阅读说明：本技术 模具与离型膜的组合、离型膜、模具、以及成形体的制造方法 (Mold and release film combination, release film, mold, and molded body manufacturing method ) 是由 酒井圭介 田中奈名恵 宫下显司 小林刚 于 2019-09-24 设计创作，主要内容包括：本发明的目的在于提供一种用来调整成形体的表面状态的技术。本发明涉及一种模具与离型膜的组合,其中模具是为了热硬化性树脂的硬化而使用,离型膜是于所述硬化中配置于所述热硬化性树脂与所述模具之间。所述离型膜包含：基材层,由热塑性树脂所形成；以及表面层,积层于所述基材层的两个面中于所述硬化中配置于热硬化性树脂侧的面,由含有粒子的氟类树脂所形成。所述模具是于在所述硬化中与所述离型膜接触的面形成有凹凸。(The purpose of the present invention is to provide a technique for adjusting the surface state of a molded body. The present invention relates to a combination of a mold used for curing a thermosetting resin and a release film disposed between the thermosetting resin and the mold during the curing. The release film comprises: a base material layer formed of a thermoplastic resin; and a surface layer laminated on one of the two surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, and formed of a fluorine-based resin containing particles. The mold has a surface contacting the release film during the hardening process, and has projections and depressions.)

1. A combination of a mold and a release film, wherein the mold is used for curing a thermosetting resin, and the release film is disposed between the thermosetting resin and the mold during the curing;

the release film comprises:

a base material layer formed of a thermoplastic resin; and

a surface layer laminated on one of the two surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, the surface layer being formed of a fluorine-based resin containing particles;

the mold has a surface contacting the release film during the curing process, and has projections and depressions.

2. The mold and release film combination of claim 1, wherein the particles have an average particle size of 1 μm to 10 μm as measured by laser diffraction particle size analysis.

3. The combination of the mold according to claim 1 or 2 and a release film, wherein the surface roughness Ra of the surface of the mold which is in contact with the release film in the hardening is 1 μm to 4 μm.

4. The combination of the mold and the release film according to any one of claims 1 to 3, wherein the fluorine-based resin of the surface layer contains a tetrafluoroethylene-based resin.

5. The mold and release film combination according to any one of claims 1 to 4, wherein the fluorine-based resin of the surface layer further contains an isocyanate-based hardener.

6. The mold and release film combination of any one of claims 1 to 5, wherein the particles are silica.

7. The mold and release film combination of any one of claims 1 to 6, wherein the thermoplastic resin of the substrate layer is a polyethylene terephthalate resin.

8. The mold and release film combination of any one of claims 1 to 7, wherein the thermosetting resin is an epoxy resin.

9. The combination of the mold and the release film according to any one of claims 1 to 8, wherein the combination is used for forming irregularities on a surface of a cured product of the thermosetting resin.

10. The combination of the mold and the release film according to claim 9, wherein the surface of the cured thermosetting resin has a different roughness from the surface of the mold.

11. The mold and release film combination according to any one of claims 1 to 10, wherein the combination is for transfer molding or compression molding.

12. A release film is characterized in that the release film is used in combination with a mold for curing a thermosetting resin;

the release film comprises:

a base material layer formed of a thermoplastic resin; and

a surface layer laminated on one of the two surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, the surface layer being formed of a fluorine-based resin containing particles;

the mold has a surface contacting the release film during the curing process, and has projections and depressions.

13. A mold is characterized in that the mold is used in combination with a release film for curing a thermosetting resin;

the mold is provided with a concave-convex part on the surface contacted with the release film during the hardening process;

and, the release film comprises:

a base material layer formed of a thermoplastic resin; and

and a surface layer laminated on one of the two surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, and formed of a fluorine-based resin containing particles.

14. A method of manufacturing a shaped body, comprising:

a placement step of placing a release film in a mold used for curing a thermosetting resin;

a curing step of curing the thermosetting resin in the mold in a state of being in contact with the release film after the disposing step; and

a releasing step of releasing the cured thermosetting resin from the mold to obtain a molded body after the curing step;

and, the release film comprises:

a base material layer formed of a thermoplastic resin; and

a surface layer laminated on one of the two surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, the surface layer being formed of a fluorine-based resin containing particles;

the mold has a surface contacting the release film during the hardening process, and has projections and depressions.

Technical Field

The present invention relates to a combination of a mold and a release film, a mold, and a method for manufacturing a molded article, and more particularly, to a combination of a mold and a release film for transfer molding or compression molding, a release film and a mold constituting the combination, and a method for manufacturing a molded article using the combination.

Background

For sealing the semiconductor with the resin, for example, a molding method such as transfer molding or compression molding can be used. In the molding method, a release film is often used in order to easily peel the molded article from the mold after the resin is cured in the mold. Heretofore, various release films and molds have been proposed.

For example, patent document 1 discloses a release film characterized by including: a coating film formed from a composition containing a fluorine resin (A) containing a functional group X and a release component (B), and a layer formed from a non-fluorinated polymer.

Patent document 2 discloses a resin sealing mold for sealing a molded article having a semiconductor chip mounted thereon by sandwiching the molded article between a first mold and a second mold facing each other and using a resin filled in the molds; the resin sealing mold is characterized in that: in at least one of the first mold and the second mold, a first heater is disposed at a position closer to a surface of the mold than a thickness of the resin filled in the mold in a direction opposite to the mold.

Documents of the prior art

Patent document 1: japanese patent laid-open publication No. 2015-74201.

Patent document 2: japanese patent laid-open No. 2012 and 256925.

Disclosure of Invention

(problems to be solved by the invention)

It is sometimes required to adjust the surface of the molded body. For example, the surface of the molded body may be printed with a laser mark, and it is sometimes required to form a surface that can improve the visibility of the printed matter and the readability of a reading device.

The object of the present invention is to provide a novel technique for adjusting the surface of the molded body.

(means for solving the problems)

The present inventors have found that a combination of a specific mold and a release film is suitable for surface conditioning of the molded article.

That is, the present invention provides a combination of a mold and a release film, wherein the mold is used for curing a thermosetting resin, and the release film is disposed between the thermosetting resin and the mold during the curing; and, the release film comprises: a base material layer formed of a thermoplastic resin; and a surface layer laminated on one of both surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, the surface layer being formed of a fluorine-based resin containing particles; the mold has a surface contacting the release film during the curing process, and has projections and depressions.

The average particle diameter of the particles may be 1 μm to 10 μm when measured according to a laser diffraction particle size analysis method.

The surface roughness Ra of the surface of the mold contacting the release film in the hardening may be 1 to 4 μm.

The fluorine-based resin of the surface layer may contain a tetrafluoroethylene-based resin.

The fluorine-based resin of the surface layer may further contain an isocyanate-based hardener.

The particles may be silica.

The thermoplastic resin of the substrate layer may be a polyethylene terephthalate resin.

The thermosetting resin may be an epoxy resin.

The combination can be used to form irregularities on the surface of the cured thermosetting resin.

The unevenness formed on the surface of the cured product of the thermosetting resin may be different from the unevenness of the mold.

The combination may be used for transfer molding or compression molding.

In addition, the invention also provides a release film which is used in combination with the mould for curing the thermosetting resin; and, the release film comprises: a base material layer formed of a thermoplastic resin; and a surface layer laminated on one of both surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, the surface layer being formed of a fluorine-based resin containing particles; the mold has a surface contacting the release film during the hardening process, and has projections and depressions.

In addition, the invention also provides a mold which is used in combination with the release film for the hardening of the thermosetting resin; the mold has a surface contacting the release film during the curing process, and has projections and depressions; and, the release film comprises: a base material layer formed of a thermoplastic resin; and a surface layer laminated on one of the two surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, and formed of a fluorine-based resin containing particles.

In addition, the present invention also provides a method for producing a molded body, comprising: a disposing step of disposing a release film in a mold used for curing a thermosetting resin; a curing step of curing the thermosetting resin in the mold in a state of being in contact with the release film after the disposing step; and a releasing step of releasing the cured thermosetting resin from the mold to obtain a molded body after the curing step; and, the release film comprises: a base material layer formed of a thermoplastic resin; and a surface layer laminated on one of both surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during curing, the surface layer being formed of a fluorine-based resin containing particles; the mold has a surface contacting the release film during the hardening process, and has projections and depressions.

(effect of the invention)

According to the present invention, the surface of the molded body can be adjusted. For example, the visibility and readability of the print marked by the laser can be improved by the present invention.

The effects of the present invention are not necessarily limited to the effects described herein, and may be any of the effects described in the present specification.

Drawings

Fig. 1 is a diagram for explaining an example of a method of using the combination of the present invention in transfer molding.

FIG. 2 is a schematic view showing an example of a laminated structure of release films constituting the combination of the present invention.

FIG. 3 is a view for explaining an example of a method of using the combination of the present invention in compression molding.

Fig. 4 is a view for explaining formation of the formed body-side surface layer.

Fig. 5 shows a graph of the observation results obtained by laser marking.

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described in detail. The embodiments described below represent examples of representative embodiments of the present invention, and the present invention is not limited to these embodiments.

