Winding roll, and base material film separation method

Abstract

Provided is a winding roll 1 in which a laminate film 90 includes: a release film including a base material film 91 and a release agent layer 92; and a ceramic green sheet including green sheet parts 931, 932. The green sheet parts 931, 932 are each arranged along a longitudinal direction of the laminate film 90. A recess 94 sandwiched by the green sheet parts 931, 932 is formed on the release agent layer 92. The laminate film 90 is wound around a shaft core 80 by traverse winding having a size of a swing width α. When viewed in a cross section orthogonal to the longitudinal direction of the laminate film 90, the size of the swing width α is, for example, greater than a width β1 from an edge end of the laminate film 90 on a first end part E1 side to an inner side of the first green sheet part 931.

Description

Method for separating take-up roll and base film

[0001] The present invention relates to a take-up roll and a method for separating a substrate film.

[0002] In recent years, from the viewpoint of global resource conservation, environmental protection, etc., there has been an increasing movement in various fields to build a recycling-oriented society through efforts to reduce waste generation, reuse, recycle, etc. For example, Patent Document 1 discloses a method for removing a coating layer, which includes: a step of cutting a laminated film having a base film and a coating layer into small pieces; a step of immersing the cut laminated film in warm water in a stirring tank and stirring it to separate the laminated film into the base film and the coating layer; a base film recovery step of recovering the separated base film; and a coating layer recovery step of recovering the separated coating layer residue, wherein the coating layer includes an intermediate layer and a release agent layer, and the intermediate layer is disposed between the base film and the release agent layer.

[0003] Japanese Patent Application Laid-Open No. 2023-148863

[0004] In the removal method described in Patent Document 1, the laminate film is cut into small pieces and then immersed in warm water to promote separation of the coating layer from the laminate film. The laminate films described in Patent Document 1 include, for example, laminate films after use in the manufacturing process of multilayer ceramic capacitors (MLCCs). Laminate films after use in the manufacturing process of MLCCs typically have a structure in which a ceramic green sheet is partially attached to a release film having a base film and a release agent layer. Because laminate film structures are so diverse, there is a need to develop new separation methods that are tailored to the structure of the laminate film in order to separate the base film from the laminate film.

[0005] An object of the present invention is to provide a take-up roll and a method for separating a base film that can easily separate a base film from a laminate film having a structure in which a ceramic green sheet is attached to a release film.

[0006] [1] A take-up roll including a core and a long laminate film wound around the outer peripheral surface of the core, wherein the laminate film has a release film having a base film and a release agent layer, and a ceramic green sheet, the base film, the release agent layer, and the ceramic green sheet being arranged in this order, the ceramic green sheet having at least a first green sheet portion attached to a first end side in the width direction of the laminate film and a second green sheet portion attached to a second end side opposite to the first end, the first green sheet portion and the second green sheet portion being respectively arranged along the longitudinal direction of the laminate film. a winding roll in which a recess sandwiched between the first green sheet portion and the second green sheet portion is formed on the release agent layer, the laminated film is wound around the shaft core in a traverse winding having an oscillation width α, and when viewed in a cross section perpendicular to the longitudinal direction of the laminated film, the oscillation width α is larger than a width β1 from an edge of the laminated film on the first end side to an inner side of the first green sheet portion, or larger than a width β2 from an edge of the laminated film on the second end side to an inner side of the second green sheet portion, or larger than both the width β1 and the width β2. [2] The ceramic green sheet has a plurality of third green sheet portions attached to the release agent layer along the width direction of the laminated film, one longitudinal end of each third green sheet portion being connected to the first green sheet portion and the other longitudinal end of each third green sheet portion being connected to the second green sheet portion, and a recess surrounded on all four sides by the first green sheet portion, the second green sheet portion, and two of the third green sheet portions is formed on the release agent layer. [3] The winding roll according to [2], wherein at least one of a plurality of corners of the recess is connected to the outside. [4] The winding roll according to any one of [1] to [3], wherein the laminated film further includes an intermediate layer disposed between the base film and the release agent layer.

[0007] [5] A method for separating a base film, comprising the steps of: preparing a take-up roll according to any one of [1] to [4]; treating the take-up roll by immersing the take-up roll in treatment water or by exposing it to water vapor; and, after the take-up roll treating step, unwinding the laminate film from the take-up roll; and separating the base film from the unwound laminate film. [6] The method for separating a base film according to [5], wherein, in the take-up roll treating step, the treatment water used to immerse the take-up roll is water or an alkaline aqueous solution. [7] The method for separating a base film according to [5] or [6], further comprising, after the separating step, winding up the base film separated from the laminate film, and performing the steps from the unwinding step to the winding step in a roll-to-roll manner.

[0008] According to one aspect of the present invention, a take-up roll and a method for separating a base film can be provided that can easily separate a base film from a laminate film having a structure in which a ceramic green sheet is attached to a release film.

[0009] FIG. 2 is a perspective view of a laminate film wound around a take-up roll of a first embodiment. FIG. 3 is a cross-sectional view of the laminate film as seen from line II-II in FIG. 1. FIG. 4 is a cross-sectional view of a laminate film according to an embodiment. FIG. 5 is a conceptual cross-sectional view of a take-up roll of a first embodiment. FIG. 6 is an example of a virtual development of a laminate film in a state in which distortion is maintained when unwound from a core in the first embodiment. FIG. 7 is a view showing a state in which the take-up roll of a first embodiment is immersed in treatment water. FIG. 8 is a schematic view of a removal device used in a separation step of a first embodiment. FIG. 9 is a view showing a state in which the take-up roll of a first embodiment is exposed to water vapor. FIG. 10 is a view showing a state in which the take-up roll of a first embodiment is exposed to water vapor. FIG. 11 is a view showing a state in which the take-up roll of a first embodiment is exposed to water vapor. FIG. 12 is a schematic view of a removal device used in a separation step according to an embodiment.

[0010] In this specification, ordinal expressions such as "first" and "second" are intended to distinguish between components and do not indicate an order. In this specification, expressions without ordinal numbers, such as "green sheet portion," are a general term for the first green sheet portion, the second green sheet portion, and the third green sheet portion, and are used when describing green sheet portions with ordinal numbers such as "first," "second," and "third."

[0011] [First embodiment] (Winding roll) A first embodiment will be described with reference to the drawings. In the first embodiment, the X-axis, Y-axis, and Z-axis are orthogonal to each other, the X-axis and Y-axis are axes within a predetermined plane, and the Z-axis is an axis orthogonal to the predetermined plane.

[0012] The take-up roll of the first embodiment includes a shaft core and a long laminate film wound around the outer peripheral surface of the shaft core. First, the long laminate film will be described. FIG. 1 is a perspective view of a laminate film 90 wound around the take-up roll 1 of the first embodiment. FIG. 2 is a cross-sectional view of the laminate film 90 as viewed along line II-II in FIG. 1 . The laminate film 90 includes a release film 95 having a base film 91 and a release agent layer 92, and a ceramic green sheet 93, with the base film 91, the release agent layer 92, and the ceramic green sheet 93 arranged in this order. The ceramic green sheet 93 includes at least a first green sheet portion 931 attached to a first end E1 side in the width direction (X-axis direction) of the laminate film 90, and a second green sheet portion 932 attached to a second end E2 side opposite the first end E1. The first green sheet portion 931 and the second green sheet portion 932 are each arranged along the longitudinal direction (Y-axis direction) of the laminate film 90, and a recess 94 sandwiched between the first green sheet portion 931 and the second green sheet portion 932 is formed on the release agent layer 92. In the case of FIG. 1 , the ceramic green sheet 93 further includes a plurality of third green sheet portions 933 attached to the release agent layer 92 along the width direction (X-axis direction) of the laminate film 90. One end of the third green sheet portion 933 in the longitudinal direction (X-axis direction) is connected to the first green sheet portion 931, and the other end of the third green sheet portion 933 in the longitudinal direction is connected to the second green sheet portion 932. A recess 94 surrounded on all four sides by the first green sheet portion 931, the second green sheet portion 932, and two third green sheet portions 933 is formed on the release agent layer 92. Each recess 94 has four corners 94A. In the laminated film 90, the base film 91 and the release agent layer 92 may or may not be in direct contact with each other. In the cases of Figures 1 and 2, the base film 91 and the release agent layer 92 are in direct contact with each other, and the release agent layer 92 is in direct contact with the green sheet portions 931, 932, and 933.

