WO2014203917A1

WO2014203917A1 - Film, film molding method, mold, molding comprising film, and molding method therefor

Info

Publication number: WO2014203917A1
Application number: PCT/JP2014/066099
Authority: WO
Inventors: 田原　久志; 鈴木　克則; 昭郎大久保
Original assignee: 三菱瓦斯化学株式会社; Ｍｇｃフィルシート株式会社
Priority date: 2013-06-20
Filing date: 2014-06-18
Publication date: 2014-12-24
Also published as: JP6525871B2; TWI626146B; TW201513992A; KR20160021806A; CN105392612A; JPWO2014203917A1; KR102196604B1; CN105392612B

Abstract

Provided are a film, for which, in addition to maintaining a favorable appearance, the occurrence of cracks has been reliably prevented, and a molding method, etc. for such films. The film, for which, in addition to maintaining a favorable appearance, the occurrence of cracks has been reliably prevented, and the molding method, etc. therefor were achieved by: closing the upper die and lower die of a molding mold, with a film fixed between the upper die and the lower die and heated, and pressing the film using an upper die pressing member on the outside of a lower die protruding section for a first forming; and then, performing a second forming of the film at least on the outside of the lower die protruding section using the pressure of a gas introduced from the upper die side.

Description

Film, molding method for molding film, mold, molded product including film, and molding method thereof

The present invention relates to a film, a molding method for thermoforming the film into a desired three-dimensional shape, a molding die, and a three-dimensional shaped article (molded article) using the film. In particular, the present invention relates to a hard coat sheet or the like. It is used suitably for manufacture of the decorative molded product containing this.

Decorated molded products (painted molded products) or in-mold molded products are attracting attention from the aspects of productivity, design and functionality. Examples of applicable objects include exterior parts of mobile phones, automobile-related parts, medical equipment, electronics products, home appliances, building materials, containers such as detergents and cosmetics, and toys.

Patent Document 1 discloses a resin molded product having a good appearance such as a mirror surface and a diaphragm surface, without forming a film layer or coating on the surface, and with a large size that can withstand high pressure as in an injection molding method. In order to be able to mold without using an apparatus, the following is disclosed. That is, a supporting member that supports the mold member in a state in which a space is secured between the mold member and the molding surface having the molding surface, and the molding surface has a Vicat softening temperature (T) ° C. or higher of the sheet-like resin to be molded. For vacuum / compression molding having heating means for heating to a temperature and cooling means for cooling the molding surface to a Vicat softening temperature (T) of −10 ° C. or less by supplying a cooling medium to the space The mold is disclosed.
In Patent Document 2, the opening 2 can be made into a square shape, a fitting member with a decorative frame or the like can be simplified, and a special operation such as extending the cooling time to prevent warping. In order to provide a technique that is not necessary, the following is disclosed. That is, in a pressure forming mold for obtaining a square-mouthed air pressure molded product in which the opening periphery green has a concave shape and the opening periphery has a rectangular shape, the opening periphery green in the mold Are formed so that each side swells outwardly, and the degree of the swell is formed so that each side of the opening circumference is linear due to deformation accompanying material cooling after molding. A pressure forming mold characterized by being defined is disclosed.

By the way, as an example of shaping in the conventional compressed air molding method, horizontal arrangement molds are summarized as follows.
(I) Secure the sheet with the sheet holder.
(Ii) Move the sheet holder to the heating zone and heat from above with infrared rays to soften the sheet to a temperature higher than its Tg.
(Iii) Move the sheet holder onto the mold core, perform mold clamping and prepare for sheet molding, and simultaneously introduce pressurized air.
(Iv) The sheet stretches rapidly until it comes into contact with the surface of the mold core by pressurized air, and when it comes into contact with the surface of the mold core, the sheet is rapidly cooled down to below the Tg of the resin. Fixed and shaped product.
(V) After discharging pressurized air, etc., take out the shaped product.

In this method, when a mold including a mold core having a rising portion substantially perpendicular to the bottom surface is used, the bottom surface of the shaped sheet (film) is finally shaped, so that Growth occurs.
Resin molded products have a problem that the surface is easily scratched, so there are many cases where hard coated sheets are used as a measure to prevent scratches, but since hard coats are hard and small in elongation, cracks occur when exceeding the limit elongation Prone to problems. When the molding method was used, the same part of the hard coat was stretched as the film was stretched, so that cracks were concentrated near the outer shape of the molded product and the bottom of the hole. Therefore, it was necessary to prevent hard coat cracks by changing the design to a shape with a gentle curvature or a reduced rise height.

In addition, by using a hard coat with improved elongation performance at the expense of some damage prevention performance by reducing hardness, the rising height is increased (generally less than 4 mm) even in a substantially vertical shape. However, since the scratching property of the resin surface is not improved so much, there is a problem that the hard coat is scratched at the time of use despite the cost.

JP-A-10-193449 JP 2004-142403 A

The inventors of the present invention have focused on the fact that cracks that are concentrated in the vicinity of the bottom surface are generated by a mechanism during shaping. That is, it is a problem that the part finally extended becomes local elongation.
When shaping only with pressurized air, only the base of the bottom surface is stretched locally, while when pressing with a mold without using pressurized air when shaping, the area near the top surface is stretched locally. It was found that cracks occurred. In addition, when all surfaces are pressed, air or the like is involved because the mold and the top of the sheet that require strict quality especially for the appearance of the design are in contact, or the mold surface is transferred to the sheet when the mold is not polished. It was found that the appearance deteriorated.
Therefore, the purpose of the present application is to provide a mold, a molding method, and the like that keep the shaped sheet appearance good, for example, so as not to generate cracks even when a hard coat having scratch resistance is used. An object of the present invention is to provide a film or sheet and a molded article including them, in which the height of the shape rises and the curvature on the top surface side can be reduced, and design restrictions are minimized. As described above, since the hard coat layer is provided for the purpose of preventing scratch resistance, the present invention is particularly preferably used in molding a hard coat sheet or the like in which cracks are easily generated.

The inventors of the present invention have completed the present invention as a result of intensive studies on a molding method in which hard coat cracks of a hard coat film are not generated by pressure forming.
That is, the present invention is as follows.
(1) A hard coat having 10 or less scratches on the surface of the film before molding in the scratch resistance test (according to ASTM D 2486-79, using a pork brush at a load of 450 g for 200 reciprocations). The film is provided with at least a layer, and is formed on the outer side of the convex portion with respect to the first region (thick portion) of the film disposed on the convex portion of the lower mold for molding used at the time of molding. The film is characterized in that the elongation ratio of the second region (edge) of the film is 100% or less.
(2) a lower mold having a convex part;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for shaping a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing a film between an upper mold and a lower mold,
In a state where the upper die pressing member is retracted, a heating step of fixing the film to the fixed frame and softening by heating,
A primary shaping step of primary shaping by pressing the film at least on the outside of the convex portion at the time of clamping the upper die and the lower die;
The film is molded by a molding method including a secondary shaping step for secondary shaping of the film at least outside the convex portion of the lower mold clamped by the pressure of the gas introduced from the upper mold side. It is a film.
(3) a lower mold having a convex part provided with a concave part for forming a hole and / or a concave part in the molded product;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for shaping a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing a film between an upper mold and a lower mold,
In a state where the upper die pressing member is retracted, a heating step of fixing the film to the fixed frame and softening by heating,
A primary shaping step of primary shaping by pressing the film at least on the outside of the convex portion at the time of clamping the upper die and the lower die;
The film is molded by a molding method including a secondary shaping step for secondary shaping of the film at least outside the convex portion of the lower mold clamped by the pressure of the gas introduced from the upper mold side. It is a film.
(4) The elongation ratio of the second region (end portion) of the film formed on the outer side of the convex portion with respect to the first region (thick portion) of the film disposed on the convex portion at the time of molding is 100. % Or less, the film according to (2) or (3).
(5) The film according to (2) or (3) above, which is a hard coat film having a hard coat layer.
(6) The film according to (1) or (5) above, wherein the film is a hard coat film printed on the surface opposite to the hard coat layer.
(7) A molded article comprising the film according to any one of (1) to (6) above.

(8) a lower mold having a convex part;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for shaping a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing a film between an upper mold and a lower mold,
With the pressing member retracted, a heating step of fixing the film to the fixed frame and heat softening;
A primary shaping step of primary shaping by pressing the film at least on the outside of the convex portion at the time of clamping the upper die and the lower die;
A film forming method comprising: a secondary shaping step of secondary shaping of the film at least outside the convex portion of the lower mold clamped by the pressure of the gas introduced from the upper mold side is there.
(9) a lower mold having a convex part provided with a concave part for forming a hole and / or a concave part in the molded product,
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for shaping a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing a film between an upper mold and a lower mold,
In a state where the upper die pressing member is retracted, a heating step of fixing the film to the fixed frame and softening by heating,
A primary shaping step of primary shaping by pressing the film at least on the outside of the convex portion at the time of clamping the upper die and the lower die;
A film forming method comprising: a secondary shaping step of secondary shaping of the film at least outside the convex portion of the lower mold clamped by the pressure of the gas introduced from the upper mold side is there.
(10) The above-mentioned (8) or (9), wherein the pressing member is advanced to introduce the primary shaping process and pressurized air is introduced within 1 second from the start of the primary shaping process to start the secondary shaping process. The molding method described in 1.
(11) The method for forming a film according to the above (8) or (9), wherein the gas is pressurized air.
(12) The film forming method as described in (8) or (9) above, wherein the film is a hard coat film having a hard coat layer.
(13) The film forming method according to (12), wherein the film is a hard coat film having a surface printed on the opposite side to the hard coat layer.
(14) The film forming method according to (8) or (9) above, wherein in the primary shaping step, the fixed frame is fitted to the upper die and the lower die at the time of mold clamping. .
(15) The gas introduction hole is formed in the upper mold, and the gas is introduced from the gas introduction hole to the surface of the film in the secondary shaping step, described in (8) or (9) above This is a film forming method.

(16) The film formed by the method according to (8) or (9) above is a hard coat film printed on the surface opposite to the hard coat layer,
A processing step of processing the hard coat film so as to correspond to the shape of the injection mold cavity;
An insert step of forming a film base by inserting a hard coat film so that the hard coat surface is in contact with the cavity in the cavity of the injection mold;
A molding method for molding a molded product, comprising: a molding step of molding the molded product by integrating the film base material and the injection molding material by injection molding.

(17) Molding including a lower mold having a convex part, an upper mold provided with a pressing member positioned outside the convex part at the time of mold clamping, and a fixing frame for fixing the film between the upper mold and the lower mold It is a metal mold.
(18) The molding die according to (17), wherein the lower mold is provided with a recess for forming a hole and / or a recess in the molded product.

(19) The molding die according to the above (17), wherein the pressing member has an inner surface substantially similar to the convex portion.
(20) The molding die according to (17) above, wherein a gas introduction hole is formed in the upper mold in order to introduce gas into the surface of the film in the secondary shaping step. .
(21) In the above (17), the difference in dimension between the inner diameter of the pressing member and the outer diameter of the convex portion is (film thickness before molding (mm) × 2) +1 mm to 4 mm. It is a molding die as described.
(22) The pressing member operates via an air cylinder or a hydraulic cylinder, and the tip cross-sectional shape of the pressing member that presses the film is chamfered and / or rounded, and the primary shaping step and the secondary shaping The molding die according to (17), wherein the molding die is not in contact with a top surface on a convex portion of the film in the process.

According to the present invention, a film or sheet, in particular, a sheet having a hard coat, and a design application shape range such as a shaped article and an in-mold molded article thereof, and a film or sheet in which no crack is generated, Further, a three-dimensional shaped product (molded product) and the like can be provided.

It is sectional drawing which shows 1st Embodiment of the metal mold | die for pressure forming of this invention. It is a schematic plan view showing a movable ring and a mold core of a pressure forming mold. It is sectional drawing which shows the state by which the sheet | seat fixing frame was fitted by the upper mold | type and the lower mold | type, the movable ring advanced, and the heated sheet | seat was primary-shaped. It is sectional drawing which shows the state in which pressurized air was introduce | transduced and the secondary shaping was carried out. It is sectional drawing corresponding to FIG. 3 which shows 2nd Embodiment of the metal mold | die for pressure forming.

Hereinafter, the configuration of the product of the present invention and the steps of the molding method will be described.

1. Film or Sheet The thickness of the film or sheet used in the present invention is preferably 0.05 to 1.2 mm, and it is preferable to have a hard coat layer as the surface layer.
The height of the molded product obtained in the present application depends on the hard coat elongation performance, but occurs in the scratch resistance test (according to ASTM D 2486-79, using a pig hair brush and 200 reciprocations at a load of 450 g). Using a practical hard coat with scratches of 10 or less scratches, it is possible to manufacture molded products having a vertical vertical wall height of 4 mm or more and a maximum height of 15 mm, which is not currently available. Become.
By using the molding method of the present application, it is possible to make the best use of the hard coat elongation performance, so the top surface and the rising surface have a round shape. It is possible to manufacture up to The hard coat (layer) preferably has 5 or less scratches, more preferably, in the scratch resistance test (according to ASTM D 2486-79, using a pork brush at 200 cycles with a load of 450 g). Is 3 or less.

Examples of the film or sheet include (1) a transparent sheet using a transparent plastic material, and (2) a resin layer having impact resistance and moderate heat resistance as a base layer, and a hard resin layer on one or both sides thereof. (3) A sheet or a multilayer sheet in which a hard coat layer is formed on one or both sides of the sheet (1) or (2).
In the present invention, it is also possible to use a material in which a printed layer or a metallized layer having design properties or the like is appropriately formed on the back surface.

Transparent plastic materials used for the film or sheet include aromatic polycarbonate, amorphous polyolefin (typical example: alicyclic polyolefin), poly (meth) acrylate, polysulfone, acetylcellulose, polystyrene, amorphous polyester ( Representative examples: cycloaliphatic polyester), transparent polyamide, polyethylene terephthalate resin, and the like, and transparent resins made of these compositions. Among these, resins used for optics are preferred, and are aromatic polycarbonate, (meth) acrylic resin, styrene- (meth) acrylate copolymer resin, hydrogenated styrene- (meth) acrylate copolymer resin (of styrene component). Examples include hydrogenated benzene rings to partially alicyclic rings), transparent polyamides, and compositions of aromatic polycarbonates and amorphous polyesters (typical examples: alicyclic polyesters).

Aromatic polycarbonate (PC) includes 2,2-bis (4-hydroxyphenyl) alkane and 2,2- (4-hydroxy-3) in terms of impact resistance, strength, heat resistance, durability, and bending workability. , 5-Dihalogenophenyl) A polymer produced by a known method using a bisphenol compound typified by alkane is preferable, and the polymer skeleton includes a structural unit derived from a fatty acid diol or a structural unit having an ester bond. In particular, an aromatic polycarbonate produced using 2,2-bis (4-hydroxyphenyl) propane is preferred.

An amorphous polyester resin used as a composition with an aromatic polycarbonate includes, for example, a dicarboxylic acid component typified by 1,4-cyclohexanedicarboxylic acid and a diol component typified by 1,4-cyclohexanedimethanol. Depending on the amount, other small components may be esterified or transesterified, and then a polymerization catalyst may be added as appropriate, and the reaction vessel may be gradually depressurized to obtain a polycondensation reaction. .
Specific examples of alicyclic dicarboxylic acids or ester-forming derivatives thereof include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-decahydronaphthalene dicarboxylic acid. And acid, 1,5-decahydronaphthalenedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, 2,7-decahydronaphthalenedicarboxylic acid, and ester-forming derivatives thereof.

Examples of the polyamide resin used in the present invention include those known as optically transparent polyamide resins. The heat distortion temperature, which is one index of heat resistance, is in the range of, for example, 100 to 170 ° C., and the aromatic polyamide resin, Examples thereof include alicyclic polyamide resins, aliphatic polyamide resins, and copolymers thereof. The alicyclic polyamide resin is preferable from the balance of mechanical strength, chemical resistance, transparency, etc., but two or more polyamide resins may be combined. Examples of such a polyamide resin include, but are not limited to, GLILAMIDTRFE5577, XE3805 (manufactured by EMS), NOVAMIDX21 (manufactured by Mitsubishi Engineering Plastics), and Toyobo Nylon T-714E (manufactured by Toyobo).

(Meth) acrylic resin is polymethyl methacrylate (PMMA), homopolymers of various (meth) acrylic esters represented by methyl methacrylate (MMA), or PMMA or MMA and one or more other monomers. A copolymer obtained by mixing a plurality of these resins may also be used. Among these, (meth) acrylates having a cyclic alkyl structure excellent in low birefringence, low hygroscopicity, and heat resistance are preferable. Examples of the (meth) acrylic resin as described above include, but are not limited to, Acripet (manufactured by Mitsubishi Rayon), Delpet (manufactured by Asahi Kasei Chemicals), and Parapet (manufactured by Kuraray).

The base material layer of (2) is a layer for maintaining basic physical properties, and as a resin to be used, an aromatic polycarbonate, a composition of an aromatic polycarbonate and an amorphous polyester resin is used because of its high impact resistance. It is given as a representative example.
The hard resin layer formed on one or both surfaces of the base material layer includes (meth) acrylic resin, styrene- (meth) acrylate copolymer resin, hydrogenated styrene- (meth) acrylate copolymer resin (styrene component benzene). Aromatic polycarbonate resins copolymerized with 2,2- (4-hydroxy-3-methylphenyl) alkane, aromatics compatible with aromatic polycarbonate resins, etc. Examples include a composition of a (meth) acrylic resin and an aromatic polycarbonate resin copolymerized with a (meth) acrylic monomer containing a ring, and a (meth) acrylic resin and a hydrogenated styrene- (meth) acrylate copolymer resin ( Those obtained by hydrogenating the benzene ring of the styrene component to partially alicyclic) are preferred.
These are usually used as a composition containing an ultraviolet absorber because of improved weather resistance.

The film or sheet is usually produced by an extrusion method or a coextrusion method, and the thickness is preferably selected as appropriate from a range of 0.05 mm to 1.2 mm.
In the case of a multilayer sheet, the thickness of the hard resin layer formed on one side or both sides of the base sheet is less than half the thickness of the multilayer sheet, and is preferably selected from 0.03 mm to 0.1 mm. If it is too thin, the hardness such as pencil hardness will be low, and if it is too thick, the effect of increasing the hardness will be lost, and the characteristic deterioration of the base sheet will increase, which is not preferable.
Then, in the extrusion step or after the extrusion, a hard coat process is performed. Usually, a material excellent in wear resistance and fingerprint resistance (fingerprint wiping property) is preferable, but since it is essential to give a desired three-dimensional shape by thermoforming, the desired thermoformability is achieved. It is preferable to select one with a hard coat shown.

As the hard coat layer, a compound that forms a known cross-linked film such as acrylic, silicon, melamine, urethane, and epoxy can be used. As the curing method, a known method such as ultraviolet curing, thermal curing, electron beam curing or the like can be used. Among these, a surface that can be made to have a pencil hardness of H or higher is preferable for the surface to be the surface side, and an acrylic type and a urethane acrylate type are preferable from the viewpoint of the balance with the heat formability.
The hard coat layer may be applied by an ordinary method, such as a coating method such as a roll coating method, a dipping method, or a transfer method.

As the acrylic compound, a crosslinkable polymerizable compound having at least two (meth) acryloyloxy groups (meaning acryloyloxy group and / or methacryloyloxy group, hereinafter the same) in the molecule can be used. The residue that binds the acryloyloxy group is a hydrocarbon or a derivative thereof, and the molecule can include an ether bond, a thioether bond, an ester bond, an amide bond, a urethane bond, and the like. Further, a long chain component having a molecular weight of 1,000 to several thousand can be appropriately included as a component imparting heat formability.

The multilayer sheet used in the present invention usually has a design print layer on the back surface.
The multilayer sheet used in the present invention preferably has a hard coat layer on the back surface from the viewpoint of handleability, suitability for printing on the back surface and metallization. In a preferred case, the back side has a hard coat layer / printing layer on a base resin, and an injection molding resin is placed on the hard coat layer / printing layer, and is heat-sealed. From this point, if there is a printing layer in the part that needs to be stretched, select the printing ink that adheres firmly to the hard coat layer, has the property of stretching moderately, and is also heat-sealed with the molding resin to be used It is preferable to do. In addition, even when the hard coat treatment is not performed on one side, it can be used without any problem.

2. Film or Sheet Forming Method In the film manufacturing method of the present invention, a mold described later is used. Specifically, it is a method for producing a three-dimensional shaped product by molding a film so as to have a predetermined three-dimensional shape using a molding die, preferably a pressure molding die, and is fixed to a fixed frame. The heated sheet is heated (heating process), the mold is clamped simultaneously with the fixed frame, the movable ring is advanced, and the film or sheet is primarily shaped to the bottom of the lower mold (primary shaping process), and then from the pressurized air introduction hole There is a secondary shaping step (secondary shaping step) in which the film or sheet is completely shaped into a core shape or a concave shape during molding by the pressure of the introduced pressurized air.
On the other hand, the conventional manufacturing process is as follows.
(I) Hold the sheet with the sheet holder.
(Ii) The sheet is moved to the heating zone together with the sheet holder and heated by infrared rays from above to soften the sheet at a temperature higher than its Tg.
(Iii) A sheet holder is fitted between the upper mold and the lower mold, and mold clamping is performed to prepare for sheet molding, and at the same time, pressurized air is introduced.
(Iv) The sheet is fixed from the part in contact with the surface of the mold core by pressurized air (below Tg of the resin), and the non-contact part rapidly expands and contacts and is fixed to the surface of the mold core. The shaped product conforms to the surface shape of the core or the recess. Only the sheet in the vicinity of the bottom surface that was the final non-contact portion is locally stretched.
(V) After discharging pressurized air, etc., take out the shaped product.

The film forming method of the present invention (manufacturing method of a three-dimensional shaped product) differs from the manufacturing steps (i) to (v) in the following points.
・ The heated sheet fixed to the holder (fixed frame) at the time of mold clamping is folded by the movable ring at an angle between the mold core and the ring so as to correspond to the rising part or recess of the mold ( At this time, the sheet is shaped until it is substantially unstretched. (Temporary shaping)
Then, by introducing gas, preferably compressed air, the sheet is shaped while being pressed against the mold core. At this time, the sheet is gradually shaped along the mold core shape (including the concave portion), and the lower portion of the rising portion is finally stretched most.
According to such a molding method of the present invention, the following effects are recognized. That is,
・ Because the bottom of the film was in contact with the mold core (including the recess) until the compressed air was introduced, the cooling did not proceed, so even the lower part of the rising part of the shaped sheet Shape shaping is possible until the bottom shape is 1 mmR or less.
-Since the amount and area stretched by secondary shaping are less than usual, the thickness is uniform throughout, so the hard coat is also stretched uniformly.
・ PET film, which cannot be shaped by pressure forming, can be shaped with a ring using hydraulic pressure.

The manufacturing method of the three-dimensional shaped article of the present invention uses the above-described novel pressure forming mold and uses the conventional conditions except that the pressure of the pressurized air is within a range that can be said to be low. can do.
The infrared heating may be a conventional normal near infrared heater or a far infrared heater.

In this invention, the 2nd area | region of the film shape | molded on the outer side of the convex part with respect to the 1st area | region (thick part) of the film arrange | positioned on the convex part of the lower mold | type of the metal mold | die at the time of shaping | molding The elongation of (edge) is 100% or less, preferably 50% or less, more preferably 40% or less. In this case, in the case of using a mold including a mold core having a rising portion substantially perpendicular to the bottom surface at the time of molding, that is, at the time of forming, a local elongation (paragraph) [0005]) can be suppressed.
The elongation percentage is calculated as follows. That is, graduation lines with an interval of 1 mm are printed on the first region (thick portion) and the second region (end portion) of the film before forming, and the film is formed. In each of the first region (thick portion) and the second region (end portion) of the film that has been formed and stretched, the distance between the scales that are most stretched by molding ([X] mm and [Y] mm) ). The elongation is calculated by the following formula.
Elongation rate (%) = ([Y] (mm) -1 (mm)) / ([X] (mm)) × 100.
(Note: [X] = interval of stretched scales in the first region, [Y] = interval of stretched scales in the second region.)

3. Molded product and molding method thereof Next, a film or sheet heat-formed into a desired shape according to the present invention, for example, a multilayer sheet is mounted on a mold for injection molding, and a molding resin material is injection molded to form a molded product. Can be manufactured.
It is essential that the resin molding material is heat-sealed with the heat-formed multilayer sheet.
Although it may heat-seal well as it is, as described above, the back side of the multilayer sheet is usually provided with a design by printing, and also serves as a protective layer for heat-seal with the injection molding resin as appropriate. Those having a primer layer formed thereon can be used.
Specific examples of molded products that can be manufactured using the film of the present invention include mobile phone exterior parts, automobile-related parts, medical equipment, electronics products, home appliances, building materials, containers for detergents and cosmetics, toys, etc. Is mentioned.

4). The difference in dimension between the inner diameter of the mold pressing member and the outer diameter of the convex portion is (film thickness before molding (mm) × 2) +1 mm to 4 mm, more preferably 1.5 mm to 4 mm. .

Hereinafter, a first embodiment of a pressure forming mold according to the present invention will be described with reference to FIGS.
FIG. 1 is a schematic view showing an embodiment of a pressure forming mold according to the present invention. A pressure-air forming mold 40 shown in FIG. 1 includes an upper mold 10 having a pressurized air introduction hole 12, a lower mold 20 having a mold core 22, and a film or sheet 32. The movable ring 15 is housed in the upper mold 10 before molding, including a fixed frame 30 fitted by the lower mold 20. The movable ring 15 advances to a position where the film heated at the time of primary shaping hits the bottom of the recess 23 provided in the lower mold 20 or the core 22 and stops, and then the pressure of the pressurized air introduced from the pressurized air introduction hole 12 is stopped. Thus, after performing the secondary shaping, it has an operation mechanism that retracts to a position before molding. In FIG. 1, a hydraulic cylinder is used as the operating mechanism, but the present invention is not limited to this.

FIG. 2 is a schematic plan view showing the same configuration as that of the compressed air molding die shown in FIG. 1 and showing a primary shape formed by the movable ring 15.
FIG. 3 is a schematic diagram showing a state in which pressurized air is introduced from the pressurized air introduction hole 12 and primary shaping is performed.

A pressure forming mold (hereinafter referred to as a main mold) 40 of the present invention includes an upper mold 10, a lower mold 20, and a fixed frame 30. The lower die 20 has a mold core 22 (convex portion) including a rising portion 24 substantially perpendicular to the bottom surface 20S. A recess 23 is formed on the bottom surface 20 </ b> S of the lower mold 20 and between the mold core 22 and the fixed frame 30. The upper mold 10 has a movable ring 15 (pressing member). The movable ring 15 can be moved back and forth in the vertical direction as indicated by an arrow A, and surrounds the outer periphery of the mold core 22 during primary shaping (see FIG. 3), which will be described later, with respect to the mold core 22 and the recess 23. Push in the sheet or film 32.
The movable ring 15 has a chamfered or rounded cross-sectional shape of the ring front end surface 15T so that the sheet is not damaged when the sheet is pushed.
The chamfering shape and chamfering amount are in the range of 0.5 to 2 mmC, and the round shape is in the range of 0.5 to 2 mmR. By setting in this way, the sheet or film 32 on the rising surface when the movable ring 15 is pushed in, for example, The hard coat sheet is not damaged.
The secondary shaping (see FIG. 4) to be described later after the primary shaping on the sheet or film 32 is performed with pressurized air. The pressure is not particularly specified, but preferably, the pressure of the pressurized air is set to a maximum set pressure of 5 MPa or less, so that the mold thickness may be thin and the shaped sheet is less likely to remain distorted. A more preferable set maximum pressure is 1 to 2 MPa.

The rising part 24 and the recessed part 23 of the mold core 22 may have a round shape or a substantially vertical wall rising. From the standpoint of local elongation of the sheet, the latter is overwhelmingly large in local elongation, so that it is a difficult shape in terms of preventing hard coat cracks. Therefore, the rising portion 24 and the recess 23 are preferably chamfered.
When attention is paid to the bottom surface of the rising portion 24, the curvature of the molded sheet is about 2 mmR in the conventional mold, whereas the mold itself is stretched uniformly and thinly when the mold of the present invention is used. In addition, the curvature can be 1 mmR or less. For this reason, when using the mold of the present invention, it becomes easy to insert into a press die at the time of punching, and it becomes possible to punch to the bottom with high accuracy, thereby causing problems such as misalignment at the time of in-mold molding. Can be resolved.

As shown in FIG. 1, the sheet or film 32 fixed to the fixed frame 30 is heated to a predetermined temperature and softened (heating step). In this state, the movable ring 15 advances toward the lower surface 20S, thereby pressing the heated sheet or film 32 to form the top surface shape and the recess 23 of the mold core 22, and the bottom surface 20S of the lower mold 20. (See Fig. 3).
The movable ring 15 is installed on the upper mold 10 in connection with an air cylinder and a hydraulic cylinder, and controls the speed and the like by a flow meter (none of which is shown) attached to the pressure forming machine.
As operation control, control is performed by a program sequence of the pressure forming machine. As timing, mold clamping is performed when the sheet reaches a predetermined heating time or a predetermined temperature, and then the movable ring 15 is advanced. The movable ring 15 is retracted to a predetermined position of the upper mold 10 immediately after the end of applying the compressed air or by the end of the exhaust process. If the movable ring 15 moves backward to the mold opening (release) step, there is a risk of scratches on the rising surface of the molded product, which is not preferable.
Further, after the movable ring 15 is operated and the sheet is pushed in to start the primary shaping, the timing time for introducing the compressed air is within one second.
If the sheet is heated to a shapeable temperature (Tg or higher) and the time from the primary shaping to the secondary shaping is not within 1 second, the film is cooled (Tg or less), and is shaped by the secondary shaping. It becomes impossible to form. As soon as the timing of introducing the pressurized air is earlier, the secondary shaping becomes better. However, if the primary shaping is not completed, a molded product having a desired height cannot be obtained.
As described above, the timing can also be adjusted by setting the speed of the movable ring 15 (hydraulic cylinder speed) to be faster with the flow meter.

As for the distance between the fixed frame 30 and the mold core 22, it is desirable to provide a distance that is at least twice the height of the rising portion 24. More preferably, it is 3 to 4 times. If the distance between the fixed frame 30 and the mold core 22 is less than twice the height of the rising portion 24, the sheet between them is actually pushed through the movable ring 15. Becomes too large locally, and even if the height of the mold core 22 is low, the sheet 32 is easily torn, and if it is a hard coat product, cracks are likely to occur.

The difference DL between the inner diameter of the movable ring 15 and the outer diameter of the mold core 22 is set as a range of +1 mm to 4 mm with respect to (sheet thickness (mm) × 2) (see FIG. 2; the sheet is not shown). ) That is, the distance DL ₁ between the rising portion 24 of the mold core 22 and the movable ring 15 in one direction, for example, the direction indicated by the arrow B in FIG. 2 (corresponding to the direction perpendicular to the paper surface in FIG. 1) is A value obtained by adding a distance of 0.5 mm to 2 mm to the sheet thickness. That is, when the sheet thickness is 0.5 mm, the distance DL ₁ between the core 22 and the movable ring 15 is 1 mm (the gap excluding the sheet thickness 0.5 mm from the distance DL ₁ is 0.5 mm) to 2.5 mm. (The gap excluding the sheet thickness of 0.5 mm from the distance DL ₁ is 2 mm). Since the range of the distance DL ₂ between the rising portion 24 of the mold core 22 and the movable ring 15 is also equal to the above-mentioned distance DL ₁ , the difference in dimension DL between the inner diameter of the movable ring 15 and the outer diameter of the mold core 22 ( DL ₁ + DL ₂ ) is defined as 2 mm to 5 mm obtained by adding 1 mm to 4 mm to 0.5 mm × 2 that is the thickness of the sheet, that is, 1 mm.
Regarding the second embodiment in which a hole (recess) is provided on the upper surface of the mold core 22 described later, the dimensional relationship between the outer diameter of the recess provided in the mold core 22 and the inner diameter of the movable ring is the above-described numerical value. Become.
As an effect of the gap, the sheet is shaped in a form close to a two-dimensional bending process, without extending the rising portion 24, so that the primary shaping can be performed with substantially uniform elongation. Become.
When a gap of less than 0.5 mm on one side (DL ₁ or DL ₂ is less than 0.5 mm), the sheet or film 32 is stretched while being dragged with the ring when pushed by the movable ring 15, and is pulled locally. As a result, hard coat cracks are likely to occur particularly on the top surface side, and the precision in producing the mold is increased, and the mold cost is also increased.
Further, if it exceeds 2 mm on one side (DL ₁ or DL ₂ is greater than ₂ mm), wrinkles will occur at positions corresponding to the four corners of the movable core 22 when pushed by the movable ring 15, or a mold during secondary shaping. Since the distance from the core becomes longer, the cooling proceeds, and when secondary shaping is performed, local elongation occurs on the bottom surface side, which is not preferable.

The shapes of the core 22 and the movable ring 15, and the recesses 23 provided in the core 22 and the movable ring 15 are preferably substantially similar.
What is necessary is just to set in the range of the dimension mentioned above, and even if the core 22 is a rectangle, the movable ring 15 may be a rounded rectangle or a substantially elliptical shape. Moreover, a round may enter in only the four corners of the core 22, or a 45 degree angle may be attached.
When the dimension range of the gap is exceeded, the above-described defect may occur.

As described above, when the heated sheet or film 32 is pressed by advancing the movable ring from the state shown in FIG. 1, the heated sheet fixed to the fixed frame is fixed to the fixed frame 30, the upper mold 10, and the lower mold. Clamp at the same time as 20 (see FIG. 3). In this way, the film or sheet 32 is moved to the bottom surface 20S of the lower mold 20 to perform primary shaping (primary shaping step). Next, pressurized air is introduced from the pressurized air introduction hole 12 of the upper mold 10 as indicated by an arrow C (see FIG. 4).
By the pressure of the pressurized air thus introduced, secondary shaping is performed in which the film or sheet 32 is completely shaped so as to correspond to the shapes of the core 22 and the recess 23 at the time of molding (secondary shaping step). . At this time, since the air introduction hole 13 is also formed in the movable ring 15, the pressurized air is efficiently introduced to the surface of the sheet or film 32.

Next, a second embodiment of the pressure forming mold will be described. As shown in FIG. 5, in the second embodiment, holes (recesses) for forming holes or recesses in the film 32 are formed on the upper surface of the mold core 22.
Hereinafter, examples of the present invention will be described with reference to examples and the like, but the present invention is not limited to these examples.

A pressure forming machine (manufactured by NK Enterprise) was used as a molding machine.
In addition, a hydraulic drive device (manufactured by Yuken Kogyo Co., Ltd.) is attached to the molding machine so as to be linked in sequence.
Aluminum was used as the material of the pressure forming mold 40 (see FIG. 1 and the like) of the present invention.
The mold core 22 provided in the lower mold 20 has a shape having a square 50 mm square (4 corner curvature R; 2 mmR) as viewed from above, a φ20, 5 mm recess in the center, and a top surface curvature of 2 mmR. The one having a substantially vertical rising surface 24 having a height of 12 mm was used. Further, as the movable ring 15 attached to the upper mold 10, a ring similar in shape to the outer periphery of the mold core 22 and the recess 23 was used. Note that the movable ring 15 is retracted before molding and is in a predetermined position of the upper mold 10.
The movable ring 15 has a chamfered shape with a thickness of 2 mm and a tip of 0.5 mmC as an outer shape and a concave ring, is attached to an upper mold, and is connected to a hydraulic drive device and hydraulic piping.
Outer ring; movable ring inner diameter (53mm)-core outer diameter dimension (50mm) =
(0.5 mm (film thickness) × 2) +2 mm = 3 mm That is, when the sheet was shaped, there was a clearance of 1 mm on one side.
Recess ring (not shown); Core recess inner diameter dimension (20 mm) −Outer diameter of recess ring provided on movable ring (16 mm) =
(0.5 mm (film thickness) × 2) +3 mm = 4 mm
That is, there was a clearance of 1.5 mm on one side when the sheet was shaped.

(Example 1)
A sheet of coextruded acrylic resin layer formed with an acrylic resin layer on the surface of a 140mm square aromatic polycarbonate resin base material layer, and a hard coat on the acrylic resin layer (MRF08U 0.5 manufactured by Mitsubishi Gas Chemical Co., Ltd.) mm (hard coat elongation: 40%, scratch resistance test (according to ASTM D 2486-79, using a pig hair brush and 200 strokes at a load of 450 g) has a scratch resistance of 5 or less. The design of the printed layer (IMB006 binder laminated on INQ-HF (white) manufactured by Teikoku Ink Co., Ltd.) on the PC surface (back surface) of the hard coat)) was used. The fixed frame 30 for fixing the sheet is a fixed frame having a window so that a 100 mm square sheet can be formed. The distance between the fixed frame 30 and the mold core 22 was 50 mm.
Set the sheet on the sheet fixing frame, convey the sheet to the heating zone, heat it with an IR heater (400 ° C setting), and confirm that it reaches 190 ° C with an infrared radiation thermometer, then see Fig. 1 Move to the indicated clamping zone and clamp. Next, the hydraulic drive device was immediately driven to advance the ring until it hits the lower mold and the bottom of the recess. After the end of the advancement, 0.5 seconds later, pressurized air set at a maximum pressure of 2 MPa was introduced into the mold 40.
The lower part of the rising part 24 and the lower part of the concave part on the top surface of the core 22 had R of 0.8 mm or less.
In the shaped hard coat sheet, no cracks were generated in the hard coat layer, despite the height of the outer peripheral height of 12 mm and the recess of 5 mm.
Subsequently, unnecessary parts were punched out with a press die to obtain a formed molded product.

(Example 2)
The molded product obtained in Example 1 was inserted into a 2 mm thick injection mold having a 51 mm square cavity and a recess φ20 on the surface, and an injection molding machine (J110AD manufactured by Nippon Steel) , Using a PC (Iupilon H3000 manufactured by Mitsubishi Engineering Plastics Co., Ltd.) with a resin temperature of 300 ° C, a mold temperature of 80 ° C, and an injection pressure of 100 MPa. A molded product was obtained.
Since the molded product punched out in Example 1 had a small bottom edge, it could be inserted neatly into the mold, and no problems were caused by injection molding.
In Example 2, an injection molded product decorated with a hard coat was obtained.

(Example 3)
Using the mold used in Example 1, the height of the mold core was changed to 5 mm.
In addition, as a sheet, a PET sheet having a hard coat extending 140 mm square (Toughtop THS 0.18 mm manufactured by Toray Industries, Inc. (hard coat elongation rate: 20%, scratch resistance test (according to ASTM D 2486-79, pig hair brush (Practical hard coat with scratch resistance of 5 or less) under a load of 450g at a load of 450g)) on the back side of the hard coat) (on INQ-HF (white) made by Teikoku Ink Co., Ltd.) The IMB006 binder was laminated). The relationship of clearance is as follows.
Outer ring; movable ring inner diameter (53mm)-core outer diameter dimension (50mm) =
(0.18 mm (film thickness) × 2) +2.64 mm = 3 mm That is, when the sheet was shaped, there was a clearance of 1.32 mm on one side.
Recess ring (not shown); Core recess inner diameter dimension (20 mm) −Outer diameter of recess ring provided on movable ring (16 mm) =
(0.18 mm (film thickness) × 2) +3.64 mm = 4 mm
That is, there was a 1.82 mm clearance on one side when the sheet was shaped.
Set the sheet on the sheet fixing frame, convey the sheet to the heating zone, heat it with an IR heater (400 ° C setting), confirm that it reaches 190 ° C with an infrared radiation thermometer, and then mold clamping zone Moved to and clamped. Next, the hydraulic drive device was immediately driven to advance the ring 15 until it hits the bottom surface 20S of the lower mold 20. After completion of the forward movement, 0.8 seconds later, pressurized air set at a maximum pressure of 2 MPa was introduced into the mold 40.
In the above embodiment, although it is a PET film that cannot be shaped by normal pressure forming, it is shaped, and the lower part of the rising part 24 and the lower part of the concave part of the top surface of the core 22 have R of 1.2 mm or less. Had.
In the shaped hard coat sheet, no crack was generated in the hard coat layer, regardless of the height of the outer periphery 5 mm and the recess 5 mm.
Subsequently, unnecessary parts were punched out with a press die to obtain a formed molded product.

(Comparative Example 1)
Using the mold used in Example 1, pressure forming was carried out under the same conditions and conditions as in Example 1 without operating the movable ring 15.
The shaped product was poorly shaped on the bottom surface, and when the shape of the sheet on the bottom surface was measured, it was about 2 mmR. Further, regarding the MRF08U sheet (see Example 1), cracks occurred in the vicinity of the bottom surface part, probably because the vicinity of the bottom surface was locally extended. Although injection molding was carried out as in Example 2, since the crack was generated in the hard coat, the appearance of the molded product was ugly.

(Comparative Example 2)
Using the mold and sheet used in Example 1, the heating conditions are the same, the movable ring 15 is operated, and after the forward end, the pressurized air set at the maximum pressure of 2 MPa is 1.5 seconds later in the mold 40. Introduced.
Since the timing of introducing the pressurized air was late, the cooling of the film progressed, and a hard coat crack occurred near the rising bottom surface.
(Comparative Example 3)
Pneumatic forming was performed using the same sheet and conditions as in Example 1 except that the dimensions of the outer ring of the mold used in Example 1 were changed.
Outer ring; inner diameter of movable ring (56mm)-outer diameter of core (50mm) =
(0.5 mm (film thickness) × 2) +5 mm = 6 mm That is, when the sheet was shaped, there was a clearance of 2.5 mm on one side.
Because the clearance is large, the distance from the primary shaping to the secondary shaping becomes long, and only the vicinity of the bottom of the rising part fixed by the ring shows the secondary elongation in the secondary shaping. Cracks have occurred.
(Comparative Example 4)
Pneumatic forming was performed using the same sheet and conditions as in Example 1 except that the dimensions of the outer ring of the mold used in Example 1 were changed.
Outer ring; inner diameter of movable ring (51mm)-outer diameter of core (50mm) =
(0.5 mm (film thickness) × 2) +1.0 mm = 2 mm That is, when the sheet was shaped, there was a clearance of 0.5 mm on one side.
Since the clearance is small, the rising top surface side was pulled by the ring during the primary shaping, and the local elongation was observed only in the vicinity of the top surface of the rising portion, so that cracks occurred in the hard coat.

According to the present invention, even if a hard coat having a practically usable hardness is used, cracks do not occur due to shaping, so there are no restrictions on design. It is easily possible to provide a molded product.
In addition, since it is possible to easily form an inexpensive PET film that has been difficult to shape, a low-cost product can be provided.
In particular, the film of the present invention and the molding method thereof are suitably used for the production of a decorative sheet molded product or an in-mold molded product, and include mobile phone exterior parts, automobile-related parts, medical machinery, electronic products, and home appliances. It can be used in the fields of building materials, containers for detergents and cosmetics, and toys.

10 Upper mold 12 Pressurized air introduction hole (air introduction hole)
15 Movable ring (pressing member)
20 Lower mold 22 Mold core (convex part)
24 Rising part 30 Sheet fixing frame (fixing frame)
32 Sheet or film 40 Pressurized molding die (molding die)

Claims

In a scratch resistance test (according to ASTM D 2486-79, using a pork brush and 200 reciprocations with a load of 450 g), it is a film provided with at least a hard coat layer having scratch resistance of 10 or less. The second region of the film formed on the outer side of the convex portion with respect to the first region (thick portion) of the film that has been disposed on the convex portion of the lower mold of the molding die used sometimes. The film is characterized in that the elongation ratio of the end portion is 100% or less.
A lower mold having a convex portion;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for forming a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing the film between the upper mold and the lower mