the performance of these components.

[0027] On the other hand, nonionic surfactants are surfactants with hydrophilic groups that do not ionize when dissolved in water. Nonionic surfactants do not contain metal ions as counterions, but when used as emulsifiers for highly hydrophobic resins, such as long-chain alkyl resins, the amount of emulsifier used tends to be high, resulting in increased peel strength of the resin layer. Furthermore, if the amount of emulsifier used is reduced without compromising the peel strength of the laminated film, the resin emulsion diameter increases, resulting in non-uniformity of the resin layer components. This can result in areas of high peel strength or areas prone to cohesive failure within the resin layer. This can lead to components of the resin layer falling off and transferring to the surface layer when peeling off the surface layer formed from the slurry.

[0028] In addition to emulsifiers, alkali metal ions and alkaline earth metals can also be found in polymer polymerization initiators, reducing agents, neutralizing agents, and lubricating particles in resin substrates. Therefore, with conventional laminate film design, these components contained in the resin layer migrate to the surface layer, causing an unavoidable problem of performance degradation in the components of electronic parts and batteries.

[0029] As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by a laminate film having a resin layer on at least one side of a resin substrate, and in which, when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity of the positive ion fragment exhibiting the greatest intensity is defined as M, and the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the positive ion peak intensity of the alkaline earth metal element is defined as T, the T / M is 0.001 or more and 0.100 or less, and the tape peel strength is 2.0 N / 19 mm or less, i.e., the first laminate film of the present invention.

[0030] In the first laminate film of the present invention, when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity of the positive ion fragment exhibiting the maximum intensity is M, and the sum of the peak intensities of the positive ions of alkali metal elements and the positive ions of alkaline earth metal elements is T. The T / M ratio must be 0.001 or more and 0.100 or less, with the upper limit of T / M being preferably 0.050, and more preferably 0.010. The lower limit of T / M is not particularly limited, but is set to 0.001 from the viewpoint of practical feasibility. When T / M satisfies the above-mentioned range, performance degradation and the occurrence of defective products can be suppressed when components of electronic components or batteries are manufactured using the laminate film of the present invention. Similarly, in the second laminate film of the present invention, the T / M ratio is preferably 0.001 or more and 0.100 or less from the above-mentioned viewpoint, with the upper and lower limits more preferably falling within the aforementioned preferred ranges. Details of the measurement method using time-of-flight secondary ion mass spectrometry will be described later.

[0031] In the laminated film of the present invention, methods for setting T / M within the above range include, for example, a method of using a nonionic surfactant and an emulsifying aid in combination as an emulsifier for the resin contained in the coating composition as described below, a method of controlling the content of the emulsifier within a preferred range, a method of introducing a structure containing a reactive emulsifier at the resin polymerization stage, a method of using organic particles as easy-slip particles in the base film, a method of reducing the amount of coating composition used by lowering the peel strength of the surface layer, a method of using in-line coating in forming the resin layer described below, etc. Note that all of these methods are not essential and can be used in appropriate combination.

[0032] The first laminate film of the present invention is required to have a tape peel strength of 2.0 N / 19 mm or less in order to be suitably used as a release film in the manufacturing process of components for electronic parts and batteries. By adopting such an embodiment, the surface layer formed by coating a slurry can be easily peeled off, and the peeling and transfer of resin layer components can be suppressed. From the above viewpoints, the tape peel strength is preferably 1.5 N / 19 mm or less, more preferably 1.0 N / 19 mm or less, and even more preferably 0.5 N / 19 mm or less.

[0033] Although there are no particular restrictions on the lower limit of the tape peeling force, it is preferably 0.005 N / 19 mm from the viewpoint of preventing peeling of the surface layer in a process in which a surface layer is provided on a resin layer to form a laminate and the laminate is transported by a roll. Also, in the second laminate film of the present invention, from the above viewpoints, the tape peeling force is preferably 2.0 N / 19 mm or less, and the upper and lower limits thereof are more preferably in the preferred ranges described above.

[0034] The tape peeling force is an index representing the magnitude of the interaction between the resin layer and the surface layer, and if the interaction between the resin layer and the surface layer is reduced, the surface layer can be peeled off from the resin layer with a lower force. If the tape peeling force exceeds 2.0 N / 19 mm, the surface layer may not peel off from the resin layer in the step of peeling off the surface layer, resulting in film rupture and a decrease in yield.

[0035] In the present invention, the tape peeling force can be measured by the following method. First, an acrylic polyester adhesive tape (Nitto Denko Corporation, No. 31B tape, 19 mm wide) is laminated onto the resin layer of the laminated film of the present invention, and a 2 kgf roller is rolled back and forth once from above. The laminated film to which the tape is attached is then left to stand for 24 hours in an environment of 25°C and 65% RH, and then the peel load measured when peeled at a peel angle of 180° and a tensile speed of 300 mm / min using a Shimadzu Corporation universal testing machine "Autograph AG-1S" is taken as the tape peeling force. A specific method for measuring the tape peeling force will be described later. Tapes having equivalent adhesive properties and measuring devices capable of similar measurements may also be used.

[0036] To control the tape peeling force to 2.0 N / 19 mm or less or within the above-mentioned preferred range, for example, methods include controlling the content of the emulsifier in the resin contained in the coating composition within a preferred range, incorporating a preferred release agent into the resin layer, increasing the content, and using a preferred crosslinking agent in the resin layer. Details of preferred release agents will be described later, but it is particularly preferable to use long-chain alkyl resins, which are oriented and crystallized perpendicular to the surface, thereby exposing alkyl groups with low surface free energy to the surface. Furthermore, it is preferable to use a melamine compound as the crosslinking agent, as it is easier to achieve light peeling. Note that all of these methods are not essential, and they can be used in combination as appropriate.

[0037] The second laminate film of the present invention has a resin layer on at least one surface of a resin substrate, and the ratio of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer (Sv / Th) is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ The ratio (Fh / Fb) of the total peak intensity Fh of the fragments derived from the resin substrate to the total peak intensity Fb of the fragments derived from the resin substrate must be 1.000 or more and 100.000 or less. It is preferable that the first laminate film of the present invention also satisfies the above requirement.

[0038] First, when the laminated film of the present invention is used as a release film for manufacturing components of electronic components or batteries, the resin layer is the surface layer that comes into contact with the components of the electronic components or batteries. Therefore, the surface shape of the resin layer is transferred to the surface layer in a reversed form of unevenness. That is, if the resin layer has protrusions, depressions will occur in the surface layer, and conversely, if the resin layer has depressions, protrusions will be formed in the surface layer.

[0039] As a result of the inventors' investigations, it was found that the stress during peeling is least transmitted to the protrusions of the surface layer formed by the flow of the slurry for forming the surface layer into the depressions in the resin layer, resulting in the transfer of part of the surface shape of the resin layer to the surface layer during peeling, or worse, hindering the production of components for electronic components or batteries. That is, the surface shape that the second laminate film of the present invention should satisfy (preferably the first laminate film of the present invention) is characterized by a small number of depressions. On the other hand, from the viewpoint of production costs when considering industrial applications, a thin resin layer is preferable, but controlling depressions becomes more difficult as the resin layer becomes thinner, so the roughness must be designed taking the thickness of the resin layer into account.

[0040] In order for the second laminate film of the present invention to be suitably used as a release film for use in the manufacturing process of components for electronic parts and batteries, it is necessary that the ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer be 0.001 or more and 0.50 or less (hereinafter, the ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer may be simply referred to as the "resin layer ratio (Sv / Th)").

[0041] If the ratio (Sv / Th) of the resin layer exceeds 0.50, it may hinder the peeling of the aforementioned electronic components and battery components, which may result in a deterioration in the performance of these electronic components and battery components. From the above perspective, the ratio (Sv / Th) of the resin layer is more preferably 0.30 or less, even more preferably 0.25 or less, and particularly preferably 0.10 or less. On the other hand, regarding the lower limit of the ratio (Sv / Th) of the resin layer, from the above perspective, it is ideal for the resin layer to have no recesses, but in reality, the surface shape varies, so 0.001 is considered to be the measurement lower limit.

[0042] In the first laminate film of the present invention, the resin layer preferably has a ratio (Sv / Th) of 0.001 or more and 0.50 or less. By setting the resin layer ratio (Sv / Th) to 0.001 or more and 0.50 or less, peeling of the surface layer is favorable, and it is possible to control T / M, where M is the peak intensity of the positive ion fragment exhibiting the maximum intensity detected when the surface of the resin layer in the first laminate film is analyzed by time-of-flight secondary ion mass spectrometry, and T is the sum of the peak intensity of the positive ion peak intensity of the alkali metal element and the positive ion peak intensity of the alkaline earth metal element.

[0043] The maximum valley depth Sv of the resin layer can be measured and calculated in accordance with ISO 25178-2:2012 and ISO 25178-3:2012, and the thickness Th of the resin layer can be measured by observing the cross section with a transmission electron microscope (details of the measurement method will be described later). However, since the maximum valley depth Sv is affected by the observation field, information contained in an observation field of approximately 500 μm observed with a 10x objective lens is used.

[0044] On the other hand, the meaning of the information obtained by TOF-SIMS analysis is as described above, and the specific measurement method will be described later. ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－The meaning of the fragments consisting of these will be explained. These fragments are derived from amphiphilic materials, which are a general term for leveling agents, surfactants, wetting agents, etc. The amphiphilic materials are added in the process of manufacturing the laminated film of the present invention for the purpose of alleviating the recessed shape of the resin layer described above. The peak intensity F detected by time-of-flight secondary ion mass spectrometry of the surface of the resin layer is a value corresponding to the number of fragments of interest. More specifically, in time-of-flight secondary ion mass spectrometry, accelerated primary ions are irradiated onto the resin layer to be measured, generating secondary ions containing components of the resin layer. These ions are then measured and analyzed using a time-of-flight mass spectrometry unit. The peak intensity F is a value corresponding to the intensity of the weight (mass number, peak position) and number (signal intensity, peak size) of each ion. ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ The total peak intensity Fh of the fragments consisting of (a) and (b) is a value corresponding to the blending ratio of the amphiphilic material contained in the resin layer. The inclusion of the amphiphilic material in the resin layer can be one of the means for adjusting the maximum valley depth Sv of the resin layer constituting the laminate film of the present invention to 0.001 or more and 0.50 or less, or to the above-mentioned preferred range.

[0045] In the laminate film of the present invention, the resin substrate is a sheet-like resin that serves as the base substrate for the resin layer. The total peak intensity Fb of fragments derived from the resin substrate is the intensity of signals derived from the base substrate that are detected by transmitting through the resin layer in TOF-SIMS analysis, and the peak intensity increases when the resin layer formed on the surface has a thickness, particularly when there are partially thinned portions (i.e., recesses). That is, in the peak intensity F detected by time-of-flight secondary ion mass spectrometry of the surface of the resin layer, ４５ C ２ H ５ O ＋ , ５９ C ３ H７ O ＋ and ７５ SiCH ３ O ２－ The ratio (Fh / Fb) of the total peak intensity Fh of the fragments consisting of the above to the total peak intensity Fb of the fragments derived from the resin substrate being 1.000 or more and 100.000 or less means that the specific composition and thickness of the resin layer are preferable for controlling the ratio (Sv / Th) of the resin layer described above within a suitable range.

[0046] In the following description, "the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ The ratio (Fh / Fb) of the total peak intensity Fh of the fragments derived from the resin substrate to the total peak intensity Fb of the fragments derived from the resin substrate is sometimes simply referred to as the "resin layer ratio (Fh / Fb)." In the laminate film of the present invention, from the above-mentioned viewpoint, there is a preferred value for the resin layer ratio (Fh / Fb), and specifically, it is preferably 1.500 or more and 50,000 or less, more preferably 1.800 or more and 7,000 or less, and particularly preferably 2.000 or more and 7,000 or less.

[0047] If the resin layer ratio (Fh / Fb) is less than 1.000, the effect of reducing recesses in the resin layer constituting the laminate film of the present invention may not be sufficiently achieved. Therefore, when the laminate film of the present invention is used as a release film for the aforementioned electronic components or battery components, the shape of the resin layer may be transferred to these components or components, hindering the formation of a uniform surface, which may result in a deterioration in the performance of these components, components, and devices using them. On the other hand, if the resin layer ratio (Fh / Fb) exceeds 100.000, an excess of amphiphilic material will be present in the resin layer. Therefore, when such a laminate film is used as a release film for the manufacturing process of electronic components or battery components, the amphiphilic material and its counterions, alkali metals and alkaline earth metals, will be more likely to migrate to these components and components, which may result in a deterioration in the performance of these components, components, and devices using them.

[0048] An example of a secondary ion classified into a fragment derived from an amphiphilic material is, for example, an alkylene glycol-derived ion. ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ (both positive ions), derived from siloxane ７５ SiCH ３ O ２ － Preferred coating compositions corresponding to the fragments derived from amphiphilic materials will be described later.

[0049] On the other hand, the secondary ions classified as fragments derived from the resin substrate in the laminated film of the present invention depend on the resin substrate actually used. For example, in the case of polyethylene terephthalate, １２１ C ７ H ５ O ２ － , ３５７ C １８ H １３ O ８ － , ４７５ C２６ H １９ O ９ － (both negative ions), and in the case of polyethylene naphthalate １２６ C １０ H ６ － , １７１ C １１ H ７ O ２ － , ２１５ C １２ H ７ O ４ － (both negative ions), and in the case of polypropylene ５５ C ４ H ７ ＋ , ６９ C ５ H ９ ＋ (both positive ions), and in the case of polyimide ３０７ C １６ H ７ N ２ O ５ － , ４２４ C ２３ H １０ N ３ O ６ － (All of these are negative ions) etc. Preferred resin substrates will be described later.

[0050] In the following, the "amphiphilic material" may be referred to as a "surfactant."

[0051] The laminate film of the present invention has a resin layer on at least one surface of the resin substrate. The resin substrate and resin layer in the laminate film of the present invention will be described in detail below. There are no particular restrictions on the type of resin substrate, but polyester films are preferably used from the viewpoints of smoothness, heat resistance, and cost (hereinafter, polyester films used as resin substrates may be referred to as "substrate films" or "substrates"). A polyester film refers to a sheet-like molded product whose main component is polyester, and the "main component" refers to a resin component that accounts for more than 50% by mass when the total resin constituting the film is taken as 100% by mass. Unless otherwise specified, the definition of "main component" can be interpreted in the same way.

[0052] The polyester used in the resin substrate of the laminate film of the present invention will now be described. First, polyester is a general term for polymers having repeating ester bonds in the main chain. The resin substrate of the laminate film of the present invention preferably comprises, as a main structural unit, at least one structural unit 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. Here, the main structural unit refers to the structural unit that is most abundant in the molecular chain constituting the resin in terms of moles; a specific example is the ethylene terephthalate unit in polyethylene terephthalate. Note that one type of polyester may be used, or multiple types may be used in combination.

[0053] The polyester film using the above polyester is preferably a biaxially oriented polyester film. A biaxially oriented polyester film is a polyester film in which molecules are oriented in two perpendicular directions, and 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 by approximately 2.5 to 5.0 times in both the longitudinal direction, which is the running direction of the film during the manufacturing process, and the width direction, which is perpendicular to the longitudinal direction within the film plane, and then subjecting it to heat treatment to complete the crystal orientation. Biaxially oriented polyester films have excellent thermal stability, particularly dimensional stability and mechanical strength, and also have good flatness.

[0054] 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.

[0055] The thickness of the polyester film is not particularly limited and is 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 100 μm in terms of mechanical strength, handleability, etc. Having a certain thickness of the polyester film ensures strength, and conversely, not making the thickness excessively large ensures handleability.

[0056] The film used as the resin substrate may be a single-layer film, a coextruded composite film, or a composite film formed by laminating the obtained films together using various methods. Examples of films having a two-layer laminate structure include those consisting of an A layer / B layer, and examples of films having a three-layer laminate structure include those having a two-type three-layer structure of an A layer / B layer / A layer, and those having a three-type three-layer structure of an A layer / B layer / C layer. Examples of films having a four or more layer laminate structure include those having an intermediate layer with a laminate structure. The same layer structure can be used whether a polyester film or other film is used as the resin substrate.

[0057] When the resin substrate in the laminated film of the present invention has a laminated structure of two or more layers, the surface layer on the side opposite to Layer A on which the resin layer is provided may contain lubricating particles within a range that does not impair the object of the present invention.

[0058] The slippery particles may be either inorganic or organic. Examples of inorganic slippery particles include calcium carbonate, agglomerated alumina, aluminum silicate, silicon oxide, barium sulfate, mica, clay, and talc. Examples of organic slippery particles include polyimide resins, olefin or modified olefin resins, cross-linked polystyrene resins, and silicone resins.

[0059] When the laminate film of the present invention contains lubricating particles in the outermost layer opposite Layer A, the lubricating particles may detach from the outermost layer opposite Layer A and migrate to the surface of the resin layer on the Layer A side when the film is wound into a roll. If this occurs, the particles may be mixed into the components of electronic components or batteries bonded to Layer A, potentially degrading the performance of these components or components. To alleviate this problem, organic particles are preferably used as the lubricating particles. Furthermore, from the perspective of suppressing the detachment of lubricating particles, a method of modifying the particle surface with a surfactant or the like to improve affinity with the resin components of the resin substrate containing the particles is also preferably employed. In particular, when the resin substrate is polyester, crosslinked polystyrene particles composed of a styrene-divinylbenzene copolymer prepared by emulsion polymerization are preferably used. Such crosslinked polystyrene particles are preferred because they have a nearly spherical particle shape, a more uniform particle size distribution, and the ability to form uniform protrusions. The above-described configuration suppresses the migration of lubricating particles to the resin layer due to detachment, thereby enabling the T / M of the laminate film to be controlled low.

[0060] From the viewpoint of reducing environmental impact, it is preferable that the resin substrate of the present invention contains at least one of biomass raw materials and recycled raw materials. To produce such a laminated film, it is preferable to use a polyester film containing at least one of biomass raw materials and recycled raw materials as the resin substrate. 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.

[0061] 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.

[0062] The lower limit of the biomass degree of the polyester constituting the laminated 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 more preferable, with 100% being the upper limit. However, from the viewpoint of achieving both production costs and a reduction of the environmental load, it is practically preferable that the upper limit of the biomass degree is 20%.

[0063] As a known method for analyzing the presence or absence of biomass raw materials, for example, the carbon isotope ( １４ C).

[0064] The recycled raw material is a raw material that is recovered and reused from polyester that has been made into a chemical product once or multiple times. Examples of the recycled raw material 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 that have been distributed in a form other than a film, such as bottles.

[0065] In the laminate film of the present invention, the proportion (recycle rate) of recycled polyester (recycled raw material) in 100% by mass of polyester contained in the laminate film is preferably 90% by mass or less. By limiting the use of recycled polyester to 90% by mass or less, the amount of highly crystalline polyester that was once made into a chemical product is reduced, thereby reducing deterioration in the thermal properties and transparency of the resulting laminate film and reducing coloration.

[0066] The laminate film of the present invention has a resin layer on at least one surface of the resin substrate for peeling off a surface layer formed on the laminate film (such as an electronic component or a battery component formed on the surface of the laminate film). Here, the resin layer refers to a layer whose main component is a resin and is located on the outermost surface. The resin layer in the laminate film of the present invention plays a role in improving releasability from the surface layer formed from a slurry.

[0067] From the viewpoint of enabling more suitable use of the laminate film of the present invention as a release film for producing components for electronic components and batteries, it is preferable that the K / M ratio be 0.001 or more and 0.050 or less, where K is the peak intensity of potassium positive ions detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry. From the above viewpoint, the upper limit of K / M is preferably 0.025, more preferably 0.010. The lower limit of K / M is not particularly limited, but is set to 0.001 from the viewpoint of practical feasibility. When K / M satisfies the above range, the crystal structure of the sintered body can be made more uniform in the step of sintering the surface layer, thereby more effectively suppressing performance degradation and the occurrence of defective products when components for electronic components and batteries are produced using the laminate film of the present invention.

[0068] Methods for setting K / M within the above range include, for example, a method of using a nonionic surfactant and an emulsifying aid in combination as an emulsifier for the resin contained in the coating composition as described below, a method of introducing a structure containing a reactive emulsifier at the polymerization stage of the resin that constitutes the resin layer, a method of controlling the content of the emulsifier within a preferred range, a method of reducing the amount of coating composition used by lowering the peel strength of the surface layer, a method of using in-line coating in forming the resin layer, etc. All of these methods are not essential and can be used in combination as appropriate.

[0069] In the laminate film of the present invention, the resin layer preferably has sea-island domains in an elastic modulus image taken with an atomic force microscope (AFM), and the long diameter Da of the island portions in the sea-island domains is preferably 0.05 μm or more and 10 μm or less. When the resin layer is formed from a coating composition containing a release agent (e.g., a long-chain alkyl resin) and resins other than the release agent and other components (e.g., a crosslinking agent, a binder resin, and an additive), the release agent, which has a relatively low surface free energy, tends to be present in large amounts in the island portions of the sea-island domains in the resulting resin layer.

[0070] A Da of 10 μm or less means that each component in the resin layer is uniformly distributed on the surface, and specific components are not locally unevenly distributed. When each component of the resin layer is locally unevenly distributed, there are areas where the peel strength is high and areas where the resin layer is prone to cohesive failure. Therefore, when peeling off the surface layer formed on the resin layer, components of the resin layer may fall off and migrate (transfer) to the surface layer. In other words, by setting Da to 10 μm or less, performance degradation of electronic components or battery components formed on the surface of the resin layer and the occurrence of defective products can be suppressed. From the above viewpoints, the upper limit of Da is preferably 5.0 μm or less, more preferably 3.9 μm or less, even more preferably 2.5 μm or less, and particularly preferably 1.0 μm or less. The lower limit of Da is not particularly limited, but is 0.001 μm, which is practically measurable.

[0071] Da can be measured by observing the surface of the resin layer side of the laminated film with an AFM, and the details of the measurement method will be described later (the same applies to Db described later). The method of setting Da within the above range can be controlled, for example, by the emulsification method or skeleton of the release agent, but in consideration of compatibility with the composition of the surface of the resin layer described above, a more preferred method is to adjust the compatibility of each component of the coating composition that forms the resin layer by controlling the ratio of reactive functional groups in the release agent or by controlling the Hansen solubility parameter (HSP value) described later.

[0072] The resin layer of the laminate film of the present invention preferably has a Da / Db ratio of 1.1 or more, where Db is the minor axis of the island portion in the sea-island domain. A Da / Db ratio in the above range means that the island portion is elliptical. When the laminate film of the present invention is used as a release film, setting Da / Db in the above range can improve the releasability when the surface layer is peeled in a direction perpendicular to the line corresponding to Da. As a result, when peeling a surface layer (corresponding to a component of an electronic component or a battery) formed on the surface of the resin layer using a slurry, for example, it is possible to reduce the detachment and migration (transfer) of the release agent and other components of the resin layer to the surface layer, thereby suppressing performance degradation of the component of the electronic component or the battery and the occurrence of defective products.

[0073] From the above viewpoints, Da / Db is more preferably 1.3 or more, even more preferably 1.5 or more, and particularly preferably 1.7 or more. The method for achieving Da / Db in the above range is not particularly limited, but examples include an in-line coating method in which a coating composition for forming a resin layer is applied to a uniaxially stretched film that has been stretched in the longitudinal direction, and the coating composition is dried and stretched in the width direction of the film in the same process, and selection of a surfactant to be used in the coating composition, particularly the combined use of two types of surfactants, etc.

[0074] In order to prevent contamination of the surface layer with silicone when the resin layer in the laminate film of the present invention is used as a release film, it is preferable that Si / M is less than 0.01, where Si is the peak intensity of a positive ion fragment derived from polydimethylsiloxane detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry.

[0075] When the peak intensity ratio Si / M in time-of-flight secondary ion mass spectrometry is within the above-mentioned preferred range, the resin layer contains fewer components derived from polydimethylsiloxane. Therefore, when the laminate film of the present invention is used as a process film for manufacturing electronic components or battery components, the silicone compound derived from polydimethylsiloxane is less likely to migrate (transfer) to the product, thereby reducing problems such as defective elements and defective products. From the viewpoint of feasibility, Si / M is more preferably less than 0.001 (the lower limit of measurement). As a method for adjusting the Si / M of the resin layer of the laminate film of the present invention to the above-mentioned range, for example, a method using a release agent that does not contain silicone can be mentioned.

[0076] In the laminate film of the present invention, the resin layer is measured by the partial electron yield method using an X-ray absorption fine structure (XAFS: X-ray Absorption Fine Structure) spectrum. In the X-ray absorption near edge structure (XANES: X-ray Absorption Near Edge Structure) spectrum at the carbon K absorption edge, the angle between the incident X-ray and the resin layer surface is θ, and the spectral intensity at 293.5 eV is I(θ). The resin layer preferably satisfies I(15°)-I(90°)≧0.50. This means that there is a bias in the orientation direction of the long-chain alkyl groups in the resin layer, specifically, that orientation is promoted in the direction perpendicular to the film surface.

[0077] By adopting such an embodiment, components of the surface layer (corresponding to a component of an electronic component or battery) of a ceramic slurry or the like are less likely to penetrate into the resin layer, improving the peelability between the resin layer and the surface layer. This reduces the likelihood of components of the resin layer falling off or migrating (transferring) to the surface layer, thereby suppressing performance degradation and the occurrence of defective products in electronic components or battery components bonded to the resin layer. From the above perspective, I(15°)-I(90°)≧0.60 is more preferable, and I(15°)-I(90°)≧0.70 is even more preferable. By setting I(15°)-I(90°) within the above-mentioned preferred range, it is possible to improve the peelability between the resin layer and the surface layer even when using a release agent that does not contain silicone.

[0078] I(θ) can be measured from an X-ray absorption fine structure (XAFS) spectrum obtained by irradiating the polished resin layer surface of a measurement sample with X-rays and measuring the amount of absorption. The measurement method will be described in detail later.

[0079] One method for achieving I(15°)-I(90°)≧0.50 is to incorporate a silicone-free release agent into the resin layer, and to adjust the type and amount of the release agent by a preferred method described below. While there are no particular limitations on the upper limit of I(15°)-I(90°), the upper limit achievable from practical materials and processes is generally 10.00, and preferably 1.00.

[0080] The thickness of the resin layer of the laminate film of the present invention is not particularly limited, but is preferably greater than 5 nm and less than 100 nm. It is more preferably 10 nm to 80 nm, and even more preferably 15 nm to 40 nm. By setting the thickness of the resin layer within the above range, it is possible to reduce the amount of coating composition used to form the resin layer and reduce the absolute amount of components migrating from the resin layer to the surface layer while ensuring the functionality of the resin layer. More specifically, a resin layer thickness of greater than 5 nm makes it easier to sufficiently ensure the functionality of the resin layer, and a resin layer thickness of less than 100 nm reduces the absolute amount of components migrating from the resin layer to the surface layer, thereby reducing performance degradation and the occurrence of defective products in electronic components or battery components formed as the surface layer.

[0081] The thickness of the resin layer can be measured from a cross-sectional photograph of the laminated film cut parallel to the thickness direction (direction perpendicular to the film surface), and the details will be described later. The thickness of the resin layer can also be adjusted by adjusting the thickness of the coating film.

[0082] A preferred coating composition for forming the resin layer of the laminated film of the present invention will now be described.

[0083] Examples of release agents that can be used in the resin layer of the laminated film of the present invention include long-chain alkyl resins, silicone resins, olefin resins, fluorine compounds, wax compounds, etc. Among these, long-chain alkyl resins are preferred because they can exhibit good release properties while suppressing component migration to the surface layer.

[0084] When a long-chain alkyl resin is used as a release agent, it is preferable that the resin contains 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 in the present invention is a copolymer resin having a long-chain alkyl group and a reactive functional group. Examples of the reactive functional group include a hydroxyl group, a carboxyl group, an amino group, a glycidyl group, an isocyanate group, a vinyl group, an acrylic group, and a methacrylic group. However, from the viewpoint of compatibility with water, which is a preferred solvent described below, a hydroxyl group is particularly preferred. The reactive functional group may be of one type or multiple types.

[0085] In the copolymer resin having a long-chain alkyl group and a reactive functional group, the ratio of the long-chain alkyl group monomer to the monomer having the reactive functional group is preferably 50 to 99% by mass, more preferably 60 to 97%, even more preferably 70 to 95%, and particularly preferably 80 to 95%. By using the long-chain alkyl group-containing monomer in the above-mentioned ratio, the compatibility of the release agent with other components (for example, crosslinking agents, binder resins, and additives) can be improved, and it becomes easy to control the long diameter Da and I(15°)-I(90°) of the island portions of the sea-island domains in an elastic modulus image obtained by atomic force microscopy (AFM) within preferred ranges.

[0086] From the viewpoint of allowing the resin layer of the laminate film of the present invention to function as a release layer, the resin layer preferably contains a long-chain alkyl resin as a release agent, and when the long-chain alkyl resin or a resin layer cut from the surface of the laminate film is heated by a differential scanning calorimeter (DSC) from 25° C. to 200° C. at 20° C. / min and then cooled from 200° C. to −50° C. at 20° C. / min, the exothermic peak temperature (Tc) during the cooling process is preferably 30° C. or higher and 90° C. or lower. The exothermic peak temperature (Tc) is more preferably 35° C. or higher and 80° C. or lower, and even more preferably 45° C. or higher and 80° C. or lower.

[0087] By setting the exothermic peak temperature (Tc) to 30° C. or higher and 90° C. or lower, the long-chain alkyl groups of the release agent are more likely to be vertically oriented. As a result, I(15°)-I(90°) can be easily controlled within a preferred range, and the surface layer exhibits easy releasability.

[0088] Commercially available long-chain alkyl resins may be used, and specifically, the "Ashio Resin" (registered trademark) series, which are long-chain alkyl compounds manufactured by Asio Sangyo Co., Ltd., the "Peeroil" (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.

[0089] 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 number of carbon atoms in the alkyl group 12 or more, hydrophobicity is increased, and sufficient performance as a release agent can be exhibited. 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 facilitates the production of the laminated film.

[0090] 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 the signal corresponding to the alkyl group obtained by TOF-SIMS. 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 the alkyl group-containing compound can also be evaluated.

[0091] In the laminated film of the present invention, the long-chain alkyl resin is preferably a block copolymer having an acrylic backbone. When the release agent is such a block copolymer, the long-chain alkyl groups of the release agent are more likely to be vertically oriented, making it easier to control I(15°)-I(90°) within a preferred range, and exhibiting easy releasability of the surface layer.

[0092] The method for producing such a block copolymer is not particularly limited as long as it is a living radical polymerization method other than atom transfer radical polymerization (ATRP), and various polymerization methods can be used, such as reversible addition-fragmentation chain transfer polymerization (RAFT), polymerization using an organotellurium compound (TERP), polymerization using an organoantimony compound (SBRP), polymerization using an organobismuth compound (BIRP), and living radical polymerization methods with an exchange chain mechanism such as iodine transfer polymerization, as well as the nitroxy radical method (NMP). Among these, the RAFT and NMP methods are preferred from the viewpoints of polymerization controllability and ease of implementation.

[0093] When the release agent is applied as a water-based coating to form a resin layer, it is preferable to emulsify the release agent with an emulsifier in order to stabilize the release agent in water. Examples of the emulsifier include general anionic surfactants and nonionic surfactants, and at least one of these can be used.

[0094] Examples of anionic surfactants include carboxylic acid types such as fatty acid monocarboxylates and N-acyloylglutamates; sulfonic acid types such as alkylbenzenesulfonates, naphthalenesulfonate-formaldehyde condensates and dialkyl sulfosuccinates; sulfate ester types such as alkyl sulfates; and phosphate ester types such as alkyl phosphates.

[0095] Examples of nonionic surfactants include ether-type surfactants such as polyoxyethylene alkylphenyl ethers and polyoxyethylene alkyl ethers, ester-ether-type surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyethylene glycol fatty acid esters and polyoxyethylene sorbitan fatty acid esters, and fatty acid alkanolamide-type surfactants.

[0096] When an anionic surfactant is used as an emulsifier for the release agent, the amount thereof is preferably 0.1 parts by mass or more and 5 parts by mass or less relative to 100 parts by mass of the release agent. The upper limit of the amount of the anionic surfactant is preferably 3 parts by mass or less, and more preferably 1.5 parts by mass or less. By setting the amount of the anionic surfactant to be in the above range, it becomes easy to maintain a low T / M value in the present invention.

[0097] When a nonionic surfactant is used as an emulsifier for the release agent, the amount thereof is preferably 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the release agent. The upper limit of the amount of the nonionic surfactant is more preferably 40 parts by mass, and even more preferably 30 parts by mass. By using the nonionic surfactant in the above amount, it becomes easy to maintain a low T / M value in the present invention, and at the same time, the peel force when peeling the surface layer from the resin layer of the laminated film can be kept low, and deterioration of the element performance of the surface layer (constituent member of electronic components and batteries) formed from the slurry due to detachment or migration (transfer) of the resin layer components can be suppressed. Furthermore, the lower limit of the amount of the emulsifier is 1 part by mass from the viewpoint of stabilizing the emulsion particles.

[0098] When a nonionic surfactant is used as an emulsifier, it is more preferable to use an emulsifying aid in combination to further enhance its effect. Examples of emulsifying aids include higher alcohols such as cetyl alcohol and lauryl alcohol, higher fatty acids such as lauric acid, palmitic acid and stearic acid, oxidized wax, chlorinated paraffin, and liquid paraffin.

[0099] The amount of emulsifier added can be appropriately set depending on the type of emulsifier, the types and amounts of other ingredients, etc., but is preferably 0.1 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the release agent. By setting the amount in this range, emulsion particles can be easily formed, and the stability of the emulsion can be improved, resulting in a laminate film with excellent surface layer peelability. From the above perspective, the upper limit of the amount of emulsifier added is more preferably 3.0 parts by mass, and even more preferably 1.0 part by mass.

[0100] The method for emulsifying the release agent is not particularly limited. For example, a method (high-pressure emulsification method) can be used in which a release agent composition is preliminarily heated and melted, heated water is added thereto, and high shear is applied using a mixer such as a pressure kneader, a colloid mill, or a high-speed stirring shaft to uniformly emulsify and disperse the mixture until the average particle size is 1 μm or less, and then the mixture is cooled so as not to cause the dispersed particles to fuse and aggregate, thereby obtaining the desired aqueous release agent. Alternatively, a method (solvent dissolution method) can be used in which a release agent composition is preliminarily dissolved in an organic solvent, and high shear is applied to the solution and water using a high-speed emulsifier to uniformly emulsify and disperse the solution components until the average particle size is 1 μm or less, and then the organic solvent is removed to obtain the desired aqueous release agent. While either method is preferably employed, the high-pressure emulsification method is more preferably employed because it does not require the removal of the organic solvent and is a simple process.

[0101] The release agent after emulsification has a Hansen solubility parameter distance (HSP distance) of 10.0 MPa from components other than the release agent (e.g., crosslinking agent, binder resin, additives). １／２ It is preferable that the pressure is not more than 8.0 MPa. １／２ By setting the HSP distance within the above-mentioned preferred range, the compatibility between the release agent and the other components is improved, the formation of island-sea domains in an elastic modulus image obtained by an atomic force microscope (AFM) is facilitated, and the major axis Da of the island portions in the island-sea domains can be controlled within a preferred range.

[0102] When a silicone resin is used as the release agent for the resin layer of the present invention, the silicone resin is not particularly limited, and known types of silicone resins such as addition-curing silicone resins and condensation-curing silicone resins can be used. Among these, it is preferable to use an addition-curing silicone resin because it generates less by-products.

[0103] In the laminated film of the present invention, it is preferable that the coating composition forming the resin layer contains a crosslinking agent, particularly from the viewpoint of sufficiently promoting the crosslinking reaction of the resin layer and facilitating peeling of the surface layer. Examples of the crosslinking agent include melamine compounds, carbodiimide compounds, isocyanate compounds, and oxazoline compounds.

