JP2017140776A - Method of producing film insert molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a film insert molding that makes distortion smaller and image display more visible and can accurately reproduce characters, patterns and the like in a resin molding having a three-dimensional shape.SOLUTION: A method of producing a film insert molding 1 comprises: a decoration process of decorating a part of a substrate film 2 to make a decorated part 6 and a remainder transparent part 7; a formed film making process of disposing heat insulating means to cover at least the transparent part 7 of the decorated substrate film 2, preheating it and then forming to make a formed film 2A in which a phase difference of the transparent part 7 at a wavelength of 540 nm is 23.4 nm or less; and an injection molding process of disposing the formed film 2A in a metal mold 14 and filling it with a molten thermoplastic resin.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a film insert molded article suitably used for a front panel such as a home appliance.

Resin molded products are used as front panels in liquid crystal display devices such as displays for home appliances, mobile phones, audio devices, and touch panel screens of automatic ticket vending machines. The surface of these front panels may be decorated with letters and patterns.
Conventionally, as a method for producing such a resin molded product, there is a method in which a decorative film is bonded to a substrate sheet such as glass or a plastic plate.
For example, Patent Document 1 below employs a method in which a decorative film (design sheet) having character information and a base material sheet are bonded to a touch panel front plate.
This method is suitable for a flat substrate sheet, but has a problem that it cannot be applied to a three-dimensional substrate sheet.

  Further, there is a film insert molding method in which a decorative film is placed in a mold as an insert film, and a resin as a base material is injected (see, for example, Patent Document 2 below). Although this method can be applied to a resin molded product having a three-dimensional shape, there is a problem that a decorative film (transfer film) is stretched by heat or the like at the time of molding / transfer of the three-dimensional shape, resulting in distortion of a pattern or the like. .

  Patent Document 3 listed below discloses a method for manufacturing a shaped article in which a heating suppression region is provided in a planar region of a film or sheet corresponding to a planar portion.

WO06 / 095684 JP 2000-309033 A JP, 2014-133320, A

However, although the invention which concerns on patent document 3 provides a heat suppression area | region in a shaped article using a masking film, it cannot be said that a masking film is enough as a heat insulation function. That is, the heating suppression region of the shaped article in Patent Document 3 cannot be the phase difference shown in the following invention of the present application (specifically, the phase difference at a wavelength of 540 nm of the transparent portion is 23.4 nm or less). Even if it uses the invention which concerns on this, the low distortion film insert molded article like this invention cannot be achieved. Further, when the masking film is peeled off, a mark may remain and the appearance may be deteriorated.
In particular, when a character is included in the decorative portion, since it is a portion to be watched, distortion is easily recognized as compared with a decorative portion consisting of only a pattern. Further, when a resin molded product is used as a front panel of a liquid crystal display device, it is difficult to visually recognize that image display is distorted, and therefore, lower distortion is required.

  Accordingly, an object of the present invention is to provide a method for producing a film insert molded product that can reduce distortion in a resin molded product having a three-dimensional shape, can easily display an image, and can accurately reproduce characters, patterns, and the like. There is to do.

  The 1st form of this invention covers at least the said transparent part of the decorating process which decorates a part of base film, and forms a decorating part and the remaining transparent part, and the decorated base film A forming film forming step for forming a forming film having a phase difference of 23.4 nm or less at a wavelength of 540 nm of the transparent portion, and forming the film after preheating after disposing the heat insulating means as described above, and the forming film And an injection molding step of filling a molten thermoplastic resin with a mold, and a method for producing a film insert molded product.

  In the manufacturing method of the above aspect, the heat insulating means is preferably a heat insulating material having a linear expansion coefficient of 50 ppm / K or more and 100 ppm / K or less.

  In the manufacturing method of the above aspect, the heat insulating means is preferably a heat insulating material having a thickness of 500 μm or more made of any one of ceramic, metal, and fiber composite material. This is because the heat insulating means has excellent heat resistance and can be sufficiently insulated as compared with a case where the heat insulating means is a heat insulating material made of a thermoplastic resin such as a protective film.

  Since the manufacturing method of the said form preheats using a heat insulation means in a shaping film formation process, the phase difference of a transparent part becomes small, it becomes a shaping film which does not produce distortion easily, and it shape | molded using it. The phase difference of the molded product can also be reduced, and a molded product having a transparent portion with small distortion can be manufactured. If the transparent part is used as a window or the like to form an image display screen, it will be easy to see. When the decorative portion of characters, patterns, etc. is insulated, the distortion of the characters, patterns, etc. is reduced and characters, patterns, etc. with clear outlines can be displayed.

  Thus, in the shaped film forming step, by forming a shaped film having a phase difference of 23.4 nm or less at a wavelength of 540 nm of the transparent portion, the phase difference of the film insert molded product after injection molding is reduced, The distortion of the transparent part of the molded product is reduced.

In the manufacturing method of one Embodiment of this invention, it is the figure which showed the decorated base film. In the manufacturing method of one Embodiment of this invention, it is the figure which showed an example of how to arrange the heat insulation means with respect to a base film. An example of the molded article manufactured with the manufacturing method of one Embodiment of this invention is shown, (A) is a perspective view, (B) is sectional drawing. In the manufacturing method of one Embodiment of this invention, it is the figure which showed typically the preheating method of a shaping film formation process. It is the perspective view which showed an example of the shaping film created in the manufacturing method of one Embodiment of this invention. In the manufacturing method of one Embodiment of this invention, (A) is the figure which showed typically the metal mold | die which performs injection molding, (B) is a figure for demonstrating the time which injects resin in the case of injection compression molding. is there. It is the figure which showed the range which arrange | positions the heat insulation means at the time of producing the shaping films 3 and 4 in an Example.

  Hereinafter, the manufacturing method of the film insert molded article of one embodiment of the present invention is explained based on a drawing. However, the present invention is not limited to this embodiment.

The method for producing a film insert molded product according to an embodiment of the present invention (hereinafter also referred to as the present production method) includes a decorating step for decorating a base film and a decorated base film by shaping. When forming the base film 2 as shown in FIG. 3, comprising a shaped film forming process for forming a shaped film and an injection molding process for injection molding by placing the shaped film in a mold Preheat using the heat insulation means 8.
As shown in FIGS. 2 (A) and 2 (B), an example film insert molded product 1 manufactured by this manufacturing method has a laminated structure of a surface-side shaped film 2A and a back surface-side base resin 3 as shown in FIGS. It is the shape which has the plane part 4 and the standing wall part 5, and is provided with the decorated part 6 and the remaining transparent part 7 which decorated.

(Base film 2)
The base film 2 used in this production method is not particularly limited, but preferably has a thickness of 1 μm or more and 10 mm or less, more preferably 50 μm or more and 500 μm or less, and particularly preferably 150 μm or more and 350 μm or less. This range is preferable from the viewpoints of preventing tearing during shaping and maintaining rigidity after shaping.

Although the base film 2 is not specifically limited, For example, the transparent resin film which consists of resin compositions, such as a polyethylene terephthalate, a polymethylmethacrylate, a polycarbonate, can be used.
As the base film 2, it is preferable to select a resin having a high glass transition temperature from the viewpoint of improving the heat resistance of the film insert molded product. The glass transition temperature is 100 ° C or higher, 170 ° C or lower, and further 120 ° C or higher. It is preferable to select a resin of 160 ° C. or lower, more preferably 140 ° C. or higher and 155 ° C. or lower. That is, when the film insert molded product of the present invention is used as a front panel requiring heat resistance, for example, it is preferable to use polymethyl methacrylate, polycarbonate, or the like.

  On the other hand, from the viewpoint of improving the shaping cycle, it is preferable to select a resin having a low glass transition temperature as the base film 2, and the upper limit value is 140 ° C. or lower, 130 ° C., 50 ° C. or higher and 150 ° C. or lower. Hereinafter, 100 ° C. or lower is preferable, and the lower limit value is preferably 60 ° C. or higher. That is, when used as a front panel for mass production of cellular phones, home appliances, etc., for example, polyethylene terephthalate is preferably used.

The base film 2 has a total light transmittance of 85% or more, preferably 90% or more, particularly 94% or more, and more preferably 98% or more.
In the present invention, the total light transmittance can be measured based on, for example, JIS K7361.
The surface of the base film 2 can be provided with AF (anti-fingerprint), AR (anti-reflection, anti-reflection, low reflection), HC (hard code) functions, and the like. These functions can be provided by a conventional method.

  Although the base film 2 is not particularly limited, the linear expansion coefficient is 30 ppm / K or more and 90 ppm / K or less, preferably 40 ppm / K or more and 80 ppm / K or less, more preferably 50 ppm / K or more and 70 ppm / K or less.

(Decoration process)
In the decorating step, the decorating part 6 decorated on the base film 2 and the remaining transparent part 7 are formed.
The decoration unit 6 may be any type of decoration, but examples thereof include solid coating, letters, patterns, and the like. The part other than the decoration part 6 becomes the transparent part 7. In this embodiment, a rectangular transparent portion 7 that is not printed (a portion that becomes the window portion of the film insert molded product 1) is provided, and a decorative portion 6 that is solidly coated with a suitable color in a rounded corner rectangular frame shape on the outside thereof. Is provided. A part of the decorative portion 6 is made transparent so that characters appear.

The decorative portion 6 can be formed by printing or by bonding metal foil or the like. More specifically, it can be formed by printing such as screen printing, gravure printing, offset printing, transfer of a patterned or coated film, transfer of a metal foil, and the like. Examples of the metal foil include aluminum, gold, copper, stainless steel, and titanium, whereby a mirror surface can be formed.
The total light transmittance of the decorative portion 6 is preferably 10% or less, particularly 6% or less, and more preferably 2% or less.

(Shaping film forming process)
In the shaped film forming step, the base film 2 is preheated using the heat insulating means 8 and shaped to form the shaped film 2A.
In this manufacturing method, the shaped film 2A is formed from the base film 2, and as shown in FIGS. 2 (A) and 2 (B), the standing wall portion 5 hanging from the periphery of the rectangular flat portion 4 is used. A shape having The three-dimensional shape is not limited to this, and can be appropriately shaped into a three-dimensional shape according to the application.
Although the shaping is not particularly limited, it can be performed by pressure forming or the like. More specifically, the base film 2 is shaped into a shaping mold that has been heated to the vicinity of the glass transition temperature of the film after preheating. It can be arranged and molded into the shape of a shaping mold by compressed air.

In the preheating step of the base film 2, the shaped film 2 </ b> A can be adjusted to a phase difference of 23.4 nm (9 / 104π) or less by appropriately insulating the portion.
Examples of the heat insulation method include a method of using a heat insulating material as the heat insulating means 8 as shown in FIG. Moreover, the range to insulate may be divided | segmented and heating temperature may be changed in each range.

As the heat insulating means 8, a heat insulating plate made of a material having a low thermal conductivity can be used. The heat insulating plate is not particularly limited, but the thermal conductivity is 0.03 W / m · K or more, 0. 20 W / m · K or less, preferably 0.04 W / m · K or more, 0.18 W / m · K or less, more preferably 0.05 W / m · K or more, 0.15 W / m · K or less Specifically, ceramic, metal, fiber composite material and the like are preferable from the viewpoint of excellent heat resistance. Examples of the metal include aluminum, gold, copper, stainless steel, titanium, iron, and silver. Examples of the ceramic include alumina, zirconia, hydroxyapatite, silicon carbide, and silicon nitride. Examples of the fiber composite material include glass fiber / epoxy resin, glass fiber / phenol resin, glass fiber / borate, glass fiber / phosphate, glass fiber / silicate, and particularly, silicate compounds and A composite material such as glass fiber is preferable because it is easier to cut than other materials and has a low thermal conductivity, so that the heat insulation effect is high. The thickness of the heat insulating plate is preferably 500 μm or more, particularly preferably 1000 μm or more.
The heat insulating plate is not particularly limited, and a material having a linear expansion coefficient of 50 ppm / K or more and 100 ppm / K or less, preferably 60 ppm / K or more and 90 ppm / K or less can be used.
In the present invention, the linear expansion coefficient can be measured based on, for example, JIS K7197.

When performing a preheating process using the heat insulation means 8, the heat insulation means 8 covers the whole transparent part. Moreover, when printing of a character etc., it is preferable from a viewpoint of reducing the distortion of the film insert molded article 1 to also cover a character part. The size of the heat insulating means 8 is not limited, but is 75% or more, preferably 78% or more, and more preferably 85% or more with respect to the projected area when the film insert molded article 1 is viewed from the front. According to this, the phase difference of the transparent part of a shaping film can be suppressed. On the other hand, from the viewpoint of sufficiently preheating the shaped film, the size of the heat insulating means 8 is preferably 99% or less, more preferably 95% with respect to the projected area when the film insert molded product 1 is viewed from the front. It is as follows.
Moreover, it is preferable that the heat insulation means 8 cover not only the whole transparent part but the range including the decorating part 6 so that it may protrude at least 0.3 cm around the transparent part.
The region of the heat insulating means 8 covering the shaped film is more preferably 0.5 cm or more, more preferably 0.8 cm around the transparent part. According to this, it is considered that the retardation remaining in the shaped film can be suppressed and the phase difference can be reduced.

In this manufacturing method, as shown in FIG.1 (b), the part which becomes the plane part 4 in the base film 2 which provided the decoration part 6 by printing etc. (for example, the range of the broken line of FIG.1 (b)) A heat insulating means 8 made of a heat insulating plate is arranged on the front and back, and as shown in FIG. 3, the film is heated and preheated by a heater device 9 such as an IR heater from both the front and back sides to form the shaped film 2A.
The heat insulating means 8 may not be arranged directly on the base film 2 but may be arranged in a state where it is not brought into contact. According to this, compared with the method in which the heat insulating means is brought into contact, there is no possibility of leaving traces and poor appearance when the heat insulating means is removed, which is preferable. As a method of disposing without contacting, there is a method of fixing a heat insulating plate to a mesh-like metal fitting installed so as to sandwich the base film 2 from above and below.

