Laminated Film

Abstract

To provide a laminated film having a resin layer having excellent antistatic property and crosslinking denseness, especially, a laminated film which achieves both excellent detachability and antistatic property without contamination by silicone.SOLUTION: A laminated film has a resin layer on at least one surface of a base material film, in which the resin layer contains an amino resin (A) whose terminal is substituted by a specific electron-donating group and a polythiophene-based compound (B), and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass analysis, a ratio (P / K) of a peak intensity (P) [-] of a fragment derived from polydimethylsiloxane to a peak intensity (K) of a fragment detected at the maximum intensity is less than 0.1.SELECTED DRAWING: None

Description

[Technical Field]

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

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

[0003] In recent years, there has been an increasing demand for films with excellent releasability and antistatic properties as protective films for adhesive layers in adhesive products and carrier films in the processing of various industrial products. As films with excellent releasability, films containing silicone compounds and amino resins in the resin layer are commonly used in terms of industrial productivity and heat resistance (Patent Document 1).

[0004] Furthermore, studies have been conducted to achieve both antistatic properties and the like by using a silicone compound in combination with an amino resin and an antistatic material (Patent Document 2). However, when these silicone compounds are contained in the resin layer, the surface free energy of the resin layer decreases, which may result in poor coatability on the adherend.

[0005] On the other hand, as a release agent that does not contain a silicone compound (hereinafter referred to as a non-silicone release agent), a technology has been reported that uses a long-chain alkyl group-containing resin, an olefin resin, a fluorine compound, or a wax-based compound, among others, a long-chain alkyl group-containing resin in combination with an amino resin that can form a dense crosslinked film and an antistatic agent (Patent Document 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-105092 [Patent Document 2] Japanese Patent Application Publication No. 2020-23690 [Patent Document 3] Patent Publication No. 2019-131826 Summary of the Invention [Problem to be solved by the invention]

[0007] As a result of the inventors' investigation of the above technology, they found that even the formulation of Reference 3, which avoids contamination by silicone compounds, did not provide sufficient resistance, as its antistatic properties depended on humidity. Furthermore, when an amino resin was used in combination with an electronically conductive antistatic agent that is not affected by humidity, the antistatic properties deteriorated, resulting in insufficient resistance. Therefore, the present invention aims to clarify the cause of the deterioration in antistatic properties and, by applying an appropriate design, provide a laminate film having a resin layer with excellent antistatic properties and the crosslinked denseness unique to amino resins, particularly a release laminate film that is free from silicone contamination and combines excellent releasability and antistatic properties. [Means for solving the problem]

[0008] In view of the above problems, the present inventors have conducted extensive research and confirmed that the antistatic properties deteriorate when a conductive compound is combined with a specific amino resin. Furthermore, they have found that the deterioration of antistatic properties can be suppressed by appropriately designing the side chain of the amino resin, and have thus completed the present invention.

[0009] The present invention comprises the following configurations: [1] A laminated film having a resin layer on at least one surface of a base film, the resin layer containing at least an amino resin (A) terminally substituted with the following electron-donating group, and a polythiophene-based compound (B), and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K)[-] of the peak intensity (P) of a fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at the maximum intensity is less than 0.1. <Electron-donating group> Any of the following functional groups: lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl groups; hydroxyl groups; and lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, and t-butoxy groups. [2] The laminated film according to [1], wherein the amino resin (A) terminally substituted with an electron-donating group is an amino resin substituted with a methylol group or an alkyl ether group. [3] The laminated film according to [1] or [2], wherein the amino resin (A) terminally substituted with an electron-donating group has a triazine ring, the total number of methylol groups and alkyl ether groups per triazine ring is 3 or more and 6 or less, and the number of imino groups per triazine ring is 3 or less. [4] A laminated film according to any one of [1] to [3], wherein, in an XAFS spectrum measured by a partial electron yield method for the resin layer, an X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge satisfies [I(15°)-0.1] / I(90°)>1, where θ is the angle between the incident X-ray and the resin layer surface and I(θ) is the spectral intensity at 293.5 eV. [5] The laminated film according to any one of [1] to [4], wherein the resin layer contains a long-chain alkyl resin as a release agent (X), and the long-chain alkyl resin has an exothermic peak temperature (Tc) of 30°C or higher and 90°C or lower during the temperature decrease process when heated from 25°C to 200°C at a rate of 20°C / min using a differential scanning calorimeter (DSC) and then cooled from 200°C to -50°C at a rate of 20°C / min. [6] A laminated film having a resin layer on at least one surface of a base film, wherein the surface resistivity of the resin layer is 9.0 × 10 8 A laminated film having a resistivity of Ω / □ or less, a tape peeling force of 3 N / 50 mm or less, and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K)[-] of the peak intensity (P) of the fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at maximum intensity is less than 0.1. [7] The laminated film according to [6], wherein, in an XAFS spectrum measured by a partial electron yield method for the resin layer, an X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge satisfies [I(15°)-0.1] / I(90°)>1, where θ is the angle between the incident X-ray and the resin layer surface and I(θ) is the spectral intensity at 293.5 eV. [8] The laminated film according to [6] or [7], wherein the resin layer contains an amino resin (A) terminally substituted with an electron-donating group and a polythiophene-based compound (B), and the electron-donating group is a methylol group or an alkyl ether group. [9] The laminated film according to [8], wherein the amino resin (A) terminally substituted with an electron-donating group has a triazine ring, the total number of methylol groups and alkyl ether groups per triazine ring is 3 or more and 6 or less, and the number of imino groups per triazine ring is 3 or less.

[10] The laminate film according to any one of [6] to [9], wherein the resin layer contains a long-chain alkyl resin as a release agent (X), and the long-chain alkyl resin has an exothermic peak temperature (Tc) of 30°C or higher and 90°C or lower during the temperature decrease process when heated from 25°C to 200°C at 20°C / min using a differential scanning calorimeter (DSC) and then cooled from 200°C to -50°C at 20°C / min. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a laminate film having a resin layer with excellent antistatic properties and crosslinked density, in particular a laminate film that is free from silicone contamination and has both excellent releasability and antistatic properties. DETAILED DESCRIPTION OF THE INVENTION

[0011] First, the characteristics of the laminated film of the present invention will be described, including the meaning of the properties and examples of methods for controlling the properties.

[0012] First, the inventors investigated the deterioration of antistatic function (deterioration of surface resistivity) during the formation of a resin layer and found that, in addition to the deterioration of performance simply due to the dilution of the concentration of the antistatic material with other components, the electrical conductivity also deteriorates sharply in certain combinations of materials. That is, the inventors confirmed that the electrical conductivity deteriorates significantly when an electron-conductive antistatic material, such as a thiophene-based material, is coexistent with an amino resin. Furthermore, the inventors conducted comparative studies and confirmed that the coexistence of an amino resin having an imino group significantly deteriorates the surface resistivity.

[0013] The reason for the deterioration of surface resistivity is thought to be that the unshared electrons of the N element in the amino resin are donated to the electron-conducting antistatic material, causing the disappearance of holes, which are positively charged elements, and reducing the conductivity of the entire material. Furthermore, based on the above hypothesis, it was found that amino resins with methylol groups or alkyl ether groups, which have the effect of relatively weakening electron-donating properties, do not reduce antistatic properties.

[0014] That is, the laminate film of the present invention is a laminate film having a resin layer on at least one surface of a base film, the resin layer containing at least an amino resin (A) terminally substituted with an electron-donating group selected from the group consisting of lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl; hydroxyl; and lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, and t-butoxy; and a polythiophene compound (B), and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K)[-] of the peak intensity (P) of the fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at maximum intensity is less than 0.1.

[0015] If the amino resin (A) does not contain the electron-donating group, the deterioration of the antistatic component described above cannot be prevented. On the other hand, if the polythiophene compound (B) is not contained, it is difficult to impart sufficient antistatic properties to the resin layer. The laminate film of the present invention will be described in detail below.