[0104] Among these, melamine compounds are preferred because they have a large amount of reactive functional groups per unit molecular weight and form dense crosslinks upon high-temperature heating. Therefore, when the laminate film is used as a release film, they can provide easy peeling when peeling off a surface layer formed from a ceramic slurry or the like from the laminate film. This easy peeling reduces the likelihood of components of the release agent or resin layer falling off or migrating (transferring) to the surface layer, thereby preventing performance degradation and the occurrence of defective products in the electronic components or battery components that are in the surface layer. To achieve good releasability while suppressing component migration to the surface layer, it is more preferred that the resin layer contain a long-chain alkyl resin and a melamine resin.

[0105] Examples of melamine compounds that can be used as crosslinking agents 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 it, and mixtures thereof. The melamine compound may be either a condensate of a monomer or a polymer of dimer or higher, or a mixture thereof.

[0106] Examples of lower alcohols that can be used for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. Examples of functional groups possessed by the crosslinking agent include imino groups, methylol groups, and alkoxymethyl groups such as methoxymethyl and butoxymethyl groups. Examples of crosslinking agents that have these functional groups in one molecule include imino group-type methylated melamine resins, methylol group-type melamine resins, methylol group-type methylated melamine resins, and fully alkylated methylated melamine resins. Among these, methylolated melamine resins are particularly preferred. Commercially available methylolated melamine resins may be used, and suitable examples include "Nicalac" (registered trademark) MW-035, MW-30M, and MW-30MLF manufactured by Sanwa Chemical Co., Ltd.

[0107] When a carbodiimide compound is used as a crosslinking agent, it is preferable to use a compound having one or more carbodiimide groups or tautomeric cyanamide groups as functional groups within the molecule. Specific examples of such carbodiimide compounds include dicyclohexylmethanecarbodiimide, dicyclohexylcarbodiimide, tetramethylxylylenecarbodiimide, and urea-modified carbodiimide, and these can be used alone or in a mixture of two or more. Commercially available carbodiimide compounds may be used; for example, "Carbodilite" (registered trademark) V-04, V-02, V-02-L2, SV-02, and the like, manufactured by Nisshinbo Chemical Inc., are suitable.

[0108] When an isocyanate compound is used as the crosslinking agent, for example, 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, meta-phenylene diisocyanate, and the like can be suitably used.

[0109] Furthermore, since isocyanate groups readily react with water, blocked isocyanate compounds in which the isocyanate groups are masked with a blocking agent or the like can be preferably used in terms of the pot life of the coating material. In this case, when heat is applied in the drying process after the coating composition for forming the resin layer is applied to the polyester film that serves as the resin substrate, the blocking agent dissociates, exposing the isocyanate groups, and causing the crosslinking reaction to proceed. Note that the isocyanate compound may be used alone or in combination with multiple types.

[0110] When an oxazoline compound is used as a crosslinking agent, it is preferable to use an oxazoline compound having an oxazoline group as a functional group in the compound, and comprising an oxazoline group-containing copolymer obtained by copolymerizing at least one monomer containing an oxazoline group and at least one other monomer.

[0111] 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.

[0112] 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. unsaturated nitriles such as those listed above, unsaturated amides such as acrylamide, methacrylamide, N-methylol acrylamide, and 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.

[0113] Furthermore, the coating composition for forming the resin layer of the laminate film of the present invention may contain a crosslinking catalyst. The inclusion of a crosslinking catalyst allows the crosslinking reaction during heat treatment to proceed efficiently, increasing the degree of crosslinking in the resin layer. As a result, when a surface layer is applied to the resin layer, penetration of the surface layer into the resin layer is less likely, 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. These catalysts may be commercially available, and suitable examples include "NACURE" (registered trademark) 5528, 5928, and 2500, manufactured by Kusumoto Chemicals Co., Ltd.

[0114] In the coating composition for forming the resin layer of the laminated film of the present invention, any resin can be used as the binder resin. As such a resin, for example, at least one selected from the group consisting of acrylic resin, methacrylic resin, epoxy resin, polyester resin, and urethane resin is preferably used. However, from the viewpoints of adjusting the crosslinking density of the resin layer and facilitating the introduction of reactive functional groups, it is more preferable to use an acrylic resin and / or a polyester resin.

[0115] Examples of reactive functional groups include hydroxyl, carboxyl, amino, glycidyl, isocyanate, vinyl, acrylic, and methacrylic groups, but from the viewpoint of adjusting the crosslinking density of the resin layer, it is preferable for the binder resin to have a hydroxyl or carboxyl group. That is, it is particularly preferable for the binder resin into which a reactive functional group has been introduced to be a copolymerized acrylic resin having both a hydroxyl and / or a carboxyl group and / or a polyester resin having a carboxyl group.

[0116] When a polyester resin is used as the binder resin, the monomer constituting the acrylic resin is not particularly limited, but examples of monomers having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and 3-methyl-3-hydroxybutyl (meth)acrylate.

[0117] Examples of monomers having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, citraconic acid, cinnamic acid, 2-(meth)acryloyloxyethyl succinate, monohydroxyethyl maleate (meth)acrylate, monohydroxyethyl fumarate (meth)acrylate, monohydroxyethyl phthalate (meth)acrylate, 1,2-dicarboxycyclohexane monohydroxyethyl (meth)acrylate, (meth)acrylic acid dimer, and ω-carboxy-polycaprolactone mono(meth)acrylate. These monomers may be polymerized alone or in combination with other types of monomers for copolymerization.

[0118] When a polyester resin is used as the binder resin, it is preferable that the polyester resin has an ester bond in the main chain or side chain and is obtained by polycondensation of a dicarboxylic acid and a diol. Aromatic, aliphatic, and alicyclic dicarboxylic acids can be used as the dicarboxylic acid raw material for the polyester resin. Examples of aromatic dicarboxylic acids that can be used include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 1,4-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2-bisphenoxyethane-pp'-dicarboxylic acid, and phenylindanedicarboxylic acid. Examples of aliphatic and alicyclic dicarboxylic acids that can be used include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid, as well as their ester-forming derivatives. These may be used alone or in combination.

[0119] Examples of diol components that can be used as raw materials for the polyester resin include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl- Examples of usable solvents include 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 4,4'-thiodiphenol, bisphenol A, 4,4'-methylenediphenol, 4,4'-(2-norbornylidene)diphenol, 4,4'-dihydroxybiphenol, o-, m-, and p-dihydroxybenzene, 4,4'-isopropylidenephenol, 4,4'-isopropylidenebindiol, cyclopentane-1,2-diol, cyclohexane-1,2'-diol, cyclohexane-1,2-diol, and cyclohexane-1,4-diol. These may be used alone or in combination.

[0120] Furthermore, modified polyester copolymers, such as block copolymers and graft copolymers modified with acrylic, urethane, epoxy, etc., can also be used as binder resins.

[0121] The binder resin of the present invention can contain an emulsifier to emulsify the resin, and it is more preferable to contain a reactive emulsifier. By containing a reactive emulsifier in the binder resin of the present invention, the emulsified state during polymerization is likely to be stable, and emulsion particles are likely to be uniform. Furthermore, since the emulsifier is contained in the polymer skeleton of the binder, which has a relatively high molecular weight, transfer of the emulsifier to the surface layer side when a resin layer is formed is unlikely to occur.

[0122] In this specification, the reactive emulsifier means a surfactant having at least one ethylenically unsaturated group. When the binder resin used in the coating composition for forming the resin layer of the laminated film of the present invention contains a reactive emulsifier, a resin is produced in which the monomer constituting the binder resin and the reactive emulsifier are copolymerized via the ethylenically unsaturated group.

[0123] The reactive emulsifier is not particularly limited as long as it is a surfactant having an ethylenically unsaturated group, and known ones can be used. Examples of reactive emulsifiers include anionic surfactants having an ethylenically unsaturated group, nonionic surfactants having an ethylenically unsaturated group, cationic surfactants having an ethylenically unsaturated group, and amphoteric surfactants having an ethylenically unsaturated group. Among these, from the viewpoint of the stability of resin particles, it is preferable to use at least one of anionic surfactants having an ethylenically unsaturated group and nonionic surfactants having an ethylenically unsaturated group, and it is more preferable to use nonionic surfactants having an ethylenically unsaturated group. One type of reactive emulsifier may be used alone, or two or more types may be used in combination.

[0124] From the viewpoint of the water dispersibility of the binder resin, the content of the reactive emulsifier is preferably 3.0 parts by mass to 20.0 parts by mass, more preferably 5.0 parts by mass to 15.0 parts by mass, and even more preferably 7.0 parts by mass to 10.0 parts by mass, relative to 100 parts by mass of the total of the monomers constituting the binder resin.

[0125] The binder resin used in the coating composition constituting the laminated film of the present invention may also contain a non-reactive emulsifier. Examples of non-reactive emulsifiers include general anionic surfactants and non-ionic surfactants, and at least one of these can be used. Among these, it is more preferable to use a non-ionic surfactant.

[0126] Examples of anionic surfactants include carboxylic acid types such as fatty acid monocarboxylates and N-acyloylglutamates; sulfonic acid types such as alkylbenzenesulfonates, naphthalenesulfonate-formaldehyde condensates and dialkyl sulfosuccinates; sulfate ester types such as alkyl sulfates; and phosphate ester types such as alkyl phosphates.

[0127] Examples of nonionic surfactants include ether-type surfactants such as polyoxyethylene alkylphenyl ethers and polyoxyethylene alkyl ethers, ester-type surfactants such as glycerin fatty acid esters, sorbitan fatty acid esters and sucrose fatty acid esters, ester-ether-type surfactants such as polyethylene glycol fatty acid esters and polyoxyethylene sorbitan fatty acid esters, and fatty acid alkanolamide-type surfactants.

[0128] From the viewpoint of dispersibility of the binder resin in an aqueous medium, the content of the non-reactive emulsifier is preferably 0.1 parts by mass to 3.0 parts by mass, more preferably 0.1 parts by mass to 2.0 parts by mass, and even more preferably 0.1 parts by mass to 1.5 parts by mass, relative to 100 parts by mass of the total of the monomers constituting the binder resin.

[0129] Furthermore, there is a preferred range for the acid value of the binder resin, preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 20 mgKOH / g or more, and particularly preferably 50 mgKOH / g or more. When the acid value of the binder resin satisfies the above-mentioned range, the binder resin can be easily dissolved or dispersed in water, and the resin layer constituting the laminate film of the present invention can easily reduce the metal ions detected by time-of-flight secondary ion mass spectrometry and the maximum recess depth Sv. While there is no upper limit to the acid value from the viewpoint of improving solubility or dispersion in water, the upper limit that can be practically stably produced is about 300 mgKOH / g.

[0130] The polymerization initiator for the binder resin used in the coating composition forming the resin layer of the laminated film of the present invention is not particularly limited and any known polymerization initiator can be used. Examples include organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butyl peroxypivalate, and t-hexyl peroxypivalate; inorganic peroxides such as potassium persulfate, ammonium persulfate, sodium persulfate, t-butyl peroxypivalate, and hydrogen peroxide; and azo compounds such as azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, azodibenzoyl, and 4,4'-azobis(4-cyanovaleric acid). Among these, the organic peroxide t-butyl peroxypivalate is particularly preferred.

[0131] When the binder resin used in the coating composition for forming the resin layer of the laminated film of the present invention contains a polymerization initiator, the content of the polymerization initiator is preferably 0.05 to 5.0 parts by mass per 100 parts by mass of the total of the monomers constituting the acrylic resin, from the viewpoint of not impairing the release properties of the resin layer.

[0132] In the coating composition for forming the resin layer in the laminated film of the present invention, there is a preferred content of the release agent. Specifically, when the total of the release agent, binder resin, and crosslinking agent is taken as 100% by mass, the content of the release agent is preferably 5% by mass or more and 40% by mass or less, more preferably 10% by mass or more and 30% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less.

[0133] When the amount of the release agent is 5% by mass or more, good releasability of the surface layer is exhibited, whereas when the amount of the release agent is 40% by mass or less, when the laminated film is used as a release film, the release agent is less likely to fall off from the laminated film, and performance degradation and defective products of components of electronic components and batteries formed on the resin layer as the surface layer can be suppressed.

[0134] There is also a preferred range for the content of the crosslinking agent. Specifically, when the total of the release agent, binder resin, and crosslinking agent is 100% by mass, the content of the crosslinking agent is preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 60% by mass or more. When the content of the crosslinking agent satisfies the above range, the degree of crosslinking of the resin layer becomes higher. As a result, when a surface layer is formed on the resin layer, penetration of the surface layer components into the resin layer becomes less likely, making it easier to improve the releasability of the surface layer. On the other hand, the upper limit of the content of the crosslinking agent depends on the blending amounts of the release agent and binder resin, but is 90% by mass, preferably 85% by mass, and more preferably 75% by mass.