[0013] The laminated film 90 is used in the production of ceramic green sheets, and is a laminated film after a portion of the ceramic green sheet has been peeled off. The ceramic green sheet is used, for example, in the production of a multilayer ceramic capacitor (MLCC). In FIG. 1 , a first green sheet portion 931, a second green sheet portion 932, and a third green sheet portion 933 are residues of the ceramic green sheet 93, and the recessed portion 94 is a space formed by peeling off a portion of the ceramic green sheet 93. The release agent layer 92 is exposed from the bottom of the recessed portion 94.

[0014] Next, a description will be given of the take-up roll 1 of the first embodiment. Fig. 4 is a conceptual cross-sectional view of the take-up roll 1 as viewed from a cross section passing through the center line 80C of the shaft core 80. The take-up roll 1 includes the shaft core 80 and a laminated film 90 wound around the outer circumferential surface of the shaft core 80. An insertion hole 82 is formed in the center of the shaft core 80. In Fig. 4, the laminated film 90 is wound around the outer circumferential surface of the shaft core 80 in a traverse winding having a swing width α. Fig. 5 is an example of a virtual development view of the laminated film 90 in a state in which the distortion is maintained when it is unwound from the shaft core 80.

[0015] The take-up roll 1 of the first embodiment is a roll of laminate film 90 wound by traverse winding with a size of oscillation width α. The width of the take-up roll 1, the width of the laminate film 90, and the oscillation width α satisfy the relationship of the following mathematical formula (1). In the case of FIG. 5, the shape of the laminate film 90 along its longitudinal direction is a sine wave (period P1). Width of take-up roll 1 = Width of laminate film 90 + oscillation width α (1). The winding performed by winding the laminate film 90 while periodically moving it in the width direction of the shaft core 80 is called traverse winding. In this specification, the movement distance in the width direction during traverse winding is referred to as the "oscillation width α." In other words, the sum of the width of the laminate film 90 and the oscillation width α is the width value of the take-up roll 1 (see FIGS. 4 and 5). The dimensions of the laminate film 90 are, for example, a width (distance from the first end E1 to the second end E2) of 100 mm or more and 1000 mm or less, preferably 200 mm or more and 600 mm or less. The length of the laminated film 90 in the take-up roll 1 is, for example, 50 m or more and 30,000 m or less, and preferably 100 m or more and 10,000 m or less. The laminated film 90 may be formed by joining a plurality of laminated films to have a predetermined length.

[0016] The width β1 from the edge of the laminate film 90 on the first end E1 side to the inner side of the first green sheet portion 931 and the width β2 from the edge of the laminate film 90 on the second end E2 side to the inner side of the second green sheet portion 932 are, for example, 1 mm or more and 60 mm or less, preferably 2 mm or more and 30 mm or less. These widths may be the same or different. The outer edge 931E of the first green sheet portion 931 may be located at the same position as the edge of the laminate film 90, or may be located away from the edge of the laminate film 90 as shown in FIG. 1 etc. When the outer edge 931E of the first green sheet portion 931 is located away from the edge of the laminate film 90, the distance D between the edge of the laminate film 90 and the outer edge 931E of the first green sheet portion 931 is １ The distance D between the outer side 932E of the second green sheet portion 932 and the edge of the laminated film 90 is, for example, 1 mm or more and 30 mm or less, and preferably 3 mm or more and 10 mm or less. ２The same applies to the width D of the first green sheet portion 931 (see FIGS. 1 and 2). １１ , the width D of the second green sheet portion 932 ２１ and the width D of the third green sheet portion 933 described later. ３１ and the width D of the recess 94 are, for example, 1 mm or more and 30 mm or less, and preferably 2 mm or more and 20 mm or less (see FIGS. 1 and 2). ９４ The length L of one recess 94 when the third green sheet portion 933 is provided is, for example, 80 mm or more and 980 mm or less, preferably 140 mm or more and 580 mm or less. ９４ is, for example, 100 mm or more and 1000 mm or less, preferably 200 mm or more and 600 mm or less (see FIG. 1).

[0017] The oscillation width α (twice the amplitude) of the winding roll 1 is preferably 3 mm or more and 100 mm or less, more preferably 10 mm or more and 50 mm or less. If the oscillation width is too narrow, it becomes difficult to introduce the treatment water or steam into the recessed portion 94, and if the oscillation width is too wide, the tension in each portion of the winding roll 1 becomes unbalanced, making winding difficult. The period of the winding roll 1 is preferably 150 mm or more and 5000 mm or less, more preferably 200 mm or more and 4000 mm or less. In the case of FIG. 5 , the period of the winding roll 1 is P1. When the winding roll 1 includes the third green sheet portion 933, one period of the winding roll 1 is the length L of the recessed portion 94 of the laminated film 90. ９４ The size is preferably 1 to 10 times, more preferably 2 to 4 times, of the winding diameter of the winding roll 1. The winding diameter of the winding roll 1 (the diameter of the winding roll 1 including the shaft core 80) is, for example, 100 mm to 1500 mm, and preferably 150 mm to 1000 mm.

[0018] In traverse winding with an oscillation width α and a period P1 as shown in Figures 4 and 5, one longitudinal side of the laminated film 90 is wound alternately with high and low tension, while the other side (opposite to the one side) is wound alternately with low and high tension. The portion wound with low tension is loosely wound, forming gaps between the laminated film 90 (in the Z direction). If the winding roll 1 in this state is immersed in treated water TW, the treated water TW can be easily guided into the recesses 94 through the gaps formed by the loose winding.

[0019] The laminated film 90 constituting the winding roll 1 may be wound around the shaft core 80 so that the ceramic green sheet 93 side faces the shaft core 80 (see Figure 4), or may be wound around the shaft core 80 so that the ceramic green sheet 93 side of the laminated film 90 faces the opposite side of the shaft core 80.

[0020] In the take-up roll 1 of this embodiment, it is preferable that at least one of the multiple corners 94A of the recess 94 is in communication with the outside. Communication of the corners 94A with the outside can be confirmed, for example, by observing the wound state of the laminate film 90 in a cross section passing through the center line 80C of the shaft core 80. The corners 94A being in communication with the outside means that, in the take-up roll 1, the corners 94A are not sandwiched between the first green sheet portion 931 or the second green sheet portion 932 and the base film 91, and the flow of liquids and gases is not obstructed. In this state, when the take-up roll 1 is immersed in treatment water (TW in FIG. 4 ) or exposed to water vapor, treatment water or water vapor is introduced into the recess 94 from at least one of the first end E1 and the second end E2 of the laminate film 90 through the corners 94A. For example, when the laminate film 90 shown in FIG. 1 is wound around the shaft core 80 shown in FIG. 4 in a traverse winding manner with a swing width α, corners 94A that communicate with the outside and corners that do not communicate with the outside are formed on the first end E1 side and the second end E2 side, respectively. Only the corners 94A that communicate with the outside are shown in FIG. 4. In FIG. 4, the laminate film 90 on the first end E1 side has a corner 94A that communicates with the outside, and a gap is formed between it and the laminate film 90 directly below it. The width of the gap (gap width 94B) is preferably 1 mm or more, and more preferably 2 mm or more and 100 mm or less, in terms of the dimension on the X coordinate.

[0021] [Second embodiment] (Method for separating base film) A method for separating a base film according to a second embodiment includes the steps of preparing a take-up roll according to the first embodiment, a take-up roll processing step of processing the take-up roll by immersing the take-up roll in treatment water, and after the take-up roll processing step, a step of unwinding the laminate film from the take-up roll, and a step of separating the base film from the unwinding laminate film (hereinafter also referred to as a separation step).

[0022] <Preparing Step> The preparing step is a step of preparing the take-up roll 1 according to the first embodiment. The take-up roll 1 is a roll obtained by winding the laminate film 90 by traverse winding with a swing width α. Examples of methods for winding the laminate film 90 by traverse winding include a method in which the core 80 is fixed and a laminate film winding guide is periodically swung to wind the laminate film 90 around the core 80, and a method in which the laminate film winding guide is fixed and the core 80 is periodically swung to wind the laminate film 90. As a result, the laminate film 90 has a waveform having a period and an amplitude (half the swing width), as shown in FIG. 5 , which is a hypothetical development diagram of the laminate film 90 unwound from the core 80 while maintaining the wound positional relationship. In this embodiment, the waveform of the take-up roll 1 is preferably a sine wave, but may also be a triangular wave or a rectangular wave.

[0023] <Wound-up Roll Treatment Step> The wind-up roll treatment step is a step of treating the wind-up roll by immersing the wind-up roll in treatment water. In the wind-up roll treatment step, the treatment water used to immerse the wind-up roll is preferably water or an alkaline aqueous solution. In the second embodiment, the container in which the wind-up roll 1 is immersed in the treatment water may be referred to as an immersion container. When water is used as the treatment water in the wind-up roll treatment step, the immersion container is, for example, a water tank. When an alkaline aqueous solution is used as the treatment water, the immersion container is, for example, an alkaline treatment tank. When superheated water is used as the treatment water, the immersion container is a pressure vessel.

[0024] (Treated Water) First, the case where water is used as treated water will be described. The water used as treated water refers to liquid water in which the take-up roll is immersed in the take-up roll treatment process. In this embodiment, the water used as treated water refers to ordinary water, i.e., preferably industrial water, and may be purified water or distilled water. Furthermore, the water may be recycled wastewater used in various industrial production processes, or recycled wastewater after use in the implementation of this embodiment. When wastewater is recycled, it may be recycled wastewater, as appropriate. From the viewpoint of improving work efficiency, the water used as treated water may contain, but preferably does not contain, additives that impart functionality. Examples of additives include surfactants and water-soluble organic solvents. When the water used as treated water contains an additive, the concentration of the active ingredient of the additive in the treated water is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, relative to the total amount of treated water. Furthermore, it is preferable that the water used as treated water does not contain any intentionally added additives. Furthermore, since there is a possibility that wastewater can be recycled simply, the water used as treated water may contain basic substances and acidic substances as additives. In this case, however, it is preferable that the pH of the treated water is 5.8 or more and 8.6 or less, so as to comply with the uniform wastewater standards (other items) based on the Water Pollution Control Act.

[0025] In the second embodiment, the take-up roll is immersed in treatment water, thereby wetting the entire surface of both sides of the laminate film with the treatment water. This increases the permeability of water to the interface between the release agent layer and the substrate film, thereby facilitating separation of the substrate film from the laminate film. Water penetration into the interface between the release agent layer and the substrate film can also be achieved in roll form by traverse-winding the laminate film, which facilitates the introduction of water into the take-up roll 1 (specifically, into the recesses 94 of the laminate film 90). Furthermore, because the release agent layer tends to have a low affinity for water, the take-up roll treatment step is preferably performed while applying ultrasonic vibrations to the treatment water. This facilitates the introduction of water into the take-up roll 1 and the removal of air from the take-up roll 1.

[0026] When the treated water used in the winding roll treatment step is hot water, the winding roll treatment step may be a step of immersing the winding roll in hot water contained in a container, a step of pouring hot water into a container containing the winding roll, or a step of heating the water to a predetermined temperature after pouring water and the winding roll into a container. A known heater can be used to heat the water. When the treated water is hot water, the temperature of the treated water is preferably 80°C or higher and 100°C or lower, more preferably 90°C or higher and 100°C or lower. In the winding roll treatment step, after the water temperature reaches a target temperature, the winding roll is held in the treated water at this temperature for a predetermined time. In this specification, the immersion time of the winding roll is defined as the time the winding roll is held in the treated water from the time the target temperature is reached. The immersion time of the winding roll is preferably 5 minutes or longer, more preferably 30 minutes or longer. The immersion time of the winding roll is preferably 10 days or shorter, more preferably 24 hours or shorter.

[0027] The water used as the treatment water may be superheated water. Superheated water is liquid water heated under pressure to a temperature exceeding 100°C. When using superheated water as the treatment water, the winding roll treatment step is a step of housing a winding roll and water in a pressure vessel, heating the housed water, and pressurizing the pressure vessel to a pressure higher than 1 atmosphere. The water housed in the pressure vessel can be water of the same quality as the "normal water" described in the winding roll treatment step of the second embodiment. Therefore, the superheated water used as the treatment water in the winding roll treatment step is obtained by heating "normal water" under pressure. In the winding roll treatment step, the air pressure in the pressure vessel and the temperature of the heated water (superheated water) are each determined by Boyle's law and are preferably in the following ranges. The air pressure in the pressure vessel is preferably 1.2 atmospheres or more, more preferably 1.4 atmospheres or more, from the viewpoint of facilitating infiltration of superheated water into the interface between the base film and the release agent layer. The pressure inside the pressure vessel is preferably 9.9 atmospheres or less, more preferably 4.7 atmospheres or less, from the viewpoint of suppressing melting of the resin component contained in the release film. The pressure inside the pressure vessel is adjusted by a pressure regulating valve or the like. The temperature of the superheated water is preferably 105°C or more, more preferably 110°C or more, from the viewpoint of facilitating infiltration of the superheated water into the interface between the base film and the release agent layer. The temperature of the superheated water is preferably 180°C or less, more preferably 150°C or less, from the viewpoint of suppressing melting of the resin component contained in the release film. In the take-up roll treatment step, the holding time of the take-up roll in the superheated water from the time the water temperature reaches the target temperature (the immersion time of the take-up roll) is, for example, preferably 5 minutes or more, more preferably 10 minutes or more. The immersion time of the take-up roll in the superheated water is preferably 60 minutes or less, more preferably 40 minutes or less.

[0028] Next, we will explain the use of an alkaline aqueous solution as the treatment water. Examples of alkaline aqueous solutions include one or more aqueous solutions selected from sodium hypochlorite aqueous solution, sodium hydroxide aqueous solution, and potassium hydroxide aqueous solution. The alkaline aqueous solution is preferably a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, and more preferably a potassium hydroxide aqueous solution. The alkaline aqueous solution may further contain an auxiliary agent. Examples of auxiliary agents include surfactants, water-soluble inorganic compounds, water-soluble organic compounds, and water-soluble solvents. Specific examples of auxiliary agents include nonionic surfactants, water-soluble inorganic salts, water-soluble organic salts, water-soluble polymers, polysaccharides, alcohols, glycols, and water-soluble organic solvents. Examples of glycols include ethylene glycol, diethylene glycol, and propylene glycol. Examples of water-soluble organic solvents include dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and ethylene glycol ethers (various cellosolves). Auxiliaries may be used alone or in combination.

[0029] The temperature of the alkaline aqueous solution is preferably 5° C. or higher, more preferably 20° C. or higher. The temperature of the alkaline aqueous solution is preferably 100° C. or lower, more preferably 80° C. or lower.

[0030] In the winding roll treatment step, the concentration of the alkaline aqueous solution when the winding roll 1 is immersed in the alkaline aqueous solution is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 3.0% by mass or more. The concentration of the alkaline aqueous solution is preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 50% by mass or less, even more preferably 47% by mass or less, and even more preferably 45% by mass or less. When the alkaline aqueous solution contains an auxiliary, the concentration of the alkaline aqueous solution refers to the total concentration of the alkaline components in the alkaline aqueous solution.

[0031] In the winding roll treatment step, the time for which the winding roll 1 is immersed in the alkaline aqueous solution is preferably 5 minutes or more, more preferably 30 minutes or more. The time for which the winding roll 1 is immersed in the alkaline aqueous solution is preferably 10 days or less, more preferably 24 hours or less. In the winding roll treatment step, by extending the immersion time of the winding roll 1, the temperature or concentration of the alkaline aqueous solution can be made mild. After the winding roll treatment step is performed, the alkaline aqueous solution used as treatment water is neutralized so that it can be disposed of.

[0032] (Form of the take-up roll) In the take-up roll treatment step, the take-up roll 1 may be immersed in the treatment water as it is, or may be immersed in the treatment water after being housed in a holding container. Alternatively, the take-up roll 1 may be immersed in the treatment water after being fixed using a jig (e.g., a clip, etc.). Examples of the holding container include containers having multiple holes (e.g., a basket, a colander, a metal mesh, etc.).

[0033] The winding roll processing step will be described with reference to specific examples 1 and 2. Note that the winding roll processing step is not limited to specific examples 1 and 2.

