Laminated film roll and method for manufacturing laminated film roll

Abstract

Provided: A laminated film roll capable of providing a resin sheet with both high smoothness and good sliding properties. A laminated film roll comprising: a polyester substrate film, a release layer disposed on at least one side of the substrate film, and a resin sheet disposed on the release layer on the side opposite to the substrate, the laminated film roll satisfying the following conditions: the resin sheet is obtained by curing a resin sheet forming composition containing at least a resin component (A) and a crosslinking agent (B), the resin sheet substantially does not contain particles, the film thickness (t1) is 1 μm or more and 20 μm or less, the arithmetic mean height (Sa) of the surface (1) of the resin sheet is 2 nm or more and 30 nm or less, the maximum cross-sectional height (St) of the surface (1) is 80 nm or more and 1000 nm or less, the static friction coefficient measured by overlapping the surface (1) of the resin sheet opposite to the release layer side with the aforementioned release layer side surface (2) of the resin sheet is 1.5 or less, and the roll hardness of the laminated film roll is 900 or less.

Description

Technical Field

[0001] This invention relates to laminated film rolls containing resin sheets. In particular, it relates to laminated film rolls containing resin sheets used in electronic components and optical applications. Background Technology

[0002] Previously, release films using polyester film as a substrate have been used as engineering films in solution film fabrication of resin sheets such as adhesive sheets, protective films, polymer electrolyte membranes, and dielectric resin sheets due to their high heat resistance and mechanical properties. In recent years, especially for electronic components such as dielectric resin sheets used in film capacitors and resin sheets used in optical applications, high smoothness and transparency are required. Therefore, high smoothness is also required for the surface of release films used as engineering films. Consequently, the technologies described in Patent Documents 1-3 have been disclosed, proposing solutions to reduce the surface roughness of the release layer.

[0003] However, in applications such as optics, high smoothness is required to improve transparency. On the other hand, high smoothness can worsen slippage, leading to concerns about scratches and reduced yield during transport processes. Similarly, in electronic components such as film capacitors, smoothness is required to improve electrical properties such as dielectric breakdown voltage. However, excessive smoothness results in poor slippage, causing misalignment and wrinkles when winding the dielectric resin sheet onto the roller, hindering proper winding and potentially degrading the performance of the film capacitor.

[0004] To address these issues, Patent Document 4 proposes a method of adding specific particles to a resin sheet used in optical applications such as polarizing plates to give it sliding properties. Additionally, Patent Document 5 proposes a method for transferring particles from a substrate film to a resin sheet used in films for film capacitors, etc.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-144021

[0008] Patent Document 2: Japanese Patent Application Publication No. 2014-154273

[0009] Patent Document 3: Japanese Patent Application Publication No. 2015-182261

[0010] Patent Document 4: Japanese Patent Application Publication No. 2019-95661

[0011] Patent Document 5: International Publication No. 2020 / 039638 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] However, in the method of Patent Document 4, the resin sheet contains particles, thus raising concerns about insufficient transparency due to increased internal haze. Furthermore, in the method of Patent Document 5, there are concerns about uneven particle transfer to the resin sheet and unstable sliding properties.

[0014] To address the aforementioned issues, this invention proposes a laminated film roll that provides a resin sheet with both high smoothness and good sliding properties, while substantially without adding particles inside the resin sheet.

[0015] Solution for solving the problem

[0016] The inventors conducted in-depth research and found that the above-mentioned problems can be solved by making the resin sheet have the technical features described in this specification in a laminated film roll having a polyester-based substrate film, a release layer disposed on at least one side of the aforementioned substrate film, and a resin sheet disposed on the opposite side of the aforementioned release layer.

[0017] That is, the present invention comprises the following components.

[0018] [1] A laminated film roll comprising: a polyester substrate film, a release layer disposed on at least one side of the substrate film, and a resin sheet disposed on the side of the release layer opposite to the substrate.

[0019] The laminated film roll satisfies the following conditions:

[0020] The resin sheet is obtained by curing a resin sheet composition containing at least resin component (A) and crosslinking agent (B).

[0021] Resin sheets do not actually contain particles.

[0022] The film thickness (t1) of the resin sheet is greater than 1 μm and less than 20 μm.

[0023] The arithmetic mean height (Sa) of the surface (1) of the resin sheet opposite to the aforementioned release layer is 2 nm or more and 30 nm or less.

[0024] The maximum cross-sectional height (St) of the surface (1) of the resin sheet opposite to the aforementioned release layer is 80 nm or more and 1000 nm or less.

[0025] The static friction coefficient measured by overlapping the surface (1) of the resin sheet opposite to the aforementioned release layer with the surface (2) of the resin sheet on the side of the aforementioned release layer is 1.5 or less.

[0026] The roll hardness of the laminated film roll surface is below 900.

[0027] [2] According to the laminated film roll of [1], wherein the crosslinking agent (B) contained in the resin sheet forming composition is liquid at 30°C.

[0028] [3] According to the laminated film roll described in [1] or [2], wherein when the total solid content of the resin sheet is set to 100% by mass, the crosslinking agent (B) contained in the resin sheet accounts for 10% by mass or more in the total resin sheet.

[0029] [4] The laminated film roll according to any one of [1] to [3] above, wherein the weight average molecular weight of the resin component (A) contained in the resin sheet is 10,000 or more.

[0030] [5] The laminated film roll according to any one of [1] to [4], wherein the surface free energy of the release layer surface is 40 mJ / m 2 The following, and the water adhesion energy is 3.0 mJ / m 2 above.

[0031] [6] The laminated film roll according to any one of [1] to [5], wherein the arithmetic mean height (Sa) of the release layer side surface of the substrate film is 20 nm or less and the maximum protrusion height (P) is 500 nm or less.

[0032] [7] In another embodiment, the present invention provides the following manufacturing method.

[0033] A method for manufacturing a laminated film roll, characterized in that it is a method for manufacturing a laminated film roll as described in any one of [1] to [6] above, wherein a resin sheet is coated on a release layer and formed by solution film forming method.

[0034] The effects of the invention

[0035] By using the laminated film rolls of the present invention, resin sheets with both high smoothness and good sliding properties can be provided, and by using the resin sheets molded in the present invention, good articles can be provided for a variety of applications. Attached Figure Description

[0036] Figure 1 A schematic cross-sectional view is provided to illustrate the structure of the present invention.

[0037] Figure 2 A schematic cross-sectional view illustrating the configuration of the invention in one embodiment. Detailed Implementation

[0038] The inventors of this application discovered that by providing a release layer on a smooth substrate film, coating a resin sheet containing at least a specific resin and a crosslinking agent under the conditions described in this specification to form a composition, and then drying / curing, the resin sheet of the present invention is obtained. Furthermore, they discovered that by winding the laminate obtained under the conditions described in this specification, unevenness caused by phase separation structure is formed on the surface of the laminated film, and the laminated film roll is successfully made to have good sliding properties without containing particles.

[0039] In this invention, the resin sheet exhibits a high degree of smoothness and slippage with good uniformity, which can, for example, suppress potential yield reductions during the conveying process. Furthermore, when the resin sheet is used in electronic components such as film capacitors, this invention's high smoothness and slippage with good uniformity improves electrical characteristics such as dielectric breakdown voltage. Moreover, in this invention, when the dielectric resin sheet is wound onto a roller, misalignment and wrinkles are suppressed, resulting in a good winding. Therefore, for example, it becomes easier to control the performance of the film capacitor as designed.

[0040] In addition, in this invention, the resin sheet is substantially free of particles, thus it is possible to suppress the slippage of particles during the manufacturing process, and to obtain resin sheets with higher precision, such as dielectric resin sheets and film capacitors.

[0041] This invention relates to a laminated film roll comprising: a polyester-based substrate film, a release layer disposed on at least one side of the aforementioned substrate film, and a resin sheet disposed on the side of the aforementioned release layer opposite to the substrate. The laminated film roll satisfies the following:

[0042] The resin sheet is obtained by curing a resin sheet composition containing at least resin component (A) and crosslinking agent (B).

[0043] Resin sheets do not actually contain particles.

[0044] The film thickness (t1) of the resin sheet is greater than 1 μm and less than 20 μm.

[0045] The arithmetic mean height (Sa) of the surface (1) of the resin sheet opposite to the aforementioned release layer is 2 nm or more and 30 nm or less.

[0046] The maximum cross-sectional height (St) of the surface (1) of the resin sheet opposite to the aforementioned release layer is 80 nm or more and 1000 nm or less.

[0047] The static friction coefficient measured by overlapping the surface (1) of the resin sheet opposite to the aforementioned release layer with the surface (2) of the resin sheet on the side of the aforementioned release layer is 1.5 or less.

[0048] The roll hardness of the laminated film roll surface is below 900.

[0049] The laminated film roll of the present invention having such characteristics is as follows: Figure 1 As shown, the laminated film is obtained by rolling the laminated film into a roll. The laminated film has a polyester substrate film 10, a release layer 11 disposed on at least one side of the substrate film 10, and a resin sheet 12 disposed on the side of the release layer 11 opposite to the substrate film 10.

[0050] In this invention, the state of rolling the laminated film into a roll is the state in which the side of the resin sheet 12 opposite to the release layer 11 is in contact with the side of the substrate film 10 opposite to the release layer 11 and is rolled up.

[0051] A laminated film roll may, for example, have a polyester-based substrate film, a release layer, and a resin sheet in sequence.

[0052] This invention can provide, for example, resin sheets that improve transparency for optical applications, and resin sheets that exhibit high smoothness. Furthermore, it can achieve both high smoothness and high slip properties, which were previously difficult to achieve; for example, it can suppress scratches during transport processes, thus preventing a decrease in yield.

