TW201806741A - Release film and method for manufacturing molded article - Google Patents

Abstract

A release film (10) having a laminated structure in which a first release layer (1) formed from a first thermoplastic resin material, a cushioning layer (2), and a second release layer (3) formed from a second thermoplastic resin material are laminated in that order in the thickness direction, wherein the thickness of the cushioning layer (2) is at least 10 [mu]m but not more than 200 [mu]m, if the total thickness of the release film (10) is deemed X and the thickness of the cushioning layer (2) is deemed Y, then Y/X is greater than 0.2 but less than 0.9, the first thermoplastic resin material and the second thermoplastic resin material each contain a thermoplastic resin and particles having an average particle size d50 of at least 4 [mu]m but not more than 60 [mu]m, the amount of particles relative to the total weight of the first release layer (1) is at least 0.5% by weight but not more than 15% by weight, and the amount of particles relative to the total weight of the second release layer (3) is at least 0.5% by weight but not more than 15% by weight.

Description

Method for producing release film and molded article

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

Generally, when manufacturing a molded article or a laminated body formed by bonding different materials, a release film is often used for the purpose of protecting the surface of such a molded article or a laminated body. For example, a cover film (hereinafter, also referred to as a "CL film") is adhered to a flexible film with an exposed circuit (hereinafter, also referred to as a "circuit exposed film") through an adhesive by hot pressing. When manufacturing a flexible printed circuit board (hereinafter, also referred to as "FPC"), a release film is used for the purpose of protecting a circuit or the like by being disposed on the CL film. It has been required to improve two characteristics described below for release films.

The characteristic of the release film requested | required first is the easy peeling property of this release film after manufacture of a molded article or a laminated body, ie, release property. The characteristic of the release film required next is the adhesion, that is, the followability, of the release film to the surface of the molded article or the laminate. Various studies have been conducted to improve characteristics such as mold release or followability in such a release film.

As a technique focusing on improving the mold release property of a release film and a technique focusing on improving the followability, there are the following, for example.

Patent Document 1 discloses a release film having a polyester layer formed on the surface with unevenness that satisfies specific conditions.

Furthermore, in the conventional manufacturing process of a flexible printed circuit board, the above-mentioned hot-pressing treatment is usually performed on a stamped object obtained by sequentially stacking a buffer material such as paper or silicone rubber, a release film, a CL film, and a circuit exposed film. (Patent Document 2 and the like). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2009-90665 [Patent Document 2] Japanese Patent Application Publication No. 2012-179827

However, in recent years, the technical level required for various characteristics of the release film has been increasing. In particular, from the viewpoint of the releasability of the release film, further improvements are required for the release films described in Patent Documents 1, 2, and the like. In addition, the present inventors have found that, when a molded article is produced using a conventional release film, the obtained molded article may sometimes cause problems such as the appearance of a finished product, such as adhesive bleeding.

The present invention provides a release film which is useful for producing a molded article with a good appearance of a finished product, and has excellent mold release properties, and a method for producing a molded article using the release film.

According to the present invention, there is provided a release film having a laminated structure. The laminated structure includes a first release layer including a first thermoplastic resin material, a buffer layer, and a second release layer including a second thermoplastic resin material in order along the thickness. The first release layer is disposed on one side of the release film, the second release layer is disposed on the other side of the release film, and the thickness of the buffer layer is 10 μm or more and 200 μm or less. The total thickness of the release film is set to X μm. When the thickness of the buffer layer is set to Y μm, Y / X is greater than 0.2 and less than 0.9. The first thermoplastic resin material and the second thermoplastic resin material both include a thermoplastic resin and an average. For particles having a particle diameter d50 of 4 μm or more and 60 μm or less, the content of the particles is 0.5% by weight or more and 15% by weight or less with respect to the total amount of the first release layer, and the content of the particles is relative to the total amount of the second release layer. The amount is 0.5% by weight or more and 15% by weight or less.

Furthermore, according to the present invention, there is provided a release film having a first release layer formed of a first thermoplastic resin material on at least one side, wherein the first thermoplastic resin material includes a thermoplastic resin and particles, and an average particle diameter of the particles. d50 is 20 μm or more and 60 μm or less, and the content of the spherical particles is 0.5% by weight or more and 15% by weight or less based on the total amount of the release layer.

In addition, according to the present invention, there is provided a method for manufacturing a molded article, comprising: a process of disposing the release film on the object such that the first release layer of the release film becomes a target side; and A process of hot-pressing the object on which the release film is disposed. In the process of disposing the release film, a surface of the object on which the release film is disposed is formed of a material containing a thermosetting resin. [Inventive effect]

According to the present invention, it is possible to provide a release film which is useful for producing a molded article with a good appearance of a finished product and has excellent mold releasability, and a method for producing a molded article using the release film.

Hereinafter, embodiments of the present invention will be described using drawings. In all drawings, the same constituent elements are denoted by the same reference numerals, and descriptions thereof are appropriately omitted.

[First Embodiment] <Release Film> FIG. 1 is a cross-sectional view of a release film according to this embodiment. As shown in FIG. 1, the release film 10 in this embodiment has a first release layer 1 including a first thermoplastic resin material, a buffer layer 2, and a second release layer 3 including a second thermoplastic resin material. Laminated structure made by stacking in the thickness direction. The first release layer 1 is disposed on one surface of the release film 10, and the second release layer 3 is disposed on the other surface of the release film 10. In the release film 10, the thickness of the buffer layer 2 is 10 μm or more and 200 μm or less. When the total thickness of the release film 10 is X μm and the thickness of the buffer layer 2 is Y μm, Y / X is greater than 0.2 and less than 0.9. In addition, in the release film 10, both the first thermoplastic resin material and the second thermoplastic resin material include a thermoplastic resin and particles having an average particle diameter d50 of 4 μm or more and 60 μm or less. In the release film 10, the content of particles is 0.5% by weight or more and 15% by weight or less with respect to the total amount of the first release layer 1, and the content of particles is 0.5% by weight or more of the total amount of the second release layer 3. 15% by weight or less.

Hereinafter, regarding the release film 10, when the release film 10 is disposed on a molding object having a circuit or the like, a resin layer forming a surface on one side in contact with the molding object is referred to as a first release layer 1, The resin layer that forms the surface opposite to the surface that is in contact with the object to be molded will be described as the second release layer 3. In addition, when the release film 10 is arrange | positioned on an object hereafter, the surface in the 1st mold release layer 1 side which contacts the object is also shown as a "1st mold release surface."

In addition, the surface of the molding object at a stage before the release film 10 is disposed is usually formed of a material containing a thermosetting resin in a semi-cured state. The release film 10 of this embodiment is used by being disposed on the surface of a molding object formed of a material containing a thermosetting resin in the above-mentioned semi-cured state, and the release film 10 can be disposed on the surface of the molding object. In this state, a desired molded article is obtained by hot pressing.

On the other hand, the second release layer 3 in the release film 10 is a resin layer on the surface that comes into contact with a cushioning material such as paper or silicone rubber when the release film 10 is hot-pressed by the method described above. The second release layer 3 side of the release film 10, that is, the surface opposite to the first release surface is also referred to as a "second release surface" hereinafter.

The release film 10 is a structure which satisfies the following three conditions simultaneously. The first condition is that the first release layer 1 and the second release layer 3 are formed of a thermoplastic resin material containing a thermoplastic resin and particles having an average particle diameter d50 of 4 μm to 60 μm. The second condition is that the content of the particles is 0.5% by weight or more and 15% by weight or less with respect to the total amount of the first release layer 1, and the content of the particles is 0.5% by weight relative to the total amount of the second release layer 3. Above 15% by weight. The third condition is that before the thickness of the buffer layer 2 is set to be 10 μm or more and 200 μm or less, the balance between the thickness of the buffer layer 2 and the total thickness of the release film 10 is controlled. Therefore, the following effects are obtained in accordance with the release film 10.

First, according to the release film 10, it is possible to express a better releasability than a conventional release film. Further, the release film 10 is, as will be described later in the examples, one having excellent releasability from both sides to the object.

Second, according to the release film 10, a molded article having a good appearance of the finished product is obtained. Further, as described later in the examples, the shape of the exuded adhesive has a difference in unevenness of less than 100 μm, and a molded article produced using the release film 10 has a good finished appearance.

Third, according to the release film 10, when a molded product is produced, even when pressure is applied to the first release surface of the first release layer 1, the occurrence of wrinkles on the surface of the molded product can be suppressed. Specifically, the release film 10 is a first release layer 1 and a second release layer 3 each having a predetermined amount of particles having an average particle diameter d50 of 4 μm or more and 60 μm or less, and is therefore provided in the first A component in which fine unevenness is formed on both the release surface and the second release surface. Therefore, according to the release film 10, due to the influence of the fine unevenness formed on both sides of the release film 10, it is possible to effectively suppress the occurrence of pressure unevenness during hot pressing, and as a result, it is possible to produce a molded product with a good appearance. .

Hereinafter, the structure of the release film 10 of this embodiment is demonstrated.

In the release film 10, the average particle diameter d50 of the particles contained in the first thermoplastic resin material forming the first release layer 1 is 4 μm or more and 60 μm or less, but it is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more. 30 μm or less. In the release film 10, when the average particle diameter d50 of the particles contained in the first thermoplastic resin material forming the first release layer 1 is controlled to be the above lower limit value or more, the rigidity of the release film can be increased. In addition, it is possible to achieve a good balance between mold release and followability. On the other hand, in the present embodiment, when the average particle diameter d50 of the particles contained in the first thermoplastic resin material is equal to or less than the above-mentioned upper limit value, it is possible to provide appropriate unevenness to the first release surface and to produce a finished product appearance. Good molded product.

In the release film 10, the average particle diameter d50 of the particles contained in the second thermoplastic resin material forming the second release layer 3 is 4 μm or more and 60 μm or less. From the viewpoint of further improving the releasability of the second release layer 3, the average particle diameter d50 of the particles is preferably 20 μm or more and 60 μm or less, and more preferably 25 μm or more and 55 μm or less. This makes it possible to impart unevenness of a desired size to the second release surface. In particular, when the average particle diameter d50 of the particles contained in the second thermoplastic resin material is controlled to fall within the above-mentioned numerical range, it is possible to reduce the impact on the cushioning material such as paper or silicone rubber when the hot-pressing is performed using the release film 10 in the above-mentioned method. The contact area can form unevenness on the second release surface of the second release layer 3 having a size that can improve the release property of the cushioning material.

In the release film 10 according to this embodiment, the content of particles is 0.5% by weight or more and 15% by weight or less based on the total amount of the first release layer 1. Regarding the first release layer 1 in the release film 10, the content of particles is preferably 0.5% by weight or more and 10% by weight from the viewpoint of improving the balance between mold release and followability. % Or less, more preferably 2% by weight or more and 10% by weight or less. This also makes it possible to suppress the occurrence of voids in a molded article produced using the release film 10.

In the release film 10 according to this embodiment, the content of particles is 0.5% by weight or more and 15% by weight or less based on the total amount of the second release layer 3. From the viewpoint of improving the releasability of the second release surface, the content of the particles is preferably 5% to 15% by weight, and more preferably 8% to 13% by weight relative to the total amount of the second release layer 3. %the following.

In addition, in the release film 10 of this embodiment, the surface 10-point average roughness Rz of the first release surface of the first release layer 1 is set to A, and the second release of the second release layer 3 is released. When the 10-point average roughness Rz of the surface is set to B, the absolute value of AB is preferably 20 or less, more preferably 1 or more and 18 or less, and even more preferably 1.5 or more and 16 or less. This makes it possible to produce a molded article having a good appearance with a high productivity.

In addition, the value of A may be the same as or different from the value of B, but from the viewpoint of improving the mold release property and producing a molded article with a good appearance, the value of B, that is, the second of the second release layer 3 The value of the 10-point average roughness Rz of the surface of the mold release surface is preferably larger than the value of A, that is, the value of the surface 10-point average roughness Rz of the first mold release surface of the first release layer 1 is larger. . For this reason, the following aspects can be cited: when producing a molded product, the shape of the surface of the cushioning material that is in contact with the second release surface of the second release layer 3 and the first release surface of the first release layer 1 When the shape of the surface of the object is compared, one of the surfaces of the cushioning material has a shape with less unevenness.

From the viewpoint of ensuring the strength of the first release layer 1 and improving the balance between the release property and the followability, the 10-point average roughness Rz of the surface of the first release surface of the first release layer 1 is 0.5. More preferably, it is more than 25 μm, more preferably 1 μm or more and 20 μm or less, and more preferably 1.6 μm or more and 18 μm or less. The 10-point average roughness Rz of the surface of the first release surface can be measured in accordance with JIS-B0601-1994.

From the viewpoint of ensuring the strength of the second release layer 3 and improving the mold release property, the surface 10-point average roughness Rz of the second release surface of the second release layer 3 is preferably 0.5 μm or more and 25 μm or less. Hereinafter, it is more preferably 5 μm or more and 23 μm or less, and still more preferably 11.5 μm or more and 22 μm or less. The 10-point average roughness Rz of the surface of the second release surface can be measured in accordance with JIS-B0601-1994.

In addition, in the release film 10 of this embodiment, the lower the peel strength of the first release surface of the first release layer 1 is, the better the value is, but it is preferably 5 N / 50 mm or less, and more preferably 3N / 50mm or less, more preferably 1N / 50mm or less. Thereby, the mold release property with respect to a molding object can be improved.

The peel strength of the first release surface can be measured, for example, by the following method. First, for a circuit-exposed film in which a coverlay film is temporarily fixed through an adhesive, the first release surface of the first release layer 1 in the release film 10 and the surface on which the coverlay film is disposed in the circuit-exposed film are made. The release film 10 was opposed to each other, and the circuit-exposed film was bonded to each other, and a heat-pressing treatment was performed at 180 ° C. and 6 MPa for 2 minutes to prepare a test piece. At this time, by not crimping the end portion of the test piece, the end portion of the release film 10 can be pinched as a free end. Then, using a tensile tester, stress was applied to the test piece from the end portion of the release film 10 in a 180 ° direction at a speed of about 1000 mm / minute, and the first release surface and the cover film of the circuit exposed film were subjected to Peeling was performed to measure the peel strength of the first release surface. In addition, it is preferable to perform a peeling test immediately after performing a hot pressing process.

In addition, in the release film 10 of this embodiment, the lower the peel strength of the second release surface of the second release layer 3 is, the better the value is, but it is preferably 3N / 50mm or less, and more preferably 1N / 50mm or less. Thereby, the mold release property with respect to a cushioning material can be improved.

The peel strength of the second release surface can be measured, for example, by the following method. First, the release film 10 and the silicone rubber sheet are bonded so that the second release surface of the second release layer 3 in the release film 10 faces the silicone rubber sheet, and the conditions are 180 ° C and 6 MPa. A test piece was produced by performing a hot pressing process for 2 minutes. At this time, by not crimping the end portion of the test piece, the end portion of the release film 10 can be pinched as a free end. Then, using a tensile tester, stress was applied to the test piece from the end portion of the release film 10 in a 180 ° direction at a speed of about 1000 mm / minute, and the second release surface and the silicone rubber sheet were peeled off, whereby the The peeling strength of the second release surface was measured. In addition, it is preferable to perform a peeling test immediately after performing a hot pressing process.

In the release film 10 of this embodiment, the first thermoplastic resin material used to form the first release layer 1 and the second thermoplastic resin material used to form the second release layer 3 are both those containing thermoplastic resin and particles. .

In this embodiment, from the viewpoint of improving the rigidity of the release film 10, the above-mentioned particle-based organic resin particles are preferable, and the cross-linked organic resin particles are more preferable. Examples of the organic resin particles include polystyrene particles, acrylic particles (acrylic beads), polyimide particles, polyester particles, polysiloxane particles, polypropylene particles, polyethylene particles, fluororesin particles, and core-shells. Particles, etc. These can be used alone or in combination of two or more. Polystyrene particles or acrylic particles (acrylic beads) are preferred from the standpoint of improving the balance between mold release and followability, and suppressing the generation of voids in the molded product. Polystyrene particles or acrylic particles having a crosslinked structure are preferred. (Acrylic beads) is more preferred.

The organic resin particles are particles containing an organic resin as a main component. The crosslinked organic resin particles are particles containing an organic resin having a crosslinked structure as a main component.

In this embodiment, examples of the thermoplastic resin included in the first thermoplastic resin material for forming the first release layer 1 and the second thermoplastic resin material for forming the second release layer 3 include polyparaphenylene. Polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polytrimethylene terephthalate resin (PTT), polyhexamethylene terephthalate resin (PHT) and other polymers Polyalkylene terephthalate resin, poly-4-methyl-1-pentene resin (TPX: hereinafter also referred to as polymethylpentene resin), syndiotactic polystyrene resin (SPS ), Polypropylene resin (PP) and copolymer resin made by copolymerizing other ingredients. These may be used singly or in combination of two or more kinds. Among them, from the viewpoint of improving the releasability of the first release layer 1 and the second release layer 3, a member selected from the group consisting of polymethylpentene resin, polybutylene terephthalate resin, and syndiotactic polystyrene is used. One or more of resins and polypropylene resins are preferred.

In this embodiment, the first thermoplastic resin material and the second thermoplastic resin material may contain, in addition to the thermoplastic resin, antioxidants, slip agents, anti-blocking agents, antistatic agents, dyes, and Colorants such as pigments, additives such as stabilizers, impact resistance imparting agents such as fluororesin and silicone rubber, inorganic fillers such as titanium oxide, calcium carbonate, and talc.

From the viewpoint of obtaining appropriate strength, the thickness of the first release layer 1 is preferably 10 μm or more, and more preferably 20 μm or more. On the other hand, the thickness of the first release layer 1 is preferably 50 μm or less, and more preferably 40 μm or less, from the viewpoint of the embedding property of the molded article.

From the viewpoint of obtaining appropriate strength, the thickness of the second release layer 3 is preferably 10 μm or more, and more preferably 20 μm or more. On the other hand, from the viewpoint of improving the appearance of the finished product, the thickness of the second release layer 3 is preferably 50 μm or less, and more preferably 40 μm or less.

The first release layer 1 and the second release layer 3 may be made of the same material or may be made of materials different from each other. The first release layer 1 and the second release layer 3 may have the same thickness or different thicknesses from each other. In addition, the particle size and content of the particles included in each of the first release layer 1 and the second release layer 3 may be the same, but from the standpoint of improving the appearance of the molded article obtained by the release film 10. It is preferable that the particle diameters and contents are different from each other. The particles included in the first release layer 1 and the second release layer 3 may be composed of the same material, or may be composed of materials different from each other.

The release film 10 has a thickness of 50 μm or more. The thickness of the release film 10 is preferably 75 μm or more, and more preferably 100 μm or more. By making it more than the said lower limit, the balance of mold release property and followability can be made favorable. On the other hand, the thickness of the release film 10 is 200 μm or less. It is preferably 150 μm or less. By making it into the said upper limit or less, a press pressure can be uniformly applied to the release film 10 at the time of manufacture of a molded article.

The buffer layer 2 is a resin containing a flexible resin, and a buffer layer is provided to the entire release film 10. With this, when the release film 10 is used, heat and pressure from the hot platen can be easily and evenly transmitted to the adherend, and the adhesion between the release film 10 and the adherend, and the release film 10 to the adherend can be easily transmitted. The followability has further improved.

The thickness of the buffer layer 2 is 10 μm or more and 200 μm or less, preferably 20 μm or more and 180 μm or less, and more preferably 30 μm or more and 150 μm or less. When the thickness of the buffer layer is equal to or more than the above-mentioned lower limit value, it is possible to suppress a decrease in the cushioning property of the release film. When the thickness of the buffer layer is equal to or less than the above-mentioned upper limit value, it is possible to suppress a decrease in mold release property.

Further, in this embodiment, when the total thickness of the release film 10 is set to X μm and the thickness of the buffer layer 2 is set to Y μm, as described above, the value of Y / X is greater than 0.2 and less than 0.9, and preferably 0.25 or more. 0.8 or less, more preferably 0.3 or more and 0.75 or less. When Y / X is at least the above lower limit value, it is possible to suppress a decrease in the cushioning property of the release film 10. When Y / X is equal to or less than the above upper limit value, it is possible to suppress a decrease in mold release property.

Specific examples of the resin material forming the buffer layer 2 include α-olefin polymers such as polyethylene and polypropylene; and ethylene, propylene, butene, pentene, hexene, and methylpentene as copolymers. Ingredients such as α-olefin copolymers, polyether fluorene, polyphenylene sulfide and other engineering plastic resins. These may be used individually by 1 type, and may use 2 or more types together. Among these, an α-olefin-based copolymer is preferable. Examples of the α-olefin-based copolymer include a copolymer of an α-olefin such as ethylene and a (meth) acrylate, a copolymer of ethylene and vinyl acetate, a copolymer of ethylene and (meth) acrylic acid, and the like. Part of the ionic cross-links. In addition, from the standpoint of obtaining a good buffering function, it is one that uses an α-olefin- (meth) acrylate copolymer such as ethylene alone, or a copolymer of polybutylene terephthalate and 1,4-cyclohexanedimethanol. A mixture of a polymerized polyethylene terephthalate and a mixture of an α-olefin-based polymer and an α-olefin- (meth) acrylate copolymer such as ethylene is preferred. For example, a mixture of ethylene and ethylene-methyl methacrylate copolymer (EMMA), a mixture of polypropylene (PP) and ethylene-methyl methacrylate copolymer (EMMA), polybutylene terephthalate (PBT ) And a mixture of polypropylene (PP) and ethylene-methyl methacrylate copolymer (EMMA) are more preferred.

The buffer layer 2 may further contain a rubber component. Examples of the rubber component include a styrene-based thermoplastic elastomer such as a styrene-butadiene copolymer and a styrene-isoprene copolymer, an olefin-based thermoplastic elastomer, a fluorene-based elastomer, and a polyester-based elastomer. And other thermoplastic elastomer materials; natural rubber, isoprene rubber, chloroprene rubber, silicone rubber and other rubber materials.

The buffer layer 2 may contain antioxidants, slip agents, antiblocking agents, antistatic agents, colorants such as dyes and pigments, additives such as stabilizers, impact resistance imparting agents such as fluororesin, silicone rubber, titanium oxide, and carbonic acid. Inorganic fillers such as calcium and talc.

Examples of the method for forming the buffer layer 2 include known methods such as an air-cooled or water-cooled inflation method, and a T-die method.

In this embodiment, the example in which the release film 10 is laminated in the order of the first release layer 1, the buffer layer 2, and the second release layer 3 has been described, but the laminated structure of the release film 10 is not limited to this. this. For example, the release film 10 may have a structure of four or more layers in which an adhesive layer, a gas barrier layer, and the like are laminated. In this case, the adhesive layer and the gas barrier layer are not particularly limited, and a known one can be used.

<The manufacturing method of the release film 10> The release film 10 in this embodiment can be manufactured using well-known methods, such as a coextrusion method, an extrusion lamination method, a dry lamination method, and an inflation method. In addition, each layer of the first release layer 1, the buffer layer 2, and the second release layer 3 can be separately manufactured, and then the release film 10 can be joined by a laminator or the like, and an air-cooled or water-cooled co-extrusion inflation method can be used. Co-extrusion T-die method is preferred for film formation. Among them, a method of forming a film by a co-extrusion T-die method is particularly preferable from the viewpoint that the thickness of each layer can be excellently controlled. In addition, the first release layer 1, the buffer layer 2, and the second release layer 3 may be directly bonded, or may be bonded via an adhesive layer.