[0135] On the other hand, the blending ratio of the binder resin can be adjusted so that the above-mentioned release agent and crosslinking agent are contained in a preferable amount. However, if the binder resin accounts for less than 5% by mass when the total of the release agent, binder resin, and crosslinking agent is taken as 100% by mass, it becomes difficult to support the resin layer, which may lead to the resin layer falling off or deterioration of quality.

[0136] The coating composition may contain a solvent or dispersion medium (hereinafter simply referred to as "solvent") to the extent that the function of the resin layer is not impaired. That is, various components may be dissolved or dispersed in a solvent to form a coating composition, which may then be applied to a polyester film serving as a resin substrate. When such a method is employed, a laminate film having a resin layer laminated thereon can be obtained by drying the solvent after application and heating.

[0137] In the coating composition for forming the resin layer of 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 a water-based solvent containing water as the main component and water-soluble organic solvents such as alcohols (e.g., methanol, ethanol, isopropyl alcohol, butanol), ketones (e.g., acetone, methyl ethyl ketone), and glycols (e.g., ethylene glycol, diethylene glycol, propylene glycol). The use of an aqueous solvent not only prevents the solvent from rapidly evaporating during the heating process, enabling the formation of a uniform resin layer, but also being environmentally friendly.

[0138] The coating composition for forming the resin layer of the laminate film of the present invention can be prepared by mixing and stirring a water-dispersed or water-soluble release agent, a binder resin, a crosslinking agent, and an aqueous solvent in any order at a desired weight ratio. Next, various additives such as lubricants, organic particles, surfactants, antioxidants, and catalysts can be added as needed in any order without deteriorating the properties of the resin layer. 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.

[0139] Among these, surfactants can be used to improve the uniformity of the coating film. Examples of surfactants include silicone-based surfactants, fluorine-based surfactants having a perfluoroalkyl group, and hydrocarbon-based surfactants such as acetylene-based surfactants. Among these, fluorine-based surfactants having a perfluoroalkyl group are preferably not used in view of the deterioration of the properties of the components of electronic components and batteries formed as the surface layer, which is the subject of the present invention, as well as in view of regulations on PFAS materials. On the other hand, acetylene-based surfactants are particularly preferred because they can prevent migration from the resin layer to the components of electronic components and batteries and, even if migration occurs, can reduce the adverse effects on device properties.

[0140] The presence or absence of a fluorochemical surfactant in the resin layer can be confirmed by time-of-flight secondary ion mass spectrometry. Specifically, the peak intensity of the negative ion fragment exhibiting the maximum intensity detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is determined as M － , , negative ions derived from fluorine element (F １７- ) is Ff, Ff / M ー It is preferable that is less than 0.01.

[0141] These surfactants may be used alone or in combination of two or more. From the viewpoint of adjusting the wettability and foaming property from the HLB value described below, it is particularly preferable to use two types of materials in combination. The HLB value (Hydrophile-Lipophile Balance) is a value that indicates the balance between hydrophilicity and hydrophobicity, and can be obtained by various calculation methods such as the Griffin method and the Davis method. If the HLB value is too low, the surfactant's ability will decrease, leading to poor appearance. On the other hand, if the HLB value is too high, foaming will occur more easily, which may cause coating defects.

[0142] Next, a method for forming a resin layer will be described. In the laminate film of the present invention, the method for providing a resin layer on at least one side of the substrate film can be 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 process of manufacturing a polyester film that serves as a resin substrate. Specifically, it refers to a method in which a coating composition for forming a resin layer is applied at any stage from melt extrusion of polyester to biaxially stretching, heat treatment, and winding up. Typically, the coating is applied to either a substantially amorphous unstretched (unoriented) polyester film (A film) obtained by quenching after melt extrusion, 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 before heat treatment.

[0143] When using the in-line coating method, it is preferable to apply a coating composition to either the A film or B film before the crystal orientation is completed, then stretch the film uniaxially or biaxially, and heat-treat the film at a temperature higher than the boiling point of the solvent to complete the crystal orientation of the film and provide a resin layer. This method has the advantage of being able to simultaneously produce a polyester film corresponding to the resin substrate and coat and dry the coating composition (i.e., form a resin layer), and it is also easy to ensure adhesion between the substrate and the resin layer.

[0144] Among these, the method of applying the coating composition to a film (B film) 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 due to stretching, and allowing for the formation of a resin layer with excellent smoothness. Furthermore, as mentioned above, applying the coating composition to a film before the completion of crystal orientation can impart adhesion between the resin layer and the polyester film.

[0145] 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 the resulting film (B film or C film) is coated with a coating composition in a process separate from the film-forming process.

[0146] In the present invention, it is preferable to produce a laminate film by an in-line coating method. By using the in-line coating method, not only can the laminate film be produced at lower cost than, for example, forming a resin layer on a biaxially stretched PET film by off-coating, but also it can promote dense crosslinking of the resin layer by performing a high-temperature heat treatment at 200°C or higher, which is essentially impossible with off-coating. As a result, when a coating agent such as a ceramic slurry is applied, the penetration of the binder components contained in the slurry into the resin layer is suppressed, allowing for easy peeling when the surface layer is peeled off, and preventing components of the resin layer from falling off or migrating (transferring) to the surface layer formed with the slurry. As a result, performance degradation and the generation of defective products of components of electronic components or batteries laminated on the surface of the resin layer as a surface layer can be suppressed. Furthermore, it is easier to control the Da / Db ratio of the sea-island domains observed in an AFM elastic modulus image within a preferred range.

[0147] In particular, it is preferable to produce the polyester film by a manufacturing method in which a coating composition is applied to at least one side 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, from the viewpoints of manufacturing costs, dimensional stability after heat treatment, heat shrinkage properties, and density of the resin layer.

[0148] When a resin layer is formed on a polyester film corresponding to a resin substrate using a conventional off-coating method, if the resin layer contains a release agent, the low surface energy of the resin layer will have poor adhesion to the film. Therefore, when a laminated film obtained using this process is rewound, the resin layer may be scraped off, resulting in poor peel strength (equivalent to tape peel strength). On the other hand, when a resin layer is laminated using an in-line coating method, applying a coating composition to a polyester film before crystal orientation is complete allows a very small amount of the coating composition to penetrate into the polyester film, thereby improving the adhesion between the resin layer and the resin substrate. As a result, easy peel strength can be achieved.

[0149] In the present invention, it is preferable to form a resin layer by applying a coating composition to at least one side of a polyester film corresponding to a resin substrate and then drying the coating composition. 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 process, and not only can a uniform and high-quality resin layer be formed, but also it is excellent in terms of environmental load.

[0150] When producing the laminated film of the present invention, drying of the coating composition is preferably carried out at a temperature range of 80 to 130°C to complete removal of the solvent. Furthermore, when using an in-line coating method, heat treatment is preferably carried out at a temperature range of 160 to 240°C to complete the crystalline orientation of the polyester film and complete the formation of the resin layer by thermal curing of the coating composition. From the above perspective, the heat treatment temperature is particularly preferably 180 to 240°C. If the heat treatment temperature is less than 160°C, the heat resistance of the resin substrate decreases, and it is difficult to obtain dense crosslinking of the resin layer, which may lead to deterioration of the peelability of the surface layer.

[0151] Next, a method for producing the laminate film of the present invention will be described. The method for producing the laminate film of the present invention is a method for producing the laminate film of the present invention, and is characterized by comprising, in this order, a coating step of coating at least one surface of a polyester resin substrate sheet with a resin composition for forming a resin layer, the resin composition being mainly water as a solvent, a stretching step of stretching the polyester resin substrate sheet in at least one axial direction after the resin composition has been applied, and a heat treatment step of heating the stretched polyester resin substrate sheet to form a resin layer. That is, the method for producing the laminate film of the present invention uses an in-line coating method in which the formation of the resin substrate and the formation of the resin layer are carried out in a continuous process.

[0152] The method for producing a laminated film of the present invention includes a coating step of coating at least one surface of a polyester resin substrate sheet with a resin composition for forming a resin layer, the resin composition containing water as the primary solvent. Here, "a resin composition containing water as the primary solvent" refers to a resin composition in which a solid component is mixed with the aqueous solvent described above. Furthermore, "at least one surface" refers to both surfaces or one surface. The coating method for the coating composition in the coating step can be any known coating method, such as bar coating, reverse coating, gravure coating, die coating, or blade coating.

[0153] The method for producing a laminated film of the present invention includes a stretching step in which the polyester resin substrate sheet after coating with the resin composition is stretched in at least one direction. Here, "stretching in at least one direction" refers to stretching in one or two directions. When stretching in one direction, a method of stretching in the longitudinal direction using a roll-type stretching machine utilizing the difference in peripheral speed between rolls, or a method of stretching in the longitudinal direction or width direction using a stenter can be used. When stretching in two directions, after stretching in the longitudinal direction using the above-mentioned method, further stretching in the width direction can be performed using a tenter device. In the stretching step, biaxial stretching is preferably performed from the viewpoints of the dimensional stability, mechanical strength, flatness, etc. of the resulting laminated film.

[0154] The method for producing a laminated film of the present invention includes a heat treatment step in which the stretched polyester resin substrate sheet is heated to form a resin layer. This heat treatment step serves to complete the crystalline orientation of the polyester resin substrate sheet and also complete the formation of the resin layer. It is believed that this heat treatment step promotes crosslinking of the resin layer. In this heating step, if necessary, a relaxation treatment of 3 to 15% may be performed in the width direction, the length direction, or both to improve dimensional stability in a high-temperature environment.

[0155] Next, the method for producing the laminated film of the present invention will be explained in more detail using an example in which the polyester resin substrate sheet is a polyethylene terephthalate (PET) film, but the laminated film of the present invention is not limited to that obtained by this production method.

[0156] First, PET pellets are thoroughly vacuum-dried and then fed into an extruder. They are melt-extruded into a sheet at 270-290°C, and then cooled and solidified on a casting drum with a surface temperature of 20-40°C to produce an unstretched (unoriented) PET film (A film, corresponding to a polyester resin substrate sheet). This A film is stretched 2.5 to 5.0 times in the longitudinal direction using a roll heated to 80-120°C to obtain a uniaxially oriented PET film (B film). A coating composition prepared to a predetermined concentration is applied to one side of this B film. Before 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 coating composition to the PET film, prevents cissing of the coating composition, and enables a uniform coating thickness to be achieved. After coating, the PET film is clamped at the edges with clips and guided to a heat treatment zone (preheating zone) at 80-130°C, where the solvent in the coating composition is dried. After drying, the film is stretched 1.1-5.0 times in the width direction. The film is then guided to a heating zone (heat treatment zone) at 150-250°C (preferably 160-240°C, more preferably 180-240°C) and heat-treated for 1-30 seconds to complete the crystal orientation and the formation of the resin layer. This heating step (heat treatment step) is believed to promote crosslinking of the resin layer. If necessary, a relaxation treatment of 3-15% may be performed in the width direction or longitudinal direction during this heating step (heat treatment step). A laminate film can be obtained in this manner, and the resulting laminate film can also be wound into a film roll.

[0157] The laminate film of the present invention is suitable for use in the manufacturing process of components for electronic components or batteries. In order to maintain high performance of electronic components or batteries, it is necessary to use components with few impurities. The laminate film of the present invention can reduce the generation of impurities due to the migration of alkali metals or alkaline earth metals through the resin layer, and therefore can be suitable for use as a process film for manufacturing components for electronic components or battery components.

[0158] 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.

[0159] [Methods for Measuring Characteristics and Evaluating Effects] The methods for measuring characteristics and evaluating effects in the present invention are as follows.

[0160] (1) Resin layer thickness Th Laminated film RuO ４ and / or OsO ４ The laminated film was then frozen and cut parallel to the thickness direction to obtain 10 ultrathin section samples for observing the cross section of the resin layer. 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 length measurement function of the microscope from the cross-sectional photographs of the 10 samples obtained, and the obtained measured values ​​were averaged to obtain the thickness Th of the resin layer of the laminated film.

[0161] (2-1) Composition of the Resin Layer Surface (Peak Intensity of Each Positive Ion) The composition of the resin layer surface of the laminated film was analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The measurement conditions were as follows. In the chart obtained by the measurement (horizontal axis: mass number / vertical axis: signal intensity), the peak intensity M of the positive ion fragment showing the maximum intensity, the sum T of the peak intensity of the positive ions of alkali metal elements and the positive ions of alkaline earth metal elements, the peak intensity K of the positive ion of potassium, the fragment of the positive ion derived from polydimethylsiloxane (SiCH ３ ＋ The peak intensity Si of the fragment ion (m / z=43) was determined. <Measurement conditions> Measurement device: TOF. SIMS 5 (manufactured by ION-TOF) Analysis software: SurfaceLab Primary ion: Bi ３ ＋＋ Primary ion acceleration voltage: 25 kV Secondary ion polarity: positive ion Mass range: m / z 0 to 1,000 Measurement range: 400 μm x 400 μm Number of scans: 25 scans Pulse width: 10.2 ns Bunching: Yes Charge neutralization: Yes Post-stage acceleration: 9.5 kV Measurement vacuum: 1 x 10 －７ Pa or less.

[0162] (2-2) ４５ C ２ H５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ The composition of the laminated film was analyzed from the surface direction of the resin layer side by time-of-flight secondary ion mass spectrometry (TOF-SIMS) under the same conditions as in (2-1), except that the secondary ion polarity detected was both positive and negative ions. From the obtained chart (horizontal axis: mass number / vertical axis: signal intensity), the peak intensities of the fragments of the amphiphilic material contained in the resin layer and the resin substrate, and the peak intensity of the fragments of the resin substrate were read. Next, in order to uniformly calculate positive and negative ions and to eliminate differences between measurements between samples, the peak intensity M of the fragment of the positive ion showing the maximum intensity or the peak intensity M of the fragment of the negative ion showing the maximum intensity was calculated. － (Hereinafter, both will be combined and referred to as maximum peak intensity MT) to normalize them into dimensionless quantities. Next, the sum of the normalized peak intensities of the fragments of the amphiphilic material was calculated as Fh / MT, and the sum of the normalized peak intensities of the fragments of the resin substrate was calculated as Fb / MT. Furthermore, the ratio Fh / Fb was calculated by dividing Fh / MT by Fb / MT.

[0163] (3) Tape Peeling Force An acrylic polyester adhesive tape (Nitto Denko Corporation, No. 31B tape, 19 mm wide) was attached to the resin layer of the laminate film, and a 2 kgf roller was rolled back and forth from above to produce a tape-attached laminate film. The tape-attached laminate film was then left to stand for 24 hours in an environment of 25°C and 65% RH. The peeling force (N / 19 mm) was measured at a peeling angle of 180° and a tensile speed of 300 mm / min using a Shimadzu Corporation "Autograph" (registered trademark) AG-1S universal testing machine. The average peeling force over a period of 5 to 10 seconds was calculated from the graph of peeling force (N / 19 mm) versus test time (sec) obtained by the measurement. This measurement was performed five times, and the average of the three measurements, excluding the maximum and minimum values, was used as the peeling force (N / 19 mm) of the laminate film.

[0164] (4) Da and Db in AFM Elastic Modulus Image Using a BRUKER atomic force microscope (AFM) "Dimension Icon ScanAsyst," absolute calibration (warpage sensitivity measurement, spring constant calibration, and probe tip curvature measurement (ScanAsystNoiseThreshold: 1.0 nm)) was performed, and then an elastic modulus image of the resin layer side surface of the laminate film was measured. The major axis Da, minor axis Db, and Da / Db of the island-sea domains were determined from the obtained elastic modulus image. The measurement conditions were as follows: <Measurement conditions> Software: "NanoScope Analysis" Measurement probe: RTESPA-300 Measurement mode: Peak Force QNM in Air Measurement range: 10 μm x 10 μm Number of measurement lines: 512 Measurement speed: 0.977 Hz Response sensitivity: 25 Indentation depth: 1 / 10 of the thickness of the resin layer Poisson's ratio: 0.3.

[0165] Analysis after measurement was performed using the following procedure. After measurement, "Roughness" was selected from "DMTModulus," and the image displayed on the screen was binarized using "ScionImage" (maximum value: 10 GPa, minimum value: 0 GPa, threshold value: 180). Areas with high elastic modulus were colored white (ocean domains), and areas with low elastic modulus were colored black (island domains). Next, of the island domains in the image, the top five island domains were extracted in order of longest axis length (major axis), and the major axis, minor axis, and their ratios for each island domain were calculated. Furthermore, 10 measurements were performed within an arbitrarily selected measurement range. The major axis, minor axis, and their ratios were calculated for up to 50 island domains, and their average values ​​were used as Da, Db, and Da / Db.

[0166] (5) Differential Scanning Calorimeter (DSC) Exothermic Peak Temperature (Tc) During Temperature Decrease Process 1 g of the release agent or resin layer cut from the surface of the laminated film was placed in a 5 cm diameter aluminum cup and dried in a hot air oven at 80 °C for 24 hours to prepare a solid sample of the dried release agent or resin layer. 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 may be a peak temperature that can be observed on a multi-stage DSC chart called a shoulder (observed in the case of a chart in which 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).

[0167] (6) X-ray Absorption Fine Structure (XAFS) Spectrum The surface opposite to the resin layer of the laminate film was polished to adjust the thickness of the laminate film 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 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 method were as follows. <Measurement conditions and analysis method> 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 ＊The peak was corrected to 255.5 eV. Analysis method: In the XAFS spectrum, the X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge was analyzed. The angle between the incident X-ray and the longitudinal vector of the resin layer surface 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°).

[0168] (7) Monomer Ratio of Long-Chain Alkyl Groups 0.65 mL of tetrahydrofuran was added to 30 mg of release agent powder, and the solution was heated to 40°C. １３ This was used as a CNMR sample. １３ The ratio of the long-chain alkyl group monomer in the release agent was calculated from the peak area ratio of the CNMR spectrum. Apparatus used: ECZ-600R (manufactured by JEOL RESONANCE Co., Ltd.) Measurement method: single 13C pulse with inverse gated 1H decoupling Measurement frequency: 150.9 MHz Pulse width: 6.20 msec Lock solvent: deuterated chloroform, deuterated THF Chemical shift reference: residual chloroform in deuterated chloroform (77.0 ppm), tetramethylsilane (TMS) (0 ppm) Number of accumulations: 1000 kai, 3000 kai Number of data points: 32768 Waiting time: 25 by Measurement temperature: room temperature (20 do), 40 do Sample rotation speed: 15 Hz.

[0169] (8) Dissolution State, HSP Distance 1 g of each of the release agent emulsion and the coating composition containing components other than the release agent was placed in a 5 cm diameter aluminum cup and dried in a hot air oven at 80°C for 24 hours to prepare a dried release agent sample and a solid sample of the resin composition containing components other than the release agent. 50 mg of the prepared solid sample was placed in several 6 mL glass screw bottles, and 1 mL of each of the following solvents was added to each. The entire sample was immersed in the test solvent at 40°C. After standing at the treatment temperature for 6 hours, the dissolution state of each sample was evaluated by visual observation according to the following criteria. The HSP value was calculated using HSP calculation software (HSPiP (Hansen Solubility Parameter in Practice) ver. 5.2.05), and the HSP distance of the release agent sample and the resin composition containing components other than the release agent was calculated. ×: Neither swelled nor dissolved. ○: Swollen or dissolved. Test solvents: n-hexane, cyclohexane, methyl isobutyl ketone, n-butyl acetate, toluene, tetrahydrofuran, methyl ethyl ketone, chloroform, methyl acetate, acetone, 1,4-dioxane, pyridine, N-methylpyrrolidone, hexafluoroisopropanol, 1-butanol, acetonitrile, diethylene glycol, N,N-dimethylformamide, γ-butyl lactone, ethanol, dimethyl sulfoxide, methanol, 2-aminoethanol, cyclohexane, d-limonene, p-xylene, diiodomethane, anisole, heptane.

[0170] (9) Peel Strength of Surface Layer The laminated polyester film was cut into a rectangle measuring 20 mm in width and 70 mm in length. Next, a ceramic slurry containing the following composition was applied to the resin layer of the laminated polyester film using a doctor blade method, with the longitudinal direction as the travel direction, to a final thickness of 5 μm and 20 μm. This was then dried in a hot air oven at 100°C for 1 minute to form a ceramic sheet (surface layer). Next, a 90° peel test was performed on the 5 μm-thick ceramic sheet, with the surface opposite the surface layer fixed to the measurement stage using a Kyowa Interface Science Co., Ltd. peeling device "VPA-2" and a 1N load cell, at a peel rate of 300 mm / min, with the longitudinal direction as the travel direction. The average peel strength at 15 to 35 mm was calculated from the resulting graph of peel force (N) vs. displacement (mm). This measurement was performed five times, and the average of the three measurements, excluding the maximum and minimum values, was used as the peel strength of the laminated film, and the following evaluations were performed. A value of A or higher was rated as good, and B was rated as a practically acceptable level. S: Less than 20 mN / cm A: 20 mN / cm or higher but less than 40 mN / cm B: 40 mN / cm or higher but less than 80 mN / cm C: 80 mN / cm or higher <Ceramic slurry (composition and manufacturing method)> BaTiO ３ (manufactured by Sakai Chemical Industry Co., Ltd., BT-05): 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

[0171] 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) to obtain a ceramic slurry.

[0172] (10) Evaluation of Defective Multilayer Ceramic Capacitors A Ni paste using dihydroterpinyl acetate as a solvent was applied to the 5 μm-thick ceramic sheet prepared in (9) by screen printing and dried in air at 80°C for 10 minutes to form internal electrodes with a thickness of 200 nm. The ceramic sheet was then peeled off from the laminate film, and 21 ceramic sheets with printed internal electrodes were stacked and thermocompressed so that the internal electrodes were alternately offset. On the top and bottom of these 21 laminates, 20 sheets of the 20 μm-thick ceramic sheets prepared in (9) were placed to form upper and lower margin layers. The thermocompression-bonded laminate was cut to a long side of 3.2 mm and a short side of 1.6 mm, and then the binder was removed in a nitrogen atmosphere at 350°C. The resulting laminate was then heated in a nitrogen atmosphere at an oxygen partial pressure of 10 －９ ~10 －１２ The ceramic sheets were fired at 1200°C for 2 hours in a reducing atmosphere consisting of hydrogen, nitrogen, and air at 1000 MPa. Ni paste was baked at 600°C in a nitrogen atmosphere on both long edge surfaces of the fired laminate, forming external electrodes electrically connected to the internal electrodes to obtain multilayer ceramic capacitors. One thousand multilayer ceramic capacitor samples were fabricated using the above method, and each was subjected to a 3000-hour voltage application test at 85°C and 40.0 V / μm. After that, multilayer ceramic capacitor samples whose insulation resistance dropped by one order of magnitude from the insulation resistance at the start of voltage application were determined as defective, and the number of defective samples was calculated and evaluated according to the following criteria (S to B were considered pass): S: 0 defectives; A: 1 to 3 defectives; B: 4 to 10 defectives; C: 10 or more defectives.

[0173] (11) Maximum valley depth Sv of resin layer A 5 cm x 5 cm square sample was obtained from the laminated film, and measured and calculated in accordance with ISO 25178-2:2012 and ISO 25178-3:2012. The measurement device used was a scanning white light interference microscope "VS1540" (manufactured by Hitachi High-Tech Science Corporation). The measurement conditions and details of the device configuration will be described later.

[0174] Sv was calculated using the data obtained by interpolating (fully interpolating) the captured image using the included analysis software, surface correction using a polynomial quartic approximation, and processing it with a median filter (3 x 3 pixels). The S-filter nesting index was set to 0.455. Measurement points were the intersection of the diagonal lines (starting point) and five points in total, 1 cm away from the starting point toward each of the four corners. Measurements and Sv calculations were performed at each measurement position, and the average of the obtained values ​​was adopted as the maximum valley depth Sv of the film. Measurements were performed on both sides of the sample. <Measurement conditions and device configuration> Objective lens: 10x Lens tube: 1x Zoom lens: 1x Wavelength filter: 530 nm white Measurement mode: Wave Measurement software: VS-Measure 10.0.4.0 Analysis software: VS-Viewer 10.0.3.0 Measurement area: 561.1 μm × 561.5 μm Number of pixels: 1,024 × 1,024.

[0175] (12) Measurement of Acid Value The resin to be measured was precisely weighed into a side-arm Erlenmeyer flask, and the mass of the resin was designated A (g). Subsequently, 50 parts by mass of benzyl alcohol was added to 1 part by mass of the resin, and the resin was dissolved by heating in a 230°C heater for 15 minutes under a nitrogen atmosphere. After cooling to room temperature, 50 parts by mass of benzyl alcohol, 100 parts by mass of chloroform, and several drops of phenolphthalein solution (10 g / L) were added, and the mixture was titrated with a 0.02N KOH solution (titer = B (ml), titer of the KOH solution = p). The titration endpoint was the point at which the solution retained a pale red color for approximately 15 seconds. A blank measurement was performed in the same manner using the same formulation but excluding the resin (titer = C (ml)), and the acid value was calculated according to the following formula: Acid value (mgKOH / g) = (B - C) × 0.02 × 56.11 × p ÷ A.

[0176] [Raw Materials for Resin Substrate] Polyester Raw Material 1 (Homopolyester) 86.5 parts by mass of terephthalic acid and 37.1 parts by mass of ethylene glycol were mixed and subjected to an esterification reaction while distilling off water at 255° C. After completion of the esterification reaction, 0.02 parts by mass of trimethyl phosphate, 0.06 parts by mass of magnesium acetate, 0.01 parts by mass of lithium acetate, and 0.0085 parts by mass of antimony trioxide were added, followed by heating to 290° C. under reduced pressure and a polycondensation reaction, thereby obtaining a polyester raw material 1 having an intrinsic viscosity of 0.63 dl / g.

[0177] Polyester raw material 2 (organic particle master pellets) Using a vented twin-screw kneader, an aqueous slurry of divinylbenzene / styrene copolymer crosslinked particles having a volume average particle diameter of 0.3 μm and a volume shape factor f = 0.51 was added to the above-mentioned polyester raw material 1 which was substantially free of particles, to obtain master pellets (polyester raw material 2) containing 2 mass % of divinylbenzene / styrene copolymer crosslinked particles having a volume average particle diameter of 0.3 μm relative to the polyester.

[0178] Polyester Raw Material 3 (Inorganic Particle Master Pellets) Calcium carbonate with an average particle size of 1.0 μm, measured by laser diffraction, was prepared and slurried in 10% ethylene glycol. This slurry was dispersed for one hour using a jet agitator and then highly precisely filtered through a filter with a collection efficiency of 95% for particles of 5 μm or larger. A transesterification reaction was carried out by adding 0.04 parts by mass of manganese acetate and 0.03 parts by mass of antimony trioxide as catalysts to 100 parts by mass of dimethyl terephthalate and 64 parts by mass of ethylene glycol. Then, 0.04 parts by mass of trimethyl phosphate as a phosphorus compound was added to the reaction product. Finally, 1.0 part by mass of the previously prepared slurry was added to carry out a polycondensation reaction, yielding calcium carbonate-containing master pellets (polyester raw material 3) containing 1% by mass of calcium carbonate with an average particle size of 1.0 μm and an intrinsic viscosity of 0.63 dl / g.

[0179] Polyester raw material 4 (recycled raw material) Resin substrate 1 described below was recovered and re-pelletized to obtain polyester raw material 4.

[0180] <Resin substrate> Resin substrate 1: Polyester film 95 parts by mass of polyester raw material 1 and 5 parts by mass of polyester raw material 2 were dry-blended and thoroughly vacuum-dried. The mixture was then fed into an extruder and melted at 280°C. The mixture was extruded into a sheet from a T-shaped die and wrapped around a mirror-finished casting drum with a surface temperature of 25°C using an electrostatic casting method, where it was cooled and solidified, thereby obtaining an unstretched film (Film A). This unstretched film was heated to 90°C and stretched 3.1 times in the longitudinal direction to obtain a uniaxially stretched film (Film B) of Resin substrate 1.

[0181] Resin substrate 2: Polyester film A uniaxially stretched film of resin substrate 2 was obtained in the same manner as in resin substrate 1, except that a raw material obtained by dry-blending 95 parts by mass of polyester raw material 4 and 5 parts by mass of polyester raw material 2 was used.

[0182] Resin substrate 3: Polyester film A uniaxially stretched film of resin substrate 3 was obtained in the same manner as resin substrate 1, except that a raw material obtained by dry-blending 95 parts by mass of polyester raw material 1 and 5 parts by mass of polyester raw material 3 was used.

[0183] Resin substrate 4: Polyethylene terephthalate (PET) film "Lumirror" (registered trademark) T60 (substrate thickness: 50 μm) manufactured by Toray Industries, Inc.

[0184] <Coating composition for forming resin layer> Release agent 1: long-chain alkyl resin (block copolymer) <Emulsifier: nonionic surfactant + emulsification aid> Release agent 1 was obtained through the following steps (I), (II), and (III).

[0185] Step (I): Polymerization of Hydrophilic Block

[0049] A 25 mL pressure-resistant glass polymerization ampoule was charged with 2-hydroxyethyl acrylate (HEA) (Kanto Chemical Co., Inc.) having a hydroxy group as a reactive functional group, α,α'-azobisisobutyronitrile (AIBN) (Kanto Chemical Co., Inc.) as a polymerization initiator, cumyl dithiobenzoate (CDB) as a RAFT agent, and toluene as a solvent in a mass ratio (g) of HEA / CDB / AIBN / toluene = 0.35 / 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 a reaction solution containing a polymer.

[0186] Step (II): Polymerization of Hydrophobic Block: Octadecyl acrylate, AIBN as a polymerization initiator, and toluene as a solvent were added to the reaction solution in the ampoule in a ratio (g) of octadecyl acrylate / AIBN / toluene = 4.65 / 0.003 / 1.3. After two cycles of freeze-degassing, the ampoule was sealed and heated at 100°C for 48 hours. The polymerization solution was then added dropwise to 20 times the mass of hexane and stirred to precipitate a solid. The resulting solid was filtered and vacuum-dried overnight at 40°C to obtain long-chain alkyl resin 1 (a block copolymer having an alkyl group with 18 carbon atoms).

[0187] Step (III): Emulsification and purification 375 parts by mass of deionized water was placed in a homomixer, and 30 parts by mass of polyoxyethylene nonylphenyl ether, 12 parts by mass of polyoxyethylene polyoxypropylene glycol, 1 part by mass of lauryl alcohol, 200 parts by mass of long-chain alkyl resin 1, and 150 parts by mass of toluene were added in that order, and the mixture was heated to 70° C. and stirred uniformly. This mixture was transferred to a pressure homogenizer and emulsified, and then the pressure was reduced while heating to distill off the toluene, and an emulsion of release agent 1 was obtained.

[0188] Release agent 2: long-chain alkyl resin (block copolymer) <emulsifier: nonionic surfactant> The long-chain alkyl resin was polymerized, emulsified, and purified in the same manner as for release agent 1, except that lauryl alcohol was not used in step (III) and the amount of 2-hydroxyethyl acrylate (HEA) added in step (I) was 0.2 g, to obtain an emulsion of release agent 2. Release agent 2 also has the same reactive functional group as release agent 1.

[0189] Release Agent 3: Long-Chain Alkyl Resin (Random Copolymer) 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 increments at 10-minute intervals over approximately two hours. After the polyvinyl alcohol addition was complete, the mixture was refluxed for another two hours to terminate the reaction. The reaction mixture was then cooled to approximately 80°C and added to methanol, and the resulting white precipitate was filtered off. 140 parts by mass of xylene was added to the resulting white precipitate, heated to completely dissolve it, and then methanol was added again to cause precipitation. This procedure was repeated several times. The resulting precipitate was then washed with methanol, dried, and pulverized to obtain Long-Chain Alkyl Resin 3 (having a polymethylene main chain and an alkyl group with 18 carbon atoms in the side chain) having a hydroxyl group as a reactive functional group. This was diluted with deionized water to a concentration of 20% by mass to obtain Release Agent 3.

[0190] Release agent 4: Long-chain alkyl resin (random copolymer) <Emulsifier: Anionic surfactant> Methyl acrylate (α), 2-hydroxyethyl acrylate (β) having a hydroxyl group as a reactive functional group, and octadecyl methacrylate (γ) were charged into a stainless steel reaction vessel in a mass ratio of (α) / (β) / (γ) = 30 / 5 / 65, and 2 parts by mass of sodium dodecylbenzenesulfonate as an emulsifier was added per 100 parts by mass of (α) to (γ) 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. Thereafter, a mixed solution 3 consisting of 45 parts by mass of mixed solution 1, 50 parts by mass of isopropyl alcohol, and 5 parts by mass of potassium persulfate was prepared. Subsequently, mixed solution 3 was added dropwise to mixed solution 2 over two hours using a dropping funnel, to prepare mixed solution 4. Mixed solution 4 was then heated to 60°C and maintained in that state for two hours, then cooled to 50°C or below, and then transferred to a container equipped with a stirrer and a pressure-reducing device. 60 parts by mass of 25% by mass ammonia water and 900 parts by mass of pure water were added thereto, and the isopropyl alcohol and unreacted monomer were recovered under reduced pressure while heating to 60°C, thereby obtaining a release agent 4 dispersed in pure water.

[0191] Release agent 5: Silicone-based resin Silicone Emulsion 400E (manufactured by Wacker Silicones, solid content concentration 50% by mass).

[0192] <Binder Resin> Binder Resin 1: Acrylic Resin A mixed solution was prepared by charging methyl methacrylate (α), ethyl acrylate (β), 2-hydroxyethyl acrylate (γ) having a hydroxyl group as a reactive functional group, and acrylonitrile (δ) in a mass ratio of (α) / (β) / (γ) / (δ) = 60 / 32 / 6 / 2 into a stainless steel reaction vessel. 50 parts by mass of the mixed solution prepared above, 200 parts by mass of isopropyl alcohol, and 0.5 parts by mass of 2,2'-azobis(isobutyronitrile) (AIBN) were charged into a reaction vessel equipped with a stirrer, reflux condenser, thermometer, and dropping funnel, and the temperature was raised to reflux. After maintaining the mixture in a reflux state for 20 minutes, a mixed solution of the remainder of the mixed solution, 60 parts by mass of isopropyl alcohol, and 1.8 parts by mass of AIBN was added dropwise over 120 minutes. Twenty minutes after the completion of the dropwise addition, a mixture of 40 parts by weight of isopropyl alcohol and 1.5 parts by weight of AIBN was added dropwise over 120 minutes, and then reflux was maintained for 120 minutes. After the temperature of the reaction solution was cooled to 50 ° C or below, it was transferred to a reaction vessel equipped with a stirrer and pressure reducing equipment, and 50 parts by weight of 25% ammonia water and 900 parts by weight of deionized water were charged. The isopropyl alcohol and unreacted monomer were recovered under reduced pressure at 60 ° C to obtain an acrylic resin aqueous dispersion 1. Furthermore, 240.5 parts by weight of deionized water and 100 parts by weight of the acrylic resin aqueous dispersion 1 prepared above were charged into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel, and the temperature was raised to 80 ° C while replacing the atmosphere in the reaction vessel with nitrogen.

[0193] Meanwhile, in a stirring vessel separate from the reaction vessel, 42.7 parts by mass of deionized exchanged water, 9 parts by mass of "ADEKA REASOAP" (registered trademark) ER-30 (nonionic reactive surfactant, active ingredient: 65% by mass, manufactured by ADEKA Corporation, reactive emulsifier), and 0.5 parts by mass of N-methylol acrylamide (NMAM) were placed and stirred, and then a solution obtained by mixing 61.3 parts by mass of methyl methacrylate (MMA) and 37.0 parts by mass of n-butyl acrylate (BA) was added and stirred to prepare a pre-emulsion.