[0053] Additionally, resin sheets exhibiting high smoothness can be provided for applications such as film capacitors and other electronic components. These resin sheets improve electrical characteristics such as dielectric breakdown voltage. Furthermore, they achieve a balance between high smoothness and high slip properties, which were previously difficult to achieve. For example, when the dielectric resin sheet is wound onto a roller, it can suppress winding misalignment and wrinkle incorporation, exhibiting excellent winding performance. Therefore, it is possible to transport the capacitor while maintaining excellent capacitor performance.

[0054] Furthermore, in this invention, the resin sheet is substantially free of particles, thus avoiding insufficient transparency due to increased internal haze. Additionally, it avoids the problem of uneven particle distribution transferred to the resin sheet, resulting in good slip properties.

[0055] (Substrate film)

[0056] This invention relates to a polyester-based substrate film. The polyester constituting the polyester film used as the substrate of this invention is not particularly limited; any polyester commonly used as a substrate film can be used for film formation. Preferably, a crystalline linear saturated polyester comprising an aromatic diacid component and a glycol component is preferred; further suitable examples include polyethylene terephthalate, polyethylene naphthalate-2,6-diethylene glycol, polybutylene terephthalate, polypropylene terephthalate, or copolymers of these resins as main components. Polyester films formed from polyethylene terephthalate are particularly suitable.

[0057] The polyethylene terephthalate (PET) contains at least 90 mol% or more, more preferably at least 95 mol% repeating terephthalate units, and may be copolymerized with small amounts of other dicarboxylic acids and glycols. For cost reasons, it is preferable to manufacture the film solely from terephthalic acid and ethylene glycol. Furthermore, known additives, such as antioxidants, light stabilizers, UV absorbers, and crystallizing agents, may be added to the extent that they do not impair the effects of the film of the present invention. Due to reasons such as high biaxial modulus of elasticity, the polyester film is preferably a biaxially oriented polyester film.

[0058] The intrinsic viscosity of the aforementioned polyethylene terephthalate film is preferably 0.50–0.70 dl / g, more preferably 0.52–0.62 dl / g. When the intrinsic viscosity is 0.50 dl / g or higher, breakage is more likely during the stretching process, which is undesirable. Conversely, when the intrinsic viscosity is 0.70 dl / g or lower, the cutability is good when cutting to the specified product width, and dimensional defects do not occur, which is therefore preferred. Furthermore, the raw material granules are preferably subjected to thorough vacuum drying.

[0059] The method for manufacturing the polyester film in this invention is not particularly limited, and conventionally used methods can be used. For example, the aforementioned polyester is melted in an extruder, extruded into a film, and cooled on a rotary cooling drum to obtain an unstretched film. This unstretched film is then stretched to obtain the desired film. For mechanical properties, biaxial stretching is preferred. The biaxially stretched film can be obtained by sequentially biaxially stretching a longitudinally or transversely uniaxially stretched film in either the transverse or longitudinal direction, or by simultaneously biaxially stretching an unstretched film in both the longitudinal and transverse directions.

[0060] In this invention, the stretching temperature during polyester film stretching is preferably set above the secondary transformation point (Tg) of the polyester. The stretching is preferably 1 to 8 times, and particularly preferably 2 to 6 times, in both the longitudinal and transverse directions.

[0061] The aforementioned polyester film preferably has a thickness of 6 μm or more and 50 μm or less, more preferably 8 μm or more and 31 μm or less, and even more preferably 10 μm or more and 28 μm or less. If the film thickness is 6 μm or more, there is no concern about heat deformation during film production, the processing of the release layer, or the molding of the resin sheet, which is preferable. On the other hand, if the film thickness is 50 μm or less, the roll diameter when wound into a roll is small, which allows for a longer roll length of the molded resin sheet, and is therefore preferable.

[0062] When the polyester film used as the substrate film has a multilayer structure as described later, the overall film thickness of the substrate film falls within the range mentioned above.

[0063] The aforementioned polyester film can be a single layer or a multilayer consisting of two or more layers. Preferably, it has at least one surface layer A that is substantially free of particles on one side. In one embodiment, the polyester film serving as the substrate film has surface layer A on the resin sheet side. When the substrate film is a multilayer polyester film consisting of two or more layers, it is preferable to have a surface layer B, which may contain particles, on the opposite side of the substantially particle-free surface layer A. As a laminated configuration, when the layer on the resin sheet side is designated as surface layer A, the layer on the opposite side is designated as surface layer B, and the other core layers are designated as layer C, a laminated structure with a thickness direction of A / B or A / C / B can be given as an example.

[0064] Layer C can be composed of multiple layers. Alternatively, surface layer B may not contain particles. In this case, to impart slip properties for winding the film into a roll, it is preferable to provide a coating containing particles and an adhesive on surface layer B.

[0065] In the polyester film of this invention, the surface layer A located on the surface where the resin sheet is formed is preferably substantially free of particles. Furthermore, the arithmetic mean height (Sa) of the surface layer A of the polyester film, i.e., the arithmetic mean height (Sa) of the release layer side surface of the substrate film, is preferably 20 nm or less. More preferably, the arithmetic mean height (Sa) is 10 nm or less. If Sa is 20 nm or less, it is less likely to cause pinholes and localized thickness unevenness during resin sheet forming, which is preferable. It can be said that the smaller the arithmetic mean height (Sa) of the surface layer A, the better, but it can also be 0.1 nm or more. Here, when the release layer, etc., described later is provided on the surface layer A, it is preferable that the release layer is substantially free of particles, and it is preferable that the arithmetic mean height (Sa) of the stacked release layers falls within the aforementioned range. In this invention, "substantially free of particles" means, for example, in the case of inorganic particles, when quantifying inorganic elements by fluorescence X-ray analysis, that the content is 50 ppm or less, preferably 10 ppm or less, and most preferably below the detection limit. This is because, even without actively adding particles to the film, contaminants from foreign matter, raw resins, or dirt adhering to pipelines and equipment during the film manufacturing process can sometimes detach and mix into the film. This definition can also be applied to technical features of the invention such as "the resin sheet substantially does not contain particles."

[0066] The maximum protrusion height (P) of the surface layer A of the polyester film, i.e., the maximum protrusion height (P) of the release layer side surface of the substrate film, is, for example, 500 nm or less, preferably 200 nm or less, more preferably 150 nm or less, further preferably 100 nm or less, for example 85 nm or less, and particularly preferably 50 nm or less. If the maximum protrusion height (P) is 500 nm or less, pinholes and localized thinning defects will not occur during resin sheet formation, resulting in a good yield, which is preferred.

[0067] The smaller the value of P in the surface layer A of the polyester film, the better, but it can also be 1 nm or more, or even 3 nm or more. Here, when a release layer or the like described later is provided on the surface layer A, it is preferable that the maximum protrusion height (P) of the release layer after stacking falls within the aforementioned range.

[0068] In the polyester film of this invention, from the viewpoint of film slippage and ease of air removal, the surface layer B, which forms the opposite side of surface layer A, preferably contains particles, and particularly preferably uses silica particles and / or calcium carbonate particles. The particle content in surface layer B, in terms of the total number of particles, is preferably 5000 to 15000 ppm. In this case, the arithmetic mean height (Sa) of the film of surface layer B is preferably in the range of 1 to 40 nm, more preferably in the range of 5 to 35 nm. When the total amount of silica particles and / or calcium carbonate particles is 5000 ppm or more and Sa is 1 nm or more, when the film is rolled into a roll, air can be uniformly removed, the roll shape is good, and the planarity is good, thus becoming suitable for manufacturing resin sheets. In addition, when the total amount of silica particles and / or calcium carbonate particles is 15000 ppm or less and Sa is 40 nm or less, lubricant aggregation is less likely to occur, and large protrusions will not form. Therefore, the quality is stable and preferred when the resin sheet is molded.

[0069] As for the particles contained in the aforementioned surface layer B, inactive inorganic particles and / or heat-resistant organic particles, other than silica and / or calcium carbonate, can be used. From the viewpoints of transparency and cost, silica particles and / or calcium carbonate particles are more preferred, but as other inorganic particles that can be used, examples include alumina-silica composite oxide particles and hydroxyapatite particles. Furthermore, as heat-resistant organic particles, examples include cross-linked polyacrylic acid particles, cross-linked polystyrene particles, and benzoguanamine-based particles. In addition, when using silica particles, porous colloidal silica is preferred; when using calcium carbonate particles, from the viewpoint of preventing lubricant detachment, light calcium carbonate with a surface treatment using a polyacrylic acid-based polymer compound is preferred.

[0070] The average particle size of the particles added to the surface layer B is preferably 0.1 μm or more and 2.0 μm or less, particularly preferably 0.5 μm or more and 1.0 μm or less. If the average particle size is 0.1 μm or more, the substrate film exhibits good sliding properties, which is preferable. Furthermore, if the average particle size is 2.0 μm or less, there is no concern about pinholes forming in the resin sheet due to coarse particles in the surface layer B, which is preferable.

[0071] The surface layer B described above may also contain particles of two or more different materials. Alternatively, it may contain particles of the same type but with different average particle sizes.

[0072] When surface layer B does not contain particles, it is preferable to have slip-resistant properties by means of a coating containing particles on surface layer B. This coating is not particularly limited, but an online coating method in which it is applied during the film-making process of a polyester film is preferred. When surface layer B does not contain particles but has a coating containing particles, for the same reasons as the arithmetic mean height (Sa) of surface layer B described above, the arithmetic mean height (Sa) of the coating surface is preferably in the range of 1 to 40 nm. More preferably, it is in the range of 5 to 35 nm.

[0073] In the layer on one side of the resin sheet, namely surface layer A, from the viewpoint of reducing pinholes, it is preferable not to use recycled raw materials to prevent the mixing of particles such as lubricant.

[0074] The thickness ratio of the layer on one side of the resin sheet, i.e., surface layer A, is preferably 20% to 50% of the total thickness of the substrate film. If it is 20% or more, it is less susceptible to the influence of particles contained in the surface layer B, etc., from within the film, and the arithmetic mean height (Sa) is more likely to meet the above range, which is preferable. If it is 50% or less of the total thickness of the substrate film, the proportion of recycled materials used in surface layer B can be increased, and the environmental impact is reduced, which is preferable.

[0075] Furthermore, from an economic point of view, 50-90% by mass of film scraps and recycled plastic bottle materials can be used in the layers other than surface layer A (surface layer B or the aforementioned intermediate layer C). In this case, it is also preferable that the type, amount, particle size, and arithmetic mean height (Sa) of the lubricant contained in surface layer B meet the above-mentioned ranges.

[0076] In addition, to improve the adhesion of subsequent coatings such as release layers, or to prevent static electricity, a coating can be applied to the surface of surface layer A and / or surface layer B on the film before stretching or after uniaxial stretching during the film-making process, or corona treatment can be performed. When a coating is applied to surface layer A, the coating preferably does not contain substantially any particles.

[0077] (release layer)

[0078] This invention includes a release layer disposed on at least one side of a substrate film, for example, a release layer between the substrate film and a resin sheet. The resin constituting the release layer is not particularly limited; silicone resins, fluoropolymers, alkyd resins, various waxes, aliphatic olefins, etc., can be used, either alone or in combination of two or more resins. When the resin sheet described later contains a crosslinking agent, the inclusion of silicone resin improves the release properties, which is therefore preferable.

[0079] It should be noted that in this specification, the laminate of the substrate and the release layer is sometimes simply referred to as the release film.

[0080] The release layer may, for example, contain a silicone resin. Silicone resins are resins with an intramolecular silicone structure; examples include curable silicone resins, silicone-grafted resins, and alkyl-modified silicone resins. However, from the viewpoint of transferability, reactive curable silicone resins are preferred. As reactive curable silicone resins, addition reaction systems, condensation reaction systems, and UV or electron beam curing systems can be used. More preferably, low-temperature curable addition reaction systems and UV or electron beam curing systems that can be processed at low temperatures are also preferred. By using these, the coating process on the polyester film can be performed at low temperatures. Therefore, a polyester film with less thermal damage during processing and high planarity is obtained, and defects such as pinholes can be reduced when manufacturing the resin sheet of the film.

[0081] Examples of silicone resins used in addition reaction systems include polydimethylsiloxanes with vinyl groups introduced into the terminal or side chains and hydrosiloxanes, which are then reacted and cured using a platinum catalyst. In this case, using a resin that can cure at 120°C for less than 30 seconds allows for lower-temperature processing, which is preferable. Examples include the low-temperature addition-curing type (LTC1006L, LTC1056L, LTC300B, LTC303E, LTC310, LTC314, LTC350G, LTC450A, LTC371G, LTC750A, LTC755, LTC760A, etc.) and the thermal UV-curing type (LTC851, BY24-510, BY24-561, BY24-562, etc.) manufactured by DowToray Co., Ltd.; the solvent addition + UV curing type (X62-5040, X62-5065, X62-5072T, KS5508, etc.) and the Dual-cure curing type (X62-2835, X62-2834, X62-1980, etc.) manufactured by Shin-Etsu Chemical Co., Ltd.

[0082] Examples of organosilicon resins used as condensation reaction systems include those that use organotin catalysts to condense polydimethylsiloxanes with OH groups at the ends and polydimethylsiloxanes with H groups at the ends to form a three-dimensional cross-linked structure.

[0083] Examples of UV-curable silicone resins include: those using the same free radical reaction as conventional silicone rubber (the most basic type); those produced by introducing unsaturated groups and then curing; those produced by decomposing onium salts under UV light to generate strong acids, thereby causing epoxy groups to crack and crosslink; and those produced by crosslinking vinylsiloxanes through the addition reaction of thiols to the onium salts. Alternatively, electron beams can be used instead of UV light. Electron beams have higher energy than UV light, and in the case of UV curing, free radical-based crosslinking reactions can occur even without an initiator. Examples of resins used include UV-curable silicones manufactured by Shin-Etsu Chemical Co., Ltd. (X62-7028A / B, X62-7052, X62-7205, X62-7622, ​​X62-7629, X62-7660, etc.), UV-curable silicones manufactured by MOMENTIVE PERFORMANCEMATERIALS KK (TPR6502, TPR6501, TPR6500, UV9300, UV9315, XS56-A2982, UV9430, etc.), and UV-curable silicones manufactured by Arakawa Chemical Industry Co., Ltd. (SILCOLEASE UV POLY200, POLY215, POLY201, KF-UV265AM, etc.).

[0084] As for the aforementioned UV-curable silicone resins, acrylate-modified or epoxy-propylene-modified polydimethylsiloxanes can also be used. When these modified polydimethylsiloxanes are mixed with multifunctional acrylate resins, epoxy resins, etc., and used in the presence of an initiator, they also exhibit good release properties.

[0085] Examples of other resins that can be used include alkyd resins modified with stearyl groups, lauryl groups, etc., acrylic resins, or alkyd resins, acrylic resins, olefin resins, etc., obtained by the reaction of methylated melamine.

[0086] Examples of amino alkyd resins obtained from the above-mentioned reactions of methylated melamine include Tesfine 303, Tesfine 305, and Tesfine 314 manufactured by Hitachi Chemical Co., Ltd. Examples of amino acrylic resins obtained from the reactions of methylated melamine include Tesfine 322 manufactured by Hitachi Chemical Co., Ltd.

[0087] When the above-described resin is used in the release layer of the present invention, it can be used alone or in combination with two or more resins. Furthermore, to adjust the peel strength, additives such as light peeling additives and heavy peeling additives can be mixed in.

[0088] The release layer of the present invention may also contain additives such as adhesion improvers and antistatic agents. In addition, in order to improve adhesion to the substrate, it is preferable to pretreat the surface of the polyester film before setting the release layer, such as by anchor coating, corona treatment, plasma treatment, or atmospheric pressure plasma treatment.

[0089] In this invention, the thickness of the release layer can be set according to its intended use and is not particularly limited. Preferably, the thickness of the cured release layer is in the range of 0.005 to 2.0 μm. If the thickness of the release layer is 0.005 μm or more, it is preferable to maintain the peeling performance. Furthermore, if the thickness of the release layer is 2.0 μm or less, the curing time is not excessively long, and there is no concern about uneven resin sheet thickness caused by reduced flatness of the release film. Additionally, since the curing time is not excessively long, there is no concern about resin aggregation forming the release coating, no concern about the formation of protrusions, and therefore, it is preferable to avoid the formation of pinholes in the resin sheet.

[0090] The surface free energy of the release layer disposed on the substrate film of the present invention is 8 mJ / m 2 The above, for example, is 10 mJ / m 2 The preferred value is 12mJ / m 2 The above. For example, 18 mJ / m 2 The above can be 20mJ / m 2 That's all. If it's 8mJ / m 2 Therefore, the solution used to coat the resin sheet is less likely to cause rejection, making it a preferred option.

[0091] Furthermore, in this invention, the surface free energy of the release layer can achieve a good balance in terms of the appropriate transfer of the release layer components to the resin sheet and the adhesion to the substrate film by satisfying the above conditions.

[0092] The surface free energy of the release layer disposed on the substrate film of the present invention is preferably 40 mJ / m 2 Below. More preferably 35 mJ / m 2 The following is a further optimization of 30mJ / m 2 Below. If it is 40mJ / m 2 The following resin sheets exhibit good peelability after molding, and are therefore preferred.

[0093] In this invention, the aforementioned surface free energy refers to the surface free energy of at least the surface of the release layer in contact with the resin sheet.

[0094] The water adhesion energy of the release layer of the present invention on the surface in contact with the resin sheet is, for example, 3.0 mJ / m. 2 The above can be 3.3 mJ / m 2 The preferred value is 3.5 mJ / m 2or more. More preferably, 4.0 mJ / m 2 or more, further preferably 5.5 mJ / m 2 or more. If it is 3.0 mJ / m 2 or more, the swelling at the coating end when coating the dissolving solution of the coated resin sheet is suppressed, so it is preferred. When the swelling at the coating end during coating is suppressed, the protrusion (Japanese original text: 耳立ち) when the laminated film is wound into a roll is suppressed, and the winding form becomes good. Therefore, the flatness of the laminated film becomes good, so it is preferred. It should be noted that in this specification, the water adhesion energy is sometimes simply referred to as the adhesion energy.

[0095] In order to improve the water adhesion energy of the surface of the release layer, it can be achieved by adding additives to the release layer or adjusting the polymer composition. For example, if it is a silicone resin, introducing a siloxane unit having a phenyl group in the side chain into the polydimethylsiloxane backbone, or adding a silicone resin such as a T unit (3-functional) or a Q unit (4-functional), can improve it.

[0096] In order to improve the water adhesion energy of the surface of the release layer, as a method other than the above, it can also be achieved by changing the composition of the silicone resin. For example, for an addition reaction system silicone resin, curing is carried out by heating polydimethylsiloxane having vinyl introduced at the end or side chain and hydrosiloxane under a platinum catalyst. By changing the molar amount of the Si-H group of the hydrosiloxane relative to the molar amount of the vinyl group (Si-Vy) at the end, the water adhesion energy can also be changed. For example, when the Si-H is more than the Si-Vy, the water adhesion energy is likely to be higher. The Si-H / Si-Vi ratio is preferably 1.0 or more, further preferably 1.5 or more, more preferably 2.0 or more.

[0097] For the release layer of the present invention, not only the above polyester substrate but also the arithmetic mean height (Sa) in the release layer is preferably 20 nm or less. Further, the arithmetic mean height (Sa) is particularly preferably 1 nm or more. For example, it is 0.2 nm or more.

[0098] In addition, the maximum protrusion height (P) of the release layer is, for example, 500 nm or less, preferably 200 nm or less, more preferably 150 nm or less, further preferably 100 nm or less, for example, 85 nm or less, and particularly preferably 50 nm or less. If the maximum protrusion height (P) is 500 nm or less, no defects such as pinholes and local thinning will occur during the formation of the resin sheet, and the yield is good, so it is preferred. The maximum protrusion height (P) of the release layer is 1 nm or more, for example, 2 nm or more.

[0099] The force required to peel off the resin sheet of the present invention, i.e., the peeling force of the release layer, is, for example, a peeling force of 800 mN / 25 mm width or less. If it is within this range, the resin sheet of the present invention can be peeled off well.

[0100] Preferably, the peel force is 300 mN / 25 mm or less, for example, 100 mN / 25 mm or less. In particular, in this invention, if the peel force is 300 mN / 25 mm or less, even a thin resin film can be protected from breakage during peeling.

[0101] In this invention, the method for forming the release layer is not particularly limited, and the following method is used: a coating liquid containing a resin with release properties is spread on one side of a polyester film of a substrate by coating or the like, the solvent is removed by drying, and then the film is dried by heating, heat-curing or UV curing is performed.

[0102] The coating method for the aforementioned release layer can be any known coating method, such as gravure coating, reverse coating, bar coating, die coating, spray coating, air knife coating, and other methods that have been known for a long time.

[0103] When a thermosetting material is used in the release layer, the drying temperature during solvent drying and heat curing is preferably below 180°C, more preferably below 160°C, further preferably below 140°C, and most preferably below 120°C. The heating time is preferably below 30 seconds, more preferably below 20 seconds, and most preferably below 10 seconds. At temperatures below 180°C, the planarity of the film is maintained, minimizing concerns about uneven resin sheet thickness. At temperatures below 120°C, processing can be performed without compromising the planarity of the film, further reducing concerns about uneven resin sheet thickness, and is therefore particularly preferred.

[0104] There is no particular limitation on the lower limit of the drying temperature, but 60°C or higher is preferred. At a temperature of 60°C or higher, no solvent residue remains in the release layer, and a release film can be obtained, which is therefore preferred.

[0105] When using a UV-curable material in the release layer, the drying temperature during solvent drying and heat curing is preferably below 120°C, more preferably below 100°C, and most preferably below 90°C. The heating time is preferably below 30 seconds, more preferably below 20 seconds, and most preferably below 10 seconds. At temperatures below 120°C, the planarity of the film is maintained, minimizing concerns about uneven resin sheet thickness. At temperatures below 90°C, processing can be performed without compromising the planarity of the film, further reducing concerns about uneven resin sheet thickness, making this particularly preferable.

[0106] There is no particular limitation on the lower limit of the drying temperature, but 60°C or higher is preferred. At a temperature of 60°C or higher, no solvent residue will remain in the release layer, and a release film can be obtained, which is therefore preferred.

[0107] When using a UV-curable material in the release layer, it is preferable to perform a curing reaction by irradiating with an active energy ray after the aforementioned solvent has dried. Known techniques such as ultraviolet light and electron beams can be used as the active energy ray, but ultraviolet light is preferred. The cumulative light intensity when using ultraviolet light can be expressed as the product of illuminance and irradiation time. For example, 10 to 500 mJ / cm² is preferred. 2 Setting the value above the aforementioned lower limit allows for sufficient curing of the release layer, which is therefore preferred. Setting the value below the aforementioned upper limit suppresses thermal damage to the film caused by heat during irradiation, thus maintaining the smoothness of the release layer surface, which is also preferred.

[0108] (Resin sheet)

[0109] The laminated film of the present invention has a resin sheet disposed on the side opposite to the substrate of the release layer.

[0110] For example, the resin sheet laminated on the release film of the present invention is obtained by curing a resin sheet forming composition containing at least resin component (A) and crosslinking agent (B).

[0111] In-depth research was conducted on the resin sheet of the present invention, and it was found that by manufacturing it under specific conditions, such as the resin sheet forming composition of the present invention described later, it is possible to cure it in a state where the resin component (A) and the crosslinking agent (B) are separated, and a suitable unevenness is formed on the surface of the resin sheet, which can exhibit the sliding properties of the resin sheet without containing particles.

[0112] The total mass ratio of resin component (A) to crosslinking agent (B) is preferably 80% or more by mass of the total solid content of the resin sheet, more preferably 90% or more by mass, and even more preferably 95% or more by mass. If it contains 80% or more by mass, the physical properties of the resin sheet, such as strength and heat resistance, are improved, so it is preferred.

[0113] The preferred mass ratio of resin component (A) to crosslinking agent (B) is (A) / (B) = 90 / 10 to 50 / 50. If the mixing ratio of crosslinking agent (B) is 10% by mass or more, the unevenness after phase separation is easily increased, and the sliding properties are improved, which is preferred. If the mixing ratio of crosslinking agent (B) is 50% by mass or less, the film strength of the resin sheet will not decrease, and the workability as a sheet is excellent, which is also preferred. It also prevents unreacted crosslinking agent from adhering to the back side of the laminated film during winding. For example, the proportion of crosslinking agent (B) in the total resin sheet is preferably 10% by mass or more and 50% by mass or less. In one embodiment, when the total solid content of the resin sheet is set to 100% by mass, the proportion of crosslinking agent (B) in the total resin sheet is 10% by mass or more, for example, 10% by mass or more and less than 50% by mass, or for example, 15% by mass or more and 45% by mass or less. By including a crosslinking agent (B) under such conditions, the above-mentioned effects can be achieved more effectively.

[0114] As for resin component (A), there are no particular limitations, and known resins can be used. For example, epoxy resins, phenoxy resins, polyester resins, polyurethane resins, fluorinated resins, acrylic resins, olefin resins, imide resins, sulfone resins, etc., can be used. One type can be used, or two or more types can be mixed. The weight-average molecular weight (Mw) of the resin component (A) used in this invention is 10,000 or more, preferably 10,000 or more and 200,000 or less, more preferably 30,000 or more and 100,000 or less. If the weight-average molecular weight (Mw) is 10,000 or more, the resin sheet has higher strength and better workability, so it is preferred. If it is 200,000 or less, the viscosity of the solution becomes lower during solution film formation, and the productivity becomes better, so it is preferred. The method for determining the weight-average molecular weight (Mw) is not particularly limited, and it can be determined using GPC or the like.

[0115] The crosslinking agent (B) is not particularly limited and any known crosslinking agent can be used. For example, isocyanates, melamine, carbodiimides, oxazoline, etc., can be used; one type or a mixture of two or more can be used. It is preferred to use an agent that reacts with the functional groups contained in the resin component (A). The crosslinking agent (B) contained in the resin sheet forming composition is preferably a liquid at 30°C. In this invention, the liquid only needs to be fluid; for example, the viscosity only needs to be below 10000 mPa·s. By being a liquid at 30°C, the phase separation from the resin component (A) during the drying of the solution-film formed resin sheet can be effectively promoted, and the surface irregularities of the resin sheet become easier to form, which is therefore preferred.

[0116] In the resin sheet, additives can be included in addition to the resin component (A) and crosslinking agent (B), provided that the above-mentioned range is met. In this invention, the resin sheet is substantially free of particles. Because the resin sheet of this invention is substantially free of particles, it is preferable to achieve, for example, higher transparency of the molded resin sheet for optical applications and improved electrical properties in electronic components such as dielectric sheets used in film capacitors, for example. For example, for optical applications, the haze of the resin sheet can be 2% or less. Alternatively, the haze can be 1% or less. In one embodiment, the haze of the resin sheet is 0.1% or more. Furthermore, for example, in electronic components such as film capacitors, the dielectric breakdown voltage of the resin sheet can be 200V / μm or more. Alternatively, the dielectric breakdown voltage can be 300V / μm or more. In one embodiment, the dielectric breakdown voltage is 500V / μm or less.

[0117] Details of the technical feature that "the resin sheet does not substantially contain particles" can be used to explain the above-mentioned content regarding the substrate for the resin sheet.

[0118] In resin sheets, additives mixed in addition to resin component (A) and crosslinking agent (B) are preferably those that have good compatibility with resin component (A) and can react with crosslinking agent (B). Examples of preferred additives include polyurethane, polyester, polyketone, polyol, polyarylate, phenoxy resin, and epoxy resin. For example, when isocyanate is used as the crosslinking agent, polyol-based resins are also preferred.

[0119] Even though the resin sheet of the present invention does not substantially contain particles, it has minute irregularities on its surface caused by phase separation of the resin component (A) and the crosslinking agent (B), thus exhibiting good sliding properties. The static friction coefficient (μs) of the resin sheet peeled from the substrate film is preferably 1.5 or less, more preferably 1.0 or less, and even more preferably 0.8 or less. A static friction coefficient of 1.5 or less provides good winding and travel properties when used as a resin sheet for optical applications and electronic component applications, making operation easier, and is therefore preferred. The static friction coefficient of the resin sheet can be 0.1 or more.

[0120] In one method, Figure 2 In this process, the static friction coefficient measured by overlapping the surface (1) of the resin sheet 12 (represented by symbol 13) opposite to the release layer 11 with the surface (2) of the resin sheet (represented by symbol 14) on the release layer side is 1.5 or less. The static friction coefficient measured under the aforementioned conditions is more preferably 1.0 or less, and even more preferably 0.8 or less. Alternatively, the static friction coefficient can be 0.1 or more.

[0121] Thus, by overlapping the two sides of the resin sheet and measuring the static friction coefficient within the above-mentioned range, the resin sheet of the present invention can achieve both high smoothness and excellent winding and travel properties.

