Release film and method for manufacturing molded article

Abstract

The present application provides a release film excellent in release property and sliding property and a method for producing a molded article using the release film. The release film (10) of the present application is a release film having a first release layer (1) composed of a first thermoplastic resin composition and a cushion layer laminated on the first release layer (1), and in the first release layer (1), the average value of the absolute value of the difference in height of each point from the average plane of the surface of the first release layer (1), that is, the arithmetic average height Sa exceeds 2.3 μm.

Description

Technical Field

[0001] This invention relates to a release film and a method for manufacturing molded articles. Background Technology

[0002] For example, as shown in Patent Document 1, a flexible printed circuit board, i.e. a laminate, is formed by bonding the cover layer film to a flexible circuit board with exposed circuitry through the adhesive layer of the cover layer film by heating and pressing. In this case, a release film is usually used.

[0003] When forming a flexible printed circuit board using this release film, in other words, a laminate of a flexible circuit board and a cover film, the release film is required to have two characteristics: excellent release properties and excellent sliding properties.

[0004] First, it is required that after the cover film is laminated on the flexible circuit board, the release film can be peeled off from the formed flexible printed circuit board with excellent release properties.

[0005] More specifically, when peeling the release film from the flexible printed circuit board, the release film is required to exhibit excellent release properties on the flexible printed circuit board to prevent wrinkling and breakage within the flexible printed circuit board.

[0006] Furthermore, by improving the sliding properties, scratches and damage to the flexible circuit board are prevented. Specifically, when the release film is roller-fed to laminate onto the flexible printed circuit board, the release film exhibits excellent sliding properties, thereby suppressing wrinkles during transport and preventing deviations during transport, roll-out, and take-up, enabling the production of laminates with good yield and efficiency.

[0007] However, previous release films have not adequately explored release properties and sliding properties, resulting in insufficient release properties and sliding properties. Therefore, problems such as wrinkling and breakage of flexible printed circuit boards or wrinkling of the release film during transport may occur.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent document 1: Japanese Patent Application Publication No. 2011-88351. Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The purpose of this invention is to provide a release film and a method for manufacturing a molded article using the release film. The release film prevents or inhibits wrinkling during transport and can be peeled off as early as possible after the release film is embedded in the recess, thereby enabling the manufacture of molded articles with excellent productivity.

[0013] means for solving problems

[0014] This objective is achieved by the present invention described in (1) to (16) below.

[0015] (1) A release film having a first release layer composed of a first thermoplastic resin composition and a buffer layer laminated thereon, wherein, In the first release layer, the arithmetic mean height Sa, which is the average of the absolute values ​​of the height differences of each point relative to the average surface of the layer, exceeds 2.3 μm.

[0016] (2) According to the release film described in (1) above, when the maximum value of the height from the average surface of the first release layer, i.e. the maximum peak height, is set as Sp[μm] and the absolute value of the minimum value of the height from the average surface, i.e. the maximum valley depth, is set as Sv[μm], the relationship Sp+Sv≥27 is satisfied.

[0017] (3) A release film having a first release layer composed of a first thermoplastic resin composition and a buffer layer laminated thereon, wherein, When the maximum value of the height from the average surface of the first demolding layer, i.e. the maximum peak height, is set as Sp[μm], and the absolute value of the minimum value of the height from the average surface, i.e. the maximum valley depth, is set as Sv[μm], the relationship Sp+Sv≥27 is satisfied.

[0018] (4) The release film according to any one of (1) to (3) above, wherein the average depth of the protruding valley, i.e. the height of the protruding valley Svk, on the surface of the first release layer is 5 μm or more.

[0019] (5) A release film having a first release layer composed of a first thermoplastic resin composition and a buffer layer laminated thereon, wherein, On the surface of the first release layer, the average depth of the protruding valley, i.e., the height of the protruding valley Svk, is 5 μm or more.

[0020] (6) The release film according to any one of (1) to (5) above, wherein the load area ratio Smr2 of dividing the core and the protruding valley is 75% or more.

[0021] (7) The release film according to any one of (1) to (6) above, wherein the maximum peak height Sp is 10 μm or more.

[0022] (8) The release film according to any one of (1) to (7) above, wherein the maximum valley depth Sv is 10 μm or more.

[0023] (9) The release film according to any one of (1) to (8) above, wherein the release film has a second release layer made of a second thermoplastic resin composition laminated on the side of the buffer layer opposite to the first release layer.

[0024] (10) The release film according to any one of (1) to (9) above, wherein the first thermoplastic resin composition contains a polyester resin or a poly4-methyl-1-pentene resin.

[0025] (11) The release film according to any one of (1) to (10) above, wherein the buffer layer is composed of a third thermoplastic resin composition containing a polyester resin and a polyolefin resin.

[0026] (12) The release film according to any one of (1) to (11) above, wherein the average thickness of the first release layer is 7 μm or more and 38 μm or less.

[0027] (13) The release film according to any one of (1) to (12) above, wherein the average thickness of the buffer layer is 40 μm or more and 110 μm or less.

[0028] (14) The release film according to any one of (1) to (13) above, wherein the average thickness of the release film is 50 μm or more and 180 μm or less.

[0029] (15) The release film according to any one of (1) to (14) above, wherein the release film is used in such a way that the surface of the first release layer side is in contact with the surface of the object formed of a material containing a thermosetting resin in a semi-cured state.

[0030] (16) A method for manufacturing a molded article, characterized in that it comprises: taking the first release layer of the release film as described in any one of (1) to (15) above as the object side, The process includes a step of applying the release film to the object; and a step of heating and pressing the object with the release film applied, wherein in the step of applying the release film, the side of the object with the release film applied is formed of a material containing a thermosetting resin in a semi-cured state.

[0031] The effects of the invention

[0032] According to one aspect of the present invention, in the first release layer, the arithmetic mean height Sa, which is the average of the absolute values ​​of the height differences of each point relative to the average surface of its surface, exceeds 2.3 μm. Therefore, when a flexible printed circuit board is obtained using a flexible circuit board and a cover film, by using this release film, the release film exhibits excellent release properties for the flexible printed circuit board when it is peeled off, and can suppress the generation of wrinkles and breaks in the flexible printed circuit board. Furthermore, it exhibits appropriate sliding properties and can prevent or suppress wrinkling of the release film during transport.

[0033] Furthermore, according to another aspect of the present invention, when the maximum value of the height from the average surface of the first release layer, i.e., the maximum peak height, is set as Sp [μm], and the absolute value of the minimum value of the height from the average surface, i.e., the maximum valley depth, is set as Sv [μm], the relationship Sp + Sv ≥ 27 is satisfied. Therefore, when a flexible printed circuit board is obtained using a flexible circuit board and a cover film, by using this release film, when the release film is peeled off from the flexible printed circuit board, the release film exhibits excellent release properties for the flexible printed circuit board, and can suppress the generation of wrinkles and breaks in the flexible printed circuit board. Furthermore, it can exhibit appropriate sliding properties, and can prevent or suppress wrinkling of the release film during transport.

[0034] Furthermore, according to another aspect of the invention, the average depth of the protruding valleys, i.e., the height Svk of the protruding valleys, on the surface of the first release layer is 5 μm or more. Therefore, when a flexible printed circuit board is obtained using a flexible circuit board and a cover film, by using this release film, the release film exhibits excellent release properties relative to the flexible printed circuit board when it is peeled off, thus suppressing wrinkles and breakage in the flexible printed circuit board. Furthermore, it exhibits appropriate sliding properties and can prevent or suppress wrinkling of the release film during transport. Attached Figure Description

[0035] Figure 1 This is a side view showing the main parts of a roll-to-roll press used to manufacture flexible printed circuit boards.

[0036] Figure 2 It means that it was used Figure 1 The longitudinal sectional view of each step in the manufacturing method of the flexible printed circuit board using the roller-to-roll press shown.

[0037] Figure 3 It means that it was used Figure 1 A longitudinal sectional view of the heating pressing process in the manufacturing method of a flexible printed circuit board using a roller-to-roll press.

[0038] Figure 4This is a longitudinal sectional view showing an embodiment of the release film of the present invention.

[0039] Figure 5 It's a local magnification. Figure 4 A partially enlarged longitudinal sectional view of part A of the release film shown. Detailed Implementation

[0040] Hereinafter, the method for manufacturing the release film and the molded article of the present invention will be described in detail with reference to the preferred embodiments shown in the accompanying drawings.

[0041] Furthermore, the following description will use a roll-to-roll press as an example to illustrate the manufacture of a flexible printed circuit board using the release film of the present invention. Before describing the manufacturing method of the release film and the molded article of the present invention, the roll-to-roll press used to manufacture this flexible printed circuit board will first be described.

[0042] <Roll-to-roll press>

[0043] Figure 1 This is a side view showing the main parts of a roll-to-roll press used to manufacture flexible printed circuit boards. Figure 2 It means that it was used Figure 1 The diagram shows longitudinal sectional views of each step in the manufacturing process of a flexible printed circuit board using a roll-to-roll press. Figure 3 It means that it was used Figure 1 This is a longitudinal sectional view of the heating pressing step in the manufacturing method of a flexible printed circuit board using a roll-to-roll press. Furthermore, for ease of explanation, the following will... Figures 1-3 The upper side is called "upper" or "above", the lower side is called "lower" or "below", the left side is called "left", and the right side is called "right".

[0044] like Figures 1 to 3 As shown, the roll-to-roll press 100 (RtoR press) includes: a conveying unit (not shown) for conveying release films 10 (10A, 10B), flexible printed circuit board 200 (hereinafter sometimes referred to as "FPC"), and glass cloths 300A, 300B; a heating and pressing unit 50 for bonding the CL film 220 to the flexible circuit board 210 and the cover film 220 (hereinafter sometimes referred to as "CL film") of the FPC 200 using the release film 10 and by heating and pressing; and a release unit 60 for demolding (peeling) the release film 10 from the FPC 200 to which the CL film 220 is bonded.

[0045] The conveying unit transports FPC200, release film 10A, release film 10B and glass cloth 300A and glass cloth 300B, which are respectively wound on different take-up rollers, along their length direction by rotating the tensioner (tension roller), and after being processed by the heating and pressing unit 50 and the demolding unit 60, they are wound by the take-up roller.

[0046] In addition, each roller is made of a metal material such as stainless steel. Furthermore, the rotation axes (central axes) of these rollers are aligned in the same direction and are spaced apart from each other.

[0047] like Figure 1 As shown, the heating pressing unit 50 has a heating pressing part 52.

[0048] The heated pressing section 52 has a pair of heated pressing plates 521. The heated pressing plates 521 are positioned opposite the glass cloth 300A, release film 10A, FPC 200, release film 10B, and glass cloth 300B, which are being conveyed by the conveying unit and are in a stacked state, with one plate above and one below the glass cloth 300A. Furthermore, when the stacked glass cloth 300A, release film 10A, FPC 200, release film 10B, and glass cloth 300B pass between the heated pressing plates 521, the FPC 200 is heated and pressurized via the glass cloth 300A, glass cloth 300B, and release films 10A and 10B. Therefore, as... Figure 2 As shown in (a), the curing reaction of the adhesive layer 222 of the CL film 220 is carried out by the heating, so that in the FPC 200, the stacked flexible circuit board 210 and the CL film 220 are bonded via the adhesive layer 222.

[0049] In other words, the cover layer 221 is bonded to the flexible circuit board 210 via the adhesive layer 222 (see reference). Figure 2 (a)). Furthermore, when the FPC200 is heated / pressurized, i.e., when the cover layer 221 is bonded to the flexible circuit board 210 via the adhesive layer 222, a release film 10 is embedded in the recess 223 formed in the cover layer 221. Therefore, the seepage of adhesive from the adhesive layer 222 into the recess 223 can be suppressed (see reference). Figure 2 (b)

[0050] Furthermore, before heat pressing by the heat pressing plate 521, the FPC 200 is in a stacked state by laminating the flexible circuit board 210 and the CL film 220, but the flexible circuit board 210 and the CL film 220 are not bonded via the adhesive layer 222 of the CL film 220. Then, by pressing based on the heat pressing plate 521, the adhesive layer 222 of the CL film 220 is brought into close contact with the flexible circuit board 210. Further, in this state, the curing reaction of the adhesive layer 222 is carried out by heating based on the heat pressing plate 521, thereby bonding the flexible circuit board 210 and the CL film 220 via the adhesive layer 222.

[0051] like Figure 1 As shown, the demolding unit 60 is positioned downstream of the heating and pressing unit 50 in the conveying direction. This demolding unit 60 is configured to separate the FPC 200 from the demolding films 10A and 10B. Here, as... Figure 2 As shown in (b), in the heating pressing portion 52 of the heating pressing unit 50, the release film 10 is embedded in the recess 223 formed in the cover layer 221. Thus, although the release film 10 is bonded to the CL film 220 (FPC200), it is configured such that the release film 10 can be peeled (demolded) from the CL film 220 (FPC200) by the action of the release unit 60 (see reference). Figure 2 (c) Therefore, based on the action of the release unit 60, the FPC 200, which is a structure formed by bonding the flexible circuit board 210 and the CL film 220 via the adhesive layer 222, can be obtained in a state of being peeled off from the release film 10.

[0052] Using the roll-to-roll press 100 described above, a flexible printed circuit board 200 (FPC 200) can be manufactured. Hereinafter, a method for manufacturing the FPC 200 using this roll-to-roll press will be described. Furthermore, a method for manufacturing a molded article according to the present invention will be applied to this method for manufacturing the FPC 200.

[0053] In this embodiment, such as Figures 1 to 3 As shown, the manufacturing method of FPC200 includes: a first step, fabricating a laminate in which glass cloth 300A, release film 10A, FPC200, release film 10B and glass cloth 300B are stacked in sequence; a second step, bonding a cover layer 221 (CL film 220) to a flexible circuit board 210 in FPC200 via an adhesive layer 222 by heating and pressing the laminate; and a third step, demolding the release films 10 (10A, 10B) from FPC200 to obtain an FPC200 with the CL film 220 bonded on the flexible circuit board 210.

[0054] The following sections will describe each of these processes in sequence.

[0055] (Step 1)

[0056] First, glass cloth 300A, release film 10A, FPC 200, release film 10B, and glass cloth 300B, each in sheet form and separately wound on a roll-up roller, are conveyed through a conveying unit to create a laminated body stacked in this order (release film preparation process, see reference). Figure 1 , Figure 2 of (a) Figure 3 。 ).

[0057] Furthermore, there is no particular limitation on the method of stacking the components (films) into a laminate. For example, the stacking can be performed by pressing with rollers or by pressing with a press. Moreover, the order in which the components are stacked can be arbitrarily set. For example, all components can be stacked at the same time, or the cover film 220 and the flexible circuit board 210 can be stacked in advance, and then the other components can be stacked at the same time.

[0058] Furthermore, the formation of the laminated body in the first step constitutes the step of placing the release film 10 on the object (FPC200) in the method for manufacturing the molded article of the present invention.

[0059] (Step 2)

[0060] Next, using the heating pressing unit 50 (heating pressing part 52), while pressing the laminate of glass cloth 300A, release film 10A, FPC 200, release film 10B and glass cloth 300B stacked in this order, heat is applied (heat pressing). This allows the adhesive layer 222 to cure while remaining in close contact with the flexible circuit board 210. Therefore, in the FPC 200, a bond is formed where the cover layer 221 (CL film 220) and the flexible circuit board 210 are bonded via the adhesive layer 222 (heat pressing process, see reference). Figure 1 , Figure 2 of (b) Figure 3 。 ).

[0061] Furthermore, at this time, while the release film 10A is in close contact with the cover layer 221, the release film 10A is embedded in the recess 223 formed in the cover layer 221, thereby suppressing the seepage of adhesive from the adhesive layer 222 into the recess 223.

[0062] In this second process (heat pressing process), the temperature at which the FPC200 is heated is not particularly limited. For example, it is preferably 100°C or higher and 250°C or lower, and more preferably 150°C or higher and 200°C or lower.

[0063] Furthermore, in the second process, when pressurizing the FPC200, the pressure set in the heated pressing part 52 is not particularly limited, but it is preferably set to 1 MPa or more and 14 MPa or less, and more preferably to 5 MPa or more and 14 MPa or less.

[0064] Furthermore, the conveying speed of the laminate is preferably set to 40 mm / s or more and 400 mm / s or less, more preferably 100 mm / s or more and 350 mm / s or less. In other words, in the second step (this step), the laminate is heated and pressed using the heating and pressing unit 50, and in the peeling step (next step), the bonding time until the release film 10 is peeled off from the bond is preferably set to 1.0 second or more and 10.0 seconds or less, more preferably 4.0 seconds or more and 7.0 seconds or less.

[0065] Furthermore, the second step constitutes the heating and pressing step of the object (FPC200) on which the release film 10 is disposed in the manufacturing method of the molded article of the present invention. When the cover layer 221 (molded article) is made of a material containing a thermosetting resin in a semi-cured state, the cover layer 221 constitutes the side of the object (FPC200) on which the release film 10 is disposed. Since the release film 10 is used in a manner where the surface of the first release layer 1 side contacts the surface of the cover layer 221, the thermosetting resin can be cured while maintaining the shape of the cover layer 221 with the recesses 223 through the release film 10. Therefore, the cover layer 221 (molded article) can be molded on the flexible circuit board 210 with excellent precision. Furthermore, since the contact time is set within the specified range, the curing reaction of the thermosetting resin constituting the cover layer 221 can be carried out while the shape of the cover layer 221 with the recesses 223 is maintained by the release film 10.

[0066] Furthermore, the method for manufacturing the molded article of the present invention includes: a step (first step) of placing the release film 10 on the object (FPC200) such that the first release layer 1 of the release film 10 is on the object (FPC200) side; and a step (second step) of heating and pressing the object (FPC200) on which the release film 10 is placed. In the step of placing the release film 10, the side of the object (FPC200) on which the release film 10 is placed is formed of a material containing a thermosetting resin in a semi-cured state. Therefore, the thermosetting resin can be cured while maintaining the shape of the cover layer 221 with the recesses 223 by the release film 10, thus enabling the cover layer 221 (molded article) to be molded on the flexible circuit board 210 with excellent precision. Furthermore, since the contact time is set within the specified range, the curing reaction of the thermosetting resin constituting the cover layer 221 can be carried out while maintaining the shape of the cover layer 221 with the recesses 223 by the release film 10.

[0067] Furthermore, this embodiment shows a unit that is heated by heating and pressing, but it is not limited to this method. For example, it can be heated by infrared rays or by heating rollers.

[0068] (Step 3)

[0069] Next, in the demolding unit 60, the demolding films 10 (10A, 10B) are demolded from the FPC 200. That is, the demolding films 10A and 10B are peeled off from the bonding between the cover film 220 and the flexible circuit board 210. Thus, an FPC 200 with the CL film 220 bonded to the flexible circuit board 210 is obtained (peeling process, reference). Figure 1 , Figure 2 (c) Figure 3 。 ).

[0070] Furthermore, there are no particular limitations on the demolding unit 60. For example, it can be a structure that peels off by drawing a vacuum through a vacuum device provided on the outside, or a structure that peels off by introducing air between the joint and the demolding film 10A and the demolding film 10B, or a structure that peels off by inserting a rod between the joint and the demolding film 10A and the demolding film 10B.

[0071] Subsequently, the bonding body of the cover film 220 and the flexible circuit board 210, as well as the glass cloth 300A, release film 10A, release film 10B, and glass cloth 300B, are respectively wound up by the winding roller.

[0072] By this winding process, the flexible circuit board 210 and the CL film 220 can be continuously obtained while the FPC 200, which is bonded by the adhesive layer 222 of the CL film 220, is wound onto the winding roller.

[0073] As described above, the flexible printed circuit board 200 can be continuously manufactured by applying the manufacturing method of the flexible printed circuit board 200 based on the roll-to-roll press 100 using the release film 10.

[0074] Additionally, after the third step described above, the following steps may be included: heating the flexible printed circuit board 200 wound onto a winding roller or a single-piece substrate cut from the wound flexible printed circuit board 200 using an oven or the like, thereby further curing the thermosetting resin constituting the cover layer 221 to cure the cover layer 221.

[0075] The release film 10 used in manufacturing the flexible printed circuit board 200 applies the release film of the present invention. Hereinafter, the release film 10 to which the release film of the present invention is applied will be described.

[0076] <Mold Release Film 10>

[0077] Figure 4 This is a longitudinal sectional view showing an embodiment of the release film of the present invention. Figure 5 It's a local magnification. Figure 4 A partially enlarged longitudinal sectional view of part A of the release film shown.

[0078] like Figure 4 As shown, in this embodiment, the release film 10 is composed of a laminate formed by sequentially stacking a first release layer 1, a buffer layer 3 and a second release layer 2, and is used in an overlapping manner such that the surface of the first release layer 1 side contacts the CL film 220 of the FPC 200.

[0079] The layers constituting the release film 10 will be described below.

[0080] <Buffer Layer 3>

[0081] First, let's explain buffer layer 3. For example... Figure 4 and Figure 5 As shown, the buffer layer 3 is configured as an intermediate layer between the first release layer 1 and the second release layer 2.

[0082] The buffer layer 3 is composed of a third thermoplastic resin composition, which preferably uses a composition that imparts embeddability to the recess 223 to the release film 10 and contains a variety of thermoplastic resins. This ensures adequate conformability.

[0083] Combinations of various thermoplastic resins can include, for example, combinations of polyester resins and polyolefin resins, combinations of polyolefin resins with each other, and combinations of polyamide resins and polyolefin resins. Among these, by selecting a combination of polyester resins and polyolefin resins, the aforementioned effects can be achieved more reliably.

[0084] The polyester resin is not particularly limited, and examples include polyethylene terephthalate (PET), polycyclohexane terephthalate (PCT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycyclohexanediol terephthalate, and polypropylene terephthalate. One or more of these resins can be used. Furthermore, when using two or more of these resins in combination, the polyester resin can be a mixture or a copolymer. Polybutylene terephthalate is particularly preferred among these. This provides excellent conformability to the recess 223 in the buffer layer 3. Moreover, when the first thermoplastic resin composition constituting the first release layer 1 contains polybutylene terephthalate, the buffer layer 3 can be made into a buffer layer that exhibits excellent adhesion to the first release layer 1.

[0085] Furthermore, the polyolefin resin is not particularly limited, and examples include polyethylene such as low-density polyethylene and high-density polyethylene, α-olefin polymers such as polypropylene, copolymers of ethylene and hexene with polymer components such as ethylene, propylene, butene, pentene, hexene, and octene, copolymers of α-olefins and (meth)acrylates, copolymers of ethylene and vinyl acetate, and copolymers of ethylene and (meth)acrylates. One or more of these can be used. Among these, at least one of copolymers of ethylene and vinyl acetate (ethylene vinyl acetate copolymer) and copolymers of ethylene and (meth)acrylates (ethylene (meth)acrylate copolymer) is preferred. This allows the buffer layer 3 to be given excellent conformability to the recess 223.

[0086] When the composition is a combination of polyester resin and polyolefin resin, the content of polyester resin in the third thermoplastic resin composition is preferably 5% by weight or more, more preferably 8% by weight or more and 40% by weight or less. This provides the release film 10 with excellent conformability to the recesses 223.

[0087] Furthermore, in the third thermoplastic resin composition constituting the buffer layer 3, in addition to the resin material (thermoplastic resin) mentioned above, it may also contain additives such as nucleating agents, antioxidants, lubricants, anti-blocking agents, antistatic agents, colorants, and stabilizers.

[0088] Furthermore, the storage elastic modulus E' of the buffer layer 3 at 150°C is preferably 0.1 MPa or more, more preferably 0.5 MPa or more and 150 MPa or less, and even more preferably 1 MPa or more and 100 MPa or less. By setting the storage elastic modulus E' of the buffer layer 3 at 150°C as described above, when the release film 10 is embedded in the recess 223 in the second step, it is possible to reliably suppress or prevent a portion of the buffer layer 3 from protruding from the edge of the release film 10 and adhering to the FPC 200. Therefore, contamination of the FPC 200 can be reliably suppressed or prevented. Furthermore, the release film 10 can be easily peeled off in the third step.

[0089] In addition, the stored elastic modulus E' of the buffer layer 3 at 150°C can be obtained, for example, by preparing a buffer layer 3 with a width of 4 mm and a length of 20 mm in accordance with JIS K7244-4, and measuring it using a dynamic viscoelasticity measuring device (manufactured by Hitachi High-Tech Science Corporation, "DMA7100") in tensile mode, at a frequency of 1 Hz and a heating rate of 5°C / min.

[0090] Furthermore, the average thickness Tk of the buffer layer 3 is preferably set to 40 μm or more and 110 μm or less, more preferably 50 μm or more and 90 μm or less. This ensures sufficient conformability.

[0091] <First Demolding Layer 1>

[0092] Next, the first release layer 1 will be explained. For example... Figure 4 and Figure 5 As shown, the first release layer 1 is stacked on one side of the buffer layer 3.

[0093] The first release layer 1 is flexible. In the above-described manufacturing method of the flexible printed circuit board 200 using the release film 10, the release film 10 is laminated in such a way that the first release layer 1 contacts the CL film 220 of the FPC 200. Then, in the second step of this manufacturing method, when the laminated flexible circuit board 210 and CL film 220 are bonded via adhesive layer 222, the first release layer 1 is a layer pressed in following the shape of the recess 223 formed by the flexible circuit board 210 and CL film 220 and functions as a protective (buffer) material to prevent the release film 10 from breaking. Furthermore, the first release layer 1 also functions as a contact layer in the third step to provide excellent release properties of the release film 10 to the CL film 220 (FPC 200).

[0094] Therefore, in the second step, when the release film 10 is embedded in the recess 223 formed in the FPC 200, the seepage of adhesive from the adhesive layer 222 can be reliably suppressed or prevented. Furthermore, after the FPC 200, formed by bonding the flexible circuit board 210 and the CL film 220 via the adhesive layer 222 of the CL film 220, is formed in the second step, when the release film 10 is peeled off from the FPC 200 in the third step, elongation and breakage of the FPC 200 can be reliably suppressed or prevented. Moreover, when the third thermoplastic resin composition constituting the buffer layer 3 contains a polyester resin, the first release layer 1 can be made into a release layer that exhibits excellent adhesion to the buffer layer 3.

[0095] Furthermore, regarding the first release layer 1, in the manufacturing method of the flexible printed circuit board 200, the first release layer 1 is in contact with the CL film 220 of the FPC 200. Therefore, in the second step of this manufacturing method, it also has the function of transferring heat from the heating pressing plate 521 to the CL film 220 when the FPC 200 is heated and pressed.

[0096] like Figure 5 As shown, the first release layer 1 has an uneven shape on its surface.

[0097] Furthermore, in the release film 10 of this embodiment, at least one of the following conditions [1] to [3] is satisfied.

[0098] [1] In the release film 10 of this embodiment, in the first release layer 1, the arithmetic mean height Sa of the absolute value of the height difference of each point relative to the average surface of its surface exceeds 2.3 μm.

[0099] [2] When the maximum value of the height from the average surface of the first demolding layer 1, i.e. the maximum peak height, is set as Sp[μm] and the absolute value of the minimum height from the average surface, i.e. the maximum valley depth, is set as Sv[μm], the relationship Sp+Sv≥27 is satisfied.

[0100] [3] On the surface of the first release layer 1, the average depth of the protruding valley, i.e. the height of the protruding valley Svk, is preferably 5 μm or more.

[0101] By satisfying at least one of the conditions in [1] to [3], the excellent release properties of the release film 10 on the CL film 220 (FPC200) can be more reliably utilized. Furthermore, the sliding properties can be improved more reliably, and the release film 10 can be transported well and smoothly.

[0102] It is sufficient to satisfy at least one of the conditions in [1] to [3], but it is preferable to satisfy two or more of them, and more preferably to satisfy three conditions. As a result, the release film 10 can be more reliably released from the CL film 220 (FPC200), the sliding properties can be more reliably improved, and the release film 10 can be transported more well and smoothly.

[0103] <Regarding the conditions of [1]>

[0104] By having a first release layer 1 that satisfies the conditions of [1], the excellent release properties of the release film 10 on the CL film 220 (FPC200) can be more reliably utilized. Furthermore, the sliding properties can be improved more reliably, and the release film 10 can be transported well and smoothly.

[0105] If the conditions in [2] and [3] are not met, and the arithmetic mean height Sa is less than 2.3 μm, the release properties and sliding properties become insufficient. During the manufacturing of the flexible printed circuit board 200, defects such as wrinkles and breaks in the flexible printed circuit board 200 or scratches on the flexible circuit board 210 may occur. Consequently, the release film 10 cannot be transported smoothly and efficiently.

[0106] The arithmetic mean height Sa is the average of the absolute values ​​of the differences in height between the protrusions, i.e., the heights of the points, relative to the surface of the first release layer 1. The arithmetic mean height Sa can be calculated according to ISO 25178. Specifically, the arithmetic mean height Sa can be calculated as follows.

[0107] Using a scanning white interferometer microscope (KEYENCE CORPORATION VK-X3000 laser microscope), with the objective lens set to 20x, four contiguous images were acquired (measurement range: approximately 2000 μm × 1500 μm). The acquired images were processed by setting an averaging plane (reference plane). Next, a Gaussian filter was applied, with the cutoff wavelengths set to S-filter: 2.5 μm and L-filter: 0.8 mm, respectively. Based on this processing result, the average of the absolute values ​​of the height differences at each point was calculated.

[0108] The above-mentioned effects can be obtained if the arithmetic mean height Sa exceeds 2.3 μm, but the arithmetic mean height Sa is preferably 2.5 μm or more and 10.0 μm or less, more preferably 2.9 μm or more and 9.0 μm or less. As a result, the excellent release properties of the release film 10 on the CL film 220 (FPC200) can be more reliably utilized, and the sliding properties can be improved more reliably, so as to transport the release film 10 smoothly and well.

[0109] By setting the arithmetic mean height Sa below the upper limit, embedment and tracking can be ensured.

[0110] There are no particular limitations on the method for setting the arithmetic mean height Sa of the surface of the first release layer 1 to be greater than 2.3 μm. Examples include methods such as incorporating fillers such as inorganic or organic particles (described later) into the first release layer 1, surface treatment methods such as plasma treatment, and roller transfer printing. By adjusting the size of the filler or adjusting the surface treatment conditions, the arithmetic mean height Sa can be set to be greater than 2.3 μm.

[0111] <Regarding the conditions of [2]>

[0112] By using a first release layer 1 that satisfies the conditions [2], the excellent release properties of the release film 10 on the CL film 220 (FPC200) can be more reliably utilized. Furthermore, the sliding properties can be improved more reliably, and the release film 10 can be transported smoothly and efficiently. Sp[μm] and Sv[μm] can be determined in accordance with ISO 25178. Specifically, Sp[μm] and Sv[μm] are determined as follows.

[0113] Using a scanning white interferometer microscope (Keyence VK-X3000 laser microscope), with the objective lens set to 20x, four contiguous images were acquired (measurement range: approximately 2000 μm × 1500 μm). The acquired images were processed to establish an average plane (reference plane). Next, a Gaussian filter was applied, with the cutoff wavelengths set to S filter: 2.5 μm and L filter: 0.8 mm. Based on this processing, the maximum height from the average plane (maximum peak height) was calculated to obtain Sp [μm], and the absolute value of the minimum height from the average plane (maximum valley depth) was calculated to obtain Sv [μm].

[0114] If the conditions in [1] and [3] are not met, and Sp + Sv < 27, the release properties and sliding properties become insufficient. During the manufacturing of the flexible printed circuit board 200, defects such as wrinkles and breaks in the flexible printed circuit board 200 or scratches on the flexible circuit board 210 may occur. Consequently, the release film 10 cannot be delivered smoothly and efficiently.

[0115] Sp+Sv is preferably 30μm or more and 90μm or less, more preferably 35μm or more and 80μm or less. This allows the excellent release properties of the release film 10 on the CL film 220 (FPC200) to be more reliably utilized, and the sliding properties to be improved more reliably, so as to transport the release film 10 smoothly and well.

[0116] There are no particular limitations on the method for setting Sp+Sv≥27 on the surface of the first release layer 1. Examples include methods such as incorporating fillers such as inorganic or organic particles (described later) into the first release layer 1, surface treatment methods such as plasma treatment, and roller transfer printing. By adjusting the size of the filler or adjusting the surface treatment conditions, it is possible to set Sp+Sv≥27.

[0117] <Regarding the conditions of [3]>

[0118] By having a first release layer 1 that meets the conditions [3], the excellent release properties of the release film 10 on the CL film 220 (FPC200) can be more reliably utilized. Furthermore, the sliding properties can be improved more reliably, and the release film 10 can be transported well and smoothly.

[0119] The height of the protruding valley, Svk[μm], can be determined according to ISO 25178. Specifically, the height of the protruding valley, Svk[μm], is determined as follows.

[0120] Using a scanning white interferometer microscope (Keyence VK-X3000 laser microscope), with the objective lens set to 20x, four contiguous images were acquired (measurement range: approximately 2000 μm × 1500 μm). The acquired images were processed by setting an average plane (reference plane). Next, a Gaussian filter was applied, with the cutoff wavelengths set to S-filter: 2.5 μm and L-filter: 0.8 mm, respectively. Based on this processing result, the average depth of the protruding valleys on the surface was calculated to determine the height of the protruding valley, Svk [μm].

[0121] If the conditions in [1] and [2] are not met, and the height of the protruding valley Svk is less than 5 μm, the release properties and sliding properties become insufficient. During the manufacturing of the flexible printed circuit board 200, defects such as wrinkles and breaks in the flexible printed circuit board 200 or scratches on the flexible circuit board 210 may occur. Consequently, the release film 10 cannot be transported smoothly and efficiently.

[0122] The height of the protruding valley, Svk, is preferably 6 μm or more and 30 μm or less, more preferably 6 μm or more and 25 μm or less. This allows the aforementioned effects to be achieved more reliably.

[0123] <Regarding conditions other than [1] to [3]>

[0124] The maximum peak height Sp of the first release layer 1 is preferably 10 μm or more. This allows for more reliable release of the release film 10 from the CL film 220 (FPC200). Furthermore, it improves sliding properties and ensures smooth and efficient transport of the release film 10.

[0125] The maximum peak height Sp of the first release layer 1 is preferably 10 μm or more, more preferably 10 μm or more and 60 μm or less, and even more preferably 15 μm or more and 50 μm or less. This allows the aforementioned effects to be achieved more reliably.

[0126] The maximum valley depth Sv of the first release layer 1 is preferably 10 μm or more. This allows for more reliable release of the release film 10 from the CL film 220 (FPC200). Furthermore, it improves sliding properties and ensures smooth and efficient transport of the release film 10.

[0127] The maximum valley depth Sv of the first release layer 1 is preferably 10 μm or more, more preferably 10 μm or more and 60 μm or less, and even more preferably 15 μm or more and 50 μm or less. This allows the aforementioned effects to be achieved more reliably.

[0128] The load area ratio Smr2 for dividing the core and protruding valleys is preferably 75% or more. This allows for more reliable release of the release film 10 from the CL film 220 (FPC200). Furthermore, it improves sliding properties and ensures smooth and efficient transport of the release film 10. The load area ratio Smr2 can be determined according to ISO 25178.

[0129] The load area ratio Smr2 is preferably 75% or more, more preferably 80% or more and 99% or less. This allows the aforementioned effects to be achieved more reliably.

[0130] The first release layer 1 is composed of a first thermoplastic resin composition. Furthermore, the first thermoplastic resin composition preferably mainly contains, for example, a polyester resin or a poly4-methyl-1-pentene resin. Therefore, the aforementioned functions can be imparted to the first release layer 1 relatively easily.

[0131] Furthermore, there are no particular limitations on the polyester resin used; for example, the same resin mentioned in the third thermoplastic resin composition described above can be used, with polybutylene terephthalate (PBT) being particularly preferred. This allows for a more significant realization of the effects obtained by using a polyester resin. Moreover, when polybutylene terephthalate is included in the third thermoplastic resin composition constituting the buffer layer 3, the first release layer 1 can be made into a release layer that exhibits excellent adhesion to the buffer layer 3.

[0132] Furthermore, when the first thermoplastic resin composition is mainly composed of a polyester resin, it may contain a thermoplastic resin other than a polyester resin. Examples of such thermoplastic resins include polyethylene, polypropylene, polyolefin resins such as poly4-methyl-1-pentene, and polystyrene resins such as syndiotactic polystyrene. One of these resins or a combination of two or more of them may be used.

[0133] Furthermore, in addition to the aforementioned thermoplastic resin, the first thermoplastic resin composition may also contain at least one of inorganic particles and organic particles.

[0134] As inorganic particles, there are no particular limitations. Examples include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, boron nitride, crystalline silicon dioxide, amorphous silicon dioxide, antimony oxide, E glass, D glass, S glass, etc. One or more of these can be used.

[0135] Furthermore, as organic particles, there are no particular limitations. Examples include polystyrene particles, acrylic particles, polyimide particles, polyester particles, silicone particles, polypropylene particles, polyethylene particles, fluoropolymer particles, and core-shell particles. One or more of these particles can be used.

[0136] Furthermore, the average particle size of the inorganic and organic particles is preferably 3 μm or more and 40 μm or less, more preferably 5 μm or more and 30 μm or less. Thus, when the first thermoplastic resin composition contains at least one of inorganic and organic particles, it is relatively easy to set the surface roughness of the surface of the first release layer 1 opposite to the buffer layer 3 within the above-mentioned range.

[0137] Furthermore, the average thickness T1 of the first release layer 1 is preferably set to 7 μm or more and 38 μm or less, and more preferably to 10 μm or more and 30 μm or less. Thus, by setting the average thickness of the first release layer 1 within an appropriate range, the first release layer 1 can be more reliably endowed with the aforementioned functions as the first release layer 1.

[0138] In addition, as described above, the average thickness T1 of the first release layer 1 is set as follows: when the surface of the first release layer 1 on the side opposite to the buffer layer 3 has a concave-convex shape, the average value of the measured values ​​obtained by measuring the thickness at the position including the convex part in the convex part and at the position including the concave part in the concave part respectively.

[0139] Furthermore, the first thermoplastic resin composition constituting the first release layer 1 may contain, in addition to the resin material, inorganic particles, and organic particles mentioned above, the same additives as those listed in the third thermoplastic resin composition.

[0140] <Second release layer 2>

[0141] Next, the second release layer 2 will be explained.

[0142] like Figure 4 and Figure 5 As shown, the release film 10 has a second release layer 2, which is stacked on the other side of the buffer layer 3, that is, the side of the buffer layer 3 opposite to the first release layer 1, and is composed of a second thermoplastic resin composition.

[0143] The second release layer 2 is flexible. In the above-described manufacturing method of the flexible printed circuit board 200 using the release film 10, the release film 10 is laminated in such a way that the first release layer 1 contacts the CL film 220 of the FPC 200. Then, in the second step of this manufacturing method, when the laminated flexible circuit board 210 and CL film 220 are bonded via the adhesive layer 222, the second release layer 2 functions as a layer that transmits the force from the heated pressing plate 521 to the buffer layer 3. Furthermore, the second release layer 2 also functions as a contact layer in the third step for providing excellent release properties between the glass cloth 300 and the release film 10.

[0144] Furthermore, regarding the second release layer 2, in the manufacturing method of the flexible printed circuit board 200, the second release layer 2 contacts the heated pressing plate 521 via the glass cloth 300. Therefore, in the second step of this manufacturing method, it also has the function of transferring heat from the heated pressing plate 521 to the buffer layer 3 when the FPC 200 is heated and pressed.

[0145] The second release layer 2 is composed of a second thermoplastic resin composition. Furthermore, similar to the first thermoplastic resin composition, this second thermoplastic resin composition preferably mainly contains a polyester resin. Therefore, the second release layer 2 can reliably possess the aforementioned functions.

[0146] Furthermore, there are no particular limitations on the polyester resin used; for example, the same resin mentioned in the third thermoplastic resin composition described above can be used, with polybutylene terephthalate (PBT) being particularly preferred. This allows for a more significant realization of the effects obtained by using a polyester resin.

[0147] In addition, when the second thermoplastic resin composition is mainly composed of a polyester resin, it may contain a thermoplastic resin other than a polyester resin, and the same resin as that mentioned in the first thermoplastic resin composition can be used as the thermoplastic resin.

[0148] Furthermore, in addition to the aforementioned thermoplastic resin, the second thermoplastic resin composition may also contain at least one of inorganic particles and organic particles.

[0149] There are no particular limitations on whether the particles are inorganic or organic, and the same materials as those mentioned in the first thermoplastic resin composition can be used.

[0150] The storage elastic modulus E' of the second release layer 2 forming this structure is preferably 50 MPa or more, more preferably 50 MPa or more and 1000 MPa or less, at 150°C. Therefore, the second release layer 2 can be reliably endowed with the aforementioned functions.

[0151] Furthermore, the average thickness T2 of the second release layer 2 is preferably set to 7 μm or more and 38 μm or less, more preferably 10 μm or more and 30 μm or less. This allows the second release layer 2 to more reliably possess the aforementioned functions.

[0152] Furthermore, the second thermoplastic resin composition constituting the second release layer 2 may contain, in addition to the resin material, inorganic particles, and organic particles described above, the same additives as those mentioned in the third thermoplastic resin composition.

[0153] Furthermore, in the first release layer 1 and the second release layer 2, the first thermoplastic resin composition and the second thermoplastic resin composition may be the same or different, but from the viewpoint of substitutability, they are preferably the same or have the same properties. In addition, in the first release layer 1 and the second release layer 2, their average thicknesses T1 and T2 may be the same or different.

[0154] In the release film 10, which has the structure of the first release layer 1, the buffer layer 3 and the second release layer 2 as described above, its average thickness Tt is preferably 50 μm or more and 180 μm or less, more preferably 80 μm or more and 150 μm or less.

[0155] In addition, in this embodiment, the release film 10 is composed of a laminate formed by sequentially stacking the first release layer 1, the buffer layer 3 and the second release layer 2, but it is not limited to this structure. For example, it may also be composed of a laminate having an intermediate layer such as an adhesive layer disposed between the first release layer 1 and the buffer layer 3 and between the second release layer 2 and the buffer layer 3.

[0156] Furthermore, as long as the release film 10 can maintain excellent release properties between the glass cloth 300 and the release film 10 in the third process, the second release layer 2 that contacts the glass cloth 300 can be omitted.

[0157] The above describes the manufacturing method of the release film and the molded article of the present invention; however, the present invention is not limited to these descriptions.

[0158] For example, in the described embodiment, the case of applying the release film of the present invention to a pressing molding method for manufacturing a flexible printed circuit board disposed between heated pressing plates as a single layer has been described. However, the number of flexible printed circuit boards stacked is not limited to one layer, and may be two or more layers.

[0159] Furthermore, the release film of the present invention can be applied to the case of pressing a flexible printed circuit board disposed between heated pressing plates using a roll-to-roll press, but it is not limited thereto. For example, the pressing of the flexible printed circuit board can be carried out by a pressing molding method, or by a vacuum pressing molding method.

[0160] Example

[0161] The present invention will now be described in detail with reference to embodiments, but the present invention is not limited thereto.

[0162] 1. Preparation of raw materials

[0163] The following materials were prepared as raw materials for manufacturing the release film.

[0164] thermoplastic resin materials

[0165] Ethylene-methyl methacrylate copolymer (EMMA, manufactured by Sumitomo Chemical Co., Ltd., "WD203-1")

[0166] Polypropylene (PP, manufactured by Prime Polymer, "E111G")

[0167] Polybutylene terephthalate (PBT, manufactured by Changchun Petrochemical Company, "1100-630S")

[0168] Copolymerized polybutylene terephthalate (PBT, manufactured by Mitsubishi Engineering-Plastics Corporation, "5505S")

[0169] 2. Manufacturing of release film

[0170] <Example 1>

[0171] First, as the first thermoplastic resin composition, a composition consisting of 70% by weight of polybutylene terephthalate (PBT, 1100-630S) and 30% by weight of copolymerized polybutylene terephthalate (PBT, 5505S) was prepared. Furthermore, as the second thermoplastic resin composition, a composition consisting of 100% by weight of polybutylene terephthalate (PBT, 1100-630S) was prepared. Additionally, as the third thermoplastic resin composition, a composition consisting of 55% by weight of ethylene-methyl methacrylate copolymer (EMMA, WD203-1), 20% by weight of polypropylene (PP, E111G), and 25% by weight of polybutylene terephthalate (PBT, 1100-630S) was prepared.

[0172] Next, a first thermoplastic resin composition, a third thermoplastic resin composition, and a second thermoplastic resin composition are supplied to three extruders and co-extruded from a multi-manifold die to obtain a release film 10 formed by sequentially stacking a first release layer 1, a buffer layer 3, and a second release layer 2.

[0173] In addition, in the obtained release film 10, the average thickness T1 of the first release layer 1 is 20 μm, the average thickness Tk of the buffer layer 3 is 80 μm, and the average thickness T2 of the second release layer 2 is 20 μm.

[0174] At this time, for the first release layer 1, at least one of the first roller and the contact roller is used to roughen the surface shape of the transfer.

[0175] Furthermore, the arithmetic mean height Sa, which is the absolute value of the height difference between points relative to the average surface of the first demolding layer 1, is 3.1 μm.

[0176] Furthermore, when the maximum value of the height from the average surface of the first demolding layer 1, i.e. the maximum peak height, is set as Sp[μm], and the absolute value of the minimum height from the average surface, i.e. the maximum valley depth, is set as Sv[μm], Sp+Sv is satisfied to be 28μm.

[0177] Furthermore, on the surface of the first release layer 1, the average depth of the protruding valley, i.e., the height of the protruding valley Svk, is 5 μm.

[0178] Furthermore, on the surface of the first demolding layer 1, the load area ratio Smr2, which divides the core and protruding valley, is 92%.

[0179] The arithmetic mean height Sa, maximum peak height Sp + maximum valley depth Sv, height of prominent valley Svk, and load area ratio Smr2 are calculated as follows.

[0180] Using a scanning white interferometer microscope (Keyence VK-X3000 laser microscope), with the objective lens set to 20x, four interconnected images were acquired (measurement range: approximately 2000 μm × 1500 μm). The acquired images were processed by setting the mean plane (reference plane). Next, a Gaussian filter was applied, with the cutoff wavelengths set to S filter: 2.5 μm and L filter: 0.8 mm. Based on the processing results, the arithmetic mean height Sa, maximum peak height Sp + maximum valley depth Sv, convex valley height Svk, and loading area ratio Smr2 were calculated. Then, the values ​​of the interconnected image in each of the four regions from quadrant 1 to quadrant 4 were calculated, and their average value was set as the mean.

[0181] <Examples 2-9, Comparative Examples 1 and 2>

[0182] On the surface of the first release layer 1, the conditions for rough surface treatment were adjusted, and the arithmetic mean height Sa, maximum peak height Sp + maximum valley depth Sv, protruding valley height Svk, and load area ratio Smr2 were changed as shown in Table 1. Otherwise, the release films 10 of Examples 2 to 9 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1.

[0183] 3. Evaluation

[0184] The following evaluations were conducted on the release films 10 of each embodiment and each comparative example.