[0016] <Base film, polyester film> The laminate film of the present invention has a resin layer on at least one surface of a base film. The base film in the laminate film of the present invention will be described in detail below. There are no particular restrictions on the type of base film, but polyester films are preferably used from the standpoints of heat resistance and cost (hereinafter, polyester films used as base films may be referred to as "base films"). A polyester film refers to a film containing polyester as the main component, and the "main component" refers to a component that accounts for more than 50% by mass when the entire resin constituting the film is taken as 100% by mass.

[0017] In the present invention, the substrate film may contain particles. When particles are contained, the content of particles is preferably 0.1% by mass or less based on the entire substrate film. By setting the particle content within the above range, the internal haze can be set to 0.2% or less, and a laminate film with excellent transparency can be obtained.

[0018] The polyester used in the base film of the laminated film of the present invention will be described below. First, polyester is a general term for polymers having ester bonds in the main chain, and preferably contains at least one component selected from ethylene terephthalate, propylene terephthalate, ethylene-2,6-naphthalate, butylene terephthalate, propylene-2,6-naphthalate, ethylene-α,β-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylate, etc.

[0019] The polyester film using the above polyester is preferably a biaxially oriented polyester film. A biaxially oriented polyester film is a polyester film oriented in two perpendicular directions, which exhibits a biaxially oriented pattern in wide-angle X-ray diffraction. A biaxially oriented polyester film is generally obtained by stretching an unstretched polyester sheet or film by approximately 2.5 to 5.0 times in both the longitudinal direction and the width direction perpendicular to the longitudinal direction, and then subjecting it to heat treatment to complete the crystal orientation. Biaxially oriented polyester films have sufficient thermal stability, particularly dimensional stability and mechanical strength, and also have good flatness.

[0020] 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.

[0021] 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 200 μm in terms of mechanical strength, handleability, etc. The polyester film may be any of a single-layer film, a composite film obtained by coextrusion, and a film obtained by laminating the obtained films by various methods.

[0022] <Resin layer> The laminate film of the present invention has a resin layer on at least one surface of a substrate film from the viewpoint of achieving both excellent releasability and antistatic properties. It is important that the resin layer of the laminate film of the present invention contains an amino resin (A) terminally substituted with the following electron-donating group and a polythiophene-based compound (B). The terminally substituted amino resin (A) is preferably an amino resin substituted with a methylol group or an alkyl ether group. Hereinafter, the amino resin (A) terminally substituted with the following electron-donating group may also be referred to as "amino resin (A) terminally substituted with an electron-donating group." <Electron-donating group> Any of the following functional groups: lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl groups; hydroxyl groups; and lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, and t-butoxy groups.

[0023] A particularly preferred embodiment is one in which the amino resin (A) terminally substituted with electron-donating groups has a triazine ring structure, the total number of methylol groups and alkyl ether groups per triazine ring is 3 to 6, and the number of imino groups per triazine ring is 3 or less. The triazine ring structure of the amino resin (A) terminally substituted with electron-donating groups improves the crosslinkability of the resin layer, reducing deterioration in quality and the abrasion and peeling of the resin layer. Furthermore, the total number of methylol groups and alkyl ether groups per triazine ring is 3 or more, and the number of imino groups per triazine ring is 3 or less, thereby improving the effect of suppressing the deterioration of the antistatic properties. Since the maximum number of functional groups that can be terminally substituted per triazine ring in industrial applications is 6, the total number of methylol groups and alkyl ether groups per triazine ring is theoretically 6 or less.

[0024] The resin layer of the laminate film of the present invention preferably has a film thickness of more than 5 nm and less than 200 nm. By making the resin layer film thickness more than 5 nm and less than 200 nm, it becomes easy to provide a resin layer having uniform coatability and releasability on a polyester film as a base film. By making the resin layer film thickness less than 200 nm, an increase in manufacturing costs is suppressed, and the occurrence of unevenness and streaks during application of a coating composition for forming the resin layer is reduced, improving the quality of the laminate film. On the other hand, by making the resin layer film thickness greater than 5 nm, the functions imparted to the resin layer are fully exhibited.

[0025] The resin layer of the present invention can be obtained by forming it from a coating composition containing an amino resin (A) terminally substituted with an electron-donating group and a polythiophene compound (B). Details will be described in the coating composition and production method sections.

[0026] On the other hand, a specific resin layer of the laminate film of the present invention is preferably a release layer, which serves to facilitate peeling in the step of peeling an adherend such as an adhesive tape or ceramic slurry from the laminate film after the adherend is further laminated on the layer.

[0027] In the laminate film of the present invention, the X-ray absorption near edge structure (XANES) spectrum at the carbon K-edge, measured by partial electron yield spectroscopy, preferably satisfies [I(15°)-0.1] / I(90°)>1, where θ is the angle between the incident X-rays and the release layer surface and I(θ) is the spectral intensity at 293.5 eV. The resin layer satisfying [I(15°)-0.1] / I(90°)>1 means that the long-chain alkyl groups in the resin layer have a high degree of vertical orientation, which makes it difficult for adherend components to penetrate the resin layer and improves the releasability of the adherend. In other words, this means that the resin layer functions well as a release layer. From the above viewpoints, [I(15°)-0.1] / I(90°) is more preferably [I(15°)-0.1] / I(90°)>1.2, and even more preferably [I(15°)-0.1] / I(90°)>1.4. By setting [I(15°)-0.1] / I(90°) within the above preferred range, it is possible to improve the tape peel strength and the peel strength of the adherend. One method for achieving [I(15°)-0.1] / I(90°)>1 is to incorporate a release agent (X) into the resin layer and adjust the type and amount of the agent. Details of the release agent (X) will be described later.

[0028] In the laminate film of the present invention, from the viewpoint of allowing the resin layer to function as a release layer, the resin layer preferably contains a long-chain alkyl resin as the release agent (X), and the long-chain alkyl resin preferably has an exothermic peak temperature (Tc) of 30°C or higher and 90°C or lower during the temperature decrease process when the temperature is increased from 25°C to 200°C at 20°C / min using a differential scanning calorimeter (DSC) and then decreased from 200°C to -50°C at 20°C / min. The exothermic peak temperature (Tc) is more preferably 35°C or higher and 80°C or lower, and even more preferably 45°C or higher and 70°C or lower. When the exothermic peak temperature Tc is 30°C or higher, the long-chain alkyl groups of the release agent (X) are more likely to be vertically oriented, making it easier to satisfy [I(15°)-0.1] / I(90°)>1.

[0029] The resin layer in the laminated film of the present invention has a surface resistivity of 9.0×10 8 It is preferable that the resistance is Ω / □ or less and the tape peeling force is 3 N / 50 mm or less. The method for measuring each of these properties will be described in detail later.

[0030] The surface resistivity of the resin layer is 9.0×10 8 If the surface resistivity exceeds Ω / □, sufficient antistatic properties may not be obtained. 8 Ω / □ or less is more preferable, and 5.0×10 7 The surface resistivity of the resin layer is particularly preferably 1.0×10 Ω / □ or less. Although there is no particular limitation on the surface resistivity of the resin layer, the lower limit is set to 1.0×10 Ω / □ from the viewpoint of feasibility. 5 It becomes Ω / □.

[0031] If the tape peeling force of the resin layer exceeds 3 N / 50 mm, the dense crosslinking property of the coating film may be insufficient. From the above viewpoint, the tape peeling force of the resin layer is more preferably 2.5 N / 50 mm or less, and even more preferably 2.0 N / 50 mm or less. Furthermore, the smaller the tape peeling force of the resin layer, the better, and there is no particular limit, but from the viewpoint of feasibility, the lower limit is 0.5 N / 50 mm.

[0032] From the viewpoint of antistatic properties, it is important that the resin layer in the laminate film of the present invention has a ratio (P / K)[-] of the peak intensity (P) of the fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at maximum intensity in time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS) of less than 0.1.

[0033] If the peak intensity ratio (P / K)[-] in time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS) exceeds 0.1, the resin layer contains many components derived from polydimethylsiloxane, and when the laminated film of the present invention is used as a process film for manufacturing electronic components, the silicone compound derived from polydimethylsiloxane may migrate (transfer) to the product side, causing problems such as poor conductivity. From the above perspective, the (P / K)[-] of the resin layer is more preferably 0.01 or less, and although there is no particular limitation, it is even more preferably 0.001 (the lower limit of measurement) or less from the standpoint of feasibility.