[0122] The arithmetic mean roughness (Sa) of the surface (1) of the resin sheet of the laminated film of the present invention, i.e., the surface (1) of the resin sheet opposite to the release layer, is 2 nm or more and 30 nm or less, more preferably 2 nm or more and 20 nm or less, and even more preferably 2.5 nm or more and 15 nm or less. If it is 2 nm or more, the sliding properties of the resin sheet are better, which is preferable. If it is 30 nm or less, the concern about the generation of defects such as pinholes is reduced when the resin sheet is peeled off from the laminated film and only the resin sheet is rolled into a roll.

[0123] The side opposite to the surface in contact with the release layer is sometimes simply referred to as the surface of the resin sheet (1).

[0124] The maximum cross-sectional height (St) of the surface (1) of the resin sheet of the laminated film of the present invention, i.e., the surface (1) of the resin sheet opposite to the release layer, is 80 nm or more and 1000 nm or less, more preferably 100 nm or more and 600 nm or less, and even more preferably 150 nm or more and 500 nm or less. If it is 80 nm or more, the sliding properties of the resin sheet are better, which is preferable. If it is 1000 nm or less, the concern about the generation of defects such as pinholes is reduced when the resin sheet is peeled off from the laminated film and only the resin sheet is rolled into a roll.

[0125] It should be noted that the maximum cross-sectional height (St) is the value obtained by adding the absolute values ​​of the maximum protrusion height (P) and the maximum valley depth (V).

[0126] The maximum protrusion height (P) of the surface (1) of the resin sheet of the laminated film of the present invention, i.e., the surface (1) of the resin sheet opposite to the release layer, is preferably 500 nm or less, more preferably 260 nm or less, even more preferably 200 nm or less, and can be 185 nm or less, for example 150 nm or less, and particularly preferably 135 nm or less. For example, it can be 100 nm or less.

[0127] If the maximum protrusion height (P) of the resin sheet surface (1) is less than 500 nm, it is preferable that no defects such as pinholes will be generated when the resin sheet is peeled off from the laminated film and simply rolled into a roll. The smaller the maximum protrusion height P, the better, but it can be more than 1 nm, more than 3 nm, or for example, more than 35 nm.

[0128] By setting the arithmetic mean roughness (Sa) and maximum cross-sectional height (St) of the resin sheet surface (1) of the laminated film of the present invention within the aforementioned ranges, good sliding properties can be obtained even on surfaces with high smoothness. It is particularly preferable to control the maximum cross-sectional height (St) within the aforementioned ranges.

[0129] In one embodiment, the maximum valley depth (V) of the surface (1) of the resin sheet of the laminated film is preferably 45 nm or more and 350 nm or less, for example, 45 nm or more and 300 nm or less, preferably 45 nm or more and 250 nm or less. By having the maximum valley depth (V) within such a range, even if the maximum protrusion height (P) is within the range of 250 nm or less, it becomes easier to control the maximum cross-sectional height (St) within the aforementioned range, which can improve the sliding properties of the resin sheet, and is therefore preferred.

[0130] The arithmetic mean roughness (Sa) of the surface (2) of the resin sheet of the laminated film of the present invention, i.e., the surface (2) of the release layer side of the resin sheet, is preferably 10 nm or less, more preferably 8 nm or less, and even more preferably 5 nm or less. If it is 10 nm or less, the concern about the generation of defects such as pinholes is reduced when the resin sheet is peeled off from the laminated film and only the resin sheet is rolled into a roll.

[0131] Preferably, the surface (2) of the resin sheet is the surface that is in contact with the release layer.

[0132] The film thickness (t1) of the resin sheet of the present invention is 1 μm or more and 20 μm or less. More preferably, it is 1 μm or more and 10 μm or less, and even more preferably, it is 2 μm or more and 8 μm or less. If the film thickness (t1) of the resin sheet is 1 μm or more, it is not easy to break after being peeled from the substrate film, and it can be handled easily, so it is preferred. If the film thickness (t1) of the resin sheet is 20 μm or less, the wet coating film thickness will not become excessively thick during solution film formation, and it is easy to form, so it is preferred.

[0133] The film thickness (t1) of the resin sheet is not particularly limited and can be measured by known methods. For example, it can be measured by a contact thickness gauge, an optical interferometer, a scanning electron microscope, or a transmission electron microscope.

[0134] As a method for laminating the resin sheet of the present invention onto a substrate film, it is preferable to coat a coating solution (i.e., a resin sheet forming composition) containing at least the above-described resin component (A) and a crosslinking agent (B) and dissolved or dispersed in an organic solvent, water, etc., onto a release layer using a solution film-forming method and then form it. The coating can be performed using a known method similar to the coating method for the release layer. For example, methods known from the past, such as gravure coating, reverse coating, bar coating, die coating, spray coating, and air knife coating, can be used.

[0135] After applying the aforementioned coating liquid to the release layer, a heating process is preferably included to allow for the drying and curing of the solvent. The heating method is not particularly limited; hot air, infrared radiation, or the like can be used to heat the coated laminated film. Preferably, the laminated film of the present invention is coated and dried using a roller-to-roll method, and the drying oven is particularly preferably dryer using hot air in a floating or roller-supported manner.

[0136] The drying temperature is as follows: the maximum temperature of the drying oven is preferably 60°C or higher and 160°C or lower, more preferably 70°C or higher and 140°C or lower, and even more preferably 70°C or higher and 130°C or lower. If the temperature is 60°C or higher, there is less residual solvent in the dried resin sheet, and there is no concern about a decrease in the performance of the resin sheet (e.g., electrical properties if used as a dielectric layer), which is preferable. If the temperature is 160°C or lower, there is no concern about wrinkles forming in the laminated film due to heat, which is also preferable. Furthermore, if the temperature is higher than 160°C, there is a concern that excessive phase separation of the resin component and crosslinking agent within the resin sheet may occur, leading to a decrease in the crosslinking density of the resin sheet; therefore, it is preferable to set the temperature to 160°C or lower.

[0137] The time from applying the aforementioned coating liquid to entering the drying oven is preferably within 5 seconds, more preferably within 3 seconds, and even more preferably within 2 seconds. If it is within 5 seconds, the phase separation between the resin component and the crosslinking agent in the coating liquid will not occur excessively, and there is no concern about a decrease in the crosslinking density of the resin sheet, which is preferable.

[0138] After applying the aforementioned coating liquid to the substrate film, the heating time in the drying oven at the maximum temperature is preferably 1 second or more, preferably 2 seconds or more. If it is 1 second or more, the reaction of the crosslinking agent will proceed, which is preferred. The upper limit of the heating time is preferably 60 seconds or less, more preferably 40 seconds or less, and even more preferably 20 seconds or less. If it is 60 seconds or less, the segregation of the crosslinking agent on the surface of the resin sheet can be suppressed, and the performance of the resin sheet will not be reduced, which is preferred.

[0139] By setting the resin sheet of the present invention to the above-described drying conditions, the phase separation of the resin component (A) and the crosslinking agent (B) can be appropriately achieved. The arithmetic mean roughness (Sa) and maximum cross-sectional height (St) of the surface (1) of the resin sheet can be controlled within the aforementioned range, thereby demonstrating good sliding properties of the resin sheet without adding particles to the resin sheet.

[0140] (Laminated thin film)

[0141] The laminated film of the present invention is used in the following steps and thereafter to peel a resin sheet from a release layer laminated on a substrate film. Therefore, it is preferable that the peel force from the release layer laminated on the substrate film is 800 mN / 25 mm width or less, so that the resin sheet can be peeled off without breakage. More preferably, it is 500 mN / 25 mm width or less, even more preferably 300 mN / 25 mm width or less, and even more preferably 200 mN / 25 mm width or less. The peel force varies depending on the laminated resin sheet; therefore, it can be adjusted according to the type of release layer laminated on the substrate film.

[0142] (Laminated film roll)

[0143] The laminated film on which resin sheets are stacked on the substrate film is preferably wound into a roll after the resin sheets are stacked. When wound into a roll, it is preferable to wind it under appropriate winding conditions to avoid crushing the unevenness formed on the surface of the resin sheets by phase separation. As long as the surface unevenness meets the static friction coefficient of the resin sheets after winding, it can be wound by known methods, and there are no particular limitations on the winding conditions. More specifically, winding is performed under the condition that the static friction coefficient measured by overlapping the surface (1) of the resin sheet opposite to the release layer and the surface (2) of the resin sheet on the release layer side is 1.5 or less. It should be noted that although it is abbreviated as surface unevenness, it specifically refers to the surface shape described in this specification, such as the arithmetic mean height (Sa) and the maximum cross-sectional height (St).

[0144] In one embodiment, the laminated film is wound under the following conditions. The initial winding tension at the start of winding the laminated film of the present invention is preferably 20 N / m or more and 400 N / m or less, more preferably 25 N / m or more and 300 N / m or less. It is also preferably 30 N / m or more and 250 N / m or less. If it is 20 N / m or more, the winding shape becomes good and winding misalignment does not occur, which is preferred. Furthermore, if it is 400 N / m or less, the stress in the radial direction of the wound film roll does not become excessively high, and the unevenness of the laminated film surface is less likely to be crushed, which is also preferred. (The unit N / m represents the tension N converted to a width of 1 m for the substrate film). The initial winding tension can be derived by measuring the winding tension of the roll.

[0145] The winding tension of the roll surface layer at the winding termination when winding the laminated film of the present invention is preferably 20 N / m or more and 360 N / m or less, more preferably 25 N / m or more and 300 N / m or less. It is also preferably 30 N / m or more and 250 N / m or less. If it is 20 N / m or more, the winding shape becomes good and winding misalignment does not occur, which is therefore preferred. Furthermore, if it is 360 N / m or less, the stress in the radial direction of the wound film roll does not become excessively high, and the unevenness of the laminated film surface is less likely to be crushed, which is also preferred.

[0146] Preferably, a taper is applied to the take-up tension so that the take-up tension of the surface layer is the same as or lower than the initial take-up tension. The take-up tension of the surface layer is set to T. E The winding tension (initial winding tension) of the roll is set to T. S When the expression satisfies the following formula, it is preferable to use the expression that satisfies the following formula.