1. Combination of mold and release film

The invention provides a combination of a mold and a release film, wherein the mold is used for curing a thermosetting resin, and the release film is arranged between the thermosetting resin and the mold during the curing. The release film comprises: a base material layer formed of a thermoplastic resin; and a surface layer laminated on one of both surfaces of the base material layer, the surface layer being disposed on the thermosetting resin side during the curing; the surface layer is formed of a fluorine-based resin containing particles. The mold has a surface contacting the release film during the hardening process, and has projections and depressions.

By using the above combination in a molding method such as transfer molding and compression molding, the surface state of the molded article can be adjusted, and for example, a desired glossiness can be imparted to the surface of the molded article. For example, the combination of the invention can be used to produce shaped bodies having a surface with a gloss of 3 to 50 at an angle of incidence of 60 °. For example, the combination of the present invention can be used to produce a molded body having a surface (particularly an epoxy resin surface) with a gloss at an incident angle of 60 ° of 3 to 15, preferably 3 to 10, more preferably 4 to 8, and still more preferably 4 to 6.

Further, by using the above combination, visibility or readability of a print or a pattern applied to the surface of the molded body can be improved. For example, the combination of the invention can be used to produce a shaped body having a surface (in particular an epoxy surface) for printing by laser marking. The printed text height can be, for example, 0.1mm to 10mm, preferably 0.2mm to 5 mm. The letter height of the lettering can also be in particular 0.5mm to 3 mm. By using the combination according to the invention, the visibility or readability of such small characters on the surface of the shaped bodies produced can be improved.

The release film is suitable for reflecting the unevenness of the surface of the mold on the surface of the molded body, and exhibits excellent release properties. In particular, the combination of the particles and the fluorine-based resin contained in the surface layer contributes to the development of excellent releasability and also contributes to the adjustment of the surface state of the molded body.

Hereinafter, an example of a method of using the combination will be described first, and then a release film and a mold, which are components of the combination, will be described in more detail.

1-1. methods of use of the combinations of the invention

The combination of the present invention can be used in various molding methods of thermosetting resins, for example. Preferably, the combination of the present invention is used for forming irregularities on the surface of the cured product of the thermosetting resin.

Such shaping methods are, for example, transfer moulding or compression moulding, in which the combination according to the invention is particularly suitable. In particular, the combination of the present invention can be used for adjusting the surface state of the molded article obtained by these molding methods, and is preferably used for forming irregularities on the surface of these molded articles.

Hereinafter, an example of a method of using the combination of the present invention in these molding methods will be described.

(1) Transfer molding

FIG. 1 is a diagram for explaining an example of a method of using the combination of the present invention in transfer molding. As shown in fig. 1 (a), the release film 11 constituting the combination of the present invention is disposed between the upper mold 12 constituting the combination of the present invention and the lower mold 13 on which the substrate 14 is placed. For example, a semiconductor module 17 may be mounted on the substrate 14. The upper mold 12 and the lower mold 13 are used for molding the thermosetting resin 15. By this molding, the semiconductor element 17 is sealed with a cured product of the thermosetting resin 15. Although fig. 1 shows one semiconductor element 17, the number of semiconductor elements 17 sealed in one molding is not limited to one, and preferably a plurality of semiconductor elements 17.

The release film 11 has a laminated structure shown in fig. 2, for example. The release film 11 has a base material layer 101, and a surface layer 102 is laminated on one surface of the base material layer 101, and a surface layer 103 is laminated on the other surface. The release film 11 will be described in detail below as "1-2. release film".

The surface layer 102 is laminated on one of both surfaces of the base material layer 101, which is disposed on the thermosetting resin side in the transfer molding. That is, the surface layer 102 is in contact with the thermosetting resin 15 in the transfer molding. The surface layer 102 is formed of a fluorine-based resin containing particles.

The surface layer 103 is laminated on one of the two surfaces of the base material layer 101, which is disposed on the upper mold 12 side in the transfer molding. That is, the surface layer 103 is in contact with the upper mold 12 in the transfer molding.

The upper mold 12 has a surface 16 with irregularities. That is, the surface 16 is in contact with the release film 11 (especially the surface layer 103 of the release film 11) during the transfer molding.

Then, as shown in fig. 1 (B), the upper mold 12 is brought into contact with the substrate 14 and the lower mold 13 in a state where the release film 11 (particularly, the surface layer 103 of the release film 11) is attached to the surface 16 of the upper mold 12.

Then, as shown in fig. 1 (C), a thermosetting resin 15 is introduced between the upper mold 12 (particularly, the release film 11) and the substrate 14, and then the thermosetting resin 15 is cured by heating.

In this curing, the uneven shape formed on the surface 16 of the upper mold 12 is reflected on the surface of the thermosetting resin 15 via the release film 11, and the surface shape of the release film 11 (particularly, the surface shape caused by the particles contained in the surface layer 102) is reflected on the surface of the thermosetting resin 15. That is, the uneven shape formed on the surface 16 of the upper mold 12 is indirectly reflected on the surface of the thermosetting resin 15, and the surface shape of the release film 11 (particularly, the surface shape caused by the particles contained in the surface layer 102) is directly reflected on the surface of the thermosetting resin 15. The thermosetting resin 15 is cured in a state where the above-described uneven shape and the above-described surface shape are reflected on the surface of the thermosetting resin 15. That is, the surface of the molded body obtained as a result of the hardening reflects the above-described irregularities and the above-described surface shape. Here, the unevenness formed on the surface of the molded body (cured product) may be different from the unevenness of the mold.

As described above, the surface state of the molded body can be adjusted by the combination of the present invention.

After hardening, as shown in fig. 1 (D), the upper mold 12 is separated from the substrate 14. The release film 11 is formed of a fluorine-based resin containing particles, and thus has excellent release properties. Therefore, in the step (D) in fig. 1, the resin is smoothly released from the cured resin 15. In the case of poor releasability, for example, as shown in fig. 1 (E), the release film 19 may be in close contact with the cured resin 15.

(2) Compression molding

FIG. 3 is a view for explaining an example of a method of using the combination of the present invention in compression molding. As shown in fig. 3 (a), the release film 11 constituting the combination of the present invention is disposed between an upper mold 22 and a lower mold 23, and the upper mold 22 is mounted with a substrate 24 on which a plurality of semiconductor modules 27 are mounted.

As described in (1) above, the release film 11 has a base material layer 101, and a surface layer 102 is laminated on one surface of the base material layer 101 and a surface layer 103 is laminated on the other surface.

The surface layer 102 is laminated on one of both surfaces of the base material layer 101, which is disposed on the thermosetting resin side in the compression molding. That is, the surface layer 102 is in contact with the thermosetting resin 25 described later in the compression molding.

The surface layer 103 is laminated on one of the two surfaces of the base material layer 101, which is disposed on the lower mold 23 side in the compression molding. That is, the surface layer 103 is in contact with the lower mold 23 in the compression molding.

The surface 26 of the lower mold 23 is formed with irregularities. That is, the surface 26 is in contact with the release film 11 (especially the surface layer 103 of the release film 11) during the compression molding.

Then, as shown in fig. 3 (B), the thermosetting resin 25 is disposed in the recess of the lower mold 23 with the release film 11 attached to the surface 26 of the lower mold 23.

Then, as shown in fig. 3 (C), the upper mold 22 is moved so that the substrate 24 is brought into contact with the thermosetting resin 25. Then, the thermosetting resin 25 is cured by heating.

In this curing, the uneven shape formed on the surface 26 of the lower mold 23 is reflected on the surface of the thermosetting resin 25 via the release film 11, and the surface shape of the release film 11 (particularly, the surface shape caused by the particles contained in the surface layer 102) is reflected on the surface of the thermosetting resin 25. That is, the uneven shape formed on the surface 26 of the lower mold 23 is indirectly reflected on the surface of the thermosetting resin 25, and the surface shape of the release film 11 (particularly, the surface shape caused by the particles contained in the surface layer 102) is directly reflected on the surface of the thermosetting resin 25. The thermosetting resin 25 is cured in a state where the above-described uneven shape and the above-described surface shape are reflected on the surface of the thermosetting resin 25. That is, the surface of the molded body obtained as a result of the hardening reflects the above-described irregularities and the above-described surface shape. Here, the unevenness formed on the surface of the molded body (cured product) may be different from the unevenness of the mold.

As described above, the surface state of the molded body can be adjusted by the combination of the present invention.

After hardening, as shown in fig. 3 (D), the upper mold 22 is separated from the lower mold 23. The release film 11 is excellent in release properties particularly when the surface layer 102 of the release film 11 is formed of a fluorine-based resin containing particles. Therefore, in the step (D) in fig. 3, the cured resin 25 can be smoothly released from the lower mold 23.

As described above, the combination of the present invention is used for curing a thermosetting resin. In particular, the combination of the present invention can be used for obtaining a molded article by curing a thermosetting resin. The thermosetting resin is, for example, an epoxy resin or a silicone resin, and preferably an epoxy resin. The combination according to the invention is particularly suitable for adjusting the surface state of these resins.

Regarding the molding temperature in the molding using the combination of the present invention, this molding temperature can be appropriately selected according to the kind of thermosetting resin. The forming temperature is, for example, 100 ℃ to 250 ℃, preferably 120 ℃ to 200 ℃, and more preferably 150 ℃ to 200 ℃.

1-2. release film

The release film constituting the combination of the present invention will be described with reference to fig. 2. As described above, fig. 2 is a schematic view showing an example of a laminated structure of the release film.

The release film 11 shown in fig. 2 includes: a base material layer 101; and a surface layer 102 (also referred to as a "molded body-side surface layer" in the present specification) laminated on one of both surfaces of the base material layer 101 which is disposed on the thermosetting resin side (molded body side) during the curing. The base material layer 101 is formed of a thermoplastic resin. The molded body-side surface layer 102 is formed of a fluorine-based resin containing particles. The release film 11 including the base material layer 101 and the molded body-side surface layer 102 contributes to the surface conditioning that can be performed as described in the above "1 to 1. method of using the combination of the present invention". The molded body-side surface layer 102 is made of a fluorine-based resin containing particles, and thus is easily detached from the cured molded body.

The release film 11 also includes a surface layer 103 (also referred to as a "mold-side surface layer" in the present specification), and the surface layer 103 is laminated on one of the two surfaces of the base material layer 101 which is disposed on the mold side during the curing. The mold-side surface layer 103 may preferably be formed of a fluorine-based resin, and more preferably may be formed of a fluorine-based resin containing particles. Thus, the release film 11 is easily released from the mold after the thermosetting resin is cured.

As described above, the release film 11 has a laminated structure in which the molding-side surface layer 102, the base layer 101, and the mold-side surface layer 103 are laminated in this order. Hereinafter, each layer will be described in more detail.

[ base Material layer ]

The base material layer 101 is formed of a thermoplastic resin. The thermoplastic resin may be a resin having a melting point which is preferably not lower than the molding temperature used for curing the thermosetting resin, and more preferably higher than the molding temperature. Thus, in the molding, the unevenness on the surface of the mold is easily reflected on the surface of the thermosetting resin through the release film 11.

The thermoplastic resin is preferably a polyester resin. The polyester resin is a polymer having an ester bond in the main chain. The polyester-based resin may be a polymer of a polyhydric alcohol and a polybasic acid, for example. The polyester-based resin is a resin containing a polyester as a main component, and may contain the polyester at a ratio of 90 mass% or more, preferably 95 mass% or more, and more preferably 98 mass% or more, relative to the mass of the resin, for example.

The thermoplastic resin may be, for example, any one or a mixture of two or more selected from the group consisting of polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyethylene naphthalate (PEN) resin, polybutylene naphthalate (PBN), and Polycarbonate (PC) resin. The thermoplastic resin is more preferably a PET resin or a PEN resin, and particularly preferably a PET resin. The PET resin is particularly suitable for reflecting the irregularities on the surface of the mold to the surface of the thermosetting resin in the molding.

The PET resin may be a general-purpose PET resin, or may be an easily moldable PET resin. The glass transition temperature of the general-purpose PET resin may be 100 ℃ or higher. In the present specification, the glass transition temperature is a glass transition temperature measured by Differential Thermal Analysis (DTA). The glass transition temperature of the easy-to-mold PET resin is less than 100 ℃, preferably 60 ℃ to 95 ℃, and more preferably 65 ℃ to 90 ℃. The easily moldable PET resin is particularly suitable for preventing contamination of a mold or a molded article by an oligomer contained in the PET resin.

As the substrate layer formed of the general-purpose PET resin, for example, a teflon (registered trademark) film can be used, but the substrate layer is not limited thereto.

The easily moldable PET resin may be, for example, a copolymerized polyethylene terephthalate resin. The copolymerized polyethylene terephthalate can be obtained, for example, by reacting terephthalic acid, ethylene glycol, and a copolymerization component, or can be obtained by mixing and melting a polymer of a copolymerization component with polyethylene terephthalate, followed by a partition reaction.

The copolymerization component may be an acid component or an alcohol component, for example. As the acid component, there may be mentioned: aromatic dibasic acids (e.g., isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid), aliphatic dicarboxylic acids (e.g., adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid), and alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid). As the alcohol component, there may be mentioned: aliphatic diols (e.g., butanediol, hexanediol, neopentyl glycol, and hexanediol) and alicyclic diols (e.g., cyclohexanedimethanol). As the copolymerization component, one or a combination of two or more of these compounds may also be used. The acid component may be, inter alia, isophthalic acid and/or sebacic acid.

As the substrate layer made of an easily moldable PET resin, commercially available ones can be used. For example, as the base layer made of an easily moldable PET resin, Teflex (trademark) FT3, and Teflex (trademark) FW2 (both manufactured by Teijin Film Solutions ltd) can be used. As the substrate layer made of an easily moldable PET resin, Emblet CTK-38 (manufactured by Unitika corporation, Inc.) can be used. As the substrate layer, CH285J (manufactured by Nan Ya Plastics) may be used.

The substrate layer formed of the easily moldable PET resin can be produced by the method described in, for example, Japanese patent application laid-open No. 2-305827, Japanese patent application laid-open No. 3-86729, or Japanese patent application laid-open No. 3-110124. According to a preferred embodiment of the present invention, the substrate layer may be formed by biaxially stretching an easily moldable PET resin so that the in-plane orientation coefficient is preferably 0.06 to 0.16, more preferably 0.07 to 0.15, as described in any of these publications.

The tensile breaking strength of the base layer is preferably 40MPa to 200MPa, more preferably 40MPa to 120MPa, still more preferably 40MPa to 110MPa, and particularly preferably 45MPa to 100MPa, when measured at 175 ℃ in accordance with JIS (Japanese Industrial Standards) K7127.

The tensile elongation at break of the base material layer is preferably 200% to 500%, more preferably 250% to 450%, and still more preferably 300% to 400%, when measured at 175 ℃ according to JIS K7127.

The thickness of the substrate layer may be, for example, 10 to 80 μm, preferably 15 to 75 μm, more preferably 20 to 70 μm, and particularly preferably 30 to 60 μm. This thickness is suitable for reflecting the uneven shape of the mold surface on the surface of the molded body.

[ body-side surface layer of molded article ]

The molded body-side surface layer 102 is formed of a fluorine-based resin containing particles. According to a preferred embodiment of the present invention, the fluorine-based resin does not contain chlorine. By not containing chlorine, the durability and/or stain resistance of this layer is improved. The fluorine-based resin may be, for example, a cured product of a fluorine-based resin composition containing a fluorine-based polymer having a reactive functional group and a curing agent.

The fluorine-based resin preferably contains a tetrafluoroethylene-based resin, and more preferably contains a tetrafluoroethylene-based resin as a main component. In the present specification, the tetrafluoroethylene resin refers to a component obtained by a curing reaction between a reactive functional group-containing tetrafluoroethylene polymer and a curing agent as described below. The tetrafluoroethylene resin as a main component means that the fluorine resin is composed of only the tetrafluoroethylene resin or the amount of the tetrafluoroethylene resin is the largest among the components contained in the fluorine resin. For example, the content ratio of the tetrafluoroethylene resin in the fluorine-based resin may be, for example, 70 mass% or more, preferably 75 mass% or more, more preferably 80 mass% or more, and particularly preferably 85 mass% or more, relative to the total mass of the fluorine-based resin. The content ratio may be, for example, 99 mass% or less, particularly 98 mass% or less, and particularly 97 mass% or less, with respect to the total mass of the fluorine-based resin.

The fluorine-based polymer containing a reactive functional group contained in the fluorine-based resin composition may be a fluorine-based polymer that can be cured by the curing agent. The reactive functional group and the hardener can be appropriately selected by the practitioner.

The reactive functional group may be, for example, a hydroxyl group, a carboxyl group, a group represented by-COOCO-, an amine group or a silicon group, and is preferably a hydroxyl group. By these groups, the reaction for obtaining the cured product can be favorably carried out.

Among these reactive functional groups, a hydroxyl group is particularly suitable for the reaction for obtaining the cured product. That is, the fluorine-based polymer having a reactive functional group is preferably a hydroxyl group-containing fluorine-based polymer, and more preferably a hydroxyl group-containing tetrafluoroethylene-based polymer.

The fluorine-containing unit of the fluorine-based polymer having a reactive functional group is preferably a perfluoroolefin-based fluorine-containing unit. More preferably, the perfluoroolefin-based fluorine-containing unit may be based on one, two or three selected from tetrafluoroethylene (hereinafter also referred to as "TFE" in the present specification), Hexafluoropropylene (HFP) and perfluoro (alkyl vinyl ether) (PAVE). Preferably, the most of the fluorounits based on TFE are among the fluorounits based on perfluoroolefin.

The hydroxyl value of the fluorine-based polymer having a reactive functional group (particularly, the hydroxyl value of the fluorine-based polymer having a hydroxyl group) is preferably from 10mgKOH/g to 300mgKOH/g, more preferably from 10mgKOH/g to 200mgKOH/g, and still more preferably from 10mgKOH/g to 150 mgKOH/g. When the hydroxyl value of the fluorine-based polymer containing a reactive functional group is not less than the lower limit of the above numerical range, the hardening properties of the resin composition can be improved. Further, the hydroxyl value of the fluorine-based polymer having a reactive functional group is not more than the upper limit of the above numerical range, which contributes to making the cured product of the resin composition suitable for multiple molding. This hydroxyl value was obtained by measurement according to the method of JIS K0070.

The acid value of the reactive functional group-containing fluorine-based polymer (especially, the acid value of the hydroxyl group-containing fluorine-based polymer) is preferably from 0.5mgKOH/g to 100mgKOH/g, more preferably from 0.5mgKOH/g to 50 mgKOH/g.

The reactive functional group of the fluorine-based polymer having the reactive functional group can be introduced into the fluorine-based polymer by copolymerizing a monomer having the reactive functional group with a fluorine-containing monomer (particularly, the above-mentioned perfluoroolefin). That is, the reactive functional group-containing fluorine-based polymer may comprise polymerized units based on the reactive functional group-containing monomer, and polymerized units based on the fluorine-containing monomer (in particular, the above-mentioned perfluoroolefin).

In the case where the reactive functional group is a hydroxyl group, the monomer having the reactive functional group is preferably a hydroxyl group-containing vinyl ether or a hydroxyl group-containing allyl ether. Examples of the hydroxyl group-containing vinyl ether include: 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxy-2-methylbutyl vinyl ether, 5-hydroxypentyl vinyl ether, and 6-hydroxyhexyl vinyl ether, and examples of the hydroxyl group-containing allyl ether include: 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether, and glycerol monoallyl ether. Alternatively, the monomer having the reactive functional group may be a hydroxyalkyl ester of (meth) acrylic acid such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate. As the monomer having the reactive functional group, one or a combination of two or more of these compounds may be used. When the reactive functional group is a hydroxyl group, the monomer having a reactive functional group is more preferably a hydroxyl group-containing vinyl ether, and particularly preferably 4-hydroxybutyl vinyl ether and/or 2-hydroxyethyl vinyl ether, from the viewpoint of the curability of the resin composition.

When the reactive functional group is a carboxyl group, the monomer having the reactive functional group is preferably an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, or an anhydride of an unsaturated carboxylic acid.

In the case where the reactive functional group is an amine group, the monomer having the reactive functional group may be, for example, an amine vinyl ether or an allyl amine.

In the case where the reactive functional group is a silicon group, the monomer having the reactive functional group is preferably a silicone-based vinyl monomer.

The fluoromonomer is preferably a perfluoroolefin. Examples of the perfluoroolefin include Tetrafluoroethylene (TFE), Hexafluoropropylene (HFP), and perfluoro (alkyl vinyl ether) (PAVE). Preferably, the fluoromonomer comprises TFE.

Preferably, the reactive functional group-containing fluorine-based polymer may contain a polymerized unit based on a fluorine-free vinyl monomer in addition to a polymerized unit based on a reactive functional group-containing monomer and a polymerized unit based on a fluorine-containing monomer. The non-fluorinated vinyl monomer may be, for example, one or a combination of two or more selected from the group consisting of vinyl carboxylate, alkyl vinyl ether, and non-fluorinated olefin.

Examples of vinyl carboxylates include: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl cyclohexylcarboxylate, vinyl benzoate, and vinyl p-tert-butylbenzoate.

Examples of alkyl vinyl ethers include: methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether.

Examples of non-fluorinated olefins include: ethylene, propylene, n-butene, isobutylene.

The reactive functional group-containing fluorine-based polymer may contain, for example, a polymerization unit based on a fluorine-based monomer other than perfluoroolefins such as vinylidene fluoride (VdF), Chlorotrifluoroethylene (CTFE), Vinyl Fluoride (VF), and vinyl fluoride ether, in addition to a polymerization unit based on a reactive functional group-containing monomer and a polymerization unit based on a fluorine-containing monomer as a perfluoroolefin.

The reactive functional group-containing fluorine-based polymer may be, for example, a TFE/non-fluorinated olefin/hydroxybutyl vinyl ether copolymer, a TFE/vinyl carboxylate/hydroxybutyl vinyl ether copolymer, or a TFE/alkyl vinyl ether/hydroxybutyl vinyl ether copolymer.

More specifically, the fluorine-based polymer having a reactive functional group may be a TFE/isobutylene/hydroxybutyl vinyl ether-based copolymer, a TFE/vinyl versatate/hydroxybutyl vinyl ether-based copolymer, or a TFE/VdF/hydroxybutyl vinyl ether-based copolymer. The fluorine-based polymer having a reactive functional group is particularly preferably a TFE/isobutylene/hydroxybutyl vinyl ether-based copolymer or a TFE/vinylversatate/hydroxybutyl vinyl ether-based copolymer.

As the fluorine-based polymer having a reactive functional group, for example, a product of Zeffle GK series can be used.

The curing agent contained in the fluorine-based resin composition may be appropriately selected by the practitioner according to the kind of the reactive functional group contained in the fluorine-based polymer having the reactive functional group.

When the reactive functional group is a hydroxyl group, the curing agent is preferably a combination of one or more selected from the group consisting of isocyanate-based curing agents, melamine resins, silicate compounds, and isocyanate group-containing silane compounds.

When the reactive functional group is a carboxyl group, the curing agent is preferably one or a combination of two or more selected from the group consisting of amine-based curing agents and epoxy-based curing agents.

In the case where the reactive functional group is an amine group, the hardener may be one or a combination of two or more selected from a carbonyl group-containing hardener, an epoxy-based hardener, and an acid anhydride-based hardener.

The content of the hardener in the fluorine-based resin composition may be, for example, 15 to 50 parts by mass, preferably 20 to 40 parts by mass, and more preferably 23 to 35 parts by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the curing agent in the cured product of the fluorine-based resin composition.

The content of the hardener can be determined by a thermal cracking Gas Chromatography (Py-GC/MS (Pyrolysis-Gas Chromatography-Mass Spectrometry)) method.

In one embodiment of the present invention, the reactive functional group contained in the fluorine-based polymer having a reactive functional group is a hydroxyl group and the hardener may be an isocyanate-based hardener. In this embodiment, the isocyanate-based curing agent is preferably a Hexamethylene Diisocyanate (HDI) -based polyisocyanate.

The content of the HDI-based isocyanate in the fluorine-based resin composition may be, for example, 15 to 50 parts by mass, preferably 20 to 40 parts by mass, and more preferably 23 to 35 parts by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the HDI-based polyisocyanate in the cured product of the fluororesin composition.

As the HDI polyisocyanate, for example, one or a combination of two or more selected from the group consisting of an isocyanuric acid type polyisocyanate, an adduct type polyisocyanate, and a biuret type polyisocyanate can be used. In the present invention, the isocyanate-based hardener is preferably an isocyanuric acid-based polyisocyanate and/or an adduct-based polyisocyanate, and more preferably a combination of an isocyanuric acid-based polyisocyanate and an adduct-based polyisocyanate.

In the case of using a combination of an isocyanate type polyisocyanate and an adduct type polyisocyanate as the hardener, the mass ratio of the two is, for example, 10: 6 to 10: 10, preferably 10: 7 to 10: 9. the total amount of both may be, for example, 15 to 50 parts by mass, preferably 20 to 40 parts by mass, and more preferably 25 to 35 parts by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer.

The content ratio of these hardeners can be determined by a thermal cracking gas chromatography (Py-GC/MS) method.

The fluorine-based resin forming the molded body-side surface layer contains particles, preferably particles having an average particle diameter of 1 μm to 10 μm, more preferably 2 μm to 9 μm, as measured by laser diffraction particle size analysis. The average particle diameter is a volume-weighted volume average particle diameter measured according to JIS Z8825. By containing the particles, the shape of the molded article due to the particles can be reflected on the surface of the molded article, and the releasability of the release film can be improved. When the average particle diameter of the particles is smaller than the lower limit of the numerical range, the surface shape of the particles may not be reflected on the surface of the molded body. When the average particle diameter of the particles is larger than the upper limit value of the numerical range, the releasability may be deteriorated or the particles may be peeled off from the fluorine-based resin. Further, when the average particle diameter of the particles is larger than the upper limit value of the numerical range, for example, streaks may occur when the fluorine-based resin is applied to the base material layer, and the production of the release film may become difficult.

The particles are preferably inorganic particles or organic particles. Examples of the inorganic particles include: silica (especially amorphous silica), calcium carbonate, magnesium carbonate, calcium phosphate, kaolin, talc, alumina, titanium oxide, aluminum oxide, barium sulfate, calcium fluoride, lithium fluoride, zeolite, and molybdenum sulfide. Examples of the organic particles include crosslinked polymer particles and calcium oxalate. In the present invention, the particles are preferably inorganic particles, more preferably silica particles, and still more preferably amorphous silica. The amorphous silica may be a sol-gel type silica. As the amorphous silica, for example, amorphous silica of the Silysia series can be used.

The content of the particles in the fluorine-based resin composition may be, for example, 1 to 30 parts by mass, preferably 2 to 25 parts by mass, and more preferably 3 to 20 parts by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the particles in the cured product of the fluororesin composition. The content within the above numerical range contributes to reflection of the surface shape of the particles on the molded body and/or contributes to improvement of the releasability of the release film.

According to a preferred embodiment of the present invention, the content of the particles in the fluorine-based resin composition may be, for example, 1 to 17 parts by mass, preferably 2 to 16 parts by mass, and particularly preferably 3 to 10 parts by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the particles in the cured product of the fluororesin composition. When the content is within the above numerical range, visibility or readability of the case where printing or a pattern is applied to the surface of the molded body by laser marking can be improved.

The content of the particles can be determined by thermogravimetric analysis (TGA).

The fluorine-based resin composition may contain a solvent. The kind of the solvent can be appropriately selected by the practitioner. Examples of the solvent include butyl acetate, ethyl acetate, and methyl ethyl ketone (also referred to as MEK). For example, a mixture of these three may be used as the solvent. This mixture is suitable for preparing the fluorine-based resin composition.

The fluorine-based resin composition may contain a release accelerator. Examples of the release accelerator include: amino-modified methylpolysiloxane, epoxy-modified methylpolysiloxane, carboxyl-modified methylpolysiloxane, and carbitol-modified methylpolysiloxane. Preferably, the release accelerator is amino-modified methyl polysiloxane.

The release promoter may be, for example, 0.01 to 3 parts by mass, preferably 0.05 to 2 parts by mass, and more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the release accelerator in the cured product of the fluororesin composition.

The thickness of the formed body-side surface layer is, for example, 1 μm to 10 μm, preferably 2 μm to 9 μm, and more preferably 3 μm to 8 μm.

The fluorine-based resin composition can be produced by mixing and stirring the above-described components by a method known to the skilled person. For the mixing and stirring, for example, a high-speed mixer, a homomixer, a paint shaker, or the like can be used. For the mixing and stirring, for example, a dissolver such as a high-speed dissolver (dissolver) of an edge turbine (edge turbine) type may be used.

The cured product of the fluorine-based resin composition is obtained by the following method: the fluorine-based resin composition is applied to the surface of the base material layer, and is heated, for example, at 100 ℃ to 200 ℃, preferably at 120 ℃ to 180 ℃ for, for example, 10 seconds to 240 seconds, preferably 30 seconds to 120 seconds. This hardened substance forms the surface layer. The amount of the fluorine-based resin composition to be applied can be appropriately set by the practitioner according to the thickness of the surface layer to be formed.

The shape of the formed body-side surface layer will be described with reference to fig. 4. The fluorine-based resin composition forming the molding body-side surface layer is applied to the base material layer. Immediately after administration, as shown in fig. 4 (a), the resin composition is in a liquid state, and particles are present in the composition. By heating the resin composition as described above, the solvent in the composition is volatilized to bring the state of (b) in fig. 4, and the shape of the particles gradually appears. Finally, the hardened product of this composition has a surface state as shown in (c) in fig. 4, that is, a concavo-convex shape due to particles appears. As shown in the schematic view of fig. 4 (d), the release film has a molded body-side surface layer 402 on a base material layer 401, and the molded body-side surface layer 402 has irregularities caused by particles. As described above, the release film constituting the combination of the present invention has the molded body-side surface layer formed with the irregularities caused by the particles.

[ surface layer on mold side ]

The mold-side surface layer 103 may be formed of a fluorine-based resin containing particles. According to a preferred embodiment of the present invention, the fluorine-based resin does not contain chlorine. The fluorine-based resin preferably contains a tetrafluoroethylene-based resin, and more preferably contains a tetrafluoroethylene-based resin as a main component. The fluorine-based resin may be, for example, a cured product of a fluorine-based resin composition containing a fluorine-based polymer having a reactive functional group and a curing agent.

The reactive functional group-containing fluorine-based polymer contained in the fluorine-based resin composition is applied to all of the above-mentioned descriptions concerning the reactive functional group-containing fluorine-based polymer contained in the molded body-side surface layer 102, and therefore the description concerning the reactive functional group-containing fluorine-based polymer is omitted.

The explanation of the curing agent contained in the fluorine-based resin composition is also applicable to the kind and content of the curing agent contained in the molded body-side surface layer 102, and therefore, the explanation of the fluorine-based polymer containing a reactive functional group is omitted.

The fluorine-based resin forming the mold-side surface layer contains particles, preferably particles having an average particle diameter of 1 μm to 10 μm, more preferably 2 μm to 9 μm, as measured by laser diffraction-type particle size analysis. The average particle diameter is a volume-weighted volume average particle diameter measured according to JIS Z8825. By containing the particles, the release property of the release film can be improved. When the average particle diameter of the particles is larger than the upper limit value of the numerical range, the releasability may be deteriorated or the particles may be peeled off from the fluorine-based resin. Further, when the average particle diameter of the particles is larger than the upper limit value of the numerical range, for example, streaks may occur when the fluorine-based resin is applied to the base material layer, and the production of the release film may become difficult.

The particles are preferably inorganic particles or organic particles. Examples of the inorganic particles include: silica (especially amorphous silica), calcium carbonate, magnesium carbonate, calcium phosphate, kaolin, talc, alumina, titanium oxide, aluminum oxide, barium sulfate, calcium fluoride, lithium fluoride, zeolite, and molybdenum sulfide. Examples of the organic particles include crosslinked polymer particles and calcium oxalate. In the present invention, the particles are preferably inorganic particles, more preferably silica particles, and still more preferably amorphous silica. The amorphous silica may be a sol-gel type silica. As the amorphous silica, for example, amorphous silica of the Silysia series can be used.

The content of the particles in the fluorine-based resin composition may be, for example, 3 to 30 parts by mass, preferably 5 to 25 parts by mass, and more preferably 10 to 20 parts by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the particles in the cured product of the fluororesin composition. The content within the above numerical range contributes to improvement of the releasability of the release film.

The content of the particles can be determined by thermogravimetric analysis (TGA).

The fluorine-based resin composition may contain a solvent. The kind of the solvent can be appropriately selected by the practitioner. Examples of the solvent include butyl acetate, ethyl acetate, and methyl ethyl ketone (also referred to as MEK). For example, a mixture of these three may be used as the solvent. This mixture is suitable for preparing the fluorine-based resin composition.

The fluorine-based resin composition may contain a release accelerator. Examples of the release accelerator include: amino-modified methylpolysiloxane, epoxy-modified methylpolysiloxane, carboxyl-modified methylpolysiloxane, and carbitol-modified methylpolysiloxane. Preferably, the release accelerator is amino-modified methyl polysiloxane.

The release promoter may be, for example, 0.01 to 3 parts by mass, preferably 0.05 to 2 parts by mass, and more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the reactive functional group-containing fluorine-based polymer. These numerical ranges are also applicable to the content of the release accelerator in the cured product of the fluororesin composition.

It is preferable that the fluorine-based resin composition for forming the mold-side surface layer does not contain a release accelerator.

The thickness of the mold-side surface layer is, for example, 1 μm to 10 μm, preferably 2 μm to 9 μm, and more preferably 3 μm to 8 μm.

The description of the method for producing the fluorine-based resin composition is applied to all of the descriptions of the method for producing the fluorine-based resin composition for forming the molded body-side surface layer 102, and thus the description of the method for producing the fluorine-based resin composition is omitted.

In a preferred embodiment of the present technology, the molded body-side surface layer is formed of a cured product of a fluorine-based resin composition containing the fluorine-based polymer having a reactive functional group (particularly, a hydroxyl group-containing tetrafluoroethylene-based polymer), the curing agent, the particles, and the release accelerator. The mold-side surface layer is formed of a cured product of a fluorine-based resin composition containing the fluorine-based polymer having a reactive functional group (particularly, a hydroxyl group-containing tetrafluoroethylene-based polymer), the curing agent, and the particles.

More preferably, the molded body-side surface layer is formed from a cured product of a fluorine-based resin composition containing a hydroxyl group-containing tetrafluoroethylene polymer, an HDI-based polyisocyanate, silica particles, and an amino-modified methylpolysiloxane. The mold-side surface layer is formed from a cured product of a fluorine-based resin composition containing a hydroxyl group-containing tetrafluoroethylene polymer, a HDI-based isocyanate, and silica particles.

The release film having such two surface layers is particularly helpful: the surface state of the molded article using the combination of the present invention can be adjusted and/or the releasability of the release film can be improved.

[ characteristics of Release film ]

According to a preferred embodiment of the present invention, the tensile break strength of the release film is 40MPa to 200MPa, more preferably 40MPa to 120MPa, still more preferably 40MPa to 110MPa, and particularly preferably 45MPa to 100MPa when measured at 175 ℃ according to JIS K7127, and the tensile break elongation of the release film is 200% to 500%, more preferably 250% to 450%, and still more preferably 300% to 400% when measured at 175 ℃ according to JIS K7127.

The tensile break strength and tensile break elongation of the release film are within the above numerical ranges, and are suitable for adjusting the surface shape of the combination according to the present invention.

The gas (O2) permeability of the release film is, for example, 5000cc/m when measured at 175 ℃ in accordance with JIS K7126-1²24 hr. atm to 50000cc/m²24 hr. atm, in particular 5000cc/m²24 hr. atm to 30000cc/m²24hr atm, more particularly 5000cc/m²24 hr. atm to 20000cc/m²24 hr. atm or less. The release film has such low gas permeability. Therefore, by molding using the release film, mold contamination due to gas generated from the resin can be suppressed.

