WO2022034834A1 - Mold release film and method for manufacturing molded product - Google Patents

Abstract

This mold release film 10 has a first mold release layer 1 composed of a first thermoplastic resin composition, and a cushion layer 3, wherein: the first mold release layer 1 has an average thickness of 12-38 μm; and the mold release film 10 has a storage elastic modulus E' of 30 MPa or more at 18℃. In addition, the mold release film 10 favorably has an average thickness of 80-180 μm, and the cushion layer 3 favorably has an average thickness of 40-110 μm. In addition, the first mold release layer 1 favorably has a ten-point average roughness (Rz) of 3-20 μｍ at the surface on the opposite side to the cushion layer 3.

Description

Manufacturing method of release film and molded product

The present invention relates to a method for manufacturing a release film and a molded product.

In recent years, when a coverlay film is bonded to a flexible circuit board whose circuit is exposed by a heat press via an adhesive layer provided in the coverlay film to form a flexible printed circuit board, that is, a laminate, it is released. Mold films are commonly used.

When forming a flexible printed circuit board using such a release film, in other words, a laminate of a flexible circuit board and a coverlay film, the release film has two characteristics, that is, embedding property and release. It has been required to have excellent moldability.

Specifically, first, a recess is formed in the flexible printed circuit board by laminating a coverlay film on the flexible circuit board, and the release film can exhibit excellent embedding property in the recess. Desired.

More specifically, the coverlay film is laminated on the flexible circuit board via the adhesive layer provided in the coverlay film. At the time of this laminating, it is required that the release film exhibits excellent embedding property in the concave portion and the exudation of the adhesive in the concave portion is suppressed.

Further, after laminating the coverlay film on the flexible circuit board as described above, it is required that the release film is peeled off from the formed flexible printed circuit board with excellent releasability.

More specifically, when the release film is peeled off from the formed flexible printed circuit board, the release film exhibits excellent releasability with respect to the flexible printed circuit board, and the flexible printed circuit board. It is required that the occurrence of creases and breaks in the above is suppressed.

For the purpose of obtaining a release film having excellent two characteristics (embedding property and releasability) as described above, for example, in Patent Document 1, a release film having a polyester-based elastomer layer and a polyester layer is used. Proposed. However, it cannot be said that the release film having such a structure has both excellent embedding property and excellent release property, and the development of a release film having a good balance between these two characteristics. Was the reality.

Further, such a problem is caused by setting a release film to be attached to an object formed of a material containing a thermosetting resin in a semi-cured state, and curing the thermosetting resin in this state. The same applies to the case where a molded product is manufactured using an object.

Japanese Unexamined Patent Publication No. 2011-88351

An object of the present invention is to provide a release film capable of achieving both excellent embedding property and excellent mold release property in a well-balanced manner, and a method for manufacturing a molded product using such a release film. be.

Such an object is achieved by the present invention described in the following (1) to (13).
(1) A release film having a first release layer made of a first thermoplastic resin composition and a cushion layer.
The first release layer has an average thickness of 12 μm or more and 38 μm or less.
The release film is a release film having a storage elastic modulus E'at 180 ° C. of 30 MPa or more.

(2) The release film according to (1) above, wherein the release film has an average thickness of 80 μm or more and 180 μm or less.

(3) The release film according to (1) or (2) above, wherein the cushion layer has an average thickness of 40 μm or more and 110 μm or less.

(4) The release according to any one of (1) to (3) above, wherein the first release layer has a 10-point average roughness (Rz) of 3 μm or more and 20 μm or less on the surface opposite to the cushion layer. Mold film.

(5) The release film according to any one of (1) to (4) above, wherein the first release layer has a storage elastic modulus E'at 180 ° C. of 60 MPa or more.

(6) When the average thickness of the first release layer is T1 [μm] and the storage elastic modulus E'of the first release layer at 180 ° C. is E'1 [MPa], E'1 /. The release film according to any one of (1) to (5) above, wherein T1 [MPa / μm] satisfies the relationship of 2.1 <E'1 / T1 <6.0.

(7) The release film according to any one of (1) to (6) above, wherein the first thermoplastic resin composition contains a poly 4-methyl-1-pentene resin.

(8) The cushion layer is made of a third thermoplastic resin composition containing a poly 4-methyl 1-pentene resin and a polyolefin-based resin different from the poly 4-methyl 1-pentene resin (1) to the above. The release film according to any one of (7).

(9) The release film has a second release layer made of a second thermoplastic resin composition laminated on the opposite side of the cushion layer to the first release layer (1) to (8). ). The release film according to any one of.

(10) The release film having a width of 270 mm is pressure-bonded to a flexible circuit board having irregularities with a pitch of 50 μm, a width of 50 μm, and a height of 18 μm under the conditions of 180 ° C., 11 MPa, and 120 sec by a roll-to-roll press machine. When the flexible circuit board and the release film are peeled off while being conveyed immediately after pressurization, the limit peeling speed at which no wrinkles are observed on the release film is 100 mm / sec or more (the above). The release film according to any one of 1) to (9).

(11) A coverlay film (manufactured by Arisawa Seisakusho Co., Ltd., "CMA0525") is provided on a flexible circuit board having irregularities having a pitch of 50 μm, a width of 50 μm, and a height of 18 μm, and an adhesive layer provided on the coverlay film is provided on the flexible circuit board. When the release film having a width of 270 mm is pushed into the laminate formed by sticking it sideways under the conditions of 180 ° C., 11 MPa, and 120 s, and then one end of the release film is held and peeled off. The release film according to any one of (1) to (10) above, wherein the maximum amount of the adhesive exuded in the concave portion of the laminated body in a plan view is 100 μm or less.

(12) The release film is formed on the surface of an object formed of a material containing a thermosetting resin in a semi-cured state.
The release film according to any one of (1) to (11) above, which is used in layers so that the surfaces on the first release layer side are in contact with each other.

(13) The first release layer of the release film according to any one of (1) to (12) above is on the object side.
In the step of arranging the release film, which includes a step of arranging the release film on the object and a step of performing a heat press on the object on which the release film is arranged. A method for producing a molded product, wherein the surface of the object on which the release film is arranged is formed of a material containing a heat-curable resin in a semi-cured state.

According to the present invention, it is possible to obtain a releasable film in which both excellent embedding property and excellent releasability are exhibited in a well-balanced manner.

Therefore, when the release film is used for forming a flexible printed circuit board using, for example, a flexible circuit board and a coverlay film, the adhesive seeps out in the recesses formed in the flexible printed circuit board. Can be accurately suppressed or prevented.

Then, when the release film is peeled off from the flexible printed circuit board after the formation of the flexible printed circuit board, it is possible to accurately suppress or prevent breakage and breakage in the flexible printed circuit board.

FIG. 1 is a side view showing a main part of a roll-to-roll press machine used for manufacturing a flexible printed circuit board. FIG. 2 is a vertical cross-sectional view showing each process in a method of manufacturing a flexible printed circuit board using the roll-to-roll press machine shown in FIG. FIG. 3 is a vertical cross-sectional view showing a heating press process in a method for manufacturing a flexible printed circuit board using the roll-to-roll press machine shown in FIG. 1. FIG. 4 is a vertical sectional view showing an embodiment of the release film of the present invention. FIG. 5 is a partially enlarged vertical sectional view of a part A of the release film shown in FIG. 4 which is partially enlarged.

Hereinafter, the method for producing the release film and the molded product of the present invention will be described in detail based on the preferred embodiments shown in the attached drawings.

In the following, a case where a flexible printed circuit board is manufactured using the release film of the present invention will be described as an example. Further, prior to explaining the method for manufacturing the release film and the molded product of the present invention, first, a roll-to-roll press machine used for manufacturing a flexible printed circuit board will be described.

<Roll-to-roll press machine>
FIG. 1 is a side view showing a main part of a roll-to-roll press machine used for manufacturing a flexible printed circuit board, and FIG. 2 is a method for manufacturing a flexible printed circuit board using the roll-to-roll press machine shown in FIG. A vertical sectional view showing each process, FIG. 3 is a vertical sectional view showing a heating press process in a method for manufacturing a flexible printed circuit board using the roll-to-roll press machine shown in FIG. 1. In the following, for convenience of explanation, the upper side in FIGS. 1 to 3 is referred to as "upper" or "upper", the lower side is referred to as "lower" or "lower", the left side is referred to as "left", and the right side is referred to as "right". ".

The roll-to-roll press machine 100 (RtoR press machine) is a transfer means (not shown) for transporting a release film 10, a flexible printed circuit board 200 (hereinafter, also referred to as “FPC”), and glass cloths 300A and 300B. ), The flexible circuit board 210 included in the FPC 200 and the coverlay film 220 (hereinafter, also referred to as “CL film”), and the CL film 220 is attached to the flexible circuit board 210 using the release film 10. It is provided with a heat press means 50 for joining by heat pressing, and a mold release means 60 for releasing (peeling) the release film 10 from the FPC 200 to which the CL film 220 is bonded to the flexible circuit board 210. ..

The transporting means is the FPC200, the release films 10A and 10B, and the glass cloths 300A and 300B wound on different unwinding rollers, respectively, by the rotation of the tensioner (tension roller) along the longitudinal direction thereof. , And after processing by the heating press means 50 and the mold release means 60, the film is wound around a take-up roller.

Each roller is made of a metal material such as stainless steel. Further, these rollers have rotation shafts (central shafts) facing in the same direction and are arranged apart from each other.
As shown in FIG. 1, the heat pressing means 50 has a heat crimping portion 52.

The heat crimping portion 52 has a pair of heat crimping plates 521. The heat-bonded plate 521 is conveyed above and below the glass cloth 300A, the release film 10A, the FPC 200, the release film 10B, and the glass cloth 300B, which are conveyed by the conveying means and are in an overlapped state. They are arranged one by one. Then, when the glass cloth 300A, the release film 10A, the FPC200, the release film 10B and the glass cloth 300B in the overlapped state pass between the heat crimping plates 521, the glass is formed by the heat crimping plate 521. The FPC 200 is heated and pressed through the cloths 300A and 300B and the release films 10A and 10B. Therefore, in the FPC 200, the laminated flexible circuit board 210 and the CL film 220 are joined via the adhesive layer 222 included in the CL film 220. In other words, the coverlay 221 and the flexible circuit board 210 are bonded via the adhesive layer 222. Further, when the FPC 200 is heated and pressurized, that is, when the coverlay 221 and the flexible circuit board 210 are bonded via the adhesive layer 222, the release film 10 is formed in the recess 223 formed in the coverlay 221. Will be embedded. Therefore, the exudation of the adhesive derived from the adhesive layer 222 in the recess 223 is suppressed (see FIG. 2B).

Before the heat crimping is performed by the heat crimping plate 521, the FPC 200 is in a state of being laminated by overlapping the flexible circuit board 210 and the CL film 220, but the flexible circuit board 210 and the CL film 220 are laminated. Is not bonded via the adhesive layer 222 included in the CL film 220.

As shown in FIG. 1, the mold release means 60 is arranged on the downstream side in the transport direction with respect to the heating press means 50. The mold release means 60 is configured to separate the FPC 200 from the mold release films 10A and B. As described above, in the heat crimping portion 52 provided in the heat pressing means 50, the release film 10 is embedded in the recess 223 formed in the coverlay 221, whereby the release film 10 is embedded in the CL film 220 (FPC200). 10 is joined. After that, the roll-to-roll press machine 100 is configured so that the release film 10 can be peeled (released) from the CL film 220 (FPC200) by the action of the mold release means 60 (FIG. 2 (c)). reference).

The flexible printed circuit board 200 (FPC200) can be manufactured by using the roll-to-roll press machine 100 as described above. Hereinafter, a method for manufacturing the FPC 200 using this roll-to-roll press machine will be described. The method for producing a molded product of the present invention is applied to the method for producing FPC200.

In the present embodiment, in the present embodiment, the glass cloth 300A, the release film 10A, the FPC200, the release film 10B, and the glass cloth 300B, each of which is in the form of a sheet, are laminated in this order. In the FPC 200, the coverlay 221 (CL film 220) is attached to the flexible circuit board 210 via the adhesive layer 222 in the first step of forming the laminated body into a state and by heating and pressing the laminated body. It has a second step of joining and a third step of releasing the release film 10 (10A, 10B) from the FPC 200 to obtain an FPC 200 to which the CL film 220 is bonded to the flexible circuit board 210. ..

Hereinafter, each of these steps will be described in sequence.
(First step)
First, when the glass cloth 300A, the release film 10A, the FPC200, the release film 10B, and the glass cloth 300B, each of which is in the shape of a sheet, are transported by the transport means. In addition, the laminated body is in a state of being overlapped in this order (see FIGS. 1, 2 (a), and 3).

The method of laminating each member (film) on the laminated body is not particularly limited, and for example, laminating may be performed while pressing with a roll, or may be performed while pressing with a press. Further, the order in which the members are laminated can be arbitrarily set. For example, all the members may be laminated at the same time, or the coverlay film 220 and the flexible circuit board 210 may be laminated in advance, and then the other members may be laminated at the same time.

Further, the formation of the laminated body in the first step constitutes a step of arranging the release film 10 on the object (FPC200) in the method for manufacturing a molded product of the present invention.

(Second step)
Next, a laminated body in which the glass cloth 300A, the release film 10A, the FPC 200, the release film 10B, and the glass cloth 300B are laminated in this order is subjected to the heat pressing means 50 (heat crimping portion 52). The coverlay 221 (CL film 220) is bonded to the flexible circuit board 210 via the adhesive layer 222 in the FPC 200 by heat-pressing (heat-pressing step, FIGS. 1, 2 (b)). ), See FIG. 3).

In this heating press step, the temperature for heating the FPC 200 is not particularly limited, but is preferably 100 ° C. or higher and 250 ° C. or lower, and more preferably 150 ° C. or higher and 200 ° C. or lower.

Further, in the heating press step, the pressure for pressurizing the FPC 200 is not particularly limited, but is preferably 1 MPa or more and 14 MPa or less, and more preferably 5 MPa or more and 14 MPa or less.

Further, the transport speed for transporting the laminated body is not particularly limited, but is preferably 40 mm / sec or more and 400 mm / sec or less, and more preferably 200 mm / sec or more and 350 mm / sec or less.

It should be noted that the heat-pressing process constitutes a process of heat-pressing the object (FPC200) on which the release film 10 is arranged in the method for producing a molded product of the present invention. When the coverlay 221 (insulating layer) is made of a material containing a thermosetting resin in a semi-cured state, it covers the surface of the object (FPC200) on the side where the release film 10 is arranged. Ray 221 constitutes. Since the release film 10 is superposed on the surface of the coverlay 221 so that the surface on the first release layer 1 side is in contact with the surface of the coverlay 221, the coverlay in which the recess 223 is formed by the release film 10 is used. The thermosetting resin can be cured while maintaining the shape of 221. As a result, the coverlay 221 (molded product) can be molded on the flexible circuit board 210 with excellent accuracy. Further, in the present embodiment, the means for heating by a heating press is shown, but the method is not necessarily limited to this method, and for example, heating may be performed by infrared rays or heating may be performed by a heating roll.

(Third step)
Next, in the mold release means 60, the mold release film 10 (10A, 10B) is released from the FPC 200. That is, the release film 10A and the release film 10B are peeled off from the bonded body of the coverlay film 220 and the flexible circuit board 210. As a result, an FPC 200 having a CL film 220 bonded to the flexible circuit board 210 is obtained (see FIGS. 1, 2 (c) and 3).

The mold release means 60 is not particularly limited, and may be configured to be peeled off by installing a vacuum device on the outside and drawing a vacuum, or the bonded body and the mold release films 10A and 10B. It may be configured to be peeled off by sending air between them, or it may be configured to be peeled off by sandwiching a rod between the bonded body and the release films 10A and 10B.

After that, the bonded body of the coverlay film 220 and the flexible circuit board 210, the glass cloth 300A, the release film 10A, the release film 10B, and the glass cloth 300B are wound by the respective take-up rollers.

By such winding, the flexible circuit board 210 and the CL film 220 are continuously obtained in a state where the FPC 200 bonded via the adhesive layer 222 included in the CL film 220 is wound by the winding roller. Will be done.

As described above, the flexible printed circuit board 200 is continuously manufactured by applying the manufacturing method of the flexible printed circuit board 200 by the roll-to-roll press machine 100 using the release film 10.

Then, as the release film 10 used in the roll-to-roll press machine 100, the release film of the present invention is used. That is, the release film 10 has a first release layer made of the first thermoplastic resin composition and a cushion layer, and the average thickness of the first release layer is 12 μm or more and 38 μm or less. , A release film characterized in that the storage elasticity E'at 180 ° C. of all layers of the release film is 30 MPa or more is used.

By forming the release film 10 in this manner, it is possible to obtain a release film in which both excellent embedding property and releasability are exhibited in a well-balanced manner.

Therefore, when the release film is used for forming the FPC200 using the flexible circuit board 210 and the CL film 220 as described above, it is adhered to the recess 223 formed in the FPC200 in the second step. It is possible to accurately suppress or prevent the adhesive derived from the agent layer 222 from seeping out.

Then, after the flexible circuit board 210 and the CL film 220 are bonded to each other via the adhesive layer 222 included in the CL film 220, the release film 10 is peeled off from the FPC 200 in the third step. At that time, it is possible to accurately suppress or prevent the FPC 200 from being broken or broken.

Hereinafter, the release film 10 to which the release film of the present invention is applied will be described. In the following, a case where the release film 10 is composed of a laminate in which the first release layer 1, the cushion layer 3, and the second release layer 2 are laminated in this order will be described.

<Release film 10>
FIG. 4 is a vertical sectional view showing an embodiment of the release film of the present invention, and FIG. 5 is a partially enlarged vertical sectional view of a part A of the release film shown in FIG. In the following description, for convenience of explanation, the upper side in FIGS. 4 and 5 is referred to as "upper" and the lower side is referred to as "lower".

As shown in FIG. 4, in the present embodiment, the release film 10 includes a first release layer 1, a cushion layer 3, and a second release layer 2 laminated in this order, and is provided in the FPC 200. It is used so as to be in contact with the surface of the first release layer 1 side with respect to the CL film 220.
Hereinafter, each layer constituting the release film 10 will be described.

<1st release layer 1>
First, the first release layer 1 will be described. The first release layer 1 is laminated on one surface side of the cushion layer 3.

The first release layer 1 has flexibility, and in the method for manufacturing a flexible printed circuit board 200 by the roll-to-roll press machine 100 using the release film 10 described above, the first release layer 1 has a flexibility with respect to the CL film 220 included in the FPC 200. Then, the release films 10 are superposed so that the first release layer 1 comes into contact with each other. Then, the first release layer 1 is a flexible circuit when the flexible circuit board 210 and the CL film 220 that are overlapped are bonded to each other via the adhesive layer 222 in the second step of this manufacturing method. It is a layer that is pushed in following the shape of the recess 223 formed by the substrate 210 and the CL film 220. As a result, the first release layer 1 functions as a protective (cushioning) material for preventing the release film 10 from breaking. Further, the first release layer 1 has a function as a contact layer for exerting the excellent release property of the release film 10 from the CL film 220 (FPC200) in the third step. ..

The first release layer 1 is composed of a first thermoplastic resin composition, and this first thermoplastic resin composition is a composition capable of setting the storage elastic modulus E'of the release film 10 at 180 ° C. to 30 MPa or more. If so, it is not particularly limited, but it is preferable to mainly contain a poly4-methyl1-pentene resin (polymethylpentene; TPX (registered trademark)). As a result, the storage elastic modulus E'can be set to 30 MPa or more relatively easily, and the above-mentioned function can be reliably imparted to the first release layer 1.

Therefore, when the release film 10 is used for forming the FPC200 using the flexible circuit board 210 and the CL film 220 as described above, in the recess 223 formed in the FPC200 in the second step, the release film 10 is formed. It is possible to accurately suppress or prevent the adhesive derived from the adhesive layer 222 from seeping out.

Then, after the flexible circuit board 210 and the CL film 220 are bonded to each other via the adhesive layer 222 included in the CL film 220, the release film 10 is peeled off from the FPC 200 in the third step. At that time, it is possible to accurately suppress or prevent the FPC 200 from being broken or broken.

Further, the poly 4-methyl-1-pentene resin preferably has a melt flow rate (MFR) of 5 g / 10 min or more and 250 g / 10 min or less measured at 260 ° C. and a 5.0 kg load, and 30 g / 10 min or more and 200 g / 10 min. It is more preferably 40 g / 10 min or more and 160 g / 10 min or less. Thereby, the effect obtained by using the poly 4-methyl 1-pentene resin can be more remarkablely exhibited.

The first thermoplastic resin composition may contain a resin material other than the poly4-methyl1-pentene resin, and the resin materials include, for example, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Such as polyester resin, polyethylene, polyolefin resin other than poly4-methyl1-pentene such as polypropylene, polystyrene resin such as syndiotactic polystyrene, etc., and one or more of these. Can be used in combination.

Further, the first thermoplastic resin composition may further contain at least one of inorganic particles and organic particles in addition to the poly4-methyl-1-pentene resin. Since the first thermoplastic resin composition contains the above-mentioned particles, particularly when an air knife-based film forming method is used, as shown in FIG. 5, the cushion layer 3 of the first release layer 1 is used. The first mold release layer 1 having a concavo-convex shape can be formed on the surface opposite to the above.

The inorganic particles are not particularly limited, and are, for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, aluminum nitride, aluminum borate whisk, and the like. Examples thereof include boron nitride, crystalline silica, amorphous silica, antimony oxide, E glass, D glass, S glass and the like, and one or more of these can be used in combination.

The organic particles are not particularly limited, and examples thereof include polystyrene particles, acrylic particles, polyimide particles, polyester particles, silicone particles, polypropylene particles, polyethylene particles, fluororesin particles, core-shell particles, and the like. One kind or a combination of two or more kinds can be used.

Further, the average particle diameter of the inorganic particles and the organic particles is preferably 3 μm or more and 20 μm or less, and more preferably 5 μm or more and 20 μm or less. As a result, the uneven shape can be surely formed on the surface of the first release layer 1 opposite to the cushion layer 3.

The first release layer 1 having this uneven shape on the surface preferably has a 10-point average roughness (Rz) of 3 μm or more and 20 μm or less, more preferably 5 μm or more and 17 μm or less, and 7 μm. It is more preferably 17 μm or less. As a result, the above-mentioned function can be more reliably imparted to the first release layer 1. Further, in the second step, when the first release layer 1 is pushed into the recess 223 formed in the FPC 200, the uneven shape is transferred to the surfaces of the flexible circuit board 210 and the CL film 220. Can be accurately suppressed or prevented. The 10-point average roughness (Rz) can be measured in accordance with JIS B 0601-1994.

The first release layer 1 having such a configuration preferably has a storage elastic modulus E'1 at 180 ° C. of 60 MPa or more, more preferably 65 MPa or more and 150 MPa or less, and 68 MPa or more and 150 MPa or less. It is more preferably 70 MPa or more and 100 MPa or less, and particularly preferably 100 MPa or less. As described above, by setting the storage elastic modulus E'1 of the first release layer 1 at 180 ° C. as described above, the storage elastic modulus E't of the release film 10 at 180 ° C. can be relatively easily set. It can be set to 30 MPa or more.

The storage elastic modulus E'1 of the first release layer 1 at 180 ° C. is based on JIS K7424-4, and the first release layer 1 having a width of 4 mm and a length of 20 mm is prepared and has dynamic viscoelasticity. It can be obtained by measuring with a pulling mode, a frequency of 1 Hz, and a heating rate of 5 ° C./min using a measuring device (“DMS6100” manufactured by SII Nanotechnology Co., Ltd.).

Further, in the present invention, the average thickness T1 of the first release layer 1 is set to 12 μm or more and 38 μm or less, preferably 14 μm or more and 36 μm or less, and more preferably 25 μm or more and 36 μm or less. As a result, the above-mentioned function can be more reliably imparted to the first release layer 1, and the storage elastic modulus E'at 180 ° C. of the release film 10 can be surely set to 30 MPa or more. ..

Further, when the average thickness of the first release layer 1 is T1 [μm] and the storage elastic modulus E'of the first release layer 1 at 180 ° C. is E'1 [MPa], E'1 / T1. [MPa / μm] preferably satisfies the relationship of 2.1 <E'1 / T1 <6.0, and more preferably satisfies the relationship of 2.2 <E'1 / T1 <5.0. It is preferable to satisfy the relationship of 2.2 <E'1 / T1 <2.9. Thereby, the effect obtained by setting the storage elastic modulus E'and the average thickness of the first release layer 1 as described above can be more remarkably exhibited.

As described above, the thickness of the first release layer 1 is such that when the surface of the first release layer 1 on the opposite side of the cushion layer 3 has an uneven shape, the convex portion includes the convex portion and the convex portion. In the recess, the thickness is measured at each position including the recess.

Further, in the first thermoplastic resin composition constituting the first release layer 1, in addition to the above-mentioned resin material, inorganic particles and organic particles, a crystal nucleating agent, an antioxidant, a slip agent, an antiblocking agent, etc. Additives such as antistatic agents, colorants and stabilizers may be included.

When the first thermoplastic resin composition contains a crystal nucleating agent, the crystallinity of polymethylpentene can be improved, and as a result, the storage elastic modulus E'is relatively easily set to 30 MPa or more. Can be set to.

Further, in this case, the content of the crystal nucleating agent in the first thermoplastic resin composition is preferably 0.1% by weight or more and 2.0% by weight or less, and 0.3% by weight or more and 0.8% by weight or less. % Or less is more preferable.

<Cushion layer 3>
Next, the cushion layer 3 will be described. The cushion layer 3 is arranged as an intermediate layer between the first release layer 1 and the second release layer 2.

The cushion layer 3 has excellent followability. As described above, in the method of manufacturing the flexible printed circuit board 200 by the roll-to-roll press machine 100 using the release film 10, the first release layer 1 comes into contact with the CL film 220 included in the FPC 200. The release film 10 is superposed on the top. Then, the cushion layer 3 is attached to the flexible circuit board 210 when the laminated flexible circuit board 210 and the CL film 220 are bonded to each other via the adhesive layer 222 in the second step of this manufacturing method. It is a layer that pushes the first release layer 1 so that the first release layer 1 follows the shape of the recess 223 formed by the CL film 220, and has a function as a cushion. Further, since the release film 10 includes the cushion layer 3, the CL film 220 can be pressed against the flexible circuit board 210 with a uniform pressure by the release film 10.

The cushion layer 3 is made of a third thermoplastic resin composition, and the third thermoplastic resin composition is not particularly limited as long as it can impart excellent followability to the cushion layer 3, but for example, poly 4 -It is preferable to contain a methyl 1-pentene resin (polymethylpentene; TPX (registered trademark)) and a polyolefin-based resin different from this poly4-methyl1-pentene resin. As a result, the cushion layer 3 can be provided with excellent followability, and the cushion layer 3 can be made to exhibit excellent adhesion to the first release layer 1 and the second release layer 2. ..

The content of the poly4-methyl-1-pentene resin in this third thermoplastic resin composition is preferably 20% by weight or more, and more preferably 20% by weight or more and 50% by weight or less. As a result, the effect obtained by the configuration containing the poly 4-methyl 1-pentene resin and the polyolefin-based resin can be more remarkably exhibited.

Further, the poly 4-methyl 1-pentene resin preferably has a melt flow rate (MFR) of 5 g / 10 min or more and 250 g / 10 min or less, and 15 g / 10 min or more and 200 g / 10 min or more, measured at 260 ° C. and a 5.0 kg load. It is more preferably 20 g / 10 min or more, and further preferably 150 g / 10 min or less. As a result, in the second step, the push-in layer that pushes the first release layer 1 so that the first release layer 1 follows the shape of the recess 223 formed by the flexible circuit board 210 and the CL film 220. Can be more reliably imparted to the cushion layer 3.

Further, the polyolefin-based resin other than the poly4-methyl1-pentene resin contained in the third thermoplastic resin composition is not particularly limited, and for example, an α-olefin polymer such as polyethylene and polypropylene, ethylene, and the like. Examples thereof include α-olefin-based copolymers having propylene, butene, penten, hexene, methylpentene and the like as polymer components, and one or a combination of two or more of these can be used.

Further, the cushion layer 3 is preferably set to have an average thickness Tk of 40 μm or more and 110 μm or less, more preferably 50 μm or more and 100 μm or less, and further preferably 60 μm or more and 85 μm or less. As a result, the above-mentioned function can be more reliably imparted to the cushion layer 3, and the storage elastic modulus E'at 180 ° C. of the release film 10 can be surely set to 30 MPa or more.

In addition to the resin material described above, the third thermoplastic resin composition constituting the cushion layer 3 may contain the same additives as those mentioned in the first thermoplastic resin composition. ..

<Second mold release layer 2>
Next, the second release layer 2 will be described. The second release layer 2 is laminated on the other surface side of the cushion layer 3, that is, on the surface side of the cushion layer 3 opposite to the first release layer 1.

The second release layer 2 has flexibility. As described above, in the method of manufacturing the flexible printed circuit board 200 by the roll-to-roll press machine 100 using the release film 10, the first release layer 1 comes into contact with the CL film 220 included in the FPC 200. The release film 10 is superposed on the top. Then, the second release layer 2 is heat-bonded when the flexible circuit board 210 and the CL film 220, which are overlapped with each other, are bonded to each other via the adhesive layer 222 in the second step of this manufacturing method. It functions as a layer that transmits the force from the plate 521 to the cushion layer 3. Further, the second release layer 2 has a function as a contact layer for exerting excellent mold release property between the glass cloths 300A and 300B and the release film 10 in the third step. There is.

The second release layer 2 is composed of a second thermoplastic resin composition, and the second thermoplastic resin composition is a composition capable of setting the storage elasticity E'of the release film 10 at 180 ° C. to 30 MPa or more. If this is the case, it is not particularly limited, but it is preferable to mainly contain a poly4-methyl1-pentene resin (polymethylpentene; TPX (registered trademark)) as in the first thermoplastic resin composition. As a result, the storage elastic modulus E'can be set to 30 MPa or more relatively easily, and the above-mentioned function can be reliably imparted to the second release layer 2.

Further, the poly 4-methyl-1-pentene resin preferably has a melt flow rate (MFR) of 5 g / 10 min or more and 250 g / 10 min or less measured at 260 ° C. and a 5.0 kg load, and 30 g / 10 min or more and 200 g / 10 min. It is more preferably 40 g / 10 min or more and 160 g / 10 min or less. Thereby, the effect obtained by using the poly 4-methyl 1-pentene resin can be more remarkablely exhibited.

The second thermoplastic resin composition may contain a resin material other than the poly4-methyl1-pentene resin, and the resin material is mentioned in the first thermoplastic resin composition. Similar ones can be used.

Further, the second thermoplastic resin composition may further contain at least one of inorganic particles and organic particles in addition to the poly4-methyl1-pentene resin. Since the second thermoplastic resin composition contains the above-mentioned particles, particularly when an air knife-based film forming method is used, as shown in FIG. 5, the cushion layer 3 of the second release layer 2 is used. The second mold release layer 2 having an uneven shape can be formed on the surface opposite to the above.

The inorganic particles and the organic particles are not particularly limited, but the same particles as those mentioned in the first thermoplastic resin composition can be used.

Further, the average particle diameter of the inorganic particles and the organic particles is preferably 3 μm or more and 20 μm or less, and more preferably 5 μm or more and 20 μm or less. As a result, the uneven shape can be reliably formed on the surface of the second release layer 2 opposite to the cushion layer 3.

The second release layer 2 having this uneven shape on the surface preferably has a 10-point average roughness (Rz) of 3 μm or more and 20 μm or less, more preferably 5 μm or more and 17 μm or less, and 7 μm. It is more preferably 17 μm or less. As a result, the above-mentioned function can be more reliably imparted to the second release layer 2. The 10-point average roughness (Rz) can be measured in accordance with JIS B 0601-1994.

The second release layer 2 having such a configuration preferably has a storage elastic modulus E'2 at 180 ° C. of 60 MPa or more, more preferably 65 MPa or more and 150 MPa or less, and 68 MPa or more and 150 MPa or less. It is more preferably 70 MPa or more and 100 MPa or less, and particularly preferably 100 MPa or less. As described above, by setting the storage elastic modulus E'of the second release layer 2 at 180 ° C. as described above, the storage elastic modulus E'at 180 ° C. of the release film 10 can be relatively easily set to 30 MPa or more. Can be set to.

Further, the average thickness T2 of the second release layer 2 is preferably 12 μm or more and 38 μm or less, more preferably 14 μm or more and 36 μm or less, and further preferably 25 μm or more and 36 μm or less. Thereby, the above-mentioned function can be more reliably imparted to the second release layer 2, and the storage elastic modulus E'at 180 ° C. of the release film 10 can be surely set to 30 MPa or more. ..

In addition to the resin material, inorganic particles, and organic particles described above, the second thermoplastic resin composition constituting the second release layer 2 is the same as that mentioned in the first thermoplastic resin composition. Additives may be included.

Further, 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 they are substitutable. From the viewpoint of having the same or the same quality, it is preferable. Further, the average thickness of the first release layer 1 and the second release layer 2 may be the same or different.

Here, in the present invention, the average thickness T1 of the first release layer 1 included in the release film 10 is set to 12 μm or more and 38 μm or less, and the storage elastic modulus E't of the release film 10 at 180 ° C. is set. It is set to 30 MPa or more.

When the release film 10 is used for forming the FPC200 using the flexible circuit substrate 210 and the CL film 220 as described above, it is pushed into the recess 223 formed in the FPC200 in the second step. By setting the average thickness of the first release layer 1 to be within the above range, and further setting the storage elastic modulus E'at 180 ° C. of the entire release film 10 at 180 ° C. to the lower limit value or more, it is excellent. It is possible to obtain a mold release film 10 in which both embedding property and mold release property are exhibited in a well-balanced manner.

Therefore, when the release film 10 is used for forming the FPC200 using the flexible circuit board 210 and the CL film 220 as described above, in the recess 223 formed in the FPC200 in the second step, the release film 10 is formed. It is possible to accurately suppress or prevent the adhesive derived from the adhesive layer 222 from seeping out.

Specifically, the coverlay film 220 (“CMA0525” manufactured by Arisawa Seisakusho Co., Ltd.) is provided on a flexible circuit board 210 having irregularities (circuits) having a pitch of 50 μm, a width of 50 μm, and a height of 18 μm. A release film 10 having a width of 270 mm was applied to a laminate formed by attaching the adhesive layer 222 to the flexible circuit board 210 side at 180 ° C., 11 MPa, 120 sec using a roll-to-roll press machine 100. The maximum amount of adhesive oozing out in a plan view in the recesses of the laminate when the release film 10 is pushed in under the above conditions and then peeled off by holding one end of the release film 10 is preferably 100 μm or less, more preferably 85 μm or less. Can be set to.

Then, after the flexible circuit board 210 and the CL film 220 are bonded to each other via the adhesive layer 222 included in the CL film 220, the release film 10 is peeled off from the FPC 200 in the third step. At that time, it is possible to accurately suppress or prevent the FPC 200 from being broken or broken.

Specifically, a roll-to-roll press machine is applied to a release film 10 having a width of 270 mm on a flexible circuit board 210 having unevenness (circuit) having a pitch of 50 μm, a width of 50 μm, and a height of 18 μm under the conditions of 180 ° C., 11 MPa, and 120 sec. When the flexible circuit board 210 and the release film 10 are peeled off while being pressure-bonded at 100 and conveyed immediately after the pressurization, the limit peeling speed at which no wrinkles are observed on the release film 10 is set. It can be preferably set to 100 mm / sec or more, more preferably 150 mm / sec or more, still more preferably 190 mm / sec or more, and particularly preferably 250 mm / sec or more.

As described above, when the maximum exudation amount is set to be equal to or lower than the upper limit value and the limit peeling speed is set to be equal to or higher than the lower limit value, the release film 10 has excellent embedding property and mold release property. It can be said that it is a release film that has a good balance between sex and sex.

Further, the storage elastic modulus E't of the release film 10 at 180 ° C. may be 30 MPa or more, but preferably 30 MPa or more and 150 MPa or less. As a result, it is possible to obtain a mold release film 10 in which both excellent embedding property and excellent mold release property are exhibited in a more balanced manner.

The storage elastic modulus E't of the release film 10 at 180 ° C. is based on JIS K7424-4, and a release film 10 having a width of 4 mm and a length of 20 mm is prepared, and a dynamic viscoelasticity measuring device (SI) is prepared. It can be obtained by measuring with a tension mode, a frequency of 1 Hz, and a heating rate of 5 ° C./min using "DMS6100" manufactured by i-Nanotechnology.

Further, the average thickness Tt of the release film 10 is preferably 80 μm or more and 180 μm or less, and more preferably 90 μm or more and 160 μm or less. Further, T1 / Tk, which is a relational expression between the average thickness Tk of the cushion layer 3 and the average thickness T1 of the first release layer 1, is preferably 0.5 or less, and is 0.3 or more and 0.4. The following is more preferable. By satisfying these thickness relationships, it is possible to obtain a mold release film 10 in which both excellent embedding property and excellent mold release property are exhibited in a more balanced manner.

In the present embodiment, the release film 10 is composed of a laminate in which the first release layer 1, the cushion layer 3, and the second release layer 2 are laminated in this order. The configuration is not limited, for example, such as an adhesive layer arranged between the first release layer 1 and the cushion layer 3 and at least one between the second release layer 2 and the cushion layer 3. It may be composed of a laminated body provided with an intermediate layer.

Further, the release film 10 comes into contact with the glass cloths 300A and 300B in the third step if the excellent mold release property can be maintained between the glass cloths 300A and 300B and the release film 10. The second release layer 2 may be omitted.

Although the method for producing the release film and the molded product of the present invention has been described above, the present invention is not limited thereto.

For example, in the above embodiment, when the release film of the present invention is used as a release film for a roll-to-roll press applied to the manufacture of a flexible printed circuit board by a roll-to-roll press machine, that is, it has a penetrating recess. Although the case where the coverlay (functional layer) is joined to the flexible circuit board (board) via the adhesive layer by a roll-to-roll method is described, the present invention is not limited thereto. Specifically, even when a functional layer having a penetrating recess is joined to a substrate via an adhesive layer by using a press molding method, a vacuum pressure pneumatic molding method, or the like, which is different from the roll-to-roll method. , The release film of the present invention can be used.

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited thereto.

1. 1. Preparation of raw materials The following materials were prepared as raw materials for producing the release film.

Thermoplastic resin material Poly4-methyl-1-pentene resin I (4-methyl-1-pentene / hexadecene / octadecene copolymer, MFR = 100 g / 10 min)
Poly 4-methyl-1-pentene resin II (4-methyl-1-pentene-decene-1 copolymer, MFR = 180 g / 10 min)
Poly 4-methyl-1-pentene resin III (4-methyl-1-pentene-decene-1 copolymer, MFR = 9 g / 10 min,)
Poly 4-methyl-1-pentene resin IV (4-methyl-1-pentene-decene-1 copolymer, MFR = 21 g / 10 min)
Low density polyethylene (LDPE, manufactured by Ube Maruzen Polyethylene, "R500")
Polypropylene (PP, manufactured by Sumitomo Chemical Co., Ltd., "FH1016")
Ethylene-methyl methacrylate copolymer (EMMA, manufactured by Sumitomo Chemical Co., Ltd., "WD106")
Ethylene-methyl acrylate copolymer (EMA, manufactured by Mitsui Dow Polychemical Co., Ltd., "Elvalois AC 1125")

-Particle material Amorphous silica (Si, manufactured by Nittetsu Chemical & Materials Co., Ltd., φ12 μm, “SC10-32F”)
Acrylic beads (manufactured by Soken Kagaku Co., Ltd., φ10 μm, “MZ-10HN”)

・ Crystal nucleating agent Gelol DXR (manufactured by NEW JAPAN CHEMICAL CO., LTD.)

2. 2. Production of Release Film <Example 1>
First, poly 4-methyl-1-pentene resin I was prepared as the first thermoplastic resin composition and the second thermoplastic resin composition, respectively. Further, as the third thermoplastic resin composition, a composition composed of 50 parts by weight of low-density polyethylene (R500), 30 parts by weight of polypropylene (FH1016), and 20 parts by weight of poly 4-methyl-1-pentene resin I. I prepared it.

Next, using the first thermoplastic resin composition, the third thermoplastic resin composition, and the second thermoplastic resin composition, they are laminated in a T-die to form one molten resin laminate, and then cooled and solidified. The release film 10 of Example 1 was obtained by forming a laminated body in which the cushion layer 3 and the second release layer 2 were laminated in this order on the first release layer 1. At the time of cooling, the molten resin was sandwiched between a metal roll having an embossed shape at 100 ° C. and a rubber roll having an embossed shape at 30 ° C., and the unevenness was transferred while cooling.

In the obtained release film 10, the average thickness T1 of the first release layer 1 is 25 μm, the average thickness Tk of the cushion layer 3 is 70 μm, and the average thickness T2 of the second release layer 2 is 25 μm. there were.

Further, for the release film 10 and the first release layer 1, the storage elastic modulus E't and the storage elastic modulus E'1 at 180 ° C. are measured by a dynamic viscoelasticity measuring device (manufactured by SII Nanotechnology), respectively. When measured using "DMS6100"), it was 34 MPa and 72 MPa.

Further, for the first release layer 1 and the second release layer 2, the 10-point average roughness (Rz) on the surface exposed on the opposite side of the cushion layer 3 is measured by a surface roughness measuring device (manufactured by Mitutoyo Co., Ltd.). When measured using "Surftest SJ-210"), it was 15.8 μm and 10.3 μm.

<Examples 2 to 10, Comparative Examples 1 to 4>
The materials shown in Table 1 were used as the first thermoplastic resin composition, the second thermoplastic resin composition, and the third thermoplastic resin composition, and the surface 10-point average roughness (Rz) and average thickness were shown in Table 1. Examples 2 to 10 and Comparative Example 1 are the same as in Example 1 except that the first release layer 1, the cushion layer 3 and the second release layer 2 are formed as shown. A release film 10 of ~ 4 was obtained. In Examples 3, 4, and 9 in which particles are contained in the first release layer and the second release layer, when the molten resin laminate is cooled, a metal roll having an embossed shape at 100 ° C. is subjected to wind pressure of an air knife. , The molten resin was pressed to expose the filler and cooled so that unevenness was formed.

3. 3. Evaluation The following evaluations were performed on the release films 10 of each example and each comparative example using the roll-to-roll press machine 100.

3-1. Release property of release film The release film 10 of each Example and each Comparative Example was formed to have a width of 270 mm. Then, the release film 10 is pressure-bonded to a flexible circuit board 210 having irregularities having a pitch of 50 μm, a width of 50 μm, and a height of 18 μm by a roll-to-roll press machine 100 at 180 ° C., 11 MPa, and 120 sec. When the flexible circuit board 210 and the release film 10 are peeled off with the release rod provided in the mold release means 60 while being conveyed immediately after pressurization, the release film 10 is peeled off to the limit where no wrinkles are observed. The speed was measured.

3-2. Embedding property of release film Each of the release films 10 of each Example and each Comparative Example was formed to have a width of 270 mm. Then, the coverlay film 220 (manufactured by Arisawa Seisakusho Co., Ltd., "CMA0525") is attached to the flexible circuit board 210 with the adhesive layer 222 included in the coverlay film 220 on the flexible circuit board 210 side. This release film 10 is pushed into a laminate having irregularities having a pitch of 50 μm, a width of 50 μm, and a height of 18 μm under the conditions of 180 ° C., 11 MPa, and 120 s using a roll-to-roll press machine 100, and then When one end of the release film 10 was held and peeled off, the maximum amount of the adhesive exuded in the concave portion of the laminated body in a plan view was measured.

3-3. Summary 3-1. Releasability of the release film and the above 3-2. Table 1 shows the evaluation results obtained in the embedding property of the release film.

[Replenishment under Rule 26 25.08.2021]

As shown in Table 1, in each example, the average thickness of the first release layer 1 is 12 μm or more and 38 μm or less, and the storage elastic modulus E't of the release film 10 at 180 ° C. is 30 MPa or more. I was satisfied with both things. As a result, the limit peeling speed is 100 mm / sec or more, and the maximum exudation amount of the adhesive is 100 μm or less, and both excellent embedding property and excellent mold releasability are exhibited in a well-balanced manner. The result is shown.

On the other hand, in each comparative example, the average thickness of the first release layer 1 is 12 μm or more and 38 μm or less, and the storage elastic modulus E't of the release film 10 at 180 ° C. is 30 MPa or more. I was not satisfied with either of them. As a result, either the limit peeling speed of 100 mm / sec or more and the maximum exudation amount of the adhesive of 100 μm or less cannot be satisfied, resulting in excellent embedding property. The results show that it cannot be said that both excellent releasability and compatibility are exhibited in a well-balanced manner.

According to the present invention, it is possible to obtain a releasable film in which both excellent embedding property and excellent releasability are exhibited in a well-balanced manner. Therefore, when the release film is used for forming a flexible printed circuit board using, for example, a flexible circuit board and a coverlay film, the adhesive seeps out in the recesses formed in the flexible printed circuit board. Can be accurately suppressed or prevented. Then, when the release film is peeled off from the flexible printed circuit board after the formation of the flexible printed circuit board, it is possible to accurately suppress or prevent breakage wrinkles and breakage in the flexible printed circuit board. Therefore, the present invention has industrial applicability.

Claims (13)

A release film having a first release layer made of a first thermoplastic resin composition and a cushion layer.
The first release layer has an average thickness of 12 μm or more and 38 μm or less.
The release film is a release film having a storage elastic modulus E'at 180 ° C. of 30 MPa or more. The release film according to claim 1, wherein the release film has an average thickness of 80 μm or more and 180 μm or less. The release film according to claim 1 or 2, wherein the cushion layer has an average thickness of 40 μm or more and 110 μm or less. The release film according to any one of claims 1 to 3, wherein the first release layer has a 10-point average roughness (Rz) of 3 μm or more and 20 μm or less on the surface opposite to the cushion layer. The release film according to any one of claims 1 to 4, wherein the first release layer has a storage elastic modulus E'at 180 ° C. of 60 MPa or more. When the average thickness of the first release layer is T1 [μm] and the storage elastic modulus E'of the first release layer at 180 ° C. is E'1 [MPa], E'1 / T1 [MPa]. / Μm] is the release film according to any one of claims 1 to 5, which satisfies the relationship of 2.1 <E'1 / T1 <6.0. The release film according to any one of claims 1 to 6, wherein the first thermoplastic resin composition contains a poly 4-methyl 1-pentene resin. One of claims 1 to 7, wherein the cushion layer comprises a third thermoplastic resin composition containing a poly 4-methyl 1-pentene resin and a polyolefin-based resin different from the poly 4-methyl 1-pentene resin. The release film according to item 1. The release film has any one of claims 1 to 8 having a second release layer made of a second thermoplastic resin composition laminated on the opposite side of the cushion layer to the first release layer. The release film described in. The release film having a width of 270 mm is pressure-bonded to a flexible circuit board having irregularities having a pitch of 50 μm, a width of 50 μm, and a height of 18 μm by a roll-to-roll press machine at 180 ° C., 11 MPa, and 120 sec. Claims 1 to 9 in which when the flexible circuit board and the release film are peeled off while being conveyed immediately after compression, the limit peeling speed at which no wrinkles are observed on the release film is 100 mm / sec or more. The release film according to any one of the above items. A coverlay film (manufactured by Arisawa Seisakusho Co., Ltd., "CMA0525") is placed on a flexible circuit board having irregularities with a pitch of 50 μm, a width of 50 μm, and a height of 18 μm, and the adhesive layer contained in the coverlay film is set to the flexible circuit board side. The release film having a width of 270 mm is pushed into the laminate formed by sticking under the conditions of 180 ° C., 11 MPa, and 120 sec, and then one end of the release film is held and peeled off. The release film according to any one of claims 1 to 10, wherein the maximum amount of the adhesive oozing out in a concave portion of the body in a plan view is 100 μm or less. The release film is applied to the surface of an object formed of a material containing a semi-cured thermosetting resin.
The release film according to any one of claims 1 to 11, which is used in layers so that the surfaces on the first release layer side are in contact with each other. The first release layer of the release film according to any one of claims 1 to 12 is on the object side.
In the step of arranging the release film, which includes a step of arranging the release film on the object and a step of performing a heat press on the object on which the release film is arranged. A method for producing a molded product, wherein the surface of the object on which the release film is arranged is formed of a material containing a heat-curable resin in a semi-cured state.

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