[0194] Next, while maintaining the internal temperature of the reaction vessel at 80°C, 1.0 part by mass (active ingredient: 0.7 part by mass) of Perbutyl PV (chemical name: t-butyl peroxypivalate, organic peroxide, active ingredient: 70% by mass, manufactured by NOF Corporation) was added to initiate the polymerization reaction. Five minutes after the addition, the pre-emulsion prepared above was added uniformly and gradually over a period of three hours to allow polymerization. The resulting polymer was aged at 80°C for two hours, cooled to room temperature, and then the pH was adjusted with an appropriate amount of aqueous ammonia solution to obtain an acrylic resin aqueous dispersion (binder resin 1) with a pH of 8.5. The acid value of the resulting resin was 65 mgKOH / g.

[0195] Binder resin 2: acrylic resin Binder resin 2 was obtained in the same manner as for binder resin 1, except that 1.0 part by mass of "EMULGEN" (registered trademark) A-60 (nonionic surfactant, active ingredient: 100% by mass, manufactured by Kao Corporation) was used as a non-reactive emulsifier instead of the reactive emulsifier. The acid value of the obtained resin was 8 mgKOH / g.

[0196] Binder Resin 3: Acrylic Resin Methyl methacrylate (α), ethyl acrylate (β), 2-hydroxyethyl acrylate (γ) having a hydroxy group as a reactive functional group, 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 was added as an emulsifier to a total of 100 parts by mass of (α) to (δ) and stirred 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, Mixed Solution 3 was prepared, consisting of 45 parts by weight of Mixed Solution 1, 50 parts by weight of isopropyl alcohol, and 5 parts by weight of potassium persulfate. Mixed Solution 3 was then added dropwise to Mixed Solution 2 over two hours using a dropping funnel to prepare Mixed Solution 4. Mixed Solution 4 was then heated to 60°C and maintained at that temperature for two hours. The resulting Mixed Solution 4 was cooled to below 50°C 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, and the isopropyl alcohol and unreacted monomer were recovered under reduced pressure while heating to 60°C, yielding Binder Resin 3 dispersed in pure water. The acid value of the resulting resin was 3 mgKOH / g.

[0197] Binder resin 4: Polyester resin "PLASCOAT" (registered trademark) Z760 (containing —COOH groups, solid content concentration 25% by mass, acid value 50 mgKOH / g), manufactured by GOO Chemical Industry Co., Ltd.

[0198] Binder resin 5: Polyester resin, manufactured by GOO Chemical Industry Co., Ltd., "PLASCOAT" (registered trademark) Z561 (-SO ３ Contains Na group, solid content concentration 25% by mass, acid value 2mgKOH / g).

[0199] <Crosslinking Agents> Crosslinking agent 1: melamine compound (methylol melamine) "Nicalac" (registered trademark) MW-035 (solid content concentration 70% by mass, solvent: water), manufactured by Sanwa Chemical Co., Ltd.

[0200] Crosslinking agent 2: Carbodiimide compound "Carbodilite" (registered trademark) V-04 (solid content concentration 40% by mass, solvent: water), manufactured by Nisshinbo Chemical Inc.

[0201] Crosslinker 3: Crosslinker for silicone resin, manufactured by Wacker Asahi Kasei Silicones Co., Ltd., CROSSLINKER V72 (solid content concentration 50 mass %, solvent: water).

[0202] <Crosslinking catalyst> Catalyst 1: Dodecylbenzenesulfonic acid "NACURE" (registered trademark) 5528, manufactured by Kusumoto Chemicals Co., Ltd. (manufacturer: KING INDUSTRIES).

[0203] <Surfactants> Surfactant 1: Acetylene diol surfactant "Olfine" (registered trademark) EXP. manufactured by Nissin Chemical Industry Co., Ltd. 4200 (HLB value: 10 to 13) Surfactant 2: Polyoxyethylene oleyl ether, product name: "EMULGEN" (registered trademark) 404, manufactured by Kao Corporation (HLB value: 9) Surfactant 3: Acetylene glycol-based ethylene oxide-added surfactant, "OLFIN" (registered trademark) E1004, manufactured by Nissin Chemical Industry Co., Ltd. (HLB value: 7 to 9) Surfactant 4: Acetylene glycol-based ethylene oxide-added surfactant, "OLFIN" (registered trademark) E1020, manufactured by Nissin Chemical Industry Co., Ltd. (HLB value: 15 to 16) Surfactant 5: Fluorine-based surfactant, "PLASCOAT" RY-2, manufactured by GOO Chemical Industry Co., Ltd. Example 1 As shown in Table 1, release agent 1 / crosslinking agent 1 / binder resin 1 were mixed so that the solids mass ratio was 20 / 70 / 10. Next, catalyst 1 was added so that the solid content was 5 parts by mass per 100 parts by mass of the total of the release agent, crosslinking agent, and binder resin, and water was added to adjust the solid content concentration according to the target coating thickness. Furthermore, in order 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 so that the amount was 0.1 part by mass per 100 parts by mass of the total mixed coating composition, thereby obtaining a coating composition for forming a resin layer.

[0204] Next, the uniaxially stretched film of resin substrate 1 traveling through the film production process was subjected to a corona discharge treatment in air, and then the coating composition for forming the resin layer was applied to a coating thickness of approximately 6 μm using a wire bar coater. The uniaxially stretched film coated with the coating composition was then gripped at both widthwise ends with clips and introduced into a tenter, where the solvent in the coating composition was dried in a preheating zone with an ambient temperature of 90-100°C. The film was then continuously stretched 3.6 times in the widthwise direction in a stretching zone at 100°C, followed by heat treatment for 20 seconds in a heat treatment zone at 230°C to form a resin layer. The polyester film was then subjected to a 5% widthwise relaxation treatment at the same temperature to complete the crystalline orientation of the polyester film. The film was then cut parallel to the longitudinal direction using a slitter, cutting and removing both widthwise ends (uncoated portions) that had been gripped by the clips, and the laminated polyester film was wound into a roll. The properties of the resulting laminated polyester film are shown in Tables 2 and 3.

[0205] (Examples 2 to 6, Comparative Example 1) Various laminated polyester films were obtained in the same manner as in Example 1, except that the resin substrate, the composition of the coating composition for forming the resin layer, and the solid content concentration according to the target coating thickness were changed as shown in Table 1. The properties of the obtained laminated films are shown in Tables 2 and 3.

[0206] (Example 7, Comparative Example 2) A release agent (silicone emulsion), crosslinking agent, and binder resin were mixed in the ratios shown in Table 1. Next, a silane coupling agent (manufactured by Shin-Etsu Silicones Co., Ltd., product name: KBM-403) was added to the mixture so that the solid content was 5 parts by mass relative to 100 parts by mass of the total of the release agent, crosslinking agent, and binder resin, and 0.15 parts by mass of polyoxyethylene oleyl ether (manufactured by Kao Corporation, product name: "Emulgen" (registered trademark) 404) was added as a surfactant relative to 100 parts by mass of the mixed coating composition, thereby obtaining a silicone emulsion coating composition. The solid content concentration of the coating liquid was 6.0% by mass. A laminated film was obtained in the same manner as in Example 1, except that the uniaxially stretched film of resin substrate 3 was used in the subsequent steps. The properties of the obtained laminated film are shown in Tables 2 and 3.

[0207] (Examples 8 to 11) Various laminated polyester films were obtained in the same manner as in Example 1, except that the surfactant composition was a combination of 0.05 parts by mass of surfactant 3 and 0.05 parts by mass of surfactant 4 per 100 parts by mass of the total coating composition, and the solids concentration according to the resin substrate, the composition of the coating composition for forming the resin layer, and the target coating thickness were changed as shown in Table 1. The properties of the obtained laminated films are shown in Tables 2 and 3.

[0208] Comparative Example 3: Using the coating composition of Example 1, a laminate film was obtained by the following method. Toray Industries, Inc.'s polyethylene terephthalate (PET) film "Lumirror" (registered trademark) T60 (substrate thickness: 50 μm) was used as the substrate. A coating composition having the composition shown in Table 1 was applied to the substrate using a wire bar. To prevent deformation due to heat, a stainless steel plate film of the same shape as the film was then placed on top, and the four sides were tightly held with double clips. The film was then dried and cured in a hot air oven at 230°C for 2 minutes to obtain a laminate film. The properties of the resulting laminate film are shown in Tables 2 and 3. Comparative Example 4: Various laminate polyester films were obtained using the same method as in Example 6, except that a fluorine-based surfactant (surfactant 5) was used as the surfactant. The properties of the resulting laminate film are shown in Tables 2 and 3.

[0209]

[0210]

[0211]

[0212] The laminated film of the present invention can be suitably used as a process film when producing electronic components such as multilayer ceramic capacitors, or components of laminated all-solid-state batteries using oxide-based solid electrolytes.

Claims

1. A laminated film having a resin layer on at least one side of a resin substrate, wherein when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity of the fragment of a positive ion exhibiting the maximum intensity is defined as M, and the sum of the peak intensity of the positive ion of an alkali metal element and the peak intensity of the positive ion of an alkaline earth metal element is defined as T, where T / M is 0.001 or more and 0.100 or less, and the tape peeling force is 2.0 N / 19 mm or less.

2. The ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry of the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ The laminate film according to claim 1, wherein the ratio (Fh / Fb) of a total peak intensity Fh of the fragments consisting of the above and a total peak intensity Fb of the fragments derived from the resin substrate is 1.000 or more and 100.000 or less.

3. A resin layer is provided on at least one surface of a resin substrate, and the ratio (Sv / Th) of the maximum valley depth Sv of the resin layer to the thickness Th of the resin layer is 0.001 or more and 0.50 or less, and the peak intensity F detected by time-of-flight secondary ion mass spectrometry on the surface of the resin layer is ４５ C ２ H ５ O ＋ , ５９ C ３ H ７ O ＋ and ７５ SiCH ３ O ２－ a ratio (Fh / Fb) of a total peak intensity Fh of the fragments derived from the resin substrate to a total peak intensity Fb of the fragments derived from the resin substrate is 1.000 or more and 100.000 or less.

4. The laminate film according to claim 3, wherein the peak intensity of the fragment of the positive ion exhibiting the maximum intensity detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry is M, and the sum of the peak intensity of the positive ion of the alkali metal element and the peak intensity of the positive ion of the alkaline earth metal element is T, and the ratio T / M is 0.001 or more and 0.100 or less.

5. The laminate film according to claim 3 or 4, wherein the tape peel strength of the resin layer is 2.0 N / 19 mm or less.

6. A laminate film according to any one of claims 1 to 5, wherein K / M is 0.001 or more and 0.050 or less, where K is the peak intensity of potassium positive ions detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry.

7. A laminate film according to any one of claims 1 to 6, wherein the resin layer has sea-island domains in an elastic modulus image taken with an atomic force microscope (AFM), and the long diameter Da of the island portions in the sea-island domains is 0.05 μm or more and 10 μm or less.

8. The laminate film according to claim 7, wherein the minor axis of the island portion in the sea-island domain is Db, and the ratio Da / Db is 1.1 or more.

9. A laminate film according to any one of claims 1 to 8, in which Si / M is less than 0.010, where Si is the peak intensity of a positive ion fragment derived from polydimethylsiloxane detected when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry.

10. The laminated film according to any one of claims 1 to 9, which contains at least one of biomass raw materials and recycled raw materials.

11. A laminate film according to any one of claims 1 to 10, wherein an X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge among X-ray absorption fine structure (XAFS) spectra measured for the resin layer by a partial electron yield method satisfies I(15°)-I(90°)≧0.50, where θ is the angle between incident X-rays and the resin layer surface and I(θ) is the spectral intensity at 293.5 eV.

12. The laminate film according to any one of claims 1 to 11, wherein the resin layer contains a long-chain alkyl resin and a melamine resin.

13. The laminate film according to claim 12, wherein the long-chain alkyl resin is a block copolymer having an acrylic main skeleton.

14. The laminate film according to any one of claims 1 to 13, wherein the resin layer further contains an acrylic resin and / or a polyester resin having an acid value of 5 mgKOH / g or more.

15. The laminated film according to any one of claims 1 to 14, which is used in the manufacturing process of components for electronic parts or batteries.

16. A method for producing a laminated film according to any one of claims 1 to 15, comprising the steps of: applying a resin composition for forming a resin layer, the resin composition containing water as a primary solvent, to at least one surface of a polyester resin base sheet; stretching the polyester resin base sheet after the resin composition has been applied in at least one axial direction; and heating the polyester resin base sheet after stretching to form a resin layer, in that order.

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