[0185] 3-1. Release properties of the release film

[0186] The release film 10 of each embodiment and each comparative example was set to a width of 270 mm, and was formed by adhering a cover film 220 (manufactured by Arisawa Manufacturing Co., Ltd., "CMA0525") to a flexible circuit board 210 with an adhesive layer 222 of the cover film 220 located on the flexible circuit board 210 side, forming an FPC 200 (laminated structure) with a pitch of 50 μm, a width of 50 μm, and a height of 18 μm. Then, it was pressed using an RtoR press (manufactured by TRM, "RR Q-CURE 100TON CONTINUOUS LAMINATOR") at 180°C and 110 kg / cm². 2 Under the set condition of 150 seconds, press the release film 10 into the mold as follows: Figure 3 The FPC200 is stacked as shown. Then, as a demolding unit 60, a structure using a bar sandwiched between the FPC200 and the demolding film 10 for peeling is applied. Under conditions of a conveying speed of 200 mm / s, a feed rate of 500 mm, and a distance of 50 mm from the heated pressing plate 521 to the demolding unit 60, the demolding film 10 is peeled off. The ease of peeling (demolding property) of the demolding film 10 is evaluated according to the following criteria.

[0187] [Evaluation Criteria]

[0188] A: It can be peeled off when the release film is removed.

[0189] B: When peeling off the release film, it is difficult to peel off due to the fusion of the buffer layers, the stretching and breaking of the release film.

[0190] 3-2. Slippery properties of the release film

[0191] (Exterior wrinkles)

[0192] The following evaluation assesses the wrinkle-suppressing effect resulting from good sliding properties.

[0193] A test piece was prepared by temporarily fixing a cover layer with an opening to the surface of an insulating substrate (FPC) with electrical wiring having an L / S ratio of 100 / 100 μm. Next, a release film 10 was applied to the test piece using a roller-to-roll press at 175°C, 11 MPa, and 120 seconds. Immediately after pressing, the test piece and the release film 10 were peeled off while being conveyed at 200 mm / s. The surface of the test piece was measured according to "7.5.7.2 Wrinkles" of the JPCA standard.

[0194] [Evaluation Criteria]

[0195] A: The wrinkle formation rate is less than 1.0%.

[0196] B: Wrinkle formation rate is above 1.0% but less than 2.0%.

[0197] C: Wrinkle formation rate above 2.0%

[0198] 3-3. Summary

[0199] The evaluation results obtained in 3-1. Demolding properties of the release film and 3-2. Slippery properties of the release film are shown in Table 1.

[0200] [Table 1]

[0201] As shown in Table 1, in each embodiment, the first release layer 1 is set in such a way that it satisfies at least one of the following conditions: the arithmetic mean height Sa exceeds 2.3 μm, the maximum peak height Sp + maximum valley depth Sv is Sp + Sv ≥ 27, and the average depth of the protruding valley, i.e., the height of the protruding valley Svk, is 5 μm or more. As a result, it shows excellent release properties and sliding properties.

[0202] In contrast, in each comparative example, the first release layer 1 did not meet any of the following conditions: the arithmetic mean height Sa exceeds 2.3 μm, the maximum peak height Sp + maximum valley depth Sv is Sp + Sv ≥ 27, and the average depth of the protruding valley, i.e., the height of the protruding valley Svk, is 5 μm or more. Therefore, the results showed that the release properties and sliding properties were not excellent.

[0203] Industrial applicability

[0204] According to the present invention, a release film with excellent release and sliding properties, and a method for manufacturing molded articles using the release film, are provided. Therefore, the present invention has industrial applicability.

[0205] Explanation of reference numerals in the attached figures

[0206] 1-First release layer, 2-Second release layer, 3-Buffer layer, 10- Release film, 10A - Release film, 10B - Release film, 50-Heating and pressing unit, 52-Heated pressing part, 60-Demolding unit, 100-roll press 200 - Flexible Printed Circuit Board (FPC) 210 - Flexible circuit board, 220 - Covering membrane (CL membrane). 221-Covering layer, 222 - Adhesive layer, 223-concave, 300A-glass cloth, 300B-glass cloth, 521-Heated pressing plate, T1 - Average thickness of the first release layer T2 - Average thickness of the second release layer Tk - Average thickness of the buffer layer Tt - Average thickness of the release film.

Claims

1. A release film having a first release layer composed of a first thermoplastic resin composition and a buffer layer laminated thereon, characterized in that, In the first release layer, the arithmetic mean height Sa, which is the average of the absolute values ​​of the height differences of each point relative to the average surface of the first release layer, exceeds 2.3 μm.

2. The release film according to claim 1, wherein, When the maximum value of the height from the average surface of the first demolding layer, i.e., the maximum peak height, is set as Sp μm, and the absolute value of the minimum height from the average surface, i.e., the maximum valley depth, is set as Sv μm, the relationship Sp+Sv≥27 is satisfied.

3. A release film having a first release layer composed of a first thermoplastic resin composition and a buffer layer laminated thereon, characterized in that, When the maximum value of the height from the average surface of the first demolding layer, i.e., the maximum peak height, is set as Sp μm, and the absolute value of the minimum height from the average surface, i.e., the maximum valley depth, is set as Sv μm, the relationship Sp+Sv≥27 is satisfied.

4. The release film according to any one of claims 1 to 3, wherein, On the surface of the first release layer, the average depth of the protruding valley, i.e., the height of the protruding valley Svk, is 5 μm or more.

5. A release film having a first release layer composed of a first thermoplastic resin composition and a buffer layer laminated thereon, characterized in that, On the surface of the first release layer, the average depth of the protruding valley, i.e., the height of the protruding valley Svk, is 5 μm or more.

6. The release film according to any one of claims 1 to 5, wherein, The load area ratio Smr2 for dividing the core and the protruding valley is 75% or more.

7. The release film according to any one of claims 1 to 6, wherein, The maximum peak height Sp is above 10 μm.

8. The release film according to any one of claims 1 to 7, wherein, The maximum valley depth Sv is greater than 10 μm.

9. The release film according to any one of claims 1 to 8, wherein, The release film has a second release layer composed of a second thermoplastic resin composition, which is laminated on the side of the buffer layer opposite to the first release layer.

10. The release film according to any one of claims 1 to 9, wherein, The first thermoplastic resin composition contains a polyester resin or a poly4-methyl-1-pentene resin.

11. The release film according to any one of claims 1 to 10, wherein, The buffer layer is composed of a third thermoplastic resin composition containing polyester resin and polyolefin resin.

12. The release film according to any one of claims 1 to 11, wherein, The average thickness of the first release layer is greater than 7 μm and less than 38 μm.

13. The release film according to any one of claims 1 to 12, wherein, The average thickness of the buffer layer is greater than 40 μm and less than 110 μm.

14. The release film according to any one of claims 1 to 13, wherein, The average thickness of the release film is greater than 50 μm and less than 180 μm.

15. The release film according to any one of claims 1 to 14, wherein, The release film is used in such a way that the surface of the first release layer side contacts the surface of the object formed of a material containing a semi-cured thermosetting resin.

16. A method for manufacturing a molded article, characterized in that, include: The process of depositing the release film on the object in such a way that the first release layer of the release film according to any one of claims 1 to 15 is the object side; and the process of heating and pressing the object on which the release film is deposited, wherein in the process of depositing the release film, the side of the object on which the release film is deposited is formed of a material containing a thermosetting resin in a semi-cured state.

Images