<The manufacturing method of a molded article> Next, the manufacturing method of the molded article of this embodiment is demonstrated. The manufacturing method of the molded article of this embodiment includes the following processes. The first process is a process in which the release film 10 is placed on the object such that the first release surface of the first release layer 1 of the release film 10 becomes the object side. The second process is a process of hot-pressing an object on which the release film 10 is disposed. Hereinafter, each process will be described in detail.

In the first process, the first release surface of the release film 10 is disposed so as to be the object side. The arrangement method is not particularly limited, and it can be arranged by a known method.

The second process is a process of hot pressing the release film 10 and the object. The hot pressing can use a known press, and can also be made into a desired shape by pressing a press die. The heating and pressurizing conditions can be appropriately designed according to the application. For example, after the pressurizing device starts heating from room temperature to 170 ° C. for 15 minutes, the temperature is maintained for 35 minutes, and then the temperature is cooled from 170 ° C. to room temperature in 50 minutes. The pressing pressure at this time can be appropriately adjusted at 5 to 15 MPa. Before the hot pressing, a material may be arranged on the second release surface of the second release layer 3 of the release film 10. Thereby, in the subsequent hot pressing, even when the surface of the object is uneven, the release film 10 and the object can be adhered well, and the object can be evenly pressed. As the material, those having cushioning properties are preferred. Examples of the material include paper, rubber, a fluororesin sheet, and cellophane, or a combination of these.

Examples of the molded article include a flexible printed circuit board. At this time, for example, the release film 10 can be used in a cover-pressing layer pressing process which is one of the manufacturing processes of a flexible printed wiring board. That is, the release film 10 is used to protect the circuit of the circuit exposed film during hot pressing, and to adhere the coverlay film to the uneven portion generated by the circuit pattern of the circuit exposed film. Specifically, first, the release film 10 is arranged so as to cover the coverlay film so that the first release surface of the release film 10 becomes the coverlay film side. Thereby, the release film 10 is interposed between the coverlay film and the subsequent punch. In this case, in order to further improve the cushioning property, the aforementioned material may be interposed between the release film 10 and the press. Next, the release film 10 is heated under pressure together with the circuit exposure film and the cover film by a press. Furthermore, after the pressure heating, the circuit-exposed film, that is, the flexible printed circuit board with the cover film adhered thereon, was taken out from the press to obtain a desired molded product.

Moreover, although the example of the flexible printed circuit board was demonstrated as a molded article mentioned above, as a molded article, the surface of the release film 10 in which the object was arrange | positioned may be formed from the material containing a thermosetting resin. In this case, the thermosetting resin may be in a semi-hardened state or a hardened state. If the semi-hardened state is used, the effect of the release film 10 becomes more significant. In particular, when the thermosetting resin is a resin composition containing an epoxy resin, it is preferable that the epoxy resin is in an intermediate stage of a curing reaction, that is, in a B-step state. According to the release film 10 according to this embodiment, even if the surface of the release film 10 on which the object is disposed is formed of a material containing a thermosetting resin, a molded article having a good appearance can be obtained.

<Usage of Release Film 10> The release film 10 includes a process of arranging the release film 10 on an object so that the first release layer of the release film 10 is on the object side, and a method for disposing the release film 10 The object of the film 10 is subjected to a hot pressing process, and can be used to obtain a molded article after the hot pressing. Thereby, a molded article having a good appearance is obtained. In addition, the surface of the object on which the release film 10 is disposed may be formed of a material containing a thermosetting resin. Among them, when the thermosetting resin is a resin composition containing an epoxy resin, it is preferable that the epoxy resin is in an intermediate stage of a curing reaction, that is, in a B-step state.

[Second Embodiment] In the first embodiment, the release film 10 has a laminated structure in which the first release layer 1, the buffer layer 2, and the second release layer 3 are sequentially laminated in the thickness direction. When the thickness is 10 μm or more and 200 μm or less, when the total thickness of the release film 10 is set to X and the thickness of the buffer layer 2 is set to Y, Y / X is greater than 0.2 and less than 0.9, and the release layer 1 and the release layer 3 are included. The particles having an average particle diameter d50 of 4 μm or more and 60 μm or less are described. In the second embodiment, the release film 20 has a first release layer 21 on at least one side, and the average particle diameter d50 of the particles is 20 μm or more and 60 μm or less. Person to explain. Hereinafter, descriptions of the same configuration, effect, manufacturing method, and the like as those of the first embodiment are appropriately omitted.

Fig. 2 is a sectional view of a release film according to a second embodiment. As shown in FIG. 2, the release film 20 includes a first release layer 21 including a first thermoplastic resin material. The first thermoplastic resin material includes a thermoplastic material and particles.

In this embodiment, the average particle diameter d50 of the particles is 20 μm or more, preferably 23 μm or more, more preferably 25 μm or more, and still more preferably 28 μm or more. By including particles having an average particle diameter d50 of the above lower limit value or more in the first release layer 21, the rigidity of the release film 20 can be improved, and the balance between the mold release property and the followability can be improved. On the other hand, the upper limit value of the average particle diameter d50 of the particles is 60 μm or less, preferably 55 μm or less, more preferably 52 μm or less, and still more preferably 51 μm or less. By including particles having an average particle diameter d50 of the above-mentioned upper limit value or less in the first release layer 21, the release properties and the followability can be improved in a well-balanced manner. In addition, in this embodiment, when the average particle diameter d50 of the particles is equal to or less than the above-mentioned upper limit value, a molded article having a good appearance can be produced.

In this embodiment, the particles are preferably spherical.

As the material constituting the particles, the same materials as those described in the first embodiment can be used.

In the present embodiment, when the release film 20 is placed on an object, the first release layer 21 corresponds to the object-side surface (release surface) in the release film 20.

In this embodiment, from the viewpoint of ensuring the strength of the first release layer 21 and obtaining stable release properties, the surface 10-point average roughness (Rz) of the release surface of the first release layer 21 is preferred. It is 4 μm or more, more preferably 4.5 μm or more, and still more preferably 5 μm or more. On the other hand, from the viewpoint of suppressing a decrease in followability, the upper limit value of the 10-point average roughness (Rz) of the surface of the release surface is preferably 20 μm or less, more preferably 18 μm or less, and still more preferably 16 μm or less. The 10-point average roughness (Rz) of the surface of the first release layer 21 can be measured in accordance with JIS-B0601-1994. The value of the 10-point average roughness (Rz) on the surface refers to a value corresponding to the surface (release surface) on the object side in the release film 20 when the release film 20 is placed on the object.

In this embodiment, from the viewpoint of ensuring the strength of the first release layer 21 and obtaining stable release properties, the average interval (Sm) of the unevenness on the release surface of the first release layer 21 is preferably 150 μm or more. , More preferably 180 μm or more. On the other hand, from the viewpoint of suppressing the occurrence of wrinkles on the surface of the molded product, the upper limit of the average interval (Sm) of the unevenness of the relief surface of the first release layer 21 is preferably 500 μm or less, and more preferably 450 μm or less. . The average interval (Sm) of the unevenness of the first release layer 21 can be measured in accordance with JIS-B0601-1994. In addition, the value of the average interval (Sm) of the unevenness refers to a value corresponding to the object-side surface (release surface) in the release film 20 when the release film 20 is disposed on the object.

In this embodiment, from the viewpoint of ensuring the strength of the first release layer 21 and obtaining the release property, the arithmetic average roughness (Ra) of the release surface of the first release layer 21 is preferably 0.5 μm or more. , More preferably 0.6 μm or more. On the other hand, from the viewpoint of suppressing the occurrence of wrinkles on the surface of the molded product, the upper limit value of the arithmetic mean roughness (Ra) of the release surface of the first release layer 21 is preferably 6 μm or less, and more preferably 5 μm or less. . The arithmetic mean roughness (Ra) of the first release layer 21 can be measured in accordance with JIS-B0601-1994. The arithmetic mean roughness (Ra) refers to a value corresponding to the surface (release surface) on the object side of the release film 20 when the release film 20 is disposed on the object.

In this embodiment, the peeling strength of the release surface of the first release layer 21 is preferably 3 N / 50 mm or less, and more preferably 1 N / 50 mm or less. Thereby, it is possible to produce a release film capable of exhibiting better release properties than a conventional release film.

The peel strength of the release surface of the first release layer 21 can be measured by the following method, for example. First, a test was carried out in which the cover layer was temporarily fixed so that the surface of one side of the cover layer (CM type) coated with an adhesive manufactured by Arisawa Mfg. Co., Ltd. was in contact with the surface of the circuit exposed film. film. Next, the release surface of the first release layer 21 in the release film 20 and the surface of one side of the test film having one of the cover layers were placed facing each other, and a test piece was produced by bonding them to each other. Thereafter, the test piece was subjected to a hot-pressing treatment under conditions of 195 ° C. and 6 MPa for 2 minutes. At this time, by not crimping the end portion of the test piece, the end portion of the release film 20 can be pinched as a free end. Then, using a tensile tester, the release surface of the first release layer 21 of the release film 20 and the test film were removed from the end portion of the release film 20 in a 180 ° direction at a speed of about 1000 mm / min. The cover layers were peeled to measure the peel strength of the release surface of the first release layer 21. In addition, it is preferable to perform the measurement of the peeling strength immediately after the hot-pressing treatment.

In the present embodiment, the thickness of the first release layer 21 is preferably 15 μm or more, and more preferably 20 μm or more, from the viewpoint of improving the embedding property with respect to a molded article. On the other hand, from the viewpoint of obtaining appropriate strength, the thickness of the first release layer 21 is preferably 100 μm or less, more preferably 75 μm or less, and most preferably 50 μm or less.

The release film 20 is one having a first release layer 21 containing a thermoplastic resin material on at least one side.

As the material constituting the first release layer 21, the same ones as those described in the first embodiment can be used.

The effect of the release film 20 of the second embodiment will be described.

The release film 20 of this embodiment is a structure which satisfies the following two conditions simultaneously. The first condition is that the first release layer 21 is formed of a thermoplastic resin material containing a thermoplastic resin and particles having an average particle diameter d50 of 20 μm to 60 μm. The second condition is controlled so that the content of particles is 0.5% by weight or more and 15% by weight or less based on the total amount of the first release layer 21. Therefore, the following effects are obtained in accordance with the release film 20.

First, according to the release film 20, it is possible to express a better release property than a conventional release film.

Second, according to the release film 20, a molded article having a good appearance can be produced. In addition, as described later in the examples, it was confirmed that the shape of the exuded shape of the adhesive had a difference in unevenness of less than 100 μm, and the molded article produced using the release film 20 had a good finished appearance.

Third, according to the release film 20, when a molded product is produced, it is possible to suppress the surface of the molded product even when a pressing pressure is applied to the release surface of the first release layer 21 of the release film 20. Wrinkles appear. Therefore, according to the release film 20, a molded article with a good appearance can be produced.

The release film 20 may have the first release layer 21 containing a thermoplastic resin material on at least one side, but the release film 20 may have other layers laminated on the first release layer 21 in the thickness direction. For example, as shown in FIG. 2, the release film 20 may be configured to further include a second release layer 23 on the other surface. In the case where the second release layer 23 is used, when the release film 20 is used, when the release film 20 is hot-pressed by a press, the releasability from the hot plate is improved, and it is possible to improve the production of a molded body or Productivity when laminated. In addition, as shown in FIG. 2, the release film 20 may include a buffer layer 22 that imparts cushioning properties in addition to the second release layer 23. The release film 20 may have a laminated structure of three or more layers in which the first release layer 21, the buffer layer 22, and the second release layer 23 are sequentially laminated in the thickness direction. At this time, as long as the first release layer 21 and the second release layer 23 are made of a material containing a thermoplastic resin, they may be formed of the same material or may be formed of different materials. The first release layer 21 and the second release layer 23 may have different thicknesses.

In addition, in this case, from the viewpoint of obtaining appropriate strength, the thickness of the second release layer 23 may be, for example, 15 μm or more, and may be 20 μm or more. On the other hand, from the viewpoint of suppressing a decrease in the followability, the upper limit value of the thickness of the second release layer 23 may be, for example, 100 μm or less, 75 μm or less, or 50 μm or less.

As a material constituting the second release layer 23, the same materials as those described in the first embodiment can be used. In addition, the second release layer 23 may contain particles as long as the effect of the release film 20 is not impaired.

In this case, the thickness of the buffer layer 22 is preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 90 μm or less, and most preferably 30 μm or more and 70 μm or less. When the thickness of the buffer layer 22 is equal to or more than the above-mentioned lower limit value, it is possible to suppress a reduction in the cushioning property of the release film 20. When the thickness of the buffer layer 23 is equal to or less than the above-mentioned upper limit value, it is possible to suppress a decrease in the mold release property.

As the material constituting the buffer layer 22, the same ones as those described in the first embodiment can be used.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention, and various structures other than the above can also be employ | adopted. [Example]

Hereinafter, the present invention will be described by examples and comparative examples, but the present invention is not limited to these.

[Example A] <Example A-1> Acrylic beads (SEKISUI) containing polymethylpentene resin (TPX (registered trademark)) (manufactured by Mitsui Chemicals, Inc., TPXD X845) and crosslinked organic resin particles were used. A thermoplastic resin material (M BX-30) manufactured by PLASTICS CO., Ltd. was used to produce a TPX film by an extrusion T-die method to obtain a first release layer. Here, the average particle diameter d50 of the acrylic beads used when producing the first release layer was 28.5 μm. In addition, the thermoplastic resin material used when producing the first release layer was formed by blending the content of the acrylic beads with the TPX so that the content of the acrylic beads becomes 4% by weight based on the total amount of the first release layer. A polymethylpentene resin (TPX (registered trademark)) (manufactured by Mitsui Chemicals, Inc., TPXDX 845) and acrylic beads (cross-linked organic resin particles) (manufactured by SEKISUI PLASTICS CO., Ltd., MB X-50) were used. ), A thermoplastic resin material, a TPX film was produced by an extrusion T-die method to obtain a second release layer. Here, the average particle diameter d50 of the acrylic beads used when preparing the second release layer was 53 μm. In addition, the thermoplastic resin material used in the production of the second release layer was prepared by blending the acrylic beads with the TPX so that the content of the acrylic beads becomes 10% by weight based on the total amount of the second release layer. Next, the first release layer obtained by the above method, including the above-mentioned TPX, polypropylene (PB270A made by SUN AROMA CO., LTD.), And modified polyethylene (ethylene-methyl Methyl acrylate copolymer, Sumitomo Chemical Company, Limited, WH102) buffer layer (combination ratio: TPX: polypropylene: ethylene-methyl methacrylate copolymer = 30:40:30), and a second release layer Thus, a release film of Example 1 was obtained. The obtained release film has a three-layer structure in which the first release layer, the buffer layer, and the second release layer are sequentially laminated in the thickness direction. The thickness of the obtained release film was 120 μm. In the obtained release film, the thickness of the first release layer and the second release layer was 30 μm, and the thickness of the buffer layer was 60 μm.

<Example A-2> Instead of SEKISUI, the first release layer was produced using a thermoplastic resin material that was blended with the TPX described above so that the content of acrylic beads was 10% by weight based on the total amount of the first release layer. MBX-50 manufactured by PLASTI CS CO., Ltd. uses MBX-30 manufactured by SEKISUI PLASTICS CO., Ltd. as acrylic beads to form a second release layer, and the thickness of the buffer layer is set to 50 μm. Except for the above points, the release film of Example A-2 was obtained in the same manner as in Example A-1.

<Example A-3> Instead of MBX-30 manufactured by SEKISUI PLASTICS CO., Ltd., MBX manufactured by SEKISUI PLASTICS CO., Ltd., having an average particle diameter d50 of 20.9 μm, was used as acrylic beads, which are crosslinked organic resin particles. -20 to obtain the first release layer, set the thickness of the first release layer to 25 μm, replace MBX-50 manufactured by SEKIS UI PLASTICS CO., Ltd., and use SEKISUI PLASTICS CO. As acrylic beads, Ltd. MBX-30 manufactured a second release layer with a thickness of 25 μm from a thermoplastic resin material blended with the TPX so that the content of acrylic beads is 12% by weight based on the total amount of the release layer. A release film of Example A-3 was obtained in the same manner as in Example A-1 except that the thickness of the buffer layer was set to 70 μm.

<Example A-4> Instead of MBX-30 manufactured by SEKISUI PLASTICS CO., Ltd., as the cross-linked organic resin particles, that is, acrylic beads, JXTG NIPPON OIL & ENERGY CORP ORATION manufactured by JXTG NIPPON OIL & ENERGY CORP ORATION with an average particle diameter d50 of 10.2 μm was used. -1020, the first release layer having a thickness of 40 μm is produced by using a thermoplastic resin material blended with the above TPX so that the content of the acrylic beads is 2% by weight relative to the total amount of the release layer, and the second release is performed. A release film of Example A-4 was obtained in the same manner as in Example A-1 except that the thickness of the layer was set to 40 μm and the thickness of the buffer layer was set to 40 μm.

<Comparative Example A-1> Instead of MBX-30 manufactured by SEKISUI PLASTICS CO., Ltd., as crosslinked organic resin particles, that is, acrylic beads, JXTG NIPPON OIL & ENERGY CORP ORATION manufactured by JXTG NIPPON OIL & ENERGY CORP ORATION with an average particle diameter d50 of 10.2 μm was used. -1020, the first release layer was made such that the content of acrylic beads was 2% by weight based on the total amount of the release layer, and the second release layer was produced using a thermoplastic resin material containing TPX without acrylic beads In this regard, a release film of Comparative Example A-1 was obtained in the same manner as in Example A-1 except for the points described above.

<Comparative Example A-2> Instead of MBX-30 manufactured by SEKISUI PLASTICS CO., Ltd., as crosslinked organic resin particles, that is, acrylic beads, an AR650MZ manufactured by TOYOBO CO., LTD. Having an average particle diameter d50 of 61.2 μm, The first mold release layer was produced by using a thermoplastic resin material blended with the above-mentioned TPX so that the content of acrylic beads was 15% by weight based on the total amount of the release layer, instead of the product made by SEKISUI PLASTICS CO., Ltd. MBX-50 is used as crosslinked organic resin particles, that is, acrylic beads. AR650MZ manufactured by TOYOBO CO., LTD. With an average particle diameter d50 of 61.2 μm is used. The content of acrylic beads relative to the total amount of the release layer becomes 15 weight. The thermoplastic resin material combined with the above TPX method was used to produce a second release layer, and the thickness of the buffer layer was set to 50 μm. Except for the above points, it was obtained in the same manner as in Example A-1. The release film of Comparative Example A-2 was shown.

<Comparative Example A-3> Instead of MBX-30 manufactured by SEKISUI PLASTICS CO., Ltd., acrylic resin beads which are cross-linked organic resin particles, that is, an average particle diameter d50 of 2.8 μm, were manufactured by Soken Chemical & Engineering Co., Ltd. MX-300 replaces SEKISUI by using a thermoplastic resin material made of the above-mentioned TPX in such a way that the content of acrylic beads is 3% by weight relative to the total amount of the release layer. MBX-50 manufactured by PLASTICS CO., Ltd. uses MX-300 manufactured by Soken Chemical & Engineering Co., Ltd. as the crosslinked organic resin particles, that is, acrylic beads, having an average particle diameter d50 of 2.8 μm. The thermoplastic resin material blended with the TPX in such a way that the content of the beads is 3% by weight based on the total amount of the release layer is a second release layer having a thickness of 25 μm and a thickness of the buffer layer is 70 μm. Except for the above, a release film of Comparative Example A-3 was obtained in the same manner as in Example A-1.

<Comparative Example A-4> Except for the points described above, the thickness of the first release layer and the second release layer was set to 40 μm, and the thickness of the buffer layer was set to 20 μm. In the same manner, a release film of Comparative Example A-4 was obtained.

<Comparative Example A-5> Except for the points described above, the thickness of the first release layer and the second release layer was set to 10 μm, and the thickness of the buffer layer was set to 180 μm. In the same manner, a release film of Comparative Example A-5 was obtained.

The following evaluations were performed using each of the release films of Examples A-1 to A-4 and Comparative Examples A-1 to A-5. The results are shown in Table 1.

<Evaluation method> The average particle diameter d50 of the particles (acrylic beads): a result obtained by measuring the particle size using a laser diffraction particle size analyzer (manufactured by Malvern Co., Ltd., Mastersizer 2000) and using water as a solvent to disperse the particles, The value of the particle diameter with a cumulative frequency of 50% was calculated as the average particle diameter d50. The unit is μm.

‧ 10-point average roughness (Rz) on the surface of the first release surface of the first release layer: The surface of the first release surface of the first release layer in the obtained release film is in accordance with JIS-B0601 -1994, the center n = 3 was measured using Handy Surf E-35B manufactured by TOKYO SEIMI TSU CO., LTD. The unit is μm.

・ 10-point average roughness (Rz) on the surface of the second release surface of the second release layer: Regarding the surface of the second release surface of the second release layer in the release film, in accordance with JIS-B0601-1994, The center n = 3 was measured using Handy Surf E-35B manufactured by TOKYO SEIMITSU CO., LTD. The unit is μm.

‧Releasability of the first release surface of the first release layer: First, a surface on the side coated with one of the adhesives (CM type) made by Arisawa Mfg. Co., Ltd. was produced. The test film having the above-mentioned cover layer was temporarily fixed in a manner of contacting the surface of the circuit exposed film. Next, a test piece was obtained in which the first release surface of the first release layer in the release film and the test film having one side of the cover layer facing each other were bonded to each other. Next, this test piece was subjected to a hot-pressing treatment at 180 ° C and 6 MPa for 2 minutes, and then a tensile tester (Force gauge AD-4932A-50N manufactured by A & D Company, Limited) was used so that the test piece was 180 ° The peeling strength between the first release surface of the first release layer of the release film and the cover layer of the test film was measured at a speed of about 1,000 mm / minute. The peel strength was measured immediately after the hot-pressing treatment, and the releasability was evaluated based on the following criteria. ：: Peel strength is 1 N / 50 mm or less. (Circle): Peeling strength is more than 1N / 50mm and 3N / 50mm or less. ×: Peeling strength indicates a value greater than 3N / 50 mm, or any film that does not easily peel off and forms a test piece is cracked.

‧Releasability of the second release surface of the second release layer: As a test piece, the second release surface of the second release layer in the release film and the silicone rubber sheet were placed so as to face each other. Combined. Next, this test piece was subjected to a hot-pressing treatment at 180 ° C and 6 MPa for 2 minutes, and then a tensile tester (Force gauge AD-4932A-50N manufactured by A & D Company, Limited) was used so that the test piece was 180 ° The peeling strength between the second release surface of the second release layer of the release film and the silicone rubber sheet was measured at a speed of about 1,000 mm / min. The measurement of peel strength was performed immediately after the hot-pressing treatment, and the releasability was evaluated based on the following criteria. ○: Peel strength is 1 N / 50 mm or less. ×: Peel strength indicates a value greater than 1 N / 50 mm.

‧Finished product appearance 1 (adhesive exudation shape): First, a 1 mm square opening was made in a cover layer (CM type) made by Arisawa Mfg. Co., Ltd. Next, a test piece in which a cover layer having the above-mentioned opening portion was temporarily fixed so that the surface on one side to which the adhesive was applied was brought into contact with the surface of the copper-clad laminate for flexible wiring boards was produced. Next, the release film and the test piece were superimposed so that the first release surface of the first release layer in the release film and the side having the cover layer on one side of the test piece faced each other, and then 180 ° A hot-pressing treatment was performed for 2 minutes at a temperature of 6 ° C and a molded article. With regard to the molded article thus obtained, the adhesive applied to the surface of the cover tape was observed to extrude from the outer edge portion of the opening portion to the shape formed in the opening portion of the cover layer (adhesive oozing shape), and evaluated based on the following criteria The finished appearance of the molded product. (Circle): The unevenness | corrugation difference of the adhesive exudation shape is less than 100 micrometers. ×: The unevenness of the adhesive exudation shape is 100 μm or more.

‧Finished Product Appearance 2 (Wrinkles): A side of the cover (CM type) made of Arisawa Mfg. Co., Ltd. coated with an adhesive and a copper-clad layer for a flexible wiring board were prepared. The test piece with the above-mentioned cover layer was temporarily fixed in a manner that the surface of the board was in contact. Next, the release film and the test piece were superimposed so that the first release surface of the first release layer in the release film and the surface having one side of the cover layer of the test piece faced each other, and then the temperature was 180 ° C. The molded product was obtained by performing hot-pressing treatment at a pressure of 6 MPa for 2 minutes. Regarding the appearance of the FPC, the wrinkle generation rate per unit area was measured by a method based on the JPCA standard "7.5.7.2 Wrinkles". The obtained measured values were evaluated based on the following criteria. (Circle): Wrinkle generation rate is less than 1.5%. ×: Wrinkle generation rate was 1.5% or more.

‧Presence or absence of voids: First, copper foils on both sides of the copper-clad laminate for flexible wiring boards were etched to produce 3 cm square openings. Next, the surface of one side of the covering layer (CM type) coated with an adhesive manufactured by Arisawa Mfg. Co., Ltd. was bonded to the opening portion formed in the copper-clad laminate for flexible wiring boards, and It overlapped so that the 1st release surface of the 1st release layer of the release film may become a cover layer side, and performed the heat-pressing process at 180 degreeC and 6 MPa for 2 minutes. After that, the release film was peeled. In the thus-obtained molded article, it was observed whether voids were generated in the adhesive which entered from the surface of the cover tape into the opening formed in the copper-clad laminate for flexible wiring boards, and the presence or absence of voids was evaluated.

【Table 1】

It can also be seen from the above Table 1 that all of the release films of Examples A-1 to A-4 are excellent in release properties on both sides. In addition, it was confirmed that the molded articles produced using the release films of Examples A-1 to A-4 all had good finished product appearances.

[Example B] <Example B-1> Acrylic beads (SEKISUI) containing polymethylpentene resin (TPX (registered trademark)) (manufactured by Mitsui Chemicals, Inc., TPXD X845) and crosslinked organic resin particles were used. A thermoplastic resin material (M BX-30) manufactured by PLASTICS CO., Ltd. was used to produce a TPX film by an extrusion T-die method to obtain a first release layer. Here, the average particle diameter d50 of the acrylic beads used when producing the first release layer was 28.5 μm. In addition, the thermoplastic resin material used in the production of the release layer was prepared by blending the content of the acrylic beads with the TPX so that the content of the acrylic beads becomes 4% by weight based on the total amount of the first release layer. Next, the first release layer obtained by the above method, including the above-mentioned TPX, polypropylene (PB270A made by SUN AROMA CO., LTD.), And modified polyethylene (ethylene-methyl Methyl acrylate copolymer, Sumitomo Chemical Company, Limited, WH102) buffer layer (combination ratio: TPX: polypropylene: ethylene-methyl methacrylate copolymer = 25:50:25), and 2 release layer, thereby obtaining a release film of Example B-1. The obtained release film has a three-layer structure in which the first release layer, the buffer layer, and the second release layer are sequentially laminated in the thickness direction. The thickness of the obtained release film was 120 μm. In the obtained release film, the thickness of the first release layer and the second release layer were 30 μm, and the thickness of the buffer layer was 60 μm.

<Example B-2> A mold release layer was prepared using a thermoplastic resin material that was blended with the TPX so that the content of the acrylic beads was 10% by weight based on the total amount of the first mold release layer. The release film of Example B-2 was obtained in the same manner as in Example B-1.

<Example B-3> Except for this point, MBX-20 manufactured by SEKIS UI PLASTICS CO., Ltd. having an average particle diameter d50 of 20.9 μm was used as acrylic beads that are crosslinked organic resin particles. The release film of Example B-3 was obtained in the same manner as in B-1.

<Example B-4> As the crosslinked organic resin particles, that is, acrylic beads, MBX-50 manufactured by SEKIS UI PLASTICS CO., Ltd. with an average particle diameter d50 of 50.9 μm was used. A thermoplastic resin material prepared by blending the first release layer with a total amount of 10% by weight with the above-mentioned TPX was used to prepare a release layer. Except for the above points, Examples were obtained in the same manner as in Example B-1. B-4 release film.

<Comparative Example B-1> A Comparative Example B-1 was obtained in the same manner as in Example B-1 except that the first release layer was produced using a thermoplastic resin material containing the TPX without acrylic beads. Release film.

<Comparative Example B-2> As acrylic beads, AR 650MZ manufactured by TOYOBO CO., LTD. With an average particle diameter d50 of 61.2 μm was used. The content of acrylic beads was 15 relative to the total amount of the first release layer. The thermoplastic resin material compounded with the above TPX in a weight percent manner was used to prepare a release layer. Except for the foregoing, a release film of Comparative Example B-2 was obtained in the same manner as in Example B-1.

<Comparative Example B-3> As the acrylic beads, SSX-110 manufactured by SEKISUI PLASTICS CO., Ltd. having an average particle diameter d50 of 10.2 μm was used. The thicknesses of the first release layer and the second release layer were respectively A release film was produced in such a manner that the thickness was 25 μm and the thickness of the buffer layer was 70 μm. Except for the above, a release film of Comparative Example B-3 was obtained in the same manner as in Example B-1.

The following evaluations were performed using each of the release films of Examples B-1 to B-4 and Comparative Examples B-1 to B-3. The results are shown in Table 2.

<Evaluation method> ‧ Average particle diameter d50 of spherical particles (acrylic beads): Obtained by using a laser diffraction particle size analyzer (manufactured by Malvern, Mastersizer 2000) to measure particle size by using water as a solvent and dispersing the particles. As a result, the value of the particle diameter with a cumulative frequency of 50% was calculated as the average particle diameter d50. The unit is μm.

‧ 10-point average roughness (Rz) on the surface of the release surface of the first release layer: Regarding the surface of the release surface of the first release layer in the obtained release film, in accordance with JIS B0601 (1994), The center n = 3 was measured using "Handy Surf E-35B manufactured by TOKYO SEIMITS U CO., LTD." The unit is μm.

‧Releasability: First, the surface of one side of the coating layer (CM type) made by Arisawa Mfg. Co., Ltd. on which the adhesive was applied was temporarily fixed to the surface of the circuit exposed film so that the cover was fixed Layer of test film. Next, a test piece was obtained in which the release surface of the first release layer in the release film and the surface of the test film having one side of the cover layer were placed facing each other. Next, this test piece was subjected to a hot-pressing treatment at 195 ° C and 6 MPa for 2 minutes, and then a tensile tester (Force gauge AD-4932A-50N manufactured by A & D Company, Limited) was used so that the test piece was 180 ° The peel strength between the release surface of the first release layer of the release film and the cover layer of the test film was measured at a speed of about 1,000 mm / minute. The measurement of peel strength was performed immediately after the hot-pressing treatment, and the releasability was evaluated based on the following criteria. ：: Peel strength is 1 N / 50 mm or less. (Circle): Peeling strength is more than 1N / 50mm and 3N / 50mm or less. ×: Peeling strength indicates a value greater than 3N / 50 mm, or any film that does not easily peel off and forms a test piece is cracked.