[0034] (Specific Example 1) The winding roll treatment process according to specific example 1 is carried out using an immersion container 20 shown in FIG. 6 . FIG. 6 shows the winding roll 1 immersed directly in the treated water TW (winding roll treatment process). The laminated film 90 is wound around a shaft 80 in a traverse winding having a size of an oscillation width α. In FIG. 6 , the treated water TW is contained in the immersion container 20. The treated water TW may be water, warm water, or an alkaline aqueous solution. By immersing the winding roll 1 directly in the treated water TW, the treated water TW penetrates into the recesses 94 in the laminated film 90 through corners 94A (external communication portions) formed on at least one side of the first end E1 and the second end E2 of the laminated film 90. This facilitates the treated water TW to penetrate the interface between the base film 91 and the release agent layer 92, thereby facilitating separation of the base film 91 from the laminated film 90 in the subsequent separation process.

[0035] (Specific Example 2) The winding roll treatment step according to specific example 2 is carried out using a pressure vessel (not shown). In this case, superheated water is used as the treated water. A known pressure vessel can be used. In the case of specific example 2, the winding roll treatment step is carried out, for example, as follows: The winding roll 1 and water are placed in the pressure vessel. The placed water is heated, and the pressure inside the pressure vessel is pressurized to a pressure higher than 1 atmosphere. After the pressure inside the pressure vessel reaches the target temperature, the water is maintained at this temperature for a predetermined time (winding roll treatment step). Thereafter, the pressure inside the pressure vessel is returned to normal pressure, the pressure lid is opened, and the winding roll 1 is removed from the treated water.

[0036] <Unwinding step> The unwinding step is performed by unwinding the laminate film 90 from the winding roll 1 after the winding roll processing step. In the unwinding step, it is preferable that the surface of the unwound laminate film 90 is not dry. In other words, it is preferable that the unwinding step is performed while the winding roll 1 is maintained in a wet state. This allows the base film 91 to be efficiently separated from the laminate film 90.

[0037] <Separation Step> The separation step is a step of separating the substrate film 91 from the unwound laminate film 90. The separation step is preferably performed while passing the unwound laminate film 90 through cleaning water. This allows the release agent layer 92 and ceramic green sheet 93 separated from the laminate film 90 to be washed off with the green sheet so that they do not reattach to the substrate film 91. The cleaning water used in the separation step can be water of the same quality as the "normal water" described in the winding roll treatment step of the second embodiment. The cleaning water may contain additives necessary for cleaning. The temperature of the cleaning water is not particularly limited and may be room temperature or hot water, but room temperature is preferred from the viewpoint of energy efficiency. When hot water is used for cleaning, the temperature of the cleaning water is, for example, preferably 40°C or higher, more preferably 60°C or higher. Furthermore, the temperature is preferably less than 100°C, more preferably 98°C or lower. If the cleaning water is warm water, even if the weakening of the interface between the base film and the release agent layer or the intermediate layer described below is insufficient in the winding roll treatment process, the interface can be weakened in the separation process, making it easy to separate the ceramic green sheet and the release agent layer.

[0038] The separation method according to this embodiment further includes a step of winding up the substrate film 91 separated from the laminate film 90 after the separation step, and preferably performs the steps from the unwinding step to the winding step in a roll-to-roll fashion. The separation step is preferably a step of scraping off the ceramic green sheet and the release agent layer from the substrate film 91 while passing the laminate film 90 unwound from the winding roll 1 through cleaning water. Examples of scraping means include blades and wire brushes. Known components can be used for the blades and wire brushes. The number and placement of the scraping means are not particularly limited. Another example of a scraping means is a high-pressure water stream. Hereinafter, the container used in the separation step may be referred to as a cleaning container. The cleaning container is, for example, a water tank. In the separation step, the laminate film unwound from the winding roll 1 is preferably passed through cleaning water contained in a cleaning container while being wound around a guide roll. The separation method according to this embodiment aims to prevent the separated ceramic green sheet and release agent layer from re-adhering to the substrate film 91, and therefore can achieve this goal in a short passage time. The time for passage in the washing water is usually from 0.01 second to 10 minutes, preferably from 0.1 second to 5 minutes. The immersion vessel used in the winding roll treatment step and the washing vessel used in the separation step may be the same or different.

[0039] When washing water is used in the separation step, the separation step is preferably a step of submerging the substrate film 91 separated from the laminate film 90 in water and floating the separated ceramic green sheet or release agent layer on the water. After the separation step, the substrate film 91 separated from the ceramic green sheet and the release agent layer is taken out of the washing water and recovered.

[0040] The separation process will be described using Specific Example 3. Note that the separation process is not limited to Specific Example 3. (Specific Example 3) The separation process according to Specific Example 3 is performed using a removal device 100 shown in FIG. 7. The removal device 100 shown in FIG. 7 includes a payout means 10, a separation means 30, a winding means 40, and multiple guide rolls GR1, GR2, and GR3. The payout means 10 is a means for paying out the laminated film 90 from the winding roll 1 and includes a support member 10A that rotatably supports the shaft core 80 of the winding roll 1. In the winding roll 1, the laminated film 90 is wound around the shaft core 80 in a traverse winding manner having an oscillation width α (see FIG. 4). The separation means 30 includes a guide roll GR2 and a wire brush 34 (an example of a scraping means) that scrapes off the ceramic green sheet and the release agent layer from the substrate film 91. In the case of FIG. 7, the separation means 30 includes a cleaning container 32. The cleaning container 32 contains cleaning water W2. The wire brush 34 is disposed opposite the guide roll GR2 so as to abut against the surface of the laminate film 90 facing the ceramic green sheet. The winding means 40 is a means for winding the substrate film 91 into a roll after the ceramic green sheet and the release agent layer have been separated, and includes a support member 40A that rotatably supports the wound roll-shaped substrate film 91. The winding shape of the substrate film 91 may be traverse winding, in which the shape of the winding roll 1 is maintained, or may be normal winding adjusted to eliminate the oscillation width α.

[0041] For example, after the winding roll processing step is performed using the method of Specific Example 1 or Specific Example 2, the core 80 of the winding roll 1 is attached to the support member 10A of the unwinding means 10, allowing the laminated film 90 to be unwound from the winding roll 1. The laminated film 90 unwound from the winding roll 1 by the unwinding means 10 is wound around a guide roll GR1 and then passes through cleaning water W2 in a cleaning container 32. Then, as the laminated film 90 is wound around a guide roll GR2 placed in the cleaning water W2, a wire brush 34 placed opposite the guide roll GR2 scrapes the ceramic green sheet and release agent layer off the substrate film 91 (separation step, scraping step). After the separation step, the substrate film 91 is removed from the cleaning container 32 and separated from the separated ceramic green sheet and release agent layer in the cleaning water W2. Thereafter, the base film 91 is wound around a guide roll GR3, and is wound around the shaft core 6A by the winding means 40 and collected.

[0042] [Third embodiment] (Method for separating a base film) The separation method according to the third embodiment is the same as the separation method according to the second embodiment, except that the winding roll treatment step is changed to a method for exposing the winding roll to water vapor. The method for separating a base film according to the third embodiment includes the steps of preparing a winding roll according to the first embodiment, a winding roll treatment step for treating the winding roll by exposing the winding roll to water vapor, and, after the winding roll treatment step, unwinding the laminate film from the winding roll, and separating the base film from the unwinding laminate film. The following description will focus on differences from the second embodiment, and similar elements will be omitted or simplified by using the same reference numerals, for example.

[0043] <Wound-up Roll Treatment Step> The wind-up roll treatment step is a step of treating the wind-up roll by exposing it to water vapor. In the wind-up roll treatment step, the wind-up roll is preferably exposed to water vapor in a container (preferably a pressure container). In the third embodiment, the container in which the wind-up roll 1 is exposed to water vapor may be referred to as a water vapor container. The water vapor container preferably has a structure that can supply water vapor into the water vapor container while the wind-up roll 1 is housed therein, or a structure that generates water vapor within the water vapor container. Examples of the water vapor container include a container with a lid and a pressure container.