The thickness of the release film is, for example, 30 to 100 μm, preferably 35 to 90 μm, and more preferably 40 to 80 μm. When the thickness of the release film is within the above numerical range, the uneven shape of the mold surface is easily reflected on the molded body.

The release film can be used for one-time forming or can also be used for multiple times of forming. The release film can be used for molding, for example, 2 times or more, preferably 4 times or more, more preferably 5 times or more, more preferably 6 times or more, and still more preferably 8 times or more. The release film can be used for, for example, formation from 2 times to 20 times, preferably from 4 times to 15 times, more preferably from 5 times to 15 times, more preferably from 6 times to 15 times, and still more preferably from 8 times to 12 times. The release film maintains the performance of the release film through multiple release and is not easy to damage. Therefore, the release film can be used for multiple forming. This can reduce the molding cost.

In addition, polyester resins (particularly PET resins) contain oligomers, which may contaminate molds and/or molded articles during molding (particularly when a release film containing the resin is repeatedly used for molding for many times). However, even when the thermoplastic resin for forming the substrate layer is a polyester resin, the release film is less likely to cause contamination of the mold and/or the molded article during molding. The release film is not liable to cause contamination of the mold and/or the molded body even when the film is repeatedly used for molding for many times. It is considered that this low staining property is derived from the surface layer formed of the fluorine-based resin in particular.

[ method for producing Release film ]

The manufacturing method of the release film comprises the following steps: a coating step of coating a fluorine-based resin composition on both sides of the base material layer; and a curing step of curing the fluorine-based resin composition after the coating step.

The substrate layer and the fluororesin composition used in the coating step are all applied as described above, and therefore, the description thereof will be omitted.

The coating process can be suitably performed by the practitioner in such a manner as to achieve the desired layer thickness. For example, the fluorine-based resin composition may be applied to both surfaces of the substrate layer by a gravure roll method, a reverse roll method, an indirect gravure (offset graure) method, a kiss (kiss) coating method, a reverse kiss coating method, a wire bar coating method, a spray coating method, or an impregnation method. The apparatus for carrying out coating by these methods can be suitably selected by the practitioner.

The hardening process comprises the following steps: the fluorine-based resin composition is heated at, for example, 100 to 200 ℃, preferably 120 to 180 ℃, for example, 10 to 240 seconds, preferably 30 to 120 seconds. The fluorine-based resin composition is cured by the heating.

1-3. mould

In the mold constituting the combination of the present invention, the surface of the mold, which is in contact with the release film during curing of the thermosetting resin, is formed with irregularities. The unevenness is reflected on the surface of the thermosetting resin through the release film. Thus, the unevenness is indirectly reflected on the surface of the thermosetting resin. Therefore, the unevenness formed on the surface of the cured product of the thermosetting resin may be different from the unevenness of the mold.

According to an embodiment of the present invention, the unevenness may be provided at a portion of the mold surface with which the release film is in contact in the molding. For example, the irregularities may be provided only in a region of the mold surface that covers a surface portion of the molded body that requires surface conditioning. This can reduce the area of the mold surface on which the irregularities are formed, and can reduce the manufacturing cost of the mold.

According to another embodiment of the present invention, the unevenness may be provided on the entire surface of the mold which the release film is in contact with during the molding.

The surface roughness Ra of the surface of the mold that is in contact with the release film during hardening is preferably 1 to 4 μm, more preferably 1.2 to 3.8 μm, and particularly preferably 1.4 to 3.6 μm. The surface of the mold having the irregularities has a surface roughness within the above numerical range, and the irregularities are easily reflected on the surface of the cured product of the thermosetting resin through the release film. In the case where the surface roughness is too small, surface conditioning may not be possible. In addition, when the surface roughness is too large, the release film may not be easily separated from the mold and/or the release film may be damaged during molding. When the surface roughness is too large, the roughness of the mold surface becomes uneven, and the appearance of the molded article may be adversely affected.

In the present specification, the surface roughness Ra is measured according to JIS B0601.

The irregularities of the mold surface may be formed by a method known in the art, such as Electrical Discharge Machining (EDM) or shot blast (shot blast), and preferably may be formed by Electrical Discharge Machining (EDM). The electric discharge machining is suitable for forming a surface having the surface roughness Ra within the above numerical range. Such electrical discharge machining is particularly suitable, for example, for imparting surface roughness to a metal surface as described above. The electrical discharge machining can be performed by a method and an apparatus known in the art, and the unevenness can be formed on the surface of the mold by setting the electrical discharge machining apparatus to form the desired unevenness and performing the electrical discharge machining treatment.

The material of the mold can be appropriately selected by a manufacturer according to the kind of thermosetting resin and/or the shape of the molded article. The material of the mold may be selected from materials commonly used in transfer molding or compression molding, for example. The material of the mold is, for example, martensite (martensite) type stainless steel, and more specifically, SUS 404C. The hardness of the mold is preferably 50HRC or more, and more preferably 55HRC or more. The mold may be manufactured by methods known in the art, for example, by NC (Numerical Control) cutting.

The mold is preferably surface treated. The kind of the surface treatment can be appropriately selected by the manufacturer according to the material of the mold. In the case where the material of the mold is martensite stainless steel, the mold may be treated with hard chromium plating, for example.

2. Release film

The present invention also provides a release film used in combination with a mold for curing a thermosetting resin. The release film is a release film constituting the combination of the present invention described in "combination of mold and release film" 1 above, and the description is also applicable to the release film of the present invention in its entirety.

The surface condition of a molded article formed of a cured product of a thermosetting resin can be adjusted by using the release film of the present invention in combination with the mold described in "combination of mold and release film" 1 above for curing the thermosetting resin. The release film of the present invention is suitable for reflecting the unevenness of the surface of the mold on the molded body.

The release film of the present invention is excellent in releasability. Although the portion of the mold surface that is in contact with the release film during the hardening is provided with projections and depressions, the release film is smoothly released from the mold.

3. Die set

The present invention also provides a mold used in combination with a release film for curing a thermosetting resin. This mold is a mold constituting the combination of the present invention described in "combination of mold and release film" 1 above, and this description is also applicable to the mold of the present invention in its entirety.

By using the mold of the present invention in combination with the release film described in "combination of mold and release film" described above in curing the thermosetting resin, the surface state of the molded article formed of the cured product of the thermosetting resin can be adjusted.

4. Method for producing molded body

The invention provides a method for manufacturing a molded body. The manufacturing method comprises the following steps: a placement step of placing a release film in a mold used for curing a thermosetting resin; a curing step of curing the thermosetting resin in the mold in a state of being in contact with the release film after the disposing step; and a releasing step of releasing the cured thermosetting resin from the mold to obtain a molded article after the curing step.

The mold and the release film used in the manufacturing method of the present invention constitute the mold and the release film of the combination of the present invention described in "combination of mold and release film" 1 above, and this description is also applicable to the manufacturing method of the present invention in its entirety. The method for producing the molded body may be, for example, a transfer molding method or a compression molding method, but is not limited thereto.

In the disposing step, the release film is disposed in the mold. The release film may be disposed in the mold such that the molding-body-side surface layer of the release film is in contact with the thermosetting resin and the mold-side surface layer is in contact with the surface of the mold on which the irregularities are formed. For example, the release film may be disposed in the disposing step so as to be in a state shown in fig. 1 (a) or fig. 3 (a) described in the above "1-1. method of using the combination of the present invention".

After the disposing step, the release film may be attached to the surface of the mold on which the irregularities are formed, for example, by suction. The release film may also be softened by heating prior to this attachment.

In the curing step, the thermosetting resin is cured in the mold.

For example, in transfer molding, a closed space may be formed before curing so that the thermosetting resin does not leak from the inside of the mold. For example, as shown in fig. 1 (B), the upper mold and the lower mold are closed to form a closed space. Then, the thermosetting resin can be introduced into the closed space as shown in fig. 1 (C), and then the thermosetting resin is cured by heating.

For example, in compression molding, a thermosetting resin may be introduced into the mold before curing. For example, as shown in fig. 3 (B), a thermosetting resin may be introduced into the recess of the lower mold. Then, as shown in fig. 3 (C), the upper mold having the semiconductor module mounting substrate is moved toward the lower mold, and the molds are closed. In a state where the molds are closed, the thermosetting resin is cured by heating.

In the curing step, the uneven shape formed on the surface of the mold is indirectly reflected on the surface of the thermosetting resin, and the surface shape of the release film (particularly, the surface shape caused by the particles contained in the molding body-side surface layer) is directly reflected on the surface of the thermosetting resin. The thermosetting resin is cured in a state where the uneven shape and the surface shape are reflected on the surface of the thermosetting resin. That is, the surface of the molded body obtained as a result of this hardening reflects the above-mentioned uneven shape and the above-mentioned surface shape. Thus, the surface state of the molded body is adjusted.

In the releasing step, the cured thermosetting resin (molded article) is released from the mold. For example, as shown in fig. 1 (D) or fig. 3 (D), a mold having a surface on which the irregularities are formed is detached from the molded body.

The manufacturing method of the present invention may further include a printing step of printing a laser mark on the surface of the molded body whose surface state is adjusted as described above, after the releasing step. The manufacturing method of the present invention can improve the visibility or readability of printed characters marked by laser. The printed text height can be, for example, 0.1mm to 10mm, preferably 0.2mm to 5 mm. The letter height of the lettering can be in particular 0.5mm to 3 mm. The surface of the molded body obtained by the production method of the present invention can improve the visibility or readability of such small characters.

The molded body with the adjusted surface state is obtained by the above steps.

The present invention will be described in more detail below with reference to examples. The following examples are illustrative of representative embodiments of the present invention, and the scope of the present invention is not limited to these examples.

Example 1: surface preparation example of molded body

(1) Production of release film

Two release films were manufactured as described below.

(1-1) production of Release film

As the substrate layer, a film made of a general-purpose polyethylene terephthalate resin (Teflon G2CW, Dirichen Co., Ltd., thickness 38 μm) was prepared.

Then, two kinds of fluorine-based resin compositions (hereinafter, referred to as a first fluorine-based resin composition and a second fluorine-based resin composition) for coating the film were prepared. The first fluorine-based resin composition is used for forming the mold-side surface layer. The second fluorine-based resin composition is used for forming the molded body-side surface layer.

The first fluorine-based resin composition is prepared by: 100 parts by mass of a composition containing a hydroxyl group-containing tetrafluoroethylene polymer (Zeffle GK570, Daikin Industry Co., Ltd., 65% by mass of which is a hydroxyl group-containing tetrafluoroethylene polymer), 11.47 parts by mass of amorphous silica (Silysia 380, Fuji-Silysia Chemical Co., Ltd.), 10 parts by mass of an isocyanuric acid type polyisocyanate (hardener, Sumidle N3300, Sumitomo Bayer Urethane (Sumitomo Bayer Urethane) Co., Ltd.), 7.79 parts by mass of an adduct type polyisocyanate (hardener, Duranate AE700-100), 6.18 parts by mass of butyl acetate, 44.62 parts by mass of ethyl acetate, and 89.25 parts by mass of MEK were mixed and stirred. The average particle diameter (volume average diameter) of the amorphous silica was 8.8 μm when measured by a laser diffraction particle size analysis method using a particle size analyzer (SALD-2200, manufactured by Shimadzu corporation).

The second fluorine-based resin composition was the same as the first fluorine-based resin composition except that 0.31 parts by mass of an amino-modified methylpolysiloxane (release accelerator, shin-Etsu chemical Co., Ltd.) was added to the first fluorine-based resin composition, the amount of ethyl acetate was changed to 44.81 parts by mass, and the amount of MEK was changed to 89.63 parts by mass.

The first fluorine-based resin composition is applied to one surface of the film, and the second fluorine-based resin composition is applied to the other surface of the film. These applications were carried out using an application apparatus of the kiss reverse type. After the coating, these compositions were heated at 150 ℃ for 60 seconds to cure them, and a release film (hereinafter referred to as "release film 1") in which a fluororesin layer was laminated on both surfaces of a general-purpose PET resin film was obtained.

The thickness of the release film 1 is 60 μm + -5 μm. The thickness of the base material layer in the release film 1 was 38 μm ± 10%. Of the two surface layers of the release film 1, the thickness of the mold-side surface layer was 5.5 μm ± 0.5 μm, and the thickness of the molding-body-side surface layer was 5.5 μm ± 0.5 μm.

The cured product (mold-side surface layer) of the first fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, and 11.98 parts by mass of the adduct type polyisocyanate per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

The cured product (molded body-side surface layer) of the second fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, 11.98 parts by mass of the adduct type polyisocyanate, and 0.48 parts by mass of the amino-modified methylpolysiloxane per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

(1-2) production of Release film

A release film (hereinafter referred to as "release film 2") was produced in the same manner as in (1-1) above, except that the composition of the second fluorine-based resin composition described in (1-1) above was changed as follows.

That is, the second fluorine-based resin composition is prepared by: 100 parts by mass of a composition containing a hydroxyl group-containing tetrafluoroethylene polymer (Zeffle GK570, Daikin Industry Co., Ltd., 65% by mass of which is a hydroxyl group-containing tetrafluoroethylene polymer), 3.42 parts by mass of amorphous silica (Silysia 430, Fuji-Silysia Chemical Co., Ltd.), 10 parts by mass of an isocyanuric acid type polyisocyanate (hardener, Sumidle N3300, Sumitomo Bayer Urethane (Sumitomo Bayer Urethane Co., Ltd.), 7.79 parts by mass of an adduct type polyisocyanate (hardener, Duranate AE700-100), 1.84 parts by mass of butyl acetate, 41.15 parts by mass of ethyl acetate, 82.30 parts by mass of MEK82.30, and 0.11 part by mass of an amino-modified methyl polysiloxane (release accelerator, Kyun Chemical Industry Co., Ltd.) were mixed and stirred. The average particle diameter (volume average diameter) of the amorphous silica was 4.1 μm when measured by a laser diffraction particle size analysis method using a particle size analyzer (SALD-2200, manufactured by Shimadzu corporation).

The thickness of the release film 2 is 60 μm + -5 μm. The thickness of the base material layer in the release film 2 was 38 μm ± 10%. Of the two surface layers of the release film 2, the thickness of the mold-side surface layer was 5.5 μm. + -. 0.5 μm, and the thickness of the molding-body-side surface layer was 3.5 μm. + -. 0.5 μm.

The cured product (mold-side surface layer) of the first fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, and 11.98 parts by mass of the adduct type polyisocyanate per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

The cured product (molded body-side surface layer) of the second fluorine-based resin composition contained 5.26 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, 11.98 parts by mass of the adduct type polyisocyanate, and 0.16 parts by mass of the amino-modified methylpolysiloxane per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

(2) Manufacture of moulds

Four molds were made. These four molds are all transfer molding molds formed by a combination of an upper mold and a lower mold, and have the same shape except for the difference in the irregularities provided on the cavity surface of the upper mold. The irregularities are provided at positions corresponding to the surface 16 of the upper mold 12 in fig. 1 (a). The irregularities are formed by electric discharge machining.

The surface roughness Ra of the regions of the four molds provided with the irregularities is 2.0. mu.m, 2.5. mu.m, 3.0. mu.m, and 3.5. mu.m, respectively, as measured in accordance with JIS B0601. Hereinafter, a mold having a surface with a surface roughness Ra of 2.0 μm is referred to as "mold 1". The molds having surface roughness Ra of 2.5 μm, 3.0 μm and 3.5 μm are similarly referred to as "mold 2", "mold 3" and "mold 4", respectively.

The main material of these four molds was SUS 440C. In addition, these four molds each had a hardness of HRC (Rockwell hardness) 55 or more, and the surfaces of these four molds were plated with hard chrome.

(3) Production of molded bodies

A thermosetting resin (epoxy resin, GE100, hitachi chemical co., ltd.) was molded using a combination of a release film and a mold as shown in table 1 below. A transfer pressure of 8.5MPa or 5.0MPa was used for this formation. The molding temperature for curing the thermosetting resin in this molding was 175 ℃. The gloss at an incident angle of 60 ° was measured on the surface of each of the molded articles obtained by the molding using a gloss meter (PG-IIM, japan electro-chromatic industries, ltd.). The measurement results are also shown in table 1 below.

[ Table 1]

As shown in table 1, in the case of using the release film 1, the gloss decreased with an increase in Ra of the mold. From these results, it was found that the irregularities of the molds 1 to 4 are reflected on the surface state of the molded body via the release film 1.

In the case of using the release film 2, the gloss is reduced with an increase in Ra of the mold as well. From this result, it was found that the irregularities of the molds 1 to 4 are reflected on the surface state of the molded body via the release film 2.

In addition, when the four results of the case of using the mold 1 are compared, the gloss of the surface of the molded article is different depending on the difference in the release film even in the same mold. The release film 1 and the release film 2 have different compositions of the surface layer on the molded body side, and particularly have different content ratios of particles in the surface layer. From these results, it was found that the shape of the surface layer of the release film, particularly the shape caused by the particles in the surface layer, was reflected on the surface state of the molded body.

From the above results, it was found that the surface state of the molded article can be adjusted by the combination of the mold and the release film of the present invention. It is known that the gloss of the surface of the shaped body can be adjusted, for example, by this combination.

The surface state (particularly, the state of surface irregularities) of all the molded articles obtained is different from the surface irregularities of the mold used and also from the surface state of the molded article-side surface layer of the release film used. From this result, it is considered that both the unevenness on the mold surface and the shape of the molded body-side surface layer of the release film contribute to the adjustment of the surface state of the molded body (particularly, the state of the unevenness on the surface).

In the molding, any release film is smoothly separated from the molded body. Therefore, it was found that the release film constituting the combination of the present invention can be smoothly separated from a molded article having irregularities on the surface thereof after molding the molded article.

Example 2: evaluation of surface of molded article printed by laser marking

(1) Production of release film

Three release films were manufactured as described below.

(1-1) production of Release film

As the substrate layer, a film made of an easily moldable polyethylene terephthalate resin (CH285J, Nana Plastics (Nan Ya Plastics) Co., Ltd., thickness 50 μm) was prepared.

Then, two kinds of fluorine-based resin compositions (hereinafter, referred to as a first fluorine-based resin composition and a second fluorine-based resin composition) for coating the film were prepared. The first fluorine-based resin composition is used for forming the mold-side surface layer. The second fluorine-based resin composition is used for forming the molded body-side surface layer.

The first fluorine-based resin composition is prepared by: 100 parts by mass of a composition containing a hydroxyl group-containing tetrafluoroethylene polymer (Zeffle GK570, Daikin Industry Co., Ltd., 65% by mass of which is a hydroxyl group-containing tetrafluoroethylene polymer), 11.47 parts by mass of amorphous silica (Silysia 380, Fuji-Silysia Chemical Co., Ltd.), 10 parts by mass of an isocyanuric acid type polyisocyanate (hardener, Sumidle N3300, Sumitomo Bayer Urethane (Sumitomo Bayer Urethane) Co., Ltd.), 7.79 parts by mass of an adduct type polyisocyanate (hardener, Duranate AE700-100), 6.18 parts by mass of butyl acetate, 44.62 parts by mass of ethyl acetate, and 89.25 parts by mass of MEK were mixed and stirred. The average particle diameter (volume average diameter) of the amorphous silica was 8.8 μm when measured by a laser diffraction particle size analysis method using a particle size analyzer (SALD-2200, manufactured by Shimadzu corporation).

The second fluorine-based resin composition was the same as the first fluorine-based resin composition except that 0.31 parts by mass of an amino-modified methylpolysiloxane (release accelerator, shin-Etsu chemical Co., Ltd.) was added to the first fluorine-based resin composition, the amount of ethyl acetate was changed to 44.81 parts by mass, and the amount of MEK was changed to 89.63 parts by mass.

The first fluorine-based resin composition is applied to one surface of the film, and the second fluorine-based resin composition is applied to the other surface of the film. These applications were performed using a touch-reverse type application apparatus. After the coating, these compositions were heated at 150 ℃ for 60 seconds to cure them, and a release film (hereinafter referred to as "release film 3") in which a fluororesin layer was laminated on both surfaces of a general-purpose PET resin film was obtained.

The thickness of the release film 3 is 70 μm + -5 μm. The thickness of the base material layer in the release film 3 is 50 μm ± 10%. Of the two surface layers of the release film 3, the thickness of the mold-side surface layer was 5.5 μm ± 0.5 μm, and the thickness of the molding-body-side surface layer was 5.5 μm ± 0.5 μm.

The cured product (mold-side surface layer) of the first fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, and 11.98 parts by mass of the adduct type polyisocyanate per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

The cured product (molded body-side surface layer) of the second fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, 11.98 parts by mass of the adduct type polyisocyanate, and 0.48 parts by mass of the amino-modified methylpolysiloxane per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

(1-2) production of Release film

A release film (hereinafter referred to as "release film 4") was produced in the same manner as the release film 3 of (1-1) above, except that the composition of the second fluorine-based resin composition of (1-1) above was changed as follows.

That is, the second fluorine-based resin composition is prepared by: 100 parts by mass of a composition containing a hydroxyl group-containing tetrafluoroethylene polymer (Zeffle GK570, Daikin Industry Co., Ltd., 65% by mass of which is a hydroxyl group-containing tetrafluoroethylene polymer), 9.71 parts by mass of amorphous silica (Silysia 380, Fuji-Silysia Chemical Co., Ltd.), 10 parts by mass of an isocyanuric acid type polyisocyanate (hardener, Sumidle N3300, Sumitomo Bayer Urethane (Sumitomo Bayer Urethane) Co., Ltd.), 7.79 parts by mass of an adduct type polyisocyanate (hardener, Duranate AE700-100), 5.23 parts by mass of butyl acetate, 44.03 parts by mass of ethyl acetate, 88.07 parts by mass of MEK 88.07, and 0.30 part by mass of an amino-modified methyl polysiloxane (release accelerator, Kyun Chemical Industry Co., Ltd.) were mixed and stirred.

The thickness of the release film 4 is 60 μm + -5 μm. The thickness of the base material layer in the release film 4 is 50 μm ± 10%. Of the two surface layers of the release film 4, the thickness of the mold-side surface layer was 5.5 μm ± 0.5 μm, and the thickness of the molding-body-side surface layer was 5.5 μm ± 0.5 μm.

The cured product (mold-side surface layer) of the first fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, and 11.97 parts by mass of the adduct type polyisocyanate per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

The cured product (molded body-side surface layer) of the second fluorine-based resin composition contained 14.94 parts by mass of the amorphous silica, 15.38 parts by mass of the isocyanurate type polyisocyanate, 11.97 parts by mass of the adduct type polyisocyanate, and 0.46 parts by mass of the amino-modified methylpolysiloxane per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

(1-3) production of Release film

A release film (hereinafter referred to as "release film 5") was produced in the same manner as the release film 3 of (1-1) above, except that the composition of the second fluorine-based resin composition of (1-1) above was changed as follows.

That is, the second fluorine-based resin composition is prepared by: 100 parts by mass of a composition containing a hydroxyl group-containing tetrafluoroethylene polymer (Zeffle GK570, Daikin Industry Co., Ltd., 65% by mass of which is a hydroxyl group-containing tetrafluoroethylene resin), 3.42 parts by mass of amorphous silica (Silysia 380, Fuji-Silysia Chemical Co., Ltd.), 10 parts by mass of an isocyanuric acid type polyisocyanate (hardener, Sumidle N3300, Sumitomo Bayer Urethane (Sumitomo Bayer Urethane) Co., Ltd.), 7.79 parts by mass of an adduct type polyisocyanate (hardener, Duranate AE700-100), 1.84 parts by mass of butyl acetate, 41.15 parts by mass of ethyl acetate, 82.30 parts by mass of MEK82.30, and 0.11 part by mass of an amino-modified methyl polysiloxane (release accelerator, Kyun Chemical Industry Co., Ltd.) were mixed and stirred.

The thickness of the release film 5 is 60 μm + -5 μm. The thickness of the base material layer in the release film 5 was 50 μm ± 10%. Of the two surface layers of the release film 5, the thickness of the mold-side surface layer was 5.5 μm. + -. 0.5 μm, and the thickness of the molding-body-side surface layer was 3.5 μm. + -. 0.5 μm.

The cured product (mold-side surface layer) of the first fluorine-based resin composition contained 17.65 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, and 11.98 parts by mass of the adduct type polyisocyanate per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

The cured product (molded body-side surface layer) of the second fluorine-based resin composition contained 5.26 parts by mass of the amorphous silica, 15.39 parts by mass of the isocyanurate type polyisocyanate, 11.98 parts by mass of the adduct type polyisocyanate, and 0.16 parts by mass of the amino-modified methylpolysiloxane per 100 parts by mass of the hydroxyl group-containing tetrafluoroethylene-based polymer.

(2) Manufacture of moulds

A mold for compression molding (hereinafter referred to as "mold 5") composed of a combination of an upper mold and a lower mold was manufactured. The lower mold constituting the mold has a surface formed with irregularities. The concave-convex is provided at a position corresponding to the surface 26 of the lower mold 23 in fig. 3 (a). The irregularities are formed by electric discharge machining. The surface roughness Ra of the region in which the above-described irregularities are formed was 1.0 μm as measured in accordance with JIS B0601.

The main material of the die 5 is SUS 440C. The mold 5 has a hardness of HRC55 or more, and the surface of the mold 5 is plated with hard chromium.

(3) Production of molded bodies

A thermosetting resin (epoxy resin, GE100, hitachi chemical co., ltd.) was molded using any one of the release films 3 to 5 and the mold 5. The molding temperature for curing the thermosetting resin in this molding was 175 ℃. The surface of each of the molded bodies obtained by the molding was printed with a laser mark (MD-S9910 type three-dimensional YVO4 laser mark, Keyence corporation). The printing conditions were as follows: the height of the characters is as follows: 1 mm; power (Power): 3.6W; switching frequency: 40 KHz; scanning speed: 700 mm/s.

The printing on the surface of each molded article was observed by a 3D microscope (VR-3200 type 3D microscope, Keyence corporation) and visual observation.

The observation results obtained by the 3D microscope are shown in fig. 5. As shown in fig. 5, the molded article obtained using the release film 4 has better visibility of characters than the molded article obtained using the release film 3, and the molded article obtained using the release film 5 has better visibility of characters than the molded article obtained using the release film 4. In the case of visual observation, the same observation results were obtained. From these results, even when a mold having the same surface irregularities is used, the surface state of the molded article can be adjusted by using release films having different shapes of the molded article-side surface layer of the release film.

From the above results, it is considered that the visibility of characters or patterns printed by laser marking can be improved by setting the particle content of the molded body-side surface layer to preferably 16 parts by mass or less, more preferably 10 parts by mass or less, with respect to 100 parts by mass of the fluorine-based resin.

(description of symbols)

11: release film

12: upper side die

13: a lower mold.