[0147] 0.2≤T E / T S ≤1

[0148] By winding under the conditions described above, a static friction coefficient of 1.5 or less can be obtained by overlapping the surface (1) of the resin sheet opposite to the release layer with the surface (2) of the resin sheet on the release layer side. Furthermore, the surface shape of the resin sheet can be maintained. As a result, the resin sheet can exhibit high smoothness and slip properties with good uniformity, and the effects described in this specification can be more significantly achieved.

[0149] When winding the laminated film of the present invention, a contact roller is preferably used during winding. The material, diameter, and conditions of the contact roller can be used without particular limitation.

[0150] The roll hardness of the laminated film roll surface of the present invention is preferably 900 or less, more preferably 850 or less, and even more preferably 750 or less. If it is 900 or less, the unevenness of the resin sheet surface is less likely to be crushed, which is preferable.

[0151] The roll hardness of the laminated film roll surface of the present invention is preferably 400 or higher, more preferably 450 or higher, and even more preferably 480 or higher. If it is 400 or higher, the laminated film will not experience winding misalignment, which is preferable.

[0152] To achieve a suitable roll hardness, the aforementioned winding conditions must be met.

[0153] Particularly suitable is setting the taper so that the initial winding tension and the winding tension of the roll surface layer are within the aforementioned range. Furthermore, the surface hardness of the laminated film roll can be measured by measuring the hardness of the outermost layer of the laminated film roll, i.e., the resin sheet located on the surface of the laminated film roll.

[0154] The roll length of the laminated film roll of the present invention is not particularly limited, but preferably 3000m or more, more preferably 6000m or more, more preferably 12000m or more, and even more preferably 18000m or more.

[0155] The width of the laminated film roll of the present invention is not particularly limited, but the lower limit is preferably 200 mm or more, more preferably 300 mm or more, and even more preferably 450 mm or more. The upper limit is preferably 2000 mm or less. Specific Implementation

[0157] Next, the details of the present invention will be described using examples and comparative examples, but the present invention is not limited to the following examples. Furthermore, the evaluation methods used in the present invention are as described below.

[0158] (Arithmetic mean height (Sa), maximum protrusion height (P), maximum valley depth (V), maximum cross-sectional height (St))

[0159] These values ​​were measured using a non-contact surface shape measurement system (Ryoka Systems Inc., VertScan R550H-M100) under the following conditions. The arithmetic mean height (Sa) is the average of five measurements. The maximum protrusion height (P) and maximum valley depth (V) were measured seven times, and the five maximum values ​​(after removing the maximum and minimum values) were used. The maximum cross-sectional height (St) is the value obtained by adding the absolute values ​​of the maximum protrusion height (P) and the maximum valley depth (V).

[0160] (Measurement conditions)

[0161] • Measurement mode: WAVE mode

[0162] • Objective lens: 10x

[0163] · 0.5× Tube lens

[0164] • Measurement area: 936 μm × 702 μm

[0165] (Analysis conditions)

[0166] • Surface calibration: 4 calibrations

[0167] • Interpolation processing: Full interpolation

[0168] • Filter processing: Gaussian cutoff 50μm

[0169] (Surface free energy)

[0170] Under conditions of 25°C and 50% RH, droplets of water (1.8 μL) and diiodomethane (0.9 μL) were prepared on the release surface of the release film using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.: DM-701 fully automatic contact angle meter), and their contact angles were measured. The contact angles were measured 10 seconds after each liquid was added to the release film. Based on the "Owens and Wendt" theory, the contact angle data of water and diiodomethane obtained by the aforementioned method were calculated. Based on the dispersion component γd of the surface free energy of the release film, hydrogen bonds, and dipole-dipole interactions, the component γh was determined, and the sum of all components was taken as the surface free energy γs. In this calculation, the analytical software in the contact angle meter software (FAMAS) was used.

[0171] (Water adhesion energy)

[0172] Under conditions of 25°C and 50% RH, water (10 μL droplet volume) was dropped onto the release surface of the release film using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.: DM-701 fully automatic contact angle meter). The stage was continuously tilted 2 seconds after the droplet was added, and the contact angle was measured for each 1° tilt. Furthermore, the droplet angle was determined as the angle at which the droplet moved 5 dots from its 0° position, and the adhesion energy was calculated from this angle. The calculations were performed using the analytical software within the contact angle meter software (FAMAS).

[0173] (Wettability Evaluation)

[0174] Using a winding bar, the following resin coating solution was applied to the release surface of the release film to achieve a dried resin film thickness of 3 μm. The film was then dried in a hot air oven at 120°C for 30 seconds. The coating width (W1) immediately after applying the resin solution and the width of the dried resin film (W2) were measured. Half of the difference between the coating width (W1) and the resin film width (W2) was taken as the end-recess width, as shown in the following formula. The wettability was evaluated based on the measured end-recess width using the following criteria.

[0175] End recess width [mm] = (W1-W2) / 2

[0176] (resin solution)

[0177] 41.3 parts by weight of methyl ethyl ketone

[0178] 22.5 parts by weight of tetrahydrofuran; PKHB solution (40% by weight of solids) 30.6 parts by weight

[0179] (Phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0180] *The solvent is 5.3 parts by weight of Millionate MTL (manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 50 mPa·s, solid content 99% by weight), prepared by dissolving phenoxy resin in tetrahydrofuran.

[0181] BYK-370 0.4 parts by weight

[0182] (Wettability Evaluation Criteria)

[0183] 〇: 0≤End recess width [mm]≤3

[0184] △: 3 < End recess width [mm] ≤ 6

[0185] ×: 6 < Width of the end recess [mm]

[0186] (film thickness)

[0187] The cut layered films were embedded in resin and then ultrathinly sectioned using an ultramicrotome. Subsequently, they were observed using a JEM2100 transmission electron microscope (TEM) at a direct magnification of 20,000, and the thickness of each layer of the layered film was determined from the observed TEM images.

[0188] (Peeling force)

[0189] The laminated film was cut into strips 25 mm wide and 150 mm long. One end of the substrate film and the release layer was fixed, and the resin sheet was held at one end. The resin sheet was stretched at a speed of 300 mm / min, and the T-peel strength was measured. A tensile testing machine (Shimadzu AUTOGRAPH AG-X) was used for the test. The measured value is the average of 5 measurements.

[0190] Peelability is evaluated based on the measured peel force using the following criteria.

[0191] 〇: It can be peeled with a low peel force of less than 100mN / 25mm width, and can also peel off from laminated films without breaking.

[0192] 〇△: Peeling can be performed with a peeling force of less than 300mN / 25mm width and greater than 100mN / 25mm width.

[0193] △: Peeling can be performed with a peel force greater than 300mN / 25mm width and less than 800mN / 25mm width. In extremely thin sections, partial rupture may sometimes occur.

[0194] ×: Unable to perform stripping.

[0195] (Evaluation of static friction coefficient and sliding properties)

[0196] The static friction coefficient of the resin sheet is determined as follows to evaluate its sliding properties.

[0197] The resin sheet was peeled off from the laminated film and fixed to the bottom of a 1.4 kg metal cuboid with the surface (2) of the resin sheet facing upwards. Next, the resin sheet was fixed to a flat metal plate with the surface (1) of the resin sheet facing upwards using adhesive tape. The metal cuboid was placed with the surface (1) in contact with the surface (2), and the static friction coefficient was measured at 23°C and 65% RH at a tensile speed of 200 mm / min.

[0198] Regarding slippage, the following criteria shall be used for judgment.

[0199] ○: 0.1 < μs ≤ 0.8

[0200] △: 0.8 < μs ≤ 1.5

[0201] ×: The coefficient of friction is too high to be measured if it exceeds 1.5 or is too high.

[0202] (Electrical properties)

[0203] An aluminum vapor-deposited film was deposited on both sides of a resin sheet peeled from a release layer laminated on a substrate film, and the dielectric breakdown voltage (V / μm) was measured at room temperature. The average value measured at 10 points was used for evaluation against the following criteria.

[0204] 〇: Dielectric breakdown voltage (BDV value) is above 300V / μm

[0205] △: Dielectric breakdown voltage is above 200V / μm

[0206] ×: Dielectric breakdown voltage is below 200V / μm

[0207] (Roll stiffness of laminated film rolls)

[0208] The surface of the laminated film roll was measured using a film roll hardness tester (FTS-Roll Tester1, manufactured by FTS., LTD.). The measurements were performed as follows: five points were measured equally along the width direction, excluding the two ends of the film roll (3 cm apart). n=3 measurements were performed at each point, and the average of the total 15 points was used.

[0209] (Preparation of polyethylene terephthalate granules (PET(I)))

[0210] The esterification reactor was a continuous esterification reactor consisting of a three-stage fully mixed tank with a stirrer, a condenser, a raw material inlet, and a product outlet. TPA (terephthalic acid) was supplied at a rate of 2 tons / hour, EG (ethylene glycol) at 2 moles per 1 mole of TPA, and antimony trioxide at 160 ppm relative to the generated PET and Sb atoms. These slurries were continuously fed to the first esterification reactor of the esterification reactor, and the reaction was carried out at atmospheric pressure, with an average residence time of 4 hours and a temperature of 255°C. Next, the reaction product from the first esterification reactor was continuously removed from the system and fed to the second esterification reactor. EG distilled from the first esterification reactor was added to the second esterification reactor at a mass ratio of 8% relative to the generated PET. Further, an EG solution containing 65 ppm of magnesium acetate tetrahydrate relative to the generated PET and 40 ppm of TMPA (trimethyl phosphate) relative to the generated PET was added. The reaction was carried out at atmospheric pressure with an average residence time of 1 hour and at 260°C. Next, the reaction product from the second esterification reactor was continuously removed from the system and fed to the third esterification reactor, where it was dispersed using a high-pressure disperser (manufactured by Nippon Seiki Co., Ltd.) at 39 MPa (400 kg / cm²). 20.2% by mass of porous colloidal silica with an average particle size of 0.9 μm, which underwent dispersion treatment for an average of 5 passes under pressure, and 0.4% by mass of synthetic calcium carbonate with an average particle size of 0.6 μm and 1% by mass of ammonium salt of polyacrylic acid attached relative to the unit calcium carbonate, were added as 10% EG slurry. The reaction was carried out at atmospheric pressure with an average residence time of 0.5 hours and at 260°C. The esterification reaction product generated in the third esterification reactor was continuously fed to a three-stage continuous polycondensation reactor for polycondensation. After filtration using a filter made of sintered stainless steel fibers with a diameter of 20 μm (95% cut), the product was ultrafiltered, extruded into water, cooled, and cut into small flakes to obtain PET flakes with an intrinsic viscosity of 0.60 dl / g (hereinafter referred to as PET(I)). The lubricant content in the PET flakes was 0.6% by mass.