‧Finished product appearance 1 (adhesive exudation shape): First, a 1 mm square opening was made in a cover layer (CM type) made by Arisawa Mfg. Co., Ltd. Next, a test piece in which a cover layer having the above-mentioned opening portion was temporarily fixed so that the surface on one side to which the adhesive was applied was brought into contact with the surface of the copper-clad laminate for flexible wiring boards was produced. Next, the release film and the test piece were superimposed so that the release surface of the first release layer in the release film and the surface having one side of the cover layer of the test piece were superposed, and then the temperature was 195 ° C, A hot-pressing treatment was performed at 6 MPa for 2 minutes to obtain a molded product. With regard to the molded article thus obtained, the adhesive applied to the surface of the cover tape was observed to extrude from the outer edge portion of the opening portion to the shape formed in the opening portion of the cover layer (adhesive oozing shape), and evaluated based on the following criteria The finished appearance of the molded product. (Circle): The unevenness | corrugation difference of the adhesive exudation shape is less than 100 micrometers. ×: The unevenness of the adhesive exudation shape is 100 μm or more.

‧Finished Product Appearance 2 (Wrinkles): A side of the cover (CM type) made of Arisawa Mfg. Co., Ltd. coated with an adhesive and a copper-clad layer for a flexible wiring board were prepared. The test piece with the above-mentioned cover layer was temporarily fixed in a manner that the surface of the board was in contact. Next, the release film and the test piece were superimposed so that the release surface of the first release layer in the release film and the surface having one side of the cover layer of the test piece faced each other, and then the temperature was 195 ° C and 6 MPa. The molded product was obtained by performing a hot-pressing treatment under the conditions of 2 minutes. Regarding the appearance of the FPC, the wrinkle generation rate per unit area was measured by a method based on the JPCA standard "7.5.7.2 Wrinkles". The obtained measured values were evaluated based on the following criteria. (Circle): Wrinkle generation rate is less than 1.5%. ×: Wrinkle generation rate was 1.5% or more.

‧Presence or absence of voids: First, copper foils on both sides of the copper-clad laminate for flexible wiring boards were etched to produce 3 cm square openings. Next, the surface of one side of the covering layer (CM type) coated with an adhesive manufactured by Arisawa Mfg. Co., Ltd. was bonded to the opening portion formed in the copper-clad laminate for flexible wiring boards, and It was superimposed so that the release surface of the 1st release layer of a release film might be a cover layer side, and it heat-processed at 195 degreeC and 6 MPa for 2 minutes. After that, the release film was peeled. In the thus-obtained molded article, it was observed whether voids were generated in the adhesive which entered from the surface of the cover tape into the opening formed in the copper-clad laminate for flexible wiring boards, and the presence or absence of voids was evaluated.

【Table 2】

As can also be seen from Table 2 above, all of the release films of the examples are those having excellent release properties. In addition, it was confirmed that the molded articles produced using the release film of Example B all had good finished product appearance.

This application claims the priority based on Japanese Patent Application No. 2016-068457 filed on March 30, 2016 and Japanese Patent Application No. 2016-151462 filed on August 1, 2016, the entire contents of which are incorporated herein .

1‧‧‧ the first release layer
2‧‧‧ buffer layer
3‧‧‧ 2nd release layer
10‧‧‧ release film
20‧‧‧ release film
21‧‧‧The first release layer
22‧‧‧ buffer layer
23‧‧‧The second release layer

The above-mentioned objects and other objects, features, and advantages will be made clearer by the preferred embodiments described below and the following drawings associated therewith.

Fig. 1 is a sectional view of a release film according to a first embodiment. Fig. 2 is a sectional view of a release film according to a second embodiment.

1‧‧‧ the first release layer

2‧‧‧ buffer layer

3‧‧‧ 2nd release layer

10‧‧‧ release film

Claims (17)

A release film having a laminated structure. The laminated structure includes a first release layer including a first thermoplastic resin material, a buffer layer, and a second release layer including a second thermoplastic resin material. The first release layer is disposed on one side of the release film, the second release layer is disposed on the other side of the release film, and the thickness of the buffer layer is 10 μm or more and 200 μm or less. When the total thickness is set to X, and the thickness of the buffer layer is set to Y, Y / X is greater than 0.2 and less than 0.9. The first thermoplastic resin material and the second thermoplastic resin material both contain a thermoplastic resin and have an average particle diameter d50 of 4 μm. For particles of 60 μm or less, the content of the particles is 0.5% by weight or more and 15% by weight or less relative to the total amount of the first release layer, and the content of the particles is 0.5% by weight or more relative to the total amount of the second release layer. Above 15% by weight. The release film according to item 1 of the scope of patent application, wherein the 10-point average roughness Rz on the surface of the release surface of the first release layer is set to A, and the release surface of the second release layer is When the 10-point average roughness Rz of the surface is set to B, the absolute value of AB is 20 or less. The release film according to item 1 or 2 of the scope of patent application, wherein the 10-point average roughness Rz of the surface of the release surface of the first release layer is 0.5 μm or more and 25 μm or less. The release film according to item 1 or 2 of the scope of patent application, wherein the 10-point average roughness Rz of the surface of the release surface of the second release layer is 0.5 μm or more and 25 μm or less. A release film having a first release layer formed of a first thermoplastic resin material on at least one side, wherein the first thermoplastic resin material includes a thermoplastic resin and particles, and an average particle diameter d50 of the particles is 20 μm or more and 60 μm or less, The content of the spherical particles is 0.5% by weight or more and 15% by weight or less based on the total amount of the release layer. The release film according to item 5 of the scope of patent application, wherein the 10-point average roughness Rz of the surface of the release surface of the first release layer is 4 μm or more and 20 μm or less. The release film according to item 5 or 6 of the scope of application for a patent, wherein the thickness of the release film is 50 μm or more and 150 μm or less. The release film according to item 5 of the scope of the patent application, wherein the release film further includes: a buffer layer; and a second release layer, the first release layer, the buffer layer, and the second release layer in this order Laminate in the thickness direction. The release film according to item 1 or 5 of the scope of the patent application, wherein the thermoplastic resin comprises a resin selected from the group consisting of poly-4-methyl-1-pentene resin, polybutylene terephthalate resin, syndiotactic One or more of the group consisting of a polystyrene resin and a polypropylene resin. The release film according to item 1 or 5 of the patent application scope, wherein the particles are organic resin particles. The release film according to item 1 or 5 of the scope of patent application, wherein the particles are crosslinked organic resin particles. The release film according to item 1 or 5 of the scope of patent application, wherein the particles comprise a particle selected from the group consisting of polystyrene particles, acrylic particles, polyimide particles, polyester particles, polysiloxane particles, and polypropylene particles. One or two or more particles in the group consisting of polyethylene particles, fluororesin particles, and core-shell particles. For example, the release film of item 1 or 8 of the patent application scope, wherein the thickness of the buffer layer is 10 μm to 180 μm, and the thickness of the release film is 50 μm to 200 μm. A method for manufacturing a molded article, comprising: arranging on the object such that the first release layer of the release film according to any one of claims 1 to 4 and 8 is applied to the object side; A process of the release film; and a process of hot pressing the object on which the release film is disposed, in the process of disposing the release film, the surface of the object on which the release film is disposed is comprised of Made of a thermosetting resin. For example, the method for manufacturing a molded article under the scope of application for a patent No. 14 further includes a process of arranging a material on a surface opposite to the first release layer of the release film before the hot pressing process. For example, the method for manufacturing a molded article under the scope of claims 14 or 15, wherein the thermosetting resin is in a semi-hardened state. Use of a release film, comprising: disposing on the object such that the first release layer of the release film according to any one of claims 1 to 4 and 8 becomes the object side A process of the release film; and a process of hot pressing the object on which the release film is arranged, and used to obtain a molded product after the hot pressing.