[0034] A preferred method for achieving the surface resistivity, tape peel strength, and (P / K)[-] of the resin layer within the above ranges is, for example, to apply a coating composition containing an amino resin (A) terminally substituted with an electron-donating group, a polythiophene compound (B), and a release agent (X) to at least one surface of a substrate film to form a resin layer.

[0035] <Paint composition> A preferred coating composition for forming the resin layer of the laminate film of the present invention is described below. The resin layer of the laminate film of the present invention is preferably formed from a coating composition containing an amino resin (A) terminally substituted with an electron-donating group, a polythiophene-based compound (B), and at least one resin selected from polyester resins, acrylic resins, and urethane resins. Here, the electron-donating group refers to "any functional group selected from the group consisting of lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl; hydroxyl groups; and lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, and t-butoxy." This composition facilitates the formation of a resin layer with excellent antistatic properties and crosslinking density. Furthermore, the inclusion of a release agent (X) facilitates the formation of a highly crosslinked resin layer with good peelability from the surface layer. Details of each material are described below.

[0036] <Amino resin (A) terminally substituted with electron-donating groups> The amino resin (A) terminally substituted with an electron-donating group that can be used in the present invention is not particularly limited, but suitable examples include terminally substituted urea resins, melamine resins, benzoguanamine derivative resins, etc. Among these, terminally substituted melamine resins are more preferred because they facilitate increasing the degree of crosslinking of the resin layer and tend to provide a light peel force from the surface.

[0037] Examples of melamine resins that can be used include melamine, methylolated melamine derivatives obtained by condensing melamine with formaldehyde, compounds obtained by reacting methylolated melamine with a lower alcohol to partially or completely etherify the melamine, and mixtures thereof. Furthermore, the melamine resin may be a condensate of a monomer or a dimer or higher polymer, or a mixture thereof. Examples of lower alcohols that can be used for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. Examples of functional groups that can be used include imino, methylol, or alkoxymethyl groups such as methoxymethyl and butoxymethyl groups per molecule, such as imino-type methylated melamine resins, methylol-type methylated melamine resins, methylol-type methylated melamine resins, and fully alkylated methylated melamine resins.

[0038] The melamine resin used here is a melamine resin terminally substituted with an electron-donating group, such as a lower alkyl group (e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or t-butyl); a hydroxyl group; or a lower alkoxy group (e.g., methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, or t-butoxy). Methylolated melamine resins, methylol-type methylated melamine resins, and fully alkylated methylated melamine resins are particularly preferred. As mentioned above, the combined use of an electron-conductive antistatic agent and a melamine resin containing imino groups results in a significant deterioration in resistance. Therefore, it is necessary for the melamine resin to contain a small amount of imino groups. Specifically, it is preferred that the amino resin (A) has triazine rings, the total number of methylol groups and alkyl ether groups per triazine ring is 3 to 6, and the number of imino groups per triazine ring is 3 or less. When multiple types of amino resins (A) terminally substituted with electron-donating groups are used in combination, the amount of functional groups corresponds to the mass average of the amounts blended. By using an amino resin (A) terminally substituted with electron-donating groups that satisfies the above requirements, it becomes easy to obtain a resin layer with excellent antistatic properties and crosslinking density.

[0039] <Polythiophene Compound (B)> The coating composition that forms the resin layer of the laminated film of the present invention contains a polythiophene-based compound (B) as a component.

[0040] Examples of the polythiophene compound (B) that can be used include compounds having a structure in which the 3rd and 4th positions of the thiophene ring are substituted. Furthermore, compounds in which oxygen atoms are bonded to the 3rd and 4th carbon atoms of the thiophene ring are also suitable. Compounds in which a hydrogen atom or a carbon atom is directly bonded to the carbon atom may not easily render the coating liquid water-soluble. The above compounds can be produced by the methods disclosed in, for example, JP-A No. 2000-6324, EP 602713, and U.S. Pat. No. 5,391,472, but other methods may also be used.

[0041] For example, 3,4-ethylenedioxythiophene is obtained using an alkali metal salt of 3,4-dihydroxythiophene-2,5-dicarboxy ester as a starting material, and then potassium peroxodisulfate, iron sulfate, and the previously obtained 3,4-ethylenedioxythiophene are introduced into an aqueous polystyrene sulfonic acid solution and reacted to obtain a composition in which a polythiophene such as poly(3,4-ethylenedioxythiophene) is complexed with an acidic polymer such as polystyrene sulfonic acid.

[0042] Furthermore, as an aqueous coating composition containing poly-3,4-ethylenedioxythiophene and polystyrene sulfonic acid, a product sold under the name "Baytron" P by HC Starck (Germany) can be used.

[0043] On the other hand, examples of acidic polymers in the free acid state include polymeric carboxylic acids, polymeric sulfonic acids, and polyvinyl sulfonic acids. Examples of polymeric carboxylic acids include polyacrylic acid, polymethacrylic acid, and polymaleic acid. Examples of polymeric sulfonic acids include polystyrene sulfonic acid, with polystyrene sulfonic acid being particularly preferred in terms of antistatic properties. The free acid may be in the form of a partially neutralized salt. It may also be used in the form of a copolymer with other copolymerizable monomers, such as acrylic acid esters, methacrylic acid esters, and styrene. The molecular weight of the polymeric carboxylic acid or polymeric sulfonic acid is not particularly limited. However, from the viewpoint of coating stability and antistatic properties, the weight-average molecular weight is preferably 1,000 to 1,000,000, and more preferably 5,000 to 150,000. Furthermore, alkali salts such as lithium salts and sodium salts, or ammonium salts, may be included in part, as long as they do not impair the properties of the invention. Neutralized salts of polyanions are also believed to function as dopants. This is because polystyrene sulfonic acid and ammonium salts, which function as very strong acids, shift the equilibrium to the acidic side as the equilibrium reaction progresses after neutralization.

[0044] <Resin> In the present invention, examples of resins other than the amino resin (A) terminally substituted with an electron-donating group that can be used in the coating composition for forming the resin layer include at least one resin selected from polyester resins, acrylic resins, and urethane resins. The resin preferably contains a functional group that serves as a crosslinking point with the amino resin (A) terminally substituted with an electron-donating group. The inclusion of a functional group that serves as a crosslinking point allows the crosslinking reaction with the amino resin (A) terminally substituted with an electron-donating group to proceed efficiently, resulting in a higher degree of crosslinking of the resin layer and making it easier to improve the releasability of the surface layer.

[0045] The polyester resin that can be used as the resin in the coating composition for forming the resin layer preferably has an ester bond in the main chain or side chain and is obtained by polycondensation of a dicarboxylic acid and a diol. Dicarboxylic acids that serve as raw materials for the polyester resin include aromatic, aliphatic, and alicyclic dicarboxylic acids. 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-p-p'-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.

[0046] 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, and 2,2,4-trimethyl- Examples of suitable polyester resins 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. Modified polyester copolymers, such as block copolymers and graft copolymers modified with acrylic, urethane, or epoxy, can also be used as the polyester resin.

[0047] The acrylic resin that can be used as the resin in the coating composition for forming the resin layer is not particularly limited, but is preferably composed of alkyl methacrylate and / or alkyl acrylate. Examples of alkyl methacrylate and / or alkyl acrylate include methacrylic acid, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-hexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, maleic acid, itaconic acid, acrylamide, N-methylolacrylamide, and diacetone acrylamide. These may be used alone or in combination.

[0048] The urethane resin that can be used as the resin in the coating composition for forming the resin layer is preferably a resin obtained by reacting a polyhydroxy compound with a polyisocyanate compound by a known urethane resin polymerization method such as emulsion polymerization or suspension polymerization.

[0049] Examples of polyhydroxy compounds include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene glycol, hexamethylene glycol, tetramethylene glycol, 1,5-pentanediol, diethylene glycol, triethylene glycol, polycaprolactone, polyhexamethylene adipate, polyhexamethylene sebacate, polytetramethylene adipate, polytetramethylene sebacate, trimethylolpropane, trimethylolethane, pentaerythritol, polycarbonate diol, and glycerin.

[0050] Examples of polyisocyanate compounds that can be used include hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, an adduct of tolylene diisocyanate and trimethylenepropane, and an adduct of hexamethylene diisocyanate and trimethylolethane.

[0051] Furthermore, 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 between the amino resin (A) terminally substituted with electron-donating groups and the resin during heat treatment to proceed efficiently, thereby 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 acid catalysts such as p-toluenesulfonic acid and amine salt catalysts.

[0052] <Release agent (X)> The release agent (X) in the laminate film of the present invention refers to a compound that, when incorporated into a coating composition, imparts releasability (i.e., properties such as reducing the surface free energy of the resin or reducing the static friction coefficient of the resin) to the surface of the resin layer. Examples of the release agent (X) that can be used in the present invention include long-chain alkyl resins, olefin resins, fluorine compounds, and wax-based compounds. Among these, long-chain alkyl resins are preferred because they are resins in which long-chain alkyl groups are covalently bonded to the main skeleton and can impart good releasability. When a long-chain alkyl resin is used, the long-chain alkyl groups, which have low surface free energy, segregate to the surface of the release layer, orient themselves perpendicular to the surface, and crystallize. As a result, the terminal methyl groups are exposed to the surface, reducing the surface free energy and thereby exhibiting easy releasability.

[0053] Furthermore, the long-chain alkyl resin used in the present invention preferably has an exothermic peak temperature (Tc) during the temperature drop process when heated from 25°C to 200°C at 20°C / min using a differential scanning calorimeter (DSC) and then cooled from 200°C to -50°C at 20°C / min of 30°C or higher and 90°C or lower, more preferably 35°C or higher and 80°C or lower, and particularly preferably 45°C or higher and 70°C or lower. Having an exothermic peak temperature Tc of 30°C or higher facilitates vertical alignment of the long-chain alkyl groups of the release agent contained in the release layer, making it easier to satisfy [I(15°)-0.1] / I(90°)>1.

[0054] Furthermore, the release agent (X) is preferably a block copolymer comprising units having a long-chain alkyl group. When the release agent is a block copolymer comprising units having a long-chain alkyl group, the long-chain alkyl group is more easily oriented. The method for producing the block copolymer is not particularly limited as long as it is a living radical polymerization method other than atom transfer radical polymerization (ATRP). Various polymerization methods can be used, including reversible addition-fragmentation chain transfer polymerization (RAFT), living radical polymerization methods with exchange chain mechanisms such as polymerization using organotellurium compounds (TERP), polymerization using organoantimony compounds (SBRP), polymerization using organobismuth compounds (BIRP), and iodine transfer polymerization, as well as the nitroxy radical method (NMP). Among these, the RAFT method and the NMP method are preferred from the viewpoints of polymerization controllability and ease of implementation.

[0055] The molar ratio of the long-chain alkyl group-containing monomer to the long-chain alkyl group-free monomer in the release agent (X) is preferably 50 to 99%, more preferably 60 to 97%, and even more preferably 70 to 95%. By using the long-chain alkyl group-containing monomer in the above-mentioned ratio, the compatibility of the release agent (X) with at least one resin selected from the polyester resin, acrylic resin, and urethane resin described above is improved, and a coating composition with stabilized dispersion can be prepared.

[0056] Commercially available long-chain alkyl group-containing compounds may be used. Specific examples include the "Ashio Resin" (registered trademark) series of long-chain alkyl compounds manufactured by Asio Sangyo Co., Ltd., the "Peiroil" series of long-chain alkyl compounds manufactured by Ipposha Yushi Co., Ltd., and the "Rezem" series of aqueous dispersions of long-chain alkyl compounds manufactured by Chukyo Yushi Co., Ltd. The release agent (X) 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 increasing the carbon number of the alkyl group to 12 or more, hydrophobicity is enhanced, allowing the release agent (X) to exhibit sufficient release performance. There is no particular upper limit on the number of carbon atoms in the alkyl group, but a carbon number of 25 or less is preferred for ease of production.

[0057] The resin having an alkyl group having 12 or more carbon atoms is more preferably a resin having a side chain of an alkyl group having 12 or more carbon atoms on a polymethylene main chain. When the main chain is polymethylene, the number of hydrophilic groups in the entire resin is reduced, and the release effect of the release agent (X) can be improved.

[0058] <Preferred composition of coating composition> The resin layer of the laminated film of the present invention is preferably formed from a coating composition containing a release agent (X), an amino resin (A) terminally substituted with an electron-donating group, and a polythiophene-based compound (B). The coating composition preferably contains 0 to 60 parts by mass of the release agent (X) per 100 parts by mass of the amino resin (A) terminally substituted with an electron-donating group and the polythiophene-based compound (B) combined. The content of the release agent (X) is preferably 40 to 50 parts by mass. Limiting the amount of the release agent (X) to 60 parts by mass or less not only suppresses defects such as cissing and pinholes during post-processing, but also ensures a sufficiently high proportion of the amino resin (A) in the coating composition. As a result, the degree of crosslinking of the resin layer is increased, resulting in excellent releasability, particularly for the surface layer. Here, "0 parts by mass" means that the release agent (X) is not included.

[0059] In the coating composition forming the resin layer of the laminated film of the present invention, the mass ratio of the amino resin (A) terminally substituted with an electron-donating group to the polythiophene compound (B) is preferably in the range of 95 / 5 to 60 / 40, more preferably 90 / 10 to 70 / 30. By setting the ratio in this range, it is possible to easily achieve both dense crosslinking and antistatic properties, which are the objectives of the present invention.

[0060] <Manufacturing method> In the laminated film of the present invention, the resin layer can be provided on at least one side of the base film by either an in-line coating method or an off-coating method, but the in-line coating method is preferred. The in-line coating method is a method in which coating is performed within the polyester film production process. Specifically, it refers to a method in which coating is performed at any stage from melt extrusion of a polyester resin to biaxial stretching, heat treatment, and winding up. Typically, coating is performed on either an unstretched (unoriented) polyester film (A film) in a substantially amorphous state obtained by melt extrusion and quenching, a uniaxially stretched (uniaxially oriented) polyester film (B film) that has been subsequently stretched in the longitudinal direction, or a biaxially stretched (biaxially oriented) polyester film (C film) that has been further stretched in the width direction and has not yet been heat treated.

[0061] On the other hand, the offline coating method is a method in which the above-mentioned A film is stretched uniaxially or biaxially, and then heat-treated to complete the crystal orientation of the polyester film (C film), and then a resin composition is applied to the resulting film in a process separate from the film-forming process.

[0062] In the present invention, it is preferable to produce a laminated film by an in-line coating method. By producing by the in-line coating method, a laminated film can be produced at a lower cost than, for example, forming a resin layer on a biaxially stretched PET film by off-coating. Furthermore, by performing a high-temperature heat treatment at 200°C or higher, which is essentially impossible with off-coating, dense crosslinking of the resin layer can be promoted, and the peel force can be reduced, especially when a release layer is formed. In particular, from the viewpoints of production cost, dimensional stability after heat treatment, heat shrinkage properties, and the density of the resin layer, it is preferable to produce the film by a production method in which a coating composition is applied to at least one side of a polyester film before the crystal orientation is completed, the polyester film is stretched at least uniaxially, and then heat-treated to complete the crystal orientation of the polyester film.

[0063] <Coating method> The resin composition can be applied to the polyester film by any known coating method, such as bar coating, reverse coating, gravure coating, die coating, blade coating, etc. Here, the adhesion between the polyester film and the resin layer will be described.

[0064] When a resin layer is formed on a polyester film using a conventional off-coating method, the low surface energy of the resin layer results in poor adhesion to the film, which can lead to problems such as the resin layer being scraped off when the film roll is rewound, resulting in a deterioration in peel strength. However, when the resin layer is laminated using an in-line coating method, applying a coating composition to the polyester film before completion of crystal orientation allows a very small amount of the coating composition to penetrate into the polyester film, thereby imparting adhesion between the resin layer and the thermoplastic resin film. As a result, excellent peel strength can be achieved.