[0211] (Preparation of polyethylene terephthalate granules (PET(II)))

[0212] On the other hand, in the manufacturing of the above-mentioned PET flakes, PET flakes with an intrinsic viscosity of 0.62 dl / g that are completely free of particles such as calcium carbonate and silica are obtained (hereafter referred to as PET(II)).

[0213] (Preparation of polyethylene terephthalate (PET(III)) pellets)

[0214] The type and content of PET(I) particles were changed to 0.75% by mass of synthetic calcium carbonate with an average particle size of 0.9 μm relative to 1% by mass of ammonium salt of polyacrylic acid attached to each unit of calcium carbonate. Otherwise, PET flakes (hereinafter referred to as PET(III)) were obtained in the same manner as PET(I). The lubricant content in the PET flakes was 0.75% by mass.

[0215] (Manufacturing of substrate film X1)

[0216] After drying, these PET flakes are melted at 285°C and then melted again at 290°C in another melt extruder. They undergo a two-stage filtration process: a filter made of 95% stainless steel fibers with a diameter of 15 μm sintered and a filter made of 95% stainless steel granules with a diameter of 15 μm sintered. The fibers are then combined in the feed head and layered with PET(I) as surface layer B and PET(II) as surface layer A. The layers are extruded (cast) into sheets at a rate of 45 m / min. Electrostatic sealing / cooling is then performed on a casting drum at 30°C to obtain unstretched polyethylene terephthalate sheets with an intrinsic viscosity of 0.59 dl / g. The layer ratio is adjusted to PET(I) / PET(II) = 60% / 40% based on the discharge rate of each extruder. Next, the unstretched sheet is heated in an infrared heater and then stretched longitudinally by 3.5 times at a roller temperature of 80°C according to the speed difference between the rollers. The film was then fed into a tenter frame and stretched 4.2 times in the transverse direction at 140°C. Next, it was heat-treated at 210°C in a heat-setting zone. Following this, a 2.3% relaxation treatment was performed in the transverse direction at 170°C to obtain a substrate film X1 with a thickness of 25 μm, consisting of a biaxially stretched polyethylene terephthalate film. The surface layer A of the obtained substrate film X1 has a Sa value of 2 nm, and the surface layer B has a Sa value of 29 nm.

[0217] (Manufacturing of substrate film X2 with release layer)

[0218] On the surface layer A of the substrate film X1 obtained above, the following release coating liquid Y1 is coated by reverse gravure coating method with a wet film thickness of 5 μm. The film is then dried / cured in a hot air drying oven at 120°C for 30 seconds to obtain the substrate film X2 with a release layer. The surface Sa of the release layer is 2 nm.

[0219] (Mold release coating liquid Y1)

[0220] 48 parts by weight of toluene

[0221] 48 parts by weight of methyl ethyl ketone

[0222] Organosilicon resin composition (1)

[0223] (Thermosetting silicone coating, Si-H / Si-Vy = 3.0, solid content 30% by mass)

[0224] 3 parts by weight

[0225] SRX212P Catalyst (Pt-based solidified catalyst manufactured by Dow Toray Co., Ltd.)

[0226] 0.1 parts by weight

[0227] (Manufacturing of substrate film X3 with release layer)

[0228] Without changing the layer composition and stretching conditions of the substrate film X1, the casting speed was changed to adjust the thickness, thus producing a 12μm thick biaxially stretched polyethylene terephthalate film. A release layer identical to that of X2 was then applied to obtain the substrate film X3. The surface layer A of the resulting film X3 has a Sa value of 3nm, and the surface layer B has a Sa value of 29nm.

[0229] (Manufacturing method of substrate film X4 with release layer)

[0230] As the substrate film X4, a release layer similar to X2 is provided on the surface layer A of an A4100 (Cosmoshine (registered trademark), manufactured by Toyobo Co., Ltd.) with a thickness of 25 μm. The A4100 is configured such that it substantially does not contain particles, except that a coating containing particles is provided on the surface layer B side by in-line coating. The surface layer A of the substrate film X4 has a thickness Sa of 1 nm, and the surface layer B has a thickness Sa of 2 nm.

[0231] (Manufacturing method of substrate film X5 with release layer)

[0232] As the substrate film X5, a release layer similar to X2 is provided on surface layer A of E5101 (TOYOBO ESTER (registered trademark) film, manufactured by Toyobo Co., Ltd.) with a thickness of 25 μm. E5101 has a composition containing particles in surface layers A and B of the film. The Sa of surface layer A and surface layer B of the substrate film X5 is 25 nm.

[0233] (Manufacturing method of substrate film X6 with release layer)

[0234] On the surface layer A of the substrate film X1, a release coating liquid Y2 is applied using a reverse gravure coating method with a wet film thickness of 5 μm. The film is then dried / cured in a hot air drying oven at 120°C for 30 seconds to obtain a substrate film X6 with a release layer. The surface Sa of the release layer is 2 nm.

[0235] (Mold release coating liquid Y2)

[0236] 48 parts by weight of toluene

[0237] 48 parts by weight of methyl ethyl ketone

[0238] Organosilicon resin composition (2)

[0239] (Thermosetting silicone coating, Si-H / Si-Vy = 1.0, solid content 30% by mass)

[0240] 3 parts by weight

[0241] SRX212P Catalyst (Pt-based solidified catalyst manufactured by Dow Toray Co., Ltd.)

[0242] 0.1 parts by weight

[0243] (Manufacturing method of substrate film X7 with release layer)

[0244] On the surface layer A of the substrate film X1, a release coating liquid Y3 is applied using a reverse gravure coating method with a wet film thickness of 5 μm. The film is then dried / cured in a hot air drying oven at 120°C for 30 seconds to obtain a substrate film X7 with a release layer. The surface Sa of the release layer is 2 nm.

[0245] (Y3 release coating liquid)

[0246] 48 parts by weight of toluene

[0247] 48 parts by weight of methyl ethyl ketone

[0248] Organosilicon resin composition (3)

[0249] (Thermosetting silicone coating, Si-H / Si-Vy = 2.2, solid content 30% by mass)

[0250] 3 parts by weight

[0251] SRX212P Catalyst (Pt-based solidified catalyst manufactured by Dow Toray Co., Ltd.)

[0252] 0.1 parts by weight

[0253] (Example 1)

[0254] Using a reverse gravure coating method, resin solution Z1 is coated onto surface layer A (i.e., the release layer) of substrate film X2 (1300 mm wide, 12500 m long) to achieve a film thickness of 3 μm after drying. After drying in a hot air drying oven at 120°C for 10 seconds, the film is wound into a roll with an initial winding tension of 100 N / m and a surface winding tension of 60 N / m, forming a laminated film (1200 mm wide, 12000 m long) of resin sheet. (The time from coating to entering the drying oven is 2 seconds). Details are shown in Tables 1A and 2A.

[0255] (Resin Solution Z1)

[0256] 41.3 parts by weight of methyl ethyl ketone

[0257] 22.5 parts by weight of tetrahydrofuran

[0258] PKHB solution (40% by weight, solid content) 30.6 parts by weight

[0259] (Phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0260] *The solvent is Millionate MR-200 5.3 parts by weight (manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 200 mPa·s, solid content 99% by weight), prepared by dissolving phenoxy resin in tetrahydrofuran.

[0261] BYK-370 0.4 parts by weight

[0262] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0263] (Examples 2-3)

[0264] The substrate film and release layer were changed to those described in Table 1, except that the laminated film roll was made in the same manner as in Example 1.

[0265] (Example 4)

[0266] The resin composition (A) was changed to a resin solution Z7 with a different weight-average molecular weight (Mw). Otherwise, the laminated film roll was prepared in the same manner as in Example 1.

[0267] (Resin Solution Z7)

[0268] 41.3 parts by weight of methyl ethyl ketone

[0269] 22.5 parts by weight of tetrahydrofuran

[0270] PKHJ solution (40% by weight solids) 30.6 parts by weight (phenoxy resin manufactured by Gabriel Phenoxies, Mw57000)

[0271] *The solvent is Millionate MR-200 5.3 parts by weight (manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 200 mPa·s, solid content 99% by weight), prepared by dissolving phenoxy resin in tetrahydrofuran.

[0272] BYK-370 0.4 parts by weight

[0273] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0274] (Example 5)

[0275] To change the type of crosslinking agent, resin solution Z2 was used instead. Otherwise, the laminated film rolls were prepared in the same manner as in Example 1.

[0276] (Resin solution Z2)

[0277] 41.3 parts by weight of methyl ethyl ketone

[0278] 22.5 parts by weight of tetrahydrofuran PKHB solution (40% by weight of solids) 30.6 parts by weight (phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0279] *The solvent is 5.3 parts by weight of Millionate MR-400 (manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 600 mPa·s, solids content 99% by weight), prepared by dissolving phenoxy resin in tetrahydrofuran.