[0044] In the third embodiment, the water vapor contained in the water vapor container is preferably either water vapor generated outside the water vapor container and then introduced into the water vapor container, or water vapor generated from water introduced into the water vapor container (hereinafter also referred to as water vapor source water). In one embodiment, the take-up roll 1 and water vapor are contained in a pressure vessel serving as the water vapor container. The water vapor source contained in the water vapor container can be water of the same quality as the "normal water" described in the take-up roll treatment process of the second embodiment. The water vapor source water changes state from liquid to gas (water vapor) when heated. Examples of means for containing water vapor in the water vapor container include (1) a means for introducing water vapor generated outside into the water vapor container, and (2) a means for introducing water vapor source water into the water vapor container and heating the water vapor source water to generate water vapor in the water vapor container. The means (1) above includes, for example, a known steam generator (such as a boiler) and a steam inlet passage for introducing the steam generated by the steam generator into the steam container, etc. The means (2) above includes, for example, water for the steam source introduced into the steam container and known heating means (such as a heater) for heating the water for the steam source.

[0045] Examples of methods for exposing the take-up roll 1 to water vapor include a method in which the take-up roll 1 is placed in a water vapor container filled with water vapor, a method in which water vapor is supplied into the water vapor container while the take-up roll 1 is contained in the water vapor container, and a method in which the take-up roll 1 and water for the water vapor source are contained in the water vapor container and then the water for the water vapor source is heated.

[0046] In the winding roll treatment step, the air pressure and temperature inside the water vapor container are preferably within the following ranges. In the winding roll treatment step, the air pressure inside the water vapor container is preferably 1.2 atmospheres or more, and more preferably 1.4 atmospheres or more. The air pressure inside the water vapor container is preferably 9.9 atmospheres or less, and more preferably 4.7 atmospheres or less. In the winding roll treatment step, the temperature inside the water vapor container is preferably 105°C or more, and more preferably 110°C or more. The temperature inside the water vapor container is preferably 180°C or less, and more preferably 150°C or less.

[0047] In the winding roll treatment step, the time for exposing the winding roll 1 to water vapor is, for example, 5 minutes or more and 60 minutes or less, and preferably 10 minutes or more and 40 minutes or less.

[0048] (Configuration of Take-up Roll 1) The configuration of the take-up roll 1 in the take-up roll treatment step of the third embodiment is preferably the same as the configuration of the take-up roll 1 described in the second embodiment. The take-up roll treatment step of the third embodiment is performed without immersing the take-up roll 1 in liquid water.

[0049] The winding roll processing step of the third embodiment will be described with reference to specific examples 4 to 6. Note that the winding roll processing step of the third embodiment is not limited to specific examples 4 to 6.

[0050] (Specific Example 4) The winding roll treatment process according to specific example 4 is carried out using a water vapor container 60 shown in FIG. 8A. FIG. 8A shows the winding roll 1 housed in the water vapor container 60 in its original form. In the winding roll 1, the laminated film 90 is wound around a shaft core 80 in a traverse winding manner with an oscillation width α. The water vapor container 60 includes a container body 62 and a lid 61. A water vapor inlet channel 63 for introducing water vapor V1 and a pressure relief pipe 64 are formed in the upper part of the lid 61. A pressure relief valve 73 for controlling the pressure inside the water vapor container 60 is disposed in the pressure relief pipe 64. The lid 61 also has a rim 601 formed along its outer periphery.

[0051] The winding roll treatment step according to Example 4 is carried out, for example, as follows. First, the winding roll 1 is placed in the water vapor container 60. Water vapor V1 generated by a water vapor generator (not shown) is introduced into the water vapor container 60 through the water vapor inlet channel 63. The winding roll 1 is exposed to the water vapor V1 introduced into the water vapor container 60 through the water vapor inlet channel 63. In Example 4, by exposing the winding roll 1 to the water vapor V1, the water vapor V1 penetrates into the recesses 94 in the laminate film 90 through corners 94A (portions communicating with the outside) formed on at least one side of the first end E1 and the second end E2 of the laminate film 90. As a result, for the same reasons as in Example 1, the base film 91 can be easily separated from the laminate film 90 in the separation step.

[0052] Specific Example 5 The winding roll treatment process according to Specific Example 5 is carried out using a pressure vessel 400 (an example of a steam vessel) shown in FIG. 8B . FIG. 8B shows a state in which the winding roll 1 is held in a basket 407 (an example of a holding container) and housed in the pressure vessel 400. Wheels 407A are provided at the bottom of the basket 407. The pressure vessel 400 includes an outer casing 402, a pressure vessel body 401 installed in the outer casing 402, and a lid 403 that seals the pressure vessel body 401 and the outer casing 402. A steam inlet pipe 404 and a steam outlet pipe 405 are provided at the top of the pressure vessel 400, and the steam inlet pipe 404 is connected to a boiler 420. Steam adjustment valves 404A and 405A are provided at the steam inlet pipe 404 and the steam outlet pipe 405, respectively. A drain pipe 406 is provided at the bottom of the pressure vessel 400. The drain pipe 406 is configured so that water W3 introduced into the pressure vessel body 401 is discharged from a drain port 406B. A drain adjustment valve 406A is disposed in the drain pipe 406. A heater 411 is disposed in the bottom of the pressure vessel 400 to heat the water W3 introduced into the pressure vessel body 401. The location of the heater 411 is not limited to that shown in FIG. 8B . For example, the heater 411 may be disposed inside the outer casing 402 and outside the pressure vessel body 401. The pressure vessel body 401 includes a water stop wall 410 at the bottom and a reservoir 409 for storing water W3, and a mounting table 408 located higher than the reservoir 409. A basket 407 holding the take-up roll 1 is disposed on the mounting table 408. The mounting table 408 has a plurality of openings 408A, through which the water vapor generated from the water W3 in the reservoir 409 diffuses into the pressure vessel body 401.

[0053] The winding roll treatment process according to Example 5 is carried out, for example, as follows. Example 5 describes a case in which the water vapor used in the winding roll treatment process is solely water vapor generated from water W3 (water for water vapor source) introduced into the interior of the pressure vessel 400 (storage section 409 in the case of FIG. 8B ). First, the winding roll 1 held in a basket 407 and water W3 are stored in the storage section 409 of the pressure vessel body 401. The water W3 is heated by a heater 411 to generate water vapor V3. The generated water vapor V3 diffuses into the pressure vessel body 401 through the opening 408A of the mounting table 408. As a result, the pressure vessel body 401 is filled with water vapor V3, and the winding roll 1 is exposed to the water vapor V3. In Example 5, by exposing the take-up roll 1 to water vapor V3, water vapor V2 penetrates into the recess 94 in the laminate film 90 through a corner 94A (a portion communicating with the outside) formed on at least one side of the first end E1 and the second end E2 of the laminate film 90. As a result, for the same reason as in Example 1, the base film 91 can be easily separated from the laminate film 90 in the separation step.

[0054] Specific Example 6 In Specific Example 6, the only steam used in the winding roll treatment step is steam generated outside the pressure vessel 400 (steam V2 generated in the boiler 420 in the case of FIG. 8B ). While FIG. 8B shows a state in which water W3 capable of generating steam has been introduced into the reservoir 409 of the pressure vessel body 401, in Specific Example 6, water W3 does not need to be introduced. First, the winding roll 1 held in the basket 407 is housed in the pressure vessel body 401. Steam V2 generated in the boiler 420 is introduced into the pressure vessel body 401 through the steam inlet 404B of the steam inlet pipe 404, and the winding roll 1 is exposed to the steam V2.

[0055] Specific Example 7 The winding roll processing step according to Specific Example 7 is carried out using a pressure vessel 60A shown in FIG. 8C instead of the pressure vessel 400 used in Specific Example 5. FIG. 8C shows the winding roll 1 housed in the pressure vessel 60A together with water W1 (water for a steam source). A mounting table 66, whose height is higher than the depth of the water W1, is installed within the pressure vessel 60A, and the winding roll 1 is placed on the mounting table 66. The pressure vessel 60A includes a pressure vessel body 62A and a pressure lid 61A. The pressure lid 61A has a rim 601A formed along its outer periphery. A pressure control unit 70 is disposed above the pressure lid 61A. The pressure control unit 70 controls the internal pressure of the pressure vessel 60A to a first pressure higher than 1 atmosphere. The pressure control unit 70 may be, for example, a pressure control valve (e.g., a safety valve), a pressure control valve (e.g., a relief valve), or a pressure regulating valve (e.g., a weight-type or spring-type) used in a typical pressure cooker. In the example shown in FIG. 8C , the pressure control unit 70 includes a relief valve 71 and a pressure sensor 72. The relief valve 71 adjusts the air pressure inside the pressure vessel 60A to a predetermined pressure by controlling the opening area of ​​a steam outlet 71A formed in the pressure lid 61A. The opening area of ​​the steam outlet 71A is controlled by a computer control unit in accordance with the air pressure value acquired by the pressure sensor 72. Control of the air pressure inside the pressure vessel 60A is not limited to this. A heater 68 for heating the water W1 is located at the bottom of the pressure vessel body 62A.

[0056] The winding roll treatment process according to Example 7 is carried out, for example, as follows. First, the winding roll 1 is placed on a mounting table 66 installed in a pressure vessel 60A, and water W1 is placed at the bottom of the pressure vessel 60A. The water W1 in the pressure vessel 60A is heated by a heater 68, and the pressure inside the pressure vessel 60A is pressurized to a pressure higher than 1 atmosphere, thereby generating water vapor inside the pressure vessel 60A and filling the pressure vessel 60A with water vapor. The winding roll 1 placed on the mounting table 66 is exposed to water vapor (not shown) without being immersed in the water W1. In Example 7, by exposing the winding roll 1 to water vapor, water vapor penetrates into the recess 94 in the laminate film 90 through a corner 94A (a portion communicating with the outside) formed on at least one side of the first end E1 and the second end E2 of the laminate film 90. As a result, for the same reasons as in Example 1, the base film 91 can be easily separated from the laminate film 90 in the separation process.

[0057] <Feeding Step and Separating Step> The feeding step and separating step according to the third embodiment can be carried out in the same manner as the feeding step and separating step described in the second embodiment.

[0058] [Modification of the Embodiment] In the first embodiment, an example in which the laminate film 90 is wound around the take-up roll 1 has been described. However, a laminate film 90B as shown in FIG. 3 may be wound around the take-up roll 1 instead of the laminate film 90. FIG. 3 is a cross-sectional view of the laminate film 90B according to one embodiment. Unlike the laminate film 90 shown in FIG. 2, the laminate film 90B further includes an intermediate layer 921 disposed between the substrate film 91 and the release agent layer 92. Except for this, the laminate film 90B has the same configuration as the laminate film 90 shown in FIG. 2. The laminate film 90B includes the substrate film 91, the intermediate layer 921, the release agent layer 92, and the ceramic green sheet 93, which are disposed in this order. The release film 95A includes the substrate film 91, the intermediate layer 921, and the release agent layer 92. In FIG. 3, "a" indicates the surface of the intermediate layer 921 facing the substrate film, and "b" indicates the surface of the intermediate layer 921 facing the release agent layer. d indicates the ceramic green sheet side surface of the release agent layer 92, and c indicates the intermediate layer side surface of the release agent layer 92. In the laminate film 90B, it is preferable that the base film 91 and the intermediate layer 921 are in direct contact with each other. In the case of FIG. 3, the base film 91 and the intermediate layer 921 are in direct contact with each other, and the intermediate layer 921 and the release agent layer 92 are in direct contact with each other. In addition, the release agent layer 92 is in direct contact with the green sheet portions 931, 932, and 933.

[0059] In Specific Example 3, the separation step is performed using the removal apparatus 100 shown in FIG. 7 . However, instead of the removal apparatus 100, the separation step may be performed using a removal apparatus 100A shown in FIG. 9 . The removal apparatus 100A shown in FIG. 9 has the same configuration as the removal apparatus 100 shown in FIG. 7 , except that it includes a circulation means 300. The circulation means 300 is a means for returning the cleaning water W2 to the cleaning container 32 after filtering it with a filter 35. The circulation means 300 includes a drain outlet 32A provided in the cleaning container 32, a filter 35 that filters the cleaning water W2, a storage section 36 that stores the filtered cleaning water W2, an inlet 38 provided at the opening of the cleaning container 32, and a circulation path 37 that connects the drain outlet 36A at the bottom of the storage section 36 and the inlet 38. 9 , the release agent layer with the green sheet separated from the laminate film 90 is discharged together with cleaning water W2 from drain outlet 32A of cleaning container 32 and filtered by filter 35. Cleaning water W2 filtered by filter 35 is stored in storage section 36, then discharged from drain outlet 36A at the bottom of storage section 36, circulates through circulation path 37, and is supplied again into cleaning container 32 from inlet 38.

[0060] In the removal device described with reference to Figures 7 and 9, a foreign matter removal means may be provided at any location between the downstream side of the cleaning container 32 (the location where the base film 91 is removed from the cleaning water W2 after the separation step) and the winding means 40. The foreign matter removal means is a means for removing foreign matter adhering to the base film 91. Examples of foreign matter include the ceramic green sheet and release agent layer remaining on the base film 91, and water droplets adhering to the base film 91. The foreign matter removal means is not particularly limited, and examples thereof include an air knife and a dryer. In the removal device described with reference to Figures 7 and 9, the number of guide rolls is not particularly limited.

[0061] The configuration of the laminate film used in the above-described embodiment will be described. [Laminate Film] The laminate film used in the above-described embodiment includes a substrate film, a release film having a release agent layer, and a ceramic green sheet. In the substrate film separation method according to the above-described embodiment, the substrate film is separated from the laminate film. That is, the laminate film is separated into the substrate film and layers other than the substrate film. Hereinafter, the "layers other than the substrate film" may be collectively referred to as coating layers. For example, when a laminate film includes a substrate film, a release agent layer, and a ceramic green sheet, the coating layer (layers other than the substrate film) is the release agent layer and the ceramic green sheet. The release agent layer may be a single layer, or may be a multilayer consisting of two or more release agent layers of the same or different types. The ceramic green sheet may be disposed on at least a portion of the release agent layer, or may be disposed entirely on the release agent layer. The coating layer may include layers other than the release agent layer and the ceramic green sheet. For example, the coating layer may include an intermediate layer, a release agent layer, and a ceramic green sheet, with the intermediate layer being disposed between the substrate film and the release agent layer. The intermediate layer may be a single layer, or may be a multilayer consisting of two or more intermediate layers of the same or different types. In one embodiment of the laminate film, a substrate film, a release agent layer, and a ceramic green sheet may be directly laminated in this order. In one embodiment of the laminate film, a substrate film, an intermediate layer, a release agent layer, and a ceramic green sheet may be directly laminated in this order.

[0062] <Substrate Film> The substrate film is a resin film formed from a resin component to be recovered. Examples of resin films that can be used include polyester films such as polyethylene terephthalate film, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene film and polypropylene film; polyimide film; polyamide film; polycarbonate film; polyacetate film; ethylene-vinyl acetate copolymer (EVA) film; ethylene-(meth)acrylic acid copolymer film; ethylene-(meth)acrylic acid ester copolymer film; cycloolefin polymer film; polyurethane film; polyphenylene sulfide film; and cellophane. Among these, polyester film is preferred from the viewpoint of heat resistance and strength. In this specification, the term "main component" or "principal component" refers to a component that accounts for 50% by mass or more of the total mass of the material. As the polyester film, a polyester film containing polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate as the main component is preferred from the viewpoint of easy resin recovery and recycling. The resin film may also contain known fillers, colorants, antistatic agents, antioxidants, organic lubricants, catalysts, etc. The resin film may be transparent or may be colored as desired. At least one surface of the substrate film may be previously subjected to a surface treatment such as sputtering, corona discharge, flame, ultraviolet irradiation, electron beam irradiation, or etching such as oxidation, as needed.

[0063] The thickness of the substrate film is not particularly limited, but from the viewpoint of strength, rigidity, etc., it is preferably 10 μm or more and 500 μm or less, more preferably 15 μm or more and 300 μm or less, and even more preferably 20 μm or more and 200 μm or less.

[0064] <Release Agent Layer> The release agent layer is preferably a layer formed from a release agent composition. The release agent composition used to form the release agent layer is not particularly limited as long as it has releasability, and for example, a release agent composition containing as a main component a silicone-based compound; a fluorine compound; a long-chain alkyl group-containing compound; or a thermoplastic resin material such as an olefin-based resin or a diene-based resin; or the like can be used. It is also preferable to use a release agent composition containing as a main component an energy ray-curable or thermosetting resin. These release agent compositions may be used alone or in combination of two or more.

[0065] In the release agent composition containing a silicone compound as a main component, examples of the silicone compound include silicone compounds having an organopolysiloxane as a basic skeleton. Examples of the silicone compound include heat-curable silicone compounds such as addition reaction type and condensation reaction type; and energy beam-curable silicone compounds such as ultraviolet-curable and electron beam-curable types.

[0066] In the release agent composition containing a fluorine compound as a main component, examples of the fluorine compound include fluorine silicone compounds, fluorine boron compounds, and poly(perfluoroalkylene ether) chain-containing compounds.

[0067] In the release agent composition containing a long-chain alkyl group-containing compound as a main component, examples of the long-chain alkyl group-containing compound include polyvinyl carbamate obtained by reacting a polyvinyl alcohol polymer with a long-chain alkyl isocyanate, alkyl urea derivatives obtained by reacting a polyethyleneimine with a long-chain alkyl isocyanate, and copolymers of long-chain alkyl (meth)acrylates. Furthermore, a long-chain alkyl-modified alkyd resin may be used, which is an alkyd resin obtained by the condensation reaction of a polyhydric alcohol and a polybasic acid and which is modified with a long-chain fatty acid as a modifier.

[0068] As a release agent composition mainly composed of an energy ray-curable resin, for example, one containing an energy ray-curable compound having a reactive functional group selected from a (meth)acryloyl group, an alkenyl group, and a maleimide group, and a polyorganosiloxane is preferred. In the release agent layer formed from this release agent composition, an energy ray-curable compound and a polyorganosiloxane having different molecular structures, polarities, and molecular weights are used, so that before curing, components derived from the polyorganosiloxane are segregated near the outer surface of the release agent layer, and then cured by energy rays, and the segregation is fixed. This improves the releasability of the release agent layer. The release agent composition mainly composed of an energy ray-curable resin may further contain a photopolymerization initiator.

[0069] Examples of release agent compositions containing a thermosetting resin as a primary component include release agent compositions containing a melamine resin as a primary component and release agent compositions containing an epoxy resin as a primary component. Release agent compositions containing a melamine resin as a primary component include compositions containing a melamine resin as a primary component, an acid catalyst for thermally curing the melamine resin, and a polyorganosiloxane that imparts release properties to the release agent layer. Furthermore, release agent compositions containing an epoxy resin as a primary component include compositions containing an epoxy resin as a primary component, an acid or basic thermosetting catalyst for thermally curing the epoxy resin, and a polyorganosiloxane that imparts release properties to the release agent layer. Before curing, components derived from the polyorganosiloxane segregate near the outer surface of the release agent layer, and then cure to solidify the segregation. This improves the release properties of the release agent layer.

[0070] The release agent layer may contain other additives in addition to the resin component, such as an antioxidant, a light stabilizer, a flame retardant, a conductive agent, an antistatic agent, and a plasticizer.

[0071] The thickness of the release agent layer can be appropriately selected and is not particularly limited, but is, for example, preferably 0.02 μm or more and 5 μm or less, more preferably 0.03 μm or more and 2 μm or less, and even more preferably 0.05 μm or more and 1.5 μm or less.

[0072] <Intermediate Layer> Examples of the intermediate layer include a water-soluble intermediate layer, an alkali-decomposable intermediate layer, and a hydrophilic and water-insoluble layer.

[0073] (Water-Soluble Intermediate Layer) When the intermediate layer is a water-soluble intermediate layer, examples of the water-soluble resin contained in the intermediate layer include water-soluble polyvinyl alcohol resin, water-soluble acrylic resin, water-soluble polyester resin, water-soluble polyester urethane resin, water-soluble ethylene ionomer resin, water-soluble polyvinylpyrrolidone resin, water-soluble poly-N-vinylacetamide resin, water-soluble polyamide resin, water-soluble ethylene-vinyl alcohol resin, and water-soluble starch. The content of the water-soluble resin in the intermediate layer is preferably 30% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 80% by mass or less, relative to the total mass of the intermediate layer. The upper limit of the content of the water-soluble resin in the intermediate layer is 100% by mass.

[0074] (Alkali-decomposable intermediate layer) When the intermediate layer is an alkali-decomposable intermediate layer, examples of the alkali-decomposable resin contained in the intermediate layer include phenolic resin, polyacrylic acid, polyamide resin, polyester resin, and polylactic acid. The content of the alkali-decomposable resin in the intermediate layer is preferably 30% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 80% by mass or less, relative to the total mass of the intermediate layer. The upper limit of the content of the water-soluble resin in the intermediate layer is 100% by mass.

[0075] (Hydrophilic and water-insoluble layer) When the intermediate layer is a hydrophilic and water-insoluble layer, it is preferable that the intermediate layer be a layer made of a silane-based compound that exhibits polycondensation properties upon hydrolysis, from the viewpoint of making it easier to separate the coating layer from the surface of the intermediate layer facing the substrate film.

[0076] Hereinafter, using the laminate film 90B shown in FIG. 3 as an example, we will explain whether the intermediate layer 921 is hydrophilic and whether the intermediate layer 921 is water-insoluble. In this specification, whether the intermediate layer 921 is "hydrophilic" is determined to be hydrophilic if the water contact angle of the surface of the intermediate layer 921 facing the base film is 55 degrees or less. In the case of the laminate film 90B shown in FIG. 3, the intermediate layer 921 is hydrophilic if the water contact angle of the surface of the intermediate layer 921 facing the base film (denoted by symbol a in FIG. 3) is 55 degrees or less. Furthermore, from the viewpoint of promoting the separability of the base film 91, the contact angle is preferably 50 degrees or less, more preferably 45 degrees or less. The contact angle is a value obtained by measuring the water contact angle of the surface (separated surface) of intermediate layer 921 that was in contact with base film 91 after separating base film 91 from laminate film 90B, i.e., after bringing intermediate layer 921 into contact with water and peeling the interface between intermediate layer 921 and base film 91. Purified water is used as the water that is brought into contact with the intermediate layer when measuring the water contact angle.

[0077] Specifically, the intermediate layer 921 is separated from the substrate film 91 by the following method, and the water contact angle of the substrate film-side surface of the intermediate layer 921 is measured. The obtained value is the water contact angle of the substrate film-side surface of the intermediate layer 921. A 50 mm wide adhesive tape (manufactured by Nitto Denko Corporation, product name "Polyester Adhesive Tape No. 31B") is attached to the release agent layer surface of the laminate film, and then cut to a size of 50 mm x 50 mm to prepare a test specimen. Next, a 500 mL glass beaker is filled with 300 mL of purified water at 90°C as treatment water, and the entire test specimen is immersed in the purified water and left for 3 hours. Thereafter, it is confirmed that the test specimen has been separated into a laminate in which the release agent layer and intermediate layer are integrally supported on the adhesive tape, and the substrate film. The adhesive tape carrying the release agent layer and intermediate layer is then removed from the purified water and dried at room temperature for 24 hours. Thereafter, the contact angle of the surface of the intermediate layer carried on the adhesive tape (the surface of the intermediate layer that had been in contact with the surface of the base film) is measured. The contact angle is measured using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., product name "DM-701") by the sessile drop method in accordance with JIS R3257:1999. Distilled water is used as the droplet.

[0078] In this specification, whether the intermediate layer 921 is "water-insoluble" or not is determined when the difference between the water contact angle of the release agent layer surface (symbol d in FIG. 3 ) and the water contact angle of the substrate film-side surface of the intermediate layer 921 (symbol a in FIG. 3 ), measured using the following method, is 30 degrees or more. The difference in contact angles is preferably 40 degrees or more, more preferably 50 degrees or more. A small difference indicates that the components constituting the intermediate layer 921 have dissolved in water, resulting in the measurement of the release agent layer 92 partially exposed. The water contact angle of the release agent layer surface is not particularly limited, but is typically 80 degrees or more, preferably 85 degrees or more, and more preferably 90 degrees or more. The upper limit of the water contact angle of the release agent layer surface is typically 150 degrees, preferably 140 degrees, and more preferably 130 degrees. The water contact angle of the release agent layer surface is measured using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., product name "DM-701") by the sessile drop method in accordance with JIS R3257: 1999. Distilled water is used as the droplet.

[0079] When the intermediate layer is a hydrophilic and water-insoluble layer, the silane compound is preferably a tetraalkoxysilane. More preferred examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Among these, from the viewpoints of availability and hydrolysis reactivity, at least one of tetramethoxysilane and tetraethoxysilane, or a mixture of tetramethoxysilane and tetraethoxysilane, is preferred. Commercially available products can also be used as the hydrolysis polycondensate of the silane compound.

[0080] The laminate film used in each embodiment is preferably a laminate film after use for a specific application. For example, when the coating layer includes an intermediate layer, a release agent layer, and a ceramic green sheet and the laminate film is used for a specific application (in practical use), the intermediate layer may contain a water-insoluble resin component together with the silane compound to improve adhesion between the substrate film and the coating layer (intermediate layer, release agent layer, and ceramic green sheet) during use. The intermediate layer may be formed by applying and curing a composition containing the water-insoluble resin component. Examples of the water-insoluble resin component include energy ray-curable resins, epoxy resins, and melamine resins. It is preferable that the water-insoluble resin component maintains its water-insolubility even after curing.

[0081] The "water-insoluble resin component" is preferably an energy ray-curable resin, and examples thereof include polyfunctional (meth)acrylates such as dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. When the intermediate layer contains a hydrophilic and water-insoluble resin (preferably the silane-based compound), the content of the hydrophilic and water-insoluble resin is preferably 30% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 80% by mass or less, relative to the total mass of the intermediate layer. The upper limit of the content of the hydrophilic and water-insoluble resin in the intermediate layer is 100% by mass. When the intermediate layer contains a hydrophilic, water-insoluble resin (preferably the silane-based compound) and a "water-insoluble resin component," the content of the hydrophilic, water-insoluble resin is preferably 30% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 80% by mass or less, relative to the total mass of the intermediate layer. The content of the "water-insoluble resin component" is preferably 10% by mass or more and 70% by mass or less, and more preferably 20% by mass or more and 60% by mass or less, relative to the total mass of the intermediate layer. The upper limit of the total content of the hydrophilic, water-insoluble resin and the "water-insoluble resin component" in the intermediate layer is 100% by mass.

[0082] Furthermore, when an energy ray-curable resin is blended in the intermediate layer, it is preferable that the intermediate layer further contains a photopolymerization initiator. Examples of the photopolymerization initiator include 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone. When the intermediate layer contains a photopolymerization initiator, the content of the photopolymerization initiator is preferably 20 parts by mass or less, and more preferably 10% by mass or less, based on 100 parts by mass of the "water-insoluble resin component."

[0083] The thickness of the intermediate layer is preferably 0.01 μm or more and 1 μm or less, more preferably 0.03 μm or more and 0.5 μm or less, and even more preferably 0.05 μm or more and 0.3 μm or less, from the viewpoint of facilitating water penetration when the intermediate layer comes into contact with water.

[0084] <Ceramic Green Sheet> The ceramic green sheet is obtained by applying a ceramic slurry to the surface of the release agent layer opposite the substrate film and then drying the ceramic slurry. Coating can be performed using, for example, a slot die coating method or a doctor blade method. The ceramic slurry contains ceramic powder, a binder component, a solvent, and the like. Examples of ceramic powders include dielectric powders such as barium titanate, titanium oxide, alumina, zirconia, zinc oxide, aluminum silicate, and silicon nitride. Examples of binder components include butyral resins and acrylic resins. Examples of solvents include organic solvents and aqueous solvents.

[0085] In the laminated film used in each of the above-described embodiments, the ceramic green sheet is not entirely attached to the release agent layer. Therefore, after the separation process, the green sheet remains partially attached to the release agent layer surface, or is not attached at all. Therefore, the properties of the green sheet-attached coating layer residue are substantially similar to those of a coating layer without a ceramic green sheet. When the laminated film used in each of the above-described embodiments has a hydrophilic, water-insoluble intermediate layer, the separated green sheet-attached coating layer residue has a release agent layer surface and a hydrophilic intermediate layer surface. When this type of residue is immersed in water, the release agent layer surface faces the air due to surface tension, and the intermediate layer surface faces the water, resulting in stability. In other words, this type of residue is more likely to exist at the water-air interface than in water. Here, because the green sheet-attached coating layer residue is an extremely thin film, even if it has a slightly high density, the buoyancy due to surface tension prevails. Furthermore, the water-insoluble intermediate layer is believed to allow it to remain floating on the water surface.

[0086] The laminate film used in each embodiment is generally used for the purpose of protecting the surfaces of other functional sheets or various parts used for specific purposes during the manufacture, transportation, storage, etc. of these functional sheets or parts. In fact, after fulfilling its role of protecting these parts, it is often peeled off from the surface and discarded. Therefore, by using the laminate film, the green sheet-attached coating layer and the substrate film can be easily separated from the laminate film, which is an application that greatly contributes from the viewpoints of resource conservation and environmental protection.

[0087] DESCRIPTION OF SYMBOLS 1...winding roll, 10...feeding means, 10A...supporting member, 20...immersion container, 30...separating means, 32...cleaning container, 32A...drain outlet, 34...wire brush, 35...filter, 36...storage section, 36A...bottom drain outlet, 37...circulation path, 38...inlet, 40...winding means, 40A...supporting member, 60...water vapor container, 60A...pressure container, 61...lid, 61A...pressure lid, 62...container body, 62A...pressure container body, 63...water vapor introduction path, 64...pressure relief pipe, 66...mounting table, 68...heater, 70...pressure control section, 71...relief valve, 71A...steam exhaust port, 72...pressure sensor, 73...pressure relief valve, 80...axial core, 82...insertion hole, 90, 90A, 90B...laminated film, 91...substrate filter film, 92...release agent layer, 93...ceramic green sheet, 94...recess, 94A...corner, 94B...gap width, 95, 95A...release film, 100, 100A...removal device, 300...circulation means, 400...pressure vessel, 401...pressure vessel body, 402...external housing, 403...lid, 404...steam inlet pipe, 404A, 405A...steam regulating valve, 404B ...Steam inlet, 405...Steam exhaust pipe, 406...Drain pipe, 406A...Drainage adjustment valve, 406B...Drain outlet, 407...Basket, 407A...Wheels, 408...Placement base, 408A...Opening, 409...Storage section, 410...Water stopping wall, 411...Heater, 420...Boiler, 601, 601A...Edge, 921...Intermediate layer, 931, 932, 933...Green sheet section.

Claims

1. A take-up roll comprising a core and a long laminate film wound around the outer circumferential surface of the core, wherein the laminate film comprises a release film having a base film and a release agent layer, and a ceramic green sheet, the base film, the release agent layer, and the ceramic green sheet being arranged in this order, the ceramic green sheet having at least a first green sheet portion attached to a first end side in the width direction of the laminate film and a second green sheet portion attached to a second end side opposite the first end, the first green sheet portion and the second green sheet portion being respectively arranged along the longitudinal direction of the laminate film, a recess sandwiched between the first green sheet portion and the second green sheet portion being formed on the release agent layer, the laminate film being wound around the core in a traverse winding having an oscillation width α, and when viewed in a cross section perpendicular to the longitudinal direction of the laminate film, the oscillation width α is greater than a width β1 from the edge of the laminate film on the first end side to the inner side of the first green sheet portion, or A winding roll having a size larger than the width β2 from the edge of the laminated film on the second end side to the inner side of the second green sheet portion, or a size larger than the width β1 and the width β2.

2. The winding roll according to claim 1, wherein the ceramic green sheet has a plurality of third green sheet portions attached to the release agent layer along the width direction of the laminated film, one longitudinal end of each third green sheet portion is connected to the first green sheet portion, and the other longitudinal end of each third green sheet portion is connected to the second green sheet portion, and a recess surrounded on all four sides by the first green sheet portion, the second green sheet portion, and two of the third green sheet portions is formed on the release agent layer.

3. The winding roll according to claim 2, wherein at least one of the plurality of corners of the recess communicates with the outside.

4. The take-up roll according to any one of claims 1 to 3, wherein the laminated film further includes an intermediate layer disposed between the base film and the release agent layer.

5. A method for separating a base film, comprising the steps of: preparing a take-up roll according to claim 1; a take-up roll treatment step of treating the take-up roll by immersing it in treatment water or by exposing it to water vapor; after the take-up roll treatment step, unwinding the laminated film from the take-up roll; and separating the base film from the unwinding laminated film.

6. The method for separating a substrate film according to claim 5, wherein the treatment water used to immerse the take-up roll in the take-up roll treatment step is water or an alkaline aqueous solution.

7. The method for separating a base film according to claim 5 or claim 6, further comprising, after the separating step, a step of winding up the base film separated from the laminated film, wherein the steps from the unwinding step to the winding step are carried out in a roll-to-roll manner.

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