[0065] <Method for forming resin layer> 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 and then drying it. In the present invention, when a solvent is contained in the coating composition, it is preferable to use an aqueous solvent as the solvent. By using an aqueous solvent, it is possible to suppress rapid evaporation of the solvent during the drying process, and not only can a uniform and high-quality resin layer be formed, but also it is excellent in terms of environmental impact.

[0066] Here, the aqueous solvent refers to water or a mixture of water and a water-soluble organic solvent, such as an alcohol such as methanol, ethanol, isopropyl alcohol, or butanol, a ketone such as acetone or methyl ethyl ketone, or a glycol such as ethylene glycol, diethylene glycol, or propylene glycol, in any ratio that does not cause phase separation.

[0067] As mentioned above, the coating composition is preferably applied to a film by in-line coating. Specifically, this refers to a method in which the coating is applied at any stage from melt extrusion of a polyester resin to biaxially stretching, heat treatment, and winding up. Typically, the coating is applied to any of the following films: an unstretched (unoriented) film (A film) in a substantially amorphous state obtained by melt extrusion and quenching, a uniaxially stretched (uniaxially oriented) film (B film) that has been subsequently stretched in the longitudinal or width direction, or a biaxially stretched (biaxially oriented) film (C film) that has been further stretched in the width direction or longitudinal direction and has not yet been heat treated.

[0068] In the present invention, it is preferable to adopt a method in which a coating composition is applied to either the above-mentioned Film A or Film B before the crystal orientation is complete, and then the film is stretched uniaxially or biaxially and heat-treated at a temperature higher than the boiling point of the solvent to complete the crystal orientation of the film and provide a resin layer. This method has the advantage of being able to simultaneously produce the film and apply and dry the coating composition (i.e., form the resin layer), and it also makes it easier to ensure the aforementioned substrate adhesion.

[0069] Among these, the method of applying the coating composition to a film (B film) that has been 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 it, 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.

[0070] Therefore, a preferred method for forming a resin layer in the present invention is to apply a coating composition using an aqueous solvent to a polyester film using an in-line coating method, followed by drying and heat treatment. A more preferred method is to in-line coat the coating composition on the uniaxially stretched B film. In the laminate film manufacturing method of the present invention, drying can be carried out at a temperature range of 80 to 130°C to complete removal of the solvent from the coating composition. Heat treatment can be carried out at a temperature range of 160 to 240°C to complete the crystalline orientation of the polyester film and complete the thermal curing of the coating composition to complete the formation of the resin layer. A temperature of 180 to 240°C is particularly preferred. Heat treatment temperatures below 160°C not only result in reduced performance of the polyester substrate film, such as a decrease in the heat resistance of the substrate, but also make it difficult to achieve the dense crosslinking of the resin layer that is the objective of the present invention. For example, if the resin layer is a release layer, this may result in poor releasability.

[0071] Furthermore, the solid content of the coating composition is preferably 40% by mass or less. By setting the solid content to 40% by mass or less, the coating composition can be endowed with good coatability, and a laminated film having a uniform resin layer can be produced.

[0072] The solid content concentration represents the ratio of the mass of the coating composition obtained by subtracting the mass of the solvent from the mass of the coating composition (i.e., [solid content concentration] = [(mass of coating composition) - (mass of solvent)] / [mass of coating composition]).

[0073] <Laminated film manufacturing method> Next, the method for producing the laminated film of the present invention will be specifically explained using an example in which the base film is a polyethylene terephthalate (PET) film, but the laminated film of the present invention is not limited to that obtained by this production method.

[0074] First, PET pellets are thoroughly vacuum-dried and then fed into an extruder. They are melt-extruded into a sheet at approximately 280°C and then cooled and solidified to produce an unstretched (unoriented) PET film (Film A). This Film A is then stretched 2.5 to 5.0 times in the longitudinal direction using rolls heated to 80 to 120°C to produce a uniaxially oriented PET film (Film B). A coating composition prepared to a predetermined concentration is applied to one side of this Film B. Prior to application, the surface of the PET film to be coated may be subjected to a surface treatment such as corona discharge treatment. Surface treatment such as corona discharge treatment improves the wettability of the resin composition to the PET film, prevents cissing of the resin composition, and achieves a uniform coating thickness.

[0075] After coating, the PET film is held by clips at the edges and transported 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 transported to a heating zone (heat treatment zone) at 150-250°C for 1-30 seconds, where it is heat-treated 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. During this heating step (heat treatment step), a relaxation treatment of 3-15% may be performed in the width direction or length direction, if necessary. A laminated film can be obtained in this manner, and the resulting laminated film can also be wound into a film roll.

[0076] <Second aspect> The laminated film of the present invention is a laminated film having a resin layer on at least one surface of a substrate film, and the resin layer has a surface resistivity of 9.0×10 8The laminated film may also have a resistivity of Ω / □ or less, a tape peeling force of 3 N / 50 mm or less, and when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the ratio (P / K)[-] of the peak intensity (P) of the fragment derived from polydimethylsiloxane to the peak intensity (K) of the fragment detected at maximum intensity is less than 0.1. Details of the methods for measuring each of these properties will be described later.

[0077] The surface resistivity of the resin layer is 9.0×10 8 If the surface resistivity exceeds Ω / □, sufficient antistatic properties may not be obtained. 8 Ω / □ or less is more preferable, and 5.0×10 7 The surface resistivity of the resin layer is particularly preferably Ω / □ or less. Although there is no particular lower limit for the surface resistivity of the resin layer, the lower limit is set to 1.0×10 from the viewpoint of feasibility. 5 It becomes Ω / □.

[0078] If the tape peeling force of the resin layer exceeds 3 N / 50 mm, the dense crosslinking property of the coating film may be insufficient. From the above viewpoint, the tape peeling force of the resin layer is more preferably 2.5 N / 50 mm or less, and even more preferably 2.0 N / 50 mm or less. Furthermore, the smaller the tape peeling force of the resin layer, the better, and there is no particular limit, but from the viewpoint of feasibility, the lower limit is 0.5 N / 50 mm.

[0079] If the peak intensity ratio (P / K)[-] in time-of-flight secondary ion mass spectrometry (GCIB-TOF-SIMS) exceeds 0.1, the resin layer contains many components derived from polydimethylsiloxane, and when the laminated film of the present invention is used as a process film for manufacturing electronic components, silicone compounds derived from polydimethylsiloxane may migrate to the product, causing problems such as poor conductivity. From the above perspective, the (P / K)[-] of the resin layer is more preferably 0.01 or less, and although there is no particular limitation, it is even more preferably 0.001 (the lower measurement limit) or less from the standpoint of feasibility.

[0080] A preferred method for setting the surface resistivity, tape peel strength, and (P / K)[-] of the resin layer within the above ranges is, for example, to apply a coating composition containing the amino resin (A) terminally substituted with the above-mentioned electron-donating group, the polythiophene compound (B), and the release agent (X) to at least one surface of the substrate film to form a resin layer.

[0081] In the laminate film of the second embodiment, it is preferable that [I(15°)-0.1] / I(90°)>1 is satisfied. It is also preferable that the resin layer contains an amino resin (A) terminally substituted with an electron-donating group and a polythiophene compound (B), wherein the electron-donating group is a methylol group or an alkyl ether group. It is also preferable that the amino resin (A) terminally substituted with an electron-donating group has a triazine ring, the total number of methylol groups and alkyl ether groups per triazine ring is 3 to 6, and the number of imino groups per triazine ring is 3 or less. It is also preferable that the resin layer contains a long-chain alkyl resin as a release agent (X), and that the long-chain alkyl resin has an exothermic peak temperature (Tc) of 30°C to 90°C during the cooling process when heated from 25°C to 200°C at 20°C / min and then cooled from 200°C to -50°C at 20°C / min as measured by a differential scanning calorimeter (DSC). The definition and more preferable range of each parameter are the same as those described above. [Example]

[0082] 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. It should be noted that Examples 5, 6, and 7 should be read as Reference Examples 5, 6, and 7, respectively.

[0083] <Methods for measuring characteristics and evaluating effects> The methods for measuring the properties and evaluating the effects in the present invention are as follows.

[0084] (1-1) Analysis method for amino resin in resin layer The method for confirming the amino resin structure in the resin forming the resin layer is not particularly limited to a specific method, but the following methods can be exemplified. For example, the presence or absence of a weight peak due to the side chain structure was confirmed by gas chromatography mass spectrometry (GC-MS). Next, the presence or absence of a peak due to the bond between each atom in the side chain structure was confirmed by Fourier transform infrared spectroscopy (FT-IR). Furthermore, proton nuclear magnetic resonance spectroscopy ( 1 H-NMR) and carbon nuclear magnetic resonance spectroscopy ( 13 Using C-NMR, the positions of the chemical shifts resulting from the positions of hydrogen and carbon atoms in each structure and the absorption line areas resulting from the number of hydrogen and carbon atoms were confirmed. These results combined confirmed the amino resin in the resin layer.

[0085] (1-2) Analysis method for amino resins in paint compositions The amount of each functional group of the amino resin in the coating composition can be determined by, for example, hydrogen nuclear magnetic resonance ( 1 Specifically, in the case of melamine compounds, 1 H-NMR analysis was performed on a Bruker AC-200 NMR instrument using a 5 mm solution probe, spinning at 20 Hz at 30 °C, with a 4-second acquisition interval, 32 scans, and a spectral frequency of 200.13 MHz with a recycle delay of 22.5 seconds. A hexamethyldisiloxane (HMDS) standard stock solution (0.05 wt.%) was prepared by dissolving 100 mg of HMDS in acetone-d6. Samples were prepared by dissolving approximately 20 mg of melamine compounds in a nominal 500 μl stock solution. Spectra were referenced by setting the methyl peak of HMDS at 0.0 ppm. For example, "imino group content" was quantified by the >NH peak at 7.0 ppm (integrated from 7.3 to 6.7 ppm). Number of moles of HMDS = (mass of stock solution)(0.0005) / 162.38 g / mol Number of moles of NH = (area of ​​NH) (18) (number of moles of HMDS) / (area of ​​HMDS) Imino content = (moles of NH) (15.01 g / mol) / (mass of sample) The factor 162.38 is the molecular weight of HMDS, 18 is the number of methyl protons in one mole of HMDS, and 15.01 is the molecular weight of the imino group. Similar quantification was performed for alkoxymethyl groups (>N-CH2OR) and methylol groups (>N-CH2OH).

[0086] (2) Presence or absence of polythiophene compounds Whether the resin layer of the present invention contains a polythiophene-based compound was determined by the infrared-visible spectrum of the resin layer. A mode typically observed in polythiophene-based compounds is 689 cm -1 , 842cm -1 and 979 cm -1 Vibrational modes of the CS bond in -1 Specifically, the resin layer was scraped off with a single-edged blade to form a KBR tablet, and the spectral intensity was measured using a Frontier FT-IR spectrometer manufactured by PerkinElmer Co., Ltd. The resolution of the spectrometer was 1 cm -1 The number of spectral integration times was 32. The spectral intensity was expressed as absorbance (arb.unit) at each wavelength, and the presence or absence of the above-mentioned peak was used to determine the presence or absence of a polythiophene-based compound.

[0087] (3) Antistatic performance To measure the surface resistivity, after preparing the laminated film to be measured, it was left at a relative humidity of 23% and 25°C for 24 hours, and then under this atmosphere, a digital ultra-high resistance / micro current meter R8340A and a resistivity chamber 12702A (manufactured by Advantest Corporation, main electrode: Φ50mm, counter electrode: Φ103mm) were used to apply a voltage of 100V for 10 seconds, after which measurements were taken. The unit of surface resistivity is Ω / □. The resin layer side of the laminated film was evaluated, and the average value of a total of 10 measurements was taken as the surface resistivity of the sample. The antistatic performance was evaluated based on the surface resistivity, and was 9.0 x 10 8 Ω / □ or less is a practical level, 9.0 x 10 8 When the resistance exceeds Ω / □, it is determined to be at a level that is problematic for practical use.

[0088] (4) Tape peeling strength The tape peeling force was measured as follows. First, an acrylic polyester adhesive tape (Nitto Denko Corporation, Nitto 31B tape, 19 mm wide) was applied to the resin layer of the laminate film, and a roller with a load of 2 kgf was rolled back and forth over it 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, after which the peeling force (N / 19 mm) was measured at a peeling angle of 180° and a pulling speed of 300 mm / min using a Shimadzu Corporation Autograph 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 from the measurement. This measurement was performed five times, and the average of the three measurements, excluding the maximum and minimum values, was taken as the peel strength of the laminated film (N / 19 mm). This value was converted to N / 50 mm and used as the initial tape peel strength (i.e., [initial tape peel strength (N / 50 mm)] = [peel strength (N / 19 mm)] / 19 × 50).

[0089] (5) Method for analyzing the composition of the resin layer surface The composition of the resin layer surface of the laminated film was analyzed using GCIB-TOF-SIMS (GCIB: Gas Cluster Ion Beam, TOF-SIMS: Time-of-Flight Secondary Ion Mass Spectroscopy). The measurement conditions are as follows. In the chart obtained by the measurement, the peak intensity of the fragment detected with the maximum intensity was determined as K, and the fragment derived from polydimethylsiloxane (SiCH3 + The peak intensity of the fragment ion (M / Z=43) was defined as P, and the ratio P / K was calculated. When P / K<0.1, it was determined that the resin layer did not substantially contain a silicone compound. <Sputtering conditions> Ion source: Argon gas cluster ion beam <Detection conditions> Primary ion: Bi 3++ (25 keV) Secondary ion polarity: Negative Mass range: m / z 0~1000 Measurement range: 200 x 200 μm2 .

[0090] (6) Resin layer thickness The laminated film was stained with RuO4 and / or OsO4. Next, the laminated film was frozen and cut in the film 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 model, manufactured by Hitachi, Ltd.), and cross-sectional photographs were obtained. The measured values ​​of the resin layer thickness of the 10 samples were averaged to obtain the resin layer thickness of the laminated film.

[0091] (7) Transfer prevention The transfer prevention property was judged based on the ratio of "adhesive tape peeling force after application and peeling (P1)" (described later) to "tape peeling force (4)" multiplied by 100 [%]. The measurement method is described below. Here, tape peeling force (4) means the tape peeling force measured by the method described in "(4) Tape peeling force".

[0092] (7-1) Adhesive tape peel strength after application and removal (P1) An adhesive tape (Nitto Denko Corporation, polyester tape No. 31B, 19 mm wide) was applied to the resin layer side of the laminated film of the present invention by rolling a 5 kg rubber roller back and forth once. The tape was then left to stand at 23°C / 65% RH for 24 hours, after which a 180° peel test was performed at a peel rate of 300 mm / min using a Shimadzu Corporation "Autograph AG-1S" universal testing machine and a 50 N load cell to remove the adhesive tape. The removed adhesive tape was then attached to a stainless steel plate (SUS304) and left to stand at 23°C / 65% RH for 24 hours. The average peel force over a period of 5 to 10 seconds was calculated from the graph of peel force (N) vs. test time (sec). This measurement was carried out five times, and the average of three measurements excluding the maximum and minimum values ​​was taken as the initial adhesive tape peel strength (P1).

[0093] (7-2) Evaluation of transfer prevention The transfer prevention ability was evaluated based on the value of the obtained peel strength: "Adhesive tape peel strength after application and peeling (P1)" / "Tape peel strength (4)" x 100 [%]. A score of A or higher was considered good, and B was considered a level that was acceptable for practical use.

[0094] S: 95% or more A: 90% or more but less than 95% B: 85% or more but less than 90% C: Less than 85%.

[0095] (8) Hayes The haze (%) of the laminated film at 23° C. was measured three times using a direct reading haze meter manufactured by Toyo Seiki Co., Ltd., and the average value was taken as the haze (%) of the laminated film.

[0096] (9) X-ray absorption near edge structure (XANES) spectrum The laminate film was polished on the side opposite the resin layer to adjust the thickness of the laminate film to 10 μm. A measurement sample was cut 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 and analysis conditions were as follows:

[0097] Spectrometer: Grating spectrometer Absorption edge: Carbon K (284.2 eV) absorption edge E0:287.319eV Pre-edge range: -20 to 10 eV Normalization range: 15 to 70 eV Horizontal axis correction: The Π* peak of highly oriented pyrolytic graphite is corrected to 255.5 eV In the XAFS spectrum, 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 Iθ. The spectral intensity I(15°) at θ = 15° and the spectral intensity I(90°) at θ = 90° were applied to the formula [I(15°)-0.1] / I(90°) to calculate the value.

[0098] (10) Differential scanning calorimeter (DSC) heat generation peak temperature Tc during the cooling process 1 g of the release agent (X) or a resin layer cut from the surface of a laminate 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 (X) or release layer. A 3 mg sample of the prepared solid sample was measured using a differential scanning calorimeter (DSC6220, Hitachi High-Tech Science Corporation). The sample was first heated from 25°C to 200°C at a rate of 20°C / min in a nitrogen atmosphere and held at 200°C for 5 minutes. The temperature was then lowered to -50°C at a rate of 20°C / min, and the peak temperature of the curve obtained during this temperature drop was measured. This measurement was repeated three times, and the average value was recorded as Tc. In this case, two or more melting peak temperatures may be observed within the temperature range, or the peak temperature may be a peak temperature that can be observed on a multi-stage DSC chart called a shoulder (observed in a chart where two or more peaks overlap), but in the present invention, the peak temperature at which the absolute value of the heat quantity (unit: mW) on the vertical axis of the DSC chart is greatest is defined as Tc (°C).

[0099] <Resins, etc. used in manufacturing laminated film> Release agent 1: Long-chain alkyl resin A four-neck flask was charged with 200 parts by weight of xylene and 600 parts by weight of octadecyl isocyanate and heated with stirring. Once the xylene began to reflux, 100 parts by weight 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 2 hours. After the polyvinyl alcohol addition was completed, the mixture was refluxed for another 2 hours to terminate the reaction. The reaction mixture was cooled to approximately 80°C and then added to methanol, resulting in the reaction product precipitating as a white precipitate. This precipitate was then filtered, and 140 parts of xylene was added and heated to completely dissolve it. This process of adding methanol to precipitate the product was repeated several times, after which the precipitate was washed with methanol, dried, and pulverized to obtain a long-chain alkyl group-containing resin (a-1: a polymethylene main chain with an alkyl group having 18 carbon atoms in the side chain). This was then diluted with water to a concentration of 20% by weight.

[0100] Release agent 2: Silicone resin As the silicone resin, a mixture of Shin-Etsu Chemical Co., Ltd.'s KM-3951, Shin-Etsu Chemical Co., Ltd.'s X-52-6015, and Shin-Etsu Chemical Co., Ltd.'s CAT-PM-10A in a mass ratio of 85:15:5 was prepared.

[0101] Release agent 3: Long-chain alkyl resin A 25 mL pressure-resistant glass polymerization ampoule was charged with methyl methacrylate (MMA) (Kanto Chemical Co., Inc.), 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 weight ratio of MMA / CDB / AIBN / toluene = 2.92 / 0.03 / 0.007 / 2.27 (g). The mixture in the ampoule was then degassed twice by freeze-degassing, after which the ampoule was sealed and heated in a 100 °C oil bath for 18 hours to obtain polymerization solution 1. Next, docosyl acrylate, AIBN as a polymerization initiator, and toluene as a solvent were added to the reaction solution in the ampoule in a weight ratio (docosyl acrylate / AIBN / toluene) of 1.37 / 0.003 / 1.3 (g). After two cycles of freeze-degassing, the ampoule was sealed and heated at 100°C for 48 hours. Polymerization Solution 1 was then added dropwise to 20 times its mass of hexane and stirred to precipitate a solid. The resulting solid was filtered and vacuum-dried overnight at 40°C to obtain a long-chain alkyl resin (a-2) with an alkyl group containing 22 carbon atoms. The resulting long-chain alkyl resin (a-2) was emulsified as follows to produce an aqueous resin emulsion. 375 g of water was placed in a 1 L homomixer, and 45 g of polyoxyethylene nonylphenyl ether, 30 g of polyoxyethylene polyoxypropylene glycol, 200 g of long-chain alkyl resin (a-2), and 150 g of toluene were added in that order, and then 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.

[0102] Crosslinking agent a1: Amino resin (iminated melamine) "Nicalac" (registered trademark) MX-730 (solid content concentration 70% by mass, solvent: water) manufactured by Sanwa Chemical Co., Ltd. was used.

[0103] Crosslinking agent A2: Amino resin (methylol melamine) "Nicalac" (registered trademark) MW-035 (solid content concentration 70% by mass, solvent: water) manufactured by Sanwa Chemical Co., Ltd. was used.

[0104] Crosslinking agent A3: Amino resin (methyl ether type melamine) Cymel 303LF (full ether type methylated melamine resin, solid content concentration 100%, manufactured by Allnex Japan Co., Ltd.) was used.

[0105] Conductive material 1: Polythiophene compound To 1,887 parts by weight of an aqueous solution containing 20.8 parts by weight of the acidic polymer compound polystyrene sulfonic acid, 49 parts by weight of a 1% by weight aqueous solution of iron (III) sulfate, 8.8 parts by weight of the thiophene compound 3,4-ethylenedioxythiophene, and 117 parts by weight of a 10.9% by weight aqueous solution of peroxodisulfuric acid were added. This mixture was stirred at 18°C ​​for 23 hours, and then 154 parts by weight of a cation exchange resin (Lewatit Monoplus S100H) and 232 parts by weight of an anion exchange resin (Lewatit Monoplus M800) were added to the mixture. After stirring for 2 hours, the ion exchange resin was filtered off to obtain a conductive material 1 (solids concentration 1.3 wt%), which was a mixture of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonic acid.

[0106] Resin 1: Acrylic resin Methyl methacrylate (α), hydroxyethyl methacrylate (β), and a urethane acrylate oligomer (manufactured by Negami Chemical Industrial Co., Ltd., "Art Resin" (registered trademark) UN-3320HA, with six acryloyl groups) (γ) were charged into a stainless steel reaction vessel in a mass ratio of (α) / (β) / (γ) = 94 / 1 / 5. Two parts by mass of sodium dodecylbenzenesulfonate as an emulsifier were added per 100 parts by mass of the total of (α) to (γ) and the mixture was stirred to prepare Mixed Solution 1. Next, a reaction apparatus equipped with a stirrer, reflux condenser, thermometer, and dropping funnel was prepared. Sixty parts by mass of 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, which was then maintained at 60°C for 20 minutes. Next, mixed solution 3 was prepared, consisting of 40 parts by mass of mixed solution 1, 50 parts by mass of isopropyl alcohol, and 5 parts by mass of potassium persulfate. 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 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 mass of 25% ammonia water and 900 parts by mass of pure water were added thereto, and the isopropyl alcohol and unreacted monomers were recovered under reduced pressure while heating to 60°C, yielding an acrylic resin dispersed in pure water.

[0107] Example 1 ·Paint composition 1 Crosslinking agent a1 / crosslinking agent a2 / conductive material 1 / resin 1 / mold release agent 1 were mixed in a solids mass ratio of 20 / 10 / 10 / 40 / 20. Furthermore, to improve coatability onto polyester film, a fluorine-based surfactant ("PLASCOAT" (registered trademark) RY-2 manufactured by GOO Chemical Industry Co., Ltd.) was added in an amount of 0.1 part by mass per 100 parts by mass of the total mixed coating composition.

[0108] Polyester film: PET pellets (intrinsic viscosity: 0.64 dl / g) containing two types of particles (4% by mass of silica particles with a primary particle size of 0.3 μm and 2% by mass of calcium carbonate particles with a primary particle size of 0.8 μm) were thoroughly vacuum-dried, then fed into an extruder, melted at 280°C, extruded into a sheet from a T-shaped die, and wrapped around a mirror-finished casting drum with a surface temperature of 25°C using an electrostatic casting method, where it was cooled and solidified. This unstretched film (Film A) was heated to 90°C and stretched 3.1 times in the longitudinal direction to produce a uniaxially stretched film (Film B).

[0109] Laminated film After corona discharge treatment in air, the uniaxially stretched film (film B) was coated with the coating composition shown in the table using a bar coater to a thickness of approximately 6 μm. The coated uniaxially stretched film was then clamped at both widthwise ends with clips and introduced into a preheating zone. The ambient temperature in the preheating zone was set to 90-100°C, allowing the solvent in the coating composition to dry. The film was then continuously stretched 3.6 times in the widthwise direction in a 100°C stretching zone, followed by a 240°C heat treatment for 20 seconds to form a resin layer. A 5% relaxation treatment in the widthwise direction at the same temperature was then performed to obtain a laminated film with complete crystalline orientation of the polyester film. The resulting laminated film had a PET film thickness of 50 μm and a resin layer thickness of 50 nm. The properties of the resulting laminated film are shown in the table.

[0110] Example 2 ·Paint composition 2: Crosslinking agent a1 / crosslinking agent a2 / conductive material 1 / resin 1 / release agent 1 were mixed in a solid mass ratio of 15 / 15 / 10 / 40 / 20, and the remaining components were prepared in the same manner as in Coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that Coating composition 2 was used. The properties of the obtained laminated film are shown in the table.

[0111] Example 3 ·Paint composition 3: Crosslinking agent a2 / conductive material b1 / resin 1 / release agent 1 were mixed to a solids mass ratio of 30 / 10 / 40 / 20, and the remaining components were prepared in the same manner as in Coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that Coating composition 3 was used. The properties of the obtained laminated film are shown in the table.

[0112] Example 4 ·Paint composition 4: A laminated film was obtained in the same manner as in Example 3, except that a coating composition (coating composition 4) prepared in the same manner as in Coating composition 3 was used, except that crosslinker a2 was changed to crosslinker a3. The properties of the obtained laminated film are shown in the table.

[0113] Example 5 ·Paint composition 5: Crosslinking agent a1 / crosslinking agent a2 / conductive material 1 / resin 1 were mixed to a solids mass ratio of 20 / 10 / 10 / 40, and the remaining components were prepared in the same manner as in coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that coating composition 5 was used. The properties of the obtained laminated film are shown in the table.

[0114] Example 6 ·Paint composition 6: Crosslinking agent a1 / crosslinking agent a2 / conductive material 1 / resin 1 were mixed to a solids mass ratio of 15 / 15 / 10 / 40, and the remaining components were prepared in the same manner as in coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that coating composition 6 was used. The properties of the obtained laminated film are shown in the table.

[0115] (Examples 7 and 8) Except for adjusting the bar coating so that the thickness of the resin layer was 10 nm and 180 nm, a laminated film was obtained in the same manner as in Example 3. The properties of the obtained laminated film are shown in the table.

[0116] Example 9 ·Paint composition 8: A laminated film was obtained in the same manner as in Example 3, except that a coating composition (coating composition 8) was used that was prepared in the same manner as coating composition 3, except that release agent 1 and release agent 2 were used in combination in the ratio shown in Table 1. The properties of the obtained laminated film are shown in the table.

[0117] Example 10 ·Paint composition 13: A laminated film was obtained in the same manner as in Example 3, except that a coating composition (coating composition 13) prepared in the same manner as coating composition 3 was used, except that release agent 1 was changed to release agent 3. The properties of the obtained laminated film are shown in the table.

[0118] Example 11 ·Paint composition 14: Crosslinking agent a2 / conductive material 1 / resin 1 / release agent 3 were mixed to a solids mass ratio of 40 / 10 / 10 / 40, and the remaining components were prepared in the same manner as in coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that coating composition 14 was used. The properties of the obtained laminated film are shown in the table.

[0119] (Comparative Example 1) ·Paint composition 9: A laminated film was obtained in the same manner as in Example 3, except that a coating composition (coating composition 9) prepared in the same manner as in Coating composition 3 was used, except that crosslinking agent a2 was changed to crosslinking agent a1. The properties of the obtained laminated film are shown in the table.

[0120] (Comparative Example 2) ·Paint composition 10: Crosslinker a1 / conductive material 1 / resin 1 were mixed to a solid mass ratio of 35 / 15 / 50, and the remaining components were prepared in the same manner as in coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that coating composition 10 was used. The properties of the obtained laminated film are shown in the table.

[0121] (Comparative Example 3) ·Paint composition 11: Conductive material 1 / resin 1 / release agent 1 were mixed to a solids mass ratio of 20 / 50 / 30, and the remaining components were prepared in the same manner as in coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that coating composition 11 was used. The properties of the obtained laminated film are shown in the table.

[0122] Comparative Example 4 ·Paint composition 12: Crosslinking agent a2 / resin 1 / release agent 1 were mixed to a solids mass ratio of 30 / 50 / 20, and the remaining components were prepared in the same manner as in coating composition 1. A laminated film was obtained in the same manner as in Example 1, except that coating composition 12 was used. The properties of the obtained laminated film are shown in the table.

[0123] (Comparative Example 5) ·Paint composition 7: A laminated film was obtained in the same manner as in Example 3, except that a coating composition (coating composition 7) prepared in the same manner as coating composition 3 was used, except that release agent 1 was changed to release agent 2. The properties of the obtained laminated film are shown in the table.

[0124] [Table 1]

[0125] [Table 2]

[0126] [Table 3]

[0127] [Table 4] [Industrial Applicability]

[0128] The laminated film of the present invention has excellent surface antistatic properties and dense crosslinking properties, and therefore has excellent coating and peelability properties for surface layers such as ceramic slurries, and can be suitably used as a process film for the production of laminated ceramic electronic components, especially inductor elements.

Claims

1. A laminated film having a resin layer on at least one surface of a base film, the resin layer comprising at least an amino resin (A) terminally substituted with the following electron-donating group, a polythiophene compound (B), a release agent (X) having an alkyl group having 12 to 25 carbon atoms, and an acrylic resin containing a functional group that serves as a crosslinking point with the amino resin (A), wherein when the surface of the resin layer is analyzed by time-of-flight secondary ion mass spectrometry, the peak intensity (K) of a fragment detected at the maximum intensity is: a ratio (P / K) of the peak intensity (P) of a fragment derived from polydimethylsiloxane to the peak intensity (P) of the fragment derived from polydimethylsiloxane is less than 0.1; and in an XAFS spectrum measured on the resin layer by a partial electron yield method, an X-ray absorption near edge structure (XANES) spectrum at the carbon K absorption edge satisfies [I(15°)-0.1] / I(90°)>1, 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; and the tape peel strength is 3 N / 50 mm or less. <Electron-donating group> A functional group selected from the group consisting of lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and t-butyl; hydroxyl; and lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, and t-butoxy.

2. 2. The laminated film according to claim 1, wherein the amino resin (A) terminally substituted with an electron-donating group is an amino resin substituted with a methylol group or a lower alkoxy group.

3. 3. The laminate film according to claim 1, wherein the amino resin (A) terminally substituted with an electron-donating group has a triazine ring, the total number of methylol groups and lower alkoxy groups per triazine ring is 3 or more and 6 or less, and the number of imino groups per triazine ring is 3 or less.

4. 4. The laminate film according to claim 1, wherein the release agent (X) has an exothermic peak temperature (Tc) of 30° C. or higher and 90° C. or lower during a temperature decrease process when the temperature of the release agent (X) is increased from 25° C. to 200° C. at a rate of 20° C. / min using a differential scanning calorimeter (DSC) and then decreased from 200° C. to −50° C. at a rate of 20° C. / min.

5. A laminated film described in any one of claims 1 to 4, wherein the acrylic resin contains at least one structural unit selected from the group consisting of 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, maleic acid, itaconic acid, acrylamide, and N-methylol acrylamide.

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