[0280] BYK-370 0.4 parts by weight

[0281] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0282] (Example 6)

[0283] The crosslinking agent was changed to resin solution Z3, but otherwise, the laminated film rolls were prepared in the same manner as in Example 1.

[0284] (Resin Solution Z3)

[0285] 41.3 parts by weight of methyl ethyl ketone

[0286] 22.5 parts by weight of tetrahydrofuran

[0287] PKHB solution (40% by weight, solid content) 30.6 parts by weight

[0288] (Phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0289] *The solvent is prepared by dissolving phenoxy resin in tetrahydrofuran. Millionate MTL 5.3 parts by weight

[0290] (Manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 50 mPa·s, solid content 99% by mass)

[0291] BYK-370 0.4 parts by weight

[0292] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0293] (Example 7)

[0294] To change the ratio of resin to crosslinking agent, resin solution Z4 was used instead. Otherwise, the laminated film rolls were prepared in the same manner as in Example 1.

[0295] (Resin Solution Z4)

[0296] 41.3 parts by weight of methyl ethyl ketone

[0297] 19.9 parts by weight of tetrahydrofuran

[0298] PKHB solution (40% by weight, solids) 35.0 parts by weight

[0299] (Phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0300] *The solvent is 3.5 parts by weight of Millionate MR-200, prepared by dissolving phenoxy resin in tetrahydrofuran.

[0301] (Manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 200 mPa·s, solid content 99% by mass)

[0302] BYK-370 0.4 parts by weight

[0303] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0304] (Example 8)

[0305] To change the ratio of resin to crosslinking agent, resin solution Z5 was used instead. Otherwise, the laminated film rolls were prepared in the same manner as in Example 1.

[0306] (Resin Solution Z5)

[0307] 41.3 parts by weight of methyl ethyl ketone

[0308] 17.3 parts by weight of tetrahydrofuran

[0309] PKHB solution (40% by weight of solids) 39.4 parts by weight

[0310] (Phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0311] *The solvent is 1.8 parts by weight of Millionate MR-200, prepared by dissolving phenoxy resin in tetrahydrofuran.

[0312] (Manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 200 mPa·s, solid content 99% by mass)

[0313] BYK-370 0.4 parts by weight

[0314] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0315] (Examples 9-11)

[0316] The substrate film with a release layer as described in Table 1 was changed, and the laminated film roll was made in the same manner as in Example 1.

[0317] (Examples 12-13)

[0318] The drying temperature of the resin sheet was changed to the temperature recorded in Table 1, and the laminated film roll was prepared in the same manner as in Example 1.

[0319] (Examples 14-15)

[0320] The winding tension was changed to the conditions described in Table 1, and the laminated film rolls were prepared in the same manner as in Example 1.

[0321] (Comparative Example 1)

[0322] The substrate film was changed to X1 without a release layer, but otherwise the laminated film roll was made in the same manner as in Example 1.

[0323] (Comparative Example 2)

[0324] The resin solution was changed to a resin solution Z6 without crosslinking agent, and the laminated film rolls were prepared in the same manner as in Example 1.

[0325] (Resin Solution Z6)

[0326] 41.3 parts by weight of methyl ethyl ketone

[0327] 14.7 parts by weight of tetrahydrofuran

[0328] PKHB solution (40% by weight of solids) 43.8 parts by weight

[0329] (Phenoxy resin manufactured by Gabriel Phenoxies, Mw32000)

[0330] *The solvent is BYK-370 0.4 parts by weight, prepared by dissolving phenoxy resin in tetrahydrofuran.

[0331] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0332] (Comparative Example 3)

[0333] The resin sheet is formed such that the maximum cross-sectional height (St) of the surface (1) opposite to the release layer is 75 nm. Otherwise, the laminated film roll is made in the same manner as in Example 1.

[0334] For the substrate films used in each embodiment, they were used after being cured at 40°C for 3 days following the processing of the release layer. Additionally, the resulting laminated films were also evaluated after curing at 40°C for 3 days.

[0335] (Example 16)

[0336] The resin type was changed to resin solution Z8, but otherwise, the laminated film rolls were made in the same manner as in Example 6.

[0337] (Resin Solution Z8)

[0338] 41.3 parts by weight of methyl ethyl ketone

[0339] 12.3 parts by weight of tetrahydrofuran

[0340] Vylon 200 solution (30% by weight solids) 40.8 parts by weight

[0341] (Polyester resin manufactured by Toyobo Co., Ltd., Mn17000, MEK / toluene solution)

[0342] *The solvent is prepared by dissolving polyester resin in a MEK / toluene solution. Millionate MTL 5.3 parts by weight

[0343] (Manufactured by Tosoh Corporation, isocyanate crosslinking agent, viscosity 50 mPa·s, solid content 99% by mass)

[0344] BYK-370 0.4 parts by weight

[0345] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0346] (Example 17)

[0347] The resin and crosslinking agent were changed to resin solution Z9, but otherwise, the laminated film rolls were made in the same manner as in Example 6.

[0348] (Resin Solution Z9)

[0349] 41.3 parts by weight of methyl ethyl ketone

[0350] 7.4 parts by weight of tetrahydrofuran

[0351] UR-4800 (32% solids by weight) 49.2 parts by weight

[0352] (Polyester urethane resin manufactured by Toyobo Co., Ltd., Mn25000, MEK / toluene solvent)

[0353] NIKALAC MW-30 1.8 parts by weight

[0354] (Made by Sanwa Chemical Co., Ltd., melamine crosslinking agent, viscosity 1800 mPa·s, solids content 100% by mass)

[0355] BYK-370 0.4 parts by weight

[0356] (Manufactured by BYK Japan Co., Ltd., silicone-based surfactant)

[0357] The composition and evaluation results of the examples and comparative examples are shown in Tables 1A, 1B, 2A and 2B.

[0358] [Table 1A]

[0359]

[0360] [Table 1B]

[0361]

[0362] [Table 2A]

[0363]

[0364] [Table 2B]

[0365]

[0366] The laminated sheet of the present invention obtained in the embodiments can provide, for example, a resin sheet that can improve transparency in optical applications, and also exhibits a resin sheet with high smoothness. Furthermore, it can balance high smoothness and high slip properties, for example, suppressing scratches during transport processes, thus avoiding a decrease in yield.

[0367] Additionally, resin sheets exhibiting high smoothness can be provided for applications such as film capacitors and other electronic components. These resin sheets improve electrical properties such as dielectric breakdown voltage. Furthermore, a balance between high smoothness and high slip properties can be achieved, for example, suppressing misalignment and wrinkling during winding the dielectric resin sheet onto the roller, resulting in excellent winding performance. Therefore, it is possible to transport the capacitor while maintaining excellent capacitor performance.

[0368] Furthermore, the resin sheet obtained in this invention is substantially free of particles, thus avoiding insufficient transparency due to increased internal haze. Additionally, it avoids the problem of uneven particle distribution on the resin sheet, resulting in good slip properties.

[0369] In contrast, Comparative Example 1 lacks the release layer of the present invention; therefore, the release properties of the resin sheet are extremely poor, making it impossible to evaluate the resin sheet. In Comparative Example 2, the resin sheet forming composition does not contain a crosslinking agent; therefore, in particular, it shows a decrease in the sliding properties of the resin sheet.

[0370] In Comparative Example 3, the maximum cross-sectional height (St) of the surface (1) of the resin sheet is not within the scope of the present invention, thus showing, in particular, the result of poor sliding properties of the resin sheet.

[0371] Industrial availability

[0372] This invention relates to laminated film rolls containing resin sheets. In particular, it relates to laminated film rolls containing resin sheets used in electronic components and optical applications.

[0373] Explanation of reference numerals in the attached figures

[0374] 10. Substrate film

[0375] 11. Release layer

[0376] 12 resin sheets

[0377] 13. Surface of resin sheet (1)

[0378] 14. Surface of resin sheet (2).

Claims

1. A laminated film roll comprising: a polyester-based substrate film, a release layer disposed on at least one side of the substrate film, and a resin sheet disposed on the release layer on the side opposite to the substrate. The laminated film roll satisfies the following: The resin sheet is obtained by curing a resin sheet composition containing at least resin component (A) and crosslinking agent (B). The resin sheet does not actually contain particles. The film thickness (t1) of the resin sheet is 1 μm or more and 20 μm or less. The arithmetic mean height (Sa) of the surface (1) of the resin sheet opposite to the release layer is 2 nm or more and 30 nm or less. The maximum cross-sectional height (St) of the surface (1) of the resin sheet opposite to the release layer is 80 nm or more and 1000 nm or less. The static friction coefficient measured by overlapping the surface (1) of the resin sheet opposite to the release layer with the surface (2) of the resin sheet on the release layer side is 1.5 or less. The roll hardness of the laminated film roll surface is below 900.

2. The laminated film roll according to claim 1, wherein, The crosslinking agent (B) contained in the resin sheet forming composition is liquid at 30°C.

3. The laminated film roll according to claim 1, wherein, When the total solid content of the resin sheet is set at 100% by mass, the crosslinking agent (B) contained in the resin sheet accounts for more than 10% by mass in the whole resin sheet.

4. The laminated film roll according to claim 1, wherein, The weight-average molecular weight of the resin component (A) contained in the resin tablet is above 10,000.

5. The laminated film roll according to claim 1, wherein, The surface free energy of the release layer is 40 mJ / m 2 The following, and the water adhesion energy is 3.0 mJ / m 2 above.

6. The laminated film roll according to claim 1, wherein, The arithmetic mean height (Sa) of the release layer side surface of the substrate film is less than 20 nm, and the maximum protrusion height (P) is less than 500 nm.

7. A method for manufacturing a laminated film roll, characterized in that, It is a method for manufacturing a laminated film roll according to any one of claims 1 to 6, wherein a resin sheet is coated on a release layer and formed by solution film formation.

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