The heat-insulated transparent portion 7 of the shaped film 2A has a phase difference of 23.4 nm (9 / 104π) or less, preferably 20.8 nm (1 / 13π) or less at a wavelength of 540 nm. By using the heat insulating means, the phase difference can be suppressed and the distortion can be reduced.
By suppressing the retardation of the shaped film 2A within the range, the retardation of the film insert molded product 1 can be adjusted to an appropriate range.

By using a heat insulating plate as the heat insulating means 8 at the time of preheating in the shaped film forming process, excessive heating can be prevented and the amount of bending of the shaped product can be suppressed. Easy to set. As a result, the transparent portion 7 and the decorative portion 6 of the film insert molded product 1 can be reduced in distortion.
In addition, the phase difference of a shaped film or a film insert molded product can be calculated by measuring a transmitted light amount difference through a polarizer before transmission and after transmission in a corresponding portion.

In the transparent part 7 of the shaped film 2A, the proportion of the area where the phase difference after shaping exceeds 62.3 nm (3 / 13π) is preferably 14% or less, more preferably 13% or less, especially 12%. It is as follows. More preferably, the area ratio in which the phase difference after shaping in the transparent portion exceeds 23.4 nm (9 / 104π), and more preferably exceeds 20.8 nm (1 / 13π) is the range.
For example, the area ratio is divided into 8 parts in the horizontal direction and 12 parts in the vertical direction in the transparent part to be measured, that is, 96 parts as a whole, and the phase difference of each divided part is measured to obtain 62.3 nm (3 / 13π) can be calculated as a ratio of the area.

(Injection molding process)
In the injection molding step, the shaping film 2A is placed in the mold 14 and filled with a thermoplastic resin.
As shown in FIG. 4, the shaping film 2 </ b> A is appropriately cut into a shape and set in a mold 14 for injection molding described later. At this time, the shaped film 2A is preferably provided with a film gate portion 10 that extends toward the gate portion 15 side of the mold 14. The area of the film gate portion 10 is preferably reduced. By doing in this way, when it is set as the film insert molded product 1, the shrinkage | contraction rate difference of front and back can be made small, and the phase difference of the film insert molded product 1 can be made small. This is because when the injection molding is performed, the film gate portion 10 is easily heated, so that residual distortion is likely to occur as compared with other portions. It is considered that by reducing the area of the film gate portion 10, it is possible to suppress the distortion remaining in the entire shaped film 2 and reduce the phase difference.
Specifically, the area of the film gate portion 10 is preferably 60% or less, particularly 55% or less, and more preferably 35% or less with respect to the front area of the gate portion 15 of the mold 14.

The base resin 3 is formed by injection molding a thermoplastic resin.
Examples of the thermoplastic resin include polyethylene terephthalate (including a copolymer), polymethyl methacrylate, polystyrene, polycarbonate, polyamide, and the like. Among these, polyethylene terephthalate, polycarbonate, and polyamide are preferable from the viewpoint of high heat resistance, and polycarbonate is more preferable from the viewpoint of high rigidity, high heat resistance, and high impact resistance.
As the thermoplastic resin of the base resin 3, it is preferable to select a resin having a high glass transition temperature when the film insert molded product is used as a front panel requiring heat resistance, like the shaped film. That is, the glass transition temperature is 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and still more preferably 140 ° C. or higher.

The thermoplastic resin is not particularly limited, but a preferable range of the shear rate at the time of injection molding is 10 (1 / s) or more and 10,000 (1 / s) or less, and more preferably 100 (1 / s) and 1000 (1 / s) or less. When used as a front panel of a liquid crystal display device, a low strain is strongly required. Therefore, the preferred range of the shear rate of this thermoplastic resin is 300 (1 / s) or less, more preferably 280 (1 / s). In the following, it is preferable that it is 250 (1 / s) or less. Within this range, distortion can be reduced.
The shear rate of the thermoplastic resin of the base resin 3 can be measured by simulation using a finite element method after setting the mold structure, the resin melt flow rate, the resin temperature, and the mold temperature.

  The linear expansion coefficient of this thermoplastic resin is not limited, but it is 30 ppm / K or more and 90 ppm / K or less, preferably 40 ppm / K or more and 80 ppm / K or less, more preferably 50 ppm / K or more and 70 ppm / K or less. It is a range. If the linear expansion coefficient is within this range, the difference in linear expansion coefficient between the shaped film 2 and the base resin 3 in the film insert molded product 1 can be suppressed, and the shrinkage difference between the front and back surfaces of the film insert molded product 1 This is because the distortion of the film insert molded product 1 can be reduced.

Therefore, the linear expansion coefficient of the thermoplastic resin is such that the difference between the linear expansion coefficient and the shaped film 2 is within 40% when the linear expansion coefficient of the shaped film 2 is 100%. Preferably, it is within 30%, more preferably within 20%. That is, the linear expansion coefficient of the thermoplastic resin is preferably 60% to 140% of the linear expansion coefficient of the shaped film 2.
In the present invention, the linear expansion coefficient can be measured based on, for example, JISK7197.

Thermoplastic resin MFR of the base resin 3 (melt flow rate, 300 ° C., 1.2 kg) ^is, 10 cm 3 / 10min or ^more, 40 cm 3 / 10min or less, preferably 15cm ³ / 10min or ^more, 35 cm 3 / 10min or less, more preferably 20 cm ³ / 10min or ^more, or less 30 cm 3 / 10min. This range is preferable from the viewpoint of moldability.
The bending elastic modulus of the thermoplastic resin of the base resin 3 is 1 GPa or more, preferably 1.5 GPa or more, more preferably 2.0 GPa or more. From the viewpoint of high rigidity.
The total light transmittance of the thermoplastic resin of the base resin 3 is 70% or more, preferably 75% or more, more preferably 80% or more, and further preferably 85% or more.
These physical property values can be measured based on, for example, JISK7210, JISK7171, JISK7361.

  The film insert molded product 1 can, for example, integrally form the shaping film 2A and the base resin 3 by injection molding the thermoplastic resin obtained by placing the shaping film 2A in the mold cavity and melting it.

  When the film insert molded product 1 is injection-molded, as shown in FIG. 5A, a cavity formed by clamping a mold 14 composed of a fixed mold 12 having a resin injection port 11 and a movable mold 13 is used. The shaped film 2A is disposed along at least one of the cavity surfaces, the molten thermoplastic resin is injected into the cavity, an injection product is first formed, and a cutting process or the like is performed to form a film insert molded product 1 Can be molded.

In the injection molding step, injection compression molding in which the thermoplastic resin is filled in the mold before closing the mold is preferable. Specifically, in the injection of the base resin, after the mold 14 is completely closed (for example, as shown in FIG. 5B), the resin is filled in the cavity, and then the mold 14 is closed. By molding, a film insert molded product 1 in which distortion hardly remains after molding can be formed.
The mold 14 is preferably provided with a resin injection port 11 on the lower side so that the resin flows from the bottom to the top from the viewpoint of reducing the distortion of the film insert molded product 1.

The molding temperature in the injection molding step is not particularly limited, but it is good as moldability to be not lower than the melting point of the injected base resin and not higher than the thermal decomposition temperature. Specifically, the resin temperature is 250 to 350 ° C., It is particularly preferable that the temperature is set within a range of 280 to 310 ° C. In addition, in order to suppress distortion of the film insert molded article 1, it is better to set the resin temperature high, and in order to suppress silver caused by the foaming component due to heating, it is better to set the resin temperature low.
The amount of resin compression in the injection mold 14 is preferably 1.2 to 2.5 times. In order to make the film insert molded article 1 have a lower strain, the compression amount is preferably in the range of 1.8 times to 2.5 times, in order to suppress appearance defects caused by the entrainment of air components in the mold 14. In this case, the compression amount is preferably 1.2 to 1.8 times.

  Although the gate part 15 of the metal mold | die 14 is not specifically limited, It is preferable that it is a fan-shaped or film-shaped structure where resin can flow uniformly. By designing in such a shape, distortion of the film insert molded product 1 after molding can be reduced.

  Note that the fan-shaped fan gate portion has an effect that the molten resin filled from the nozzle spreads in the product width direction and is made constant while reducing the speed. The film-shaped film gate portion can reduce warpage and deformation by flowing a molten resin spread over the width of the product at a constant speed within the range of the gate width.

  The injection product taken out from the mold 14 is preferably annealed for relaxation of residual stress. Annealing is preferably performed in a temperature region near the glass transition point, for example, by heat treatment at 100 ° C. to 130 ° C. for 1 hour to 3 hours, more specifically, by heat treatment at about 105 ° C. × about 2 hours. Can do.

  As a mechanism for generating distortion of the film insert molded product 1, at the time of injection molding, after the resin in a fluid state is filled in the mold 14, it is cooled by contacting the mold 14, and the resin in the vicinity of the mold 14 is before shrinkage. While the resin solidifies (residual stress of compression), the resin in the vicinity of the center of the mold 14 is delayed in solidification, and then tries to shrink. However, the resin in the vicinity of the surface layer is solidified and cannot shrink (residual tension). stress). It is considered that distortion occurs due to these residual stresses. Therefore, by annealing again in the temperature region near the glass transition point of the resin, the residual stress due to the cooling and solidification of the resin is released, and the film insert molded product 1 has a low distortion. It becomes.

It is preferable to cut the overhang formed on the gate portion 15 side after annealing the injection product. By cutting the overhanging portion, the residual stress due to the cooling and solidification of the resin generated by the above mechanism is released at the cut portion, and the film insert molded article 1 is reduced in distortion.
Cutting may be performed before annealing.

(Film insert molding 1)
In the film insert molded article 1 produced by this production method, the average value of the phase difference at a wavelength of 540 nm in the transparent portion 7 is 49.3 nm (19 / 104π) or less, preferably 44.1 nm (17 / 104π) or less, It is preferably 38.9 nm (15 / 104π) or less.
In the film insert molded article 1 produced by this production method, the area ratio in which the retardation in the transparent part exceeds 62.3 nm (3 / 13π) is preferably 40% or less, more preferably 35% or less. .
This area ratio can be calculated by the same method as for the shaped film.
The film insert molded product 1 manufactured by this manufacturing method is used as a resin molded product in all fields, and in particular, has a three-dimensional shape and is required to have high quality aesthetics and accurate pattern reproducibility. Is preferably used. Among them, it is suitably used as a front panel mounted on a touch panel screen, home appliances, mobile phones, audio equipment, in-vehicle equipment, etc. used in automatic ticket machines such as ATMs of financial institutions, railway stations and restaurants.

  The film insert molded product 1 can be used as a front panel instead of a conventional resin substrate or glass substrate, and can be formed as a front panel by forming an adhesive layer on the back surface and attaching a sensor (electrode). . According to this, it is possible to create a front panel having a three-dimensional shape that has excellent pattern reproducibility and excellent visibility.

  Hereinafter, an example of the present invention will be shown to specifically explain the present invention. However, the present invention is not limited to this example.

  In order to produce a film insert molded article having a form as shown in FIG. 2, each shaped film was produced by the following procedure.

<Creation of shaped film>
(Shaping film 1)
A film obtained by forming a polycarbonate film with a T-die was used, and this film was coated with a coating agent having an AR, AF, or HC function by a roll coating method. This was cut into sheets and then decorated by screen printing to obtain a base film having a decorated part and a transparent part (linear expansion coefficient 60 ppm / K).
Next, this base film was preheated from above and below with an IR heater. The preheating temperature was 210 ° C. Thereafter, the preheated film was set in a shaping mold and shaped by compressed air under conditions of 280 ° C. and 8 MPa. It was 93.5 nm (9/26 (pi)) when the phase difference of the transparent part of the obtained shaped film was measured and the average value was computed. Moreover, the ratio of the area which exceeds retardation 62.3nm (3/13 (pi)) in the transparent part of the obtained shaped film was 65%.

(Shaping film 2)
Except for adjusting the temperature of the character part and the transparent part to 100 to 120 ° C and the temperature of the other part to 200 to 220 ° C in the preheating step using the base film used in the film 1, A shaped film was prepared in the same procedure as the film 1 described above.

Specifically, the preheating area was divided into 6 × 6 blocks, the preheating was performed by changing the set temperature of the IR heater for each block, and the temperature of each part was set as described above. It was 46.7 nm (9/52 (pi)) when the phase difference of the transparent part of the obtained shaped film was measured and the average value was computed.
In the transparent part, the ratio of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 32%.

(Shaping film 3)
The base film used in the film 1 is used, and in the preheating step, the size occupies 70% of the front projection area of the film insert molded product (252 cm ² ; width 12 cm × length 21 cm). A shaped film was prepared in the same procedure as the film 2 except that the heat insulating plate was arranged as indicated by the chain line 8a.

As the heat insulating plate, a fiber composite material “HIMAL manufactured by MISUMI Corporation” composed of a binder of silicate compound and glass fiber (thickness 5 mm, linear expansion coefficient 7.3 × 10 ⁻⁵ / ° C., thermal conductivity 0.08 W / m -K) was used. As shown in FIG. 3, the heat insulating plate was preheated by placing it so as not to contact the upper and lower sides of the decorative portion and the transparent portion of the base film, so that the heat of the IR heater was blocked at that location. The size of the heat insulating plate was set to cover the entire transparent portion as indicated by a two-dot chain line 8a in FIG. It was 26.0 nm (5/52 (pi)) when the phase difference in the transparent part of the obtained shaped film was measured and the average value was computed.
In the transparent part, the ratio of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 15%.

(Shaping film 4)
The size of the heat insulating plate used in the preheating step is 79% with respect to the front projection area of the film insert molded product (size covering the entire decoration portion (286 cm ² ; width 13 cm × length 22 cm)). As shown by the dotted line 8b, the above-mentioned emphasis is given except that the area extending beyond about 1 cm is covered all around the transparent part and the character part so that the range including the decorative part is insulated. A shaped film was prepared in the same procedure as the shaped film 3. When the phase difference of the transparent part of the obtained shaped film was measured and the average value was calculated, it was 20.8 nm (1 / 13π).
In the transparent part, the ratio of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 12%.

(Shaping film 5)
A shaped film was prepared in the same procedure as the shaped film 4 except that a film that was not decorated was used. When the phase difference of the obtained shaped film was measured and the average value was calculated, it was 51.9 nm (5 / 26π), and the phase difference at the standing wall portion was measured and the average value was calculated to be 93.5 nm. (9 / 26π). Moreover, the ratio of the area which exceeds retardation 62.3nm (3/13 (pi)) among the whole film projection areas was 35%.

(Measurement)
The retardation of the films 1 to 5 was measured as follows. Moreover, the presence or absence of the bending in a shaping film creation process was determined as follows. These results are shown in Table 1 below.

<Phase difference>
The retardation of the shaped film was measured by a two-dimensional birefringence evaluation system PA-110 manufactured by Photonic Lattice. More specifically, the phase difference in the surface direction was found by grasping the transmitted light amount difference between the incident light before transmission and the transmitted light after transmission through the polarizer in the corresponding part. In addition, as described above, the area ratio was determined by measuring the phase difference of each divided portion divided into 96 sections and calculating the ratio of the area exceeding the phase difference of 62.3 nm (3 / 13π) at the wavelength of 540 nm.

<Deflection>
The presence or absence of deflection in the shaped film preparation process was visually observed, and those that did not largely follow the shape of the shaped mold cavity were determined to have deflection.

<Film insert molded product>
The shaped film 3 or 4 was placed on the cavity surface of the mold, and the molten thermoplastic resin was injected to produce film insert molded articles of Examples 1 to 5 and Comparative Examples 1 to 3.
The resin composition constituting the base resin, a polycarbonate resin (shear rate 250 [1 / s], the glass transition temperature of 140 ° C., a melt flow rate (300 ° C., 1.2 kg) is 30 cm ³ / 10min, flexural modulus 2.4 GPa, total light transmittance 88%, linear expansion coefficient 70 ppm / K).
As shown in FIG. 5, a mold having a resin injection port provided below was used.

<Annealing>
In producing the film insert molded article, annealing was performed. The annealing conditions were 105 ° C. × 2 hours.

<Cutting>
In the cutting process, the overhang portion formed on the gate portion side of the mold was cut off by the resin composition.

Example 1
The shaped film 4 is placed so that the area of the film gate portion is 50% of the front area of the mold gate portion, and the thermoplastic resin is set at a resin temperature of 300 ° C. and a compression amount of 1.83 times. Injection and film insert molding were performed. Next, annealing was performed under the above conditions, and the overhang portion was cut to produce a film insert molded product. When the phase difference of this transparent part was measured, it was 41.5 nm (2 / 13π). In the transparent part, the ratio of the area exceeding the retardation 62.3 nm (3 / 13π) was 27%.

(Example 2)
After performing the film insert molding, a film insert molded product was obtained by the same procedure as in Example 1 except that the overhanging part was cut and annealed. When the phase difference of this transparent part was measured, it was 41.5 nm (2 / 13π). In the transparent part, the ratio of the area exceeding the retardation 62.3 nm (3 / 13π) was 27%.

(Example 3)
A film insert molded product was obtained in the same procedure as in Example 1 except that film insert molding was performed at a resin temperature of 320 ° C. The phase difference of the transparent part was measured and found to be 38.9 nm (15 / 104π). In the transparent part, the proportion of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 25%.

Example 4
A film insert molded product was obtained in the same procedure as in Example 1 except that the mold was turned upside down and the resin injection port was turned up during film insert molding. When the phase difference of this transparent part was measured, it was 46.7 nm (9 / 52π). In the transparent part, the ratio of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 32%.

(Example 5)
A film insert molded article was obtained in the same procedure as in Example 1 except that the amount of compression at the time of film insert molding was approximately doubled. When the phase difference of this transparent part was measured, it was 36.3 nm (7 / 52π). In the transparent part, the ratio of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 23%.

(Comparative Example 1)
A film insert molded article was obtained in the same procedure as in Example 1 except that the film insert molding was performed using the shaped film 3. When the phase difference of the transparent part was measured, it was 62.3 nm (3 / 13π) or less. In the transparent part, the proportion of the area exceeding the phase difference of 62.3 nm (3 / 13π) was 45%.

(test)
Using the film insert molded products of Examples 1 to 5 and Comparative Example 1, the following tests were performed. In addition, the phase difference of each film insert molded product was measured similarly to the phase difference of the shaped film. These results are shown in Table 2 below.

<Appearance>
Appearance was evaluated by applying a backlight from behind the transparent part of the film insert molded product, passing through a polarizing plate from the front side, visually checking for the occurrence of rainbow unevenness and silver, and evaluating with the following indicators.
◎: Both rainbow unevenness and silver do not occur, and it is excellent in visibility. ○: Silver is seen a little, but there is no rainbow unevenness and it is excellent in visibility. ×: Rainbow unevenness has occurred and visibility is poor.

<Film setting>
The film setting property was evaluated by the following index when the shaped product was fixed to the mold in film insert molding.
○: When there is no deflection in the shaped product and it is fixed to the mold, there is no hindrance. ×: Deflection that causes trouble in fixing to the mold occurs in the shaped product.

(Test results)
As shown in Table 2, Examples 1 to 5, which are film insert molded products obtained by using the production method of the present invention, are film insert molded products that have a small phase difference in the transparent portion and are three-dimensionally molded. Although there was no distortion and rainbow unevenness, it was excellent in visibility. Moreover, since Examples 1-5 prevent the excessive amount of heat by using the heat insulation board at the time of film preheating in the shaping process and suppress the amount of deflection of the shaped product, the film setting property is excellent. It has been shown.

  On the other hand, Comparative Example 1 had a high phase difference in the transparent portion, was inferior in visibility, and was not suitable for printing. In Comparative Example 1 having a particularly high retardation, the amount of deflection was large from the standpoint of film setability, and the molding was hindered.

  As described above, it is demonstrated from the effects of the above-described Examples and Comparative Examples that the film insert molded product produced by the production method of the present invention is reduced in distortion and has a large difference in appearance and film setability. It was.

DESCRIPTION OF SYMBOLS 1 Film insert molded product 2 Base film 2A shaping film 3 Base resin 4 Flat surface part 5 Standing wall part 6 Decoration part 7 Transparent part 8 Heat insulation means 9 Heater apparatus 10 Film gate part 11 Resin injection port 12 Solid mold 13 Movable Mold 14 Mold 15 Gate part

The 1st form of this invention covers at least the said transparent part of the decorating process which decorates a part of base film, and forms a decorating part and the remaining transparent part, and the decorated base film In this way, the heat insulating means is arranged in a state where it is not in contact with the base film , preheated, and then shaped to form a shaped film having an average phase difference at a wavelength of 540 nm of the transparent portion of 23.4 nm or less. A method for producing a film insert molded article, comprising: a shaped film forming step; and an injection molding step of placing the shaped film in a mold and filling a molten thermoplastic resin.

Claims (13)

A decoration process for decorating a part of the base film to form a decorative part and the remaining transparent part;
A heat insulating means is disposed so as to cover at least the transparent part of the decorated base film, and then preheated, and then shaped to form a shaped film having a phase difference of 23.4 nm or less at a wavelength of 540 nm of the transparent part. A forming film forming process,
An injection molding step in which the shaped film is placed in a mold and filled with a molten thermoplastic resin, and a method for producing a film insert molded product.   The method for producing a film insert molded article according to claim 1, wherein the heat insulating means is a heat insulating material having a linear expansion coefficient of 50 ppm / K or more and 100 ppm / K or less.   The method for producing a film insert molded article according to claim 1, wherein the heat insulating means is a heat insulating material having a thickness of 500 μm or more made of any one of ceramic, metal, and fiber composite material.   The manufacturing method of the film insert molded article in any one of Claims 1-3 which arrange | positions the said heat insulation means in the state which is not made to contact the decorated base film. The heat insulating means insulates the entire transparent part of the base film, and the range including the decorative part of the base film,
The said heat insulation means covers the magnitude | size of 75% or more with respect to the front projection area of an insert molded product, The manufacturing method of the film insert molded product in any one of Claims 1-4.   The method for producing a film insert molded article according to any one of claims 1 to 5, wherein the shaped film has an area ratio in which the phase difference of the transparent portion exceeds 62.3 nm is 14% or less.   The linear expansion coefficient of the thermoplastic resin has a difference from the linear expansion coefficient of the shaped film within 40% when the linear expansion coefficient of the shaped film is 100%. The manufacturing method of the film insert molded article of description.   Furthermore, the manufacturing method of the film insert molded article in any one of Claims 1-7 which anneals.   The method for producing a film insert molded article according to any one of claims 1 to 8, wherein in the injection molding step, injection compression molding is performed to fill the thermoplastic resin before closing the mold.   The manufacturing method of the film insert molded article in any one of Claims 1-9 which cuts the overhang | projection part formed in the gate side in the said injection molding process.   The method for producing a film insert molded article according to any one of claims 1 to 10, wherein a molding temperature in the injection molding step is 250C to 350C.   The method for producing a film insert molded article according to any one of claims 1 to 11, wherein the film insert molded article has a phase difference of 49.3 nm or less at a wavelength of 540 nm. The method for producing a film insert molded article according to any one of claims 1 to 5, wherein in the film insert molded article, an area ratio in which the retardation of the transparent portion exceeds 62.3 nm is 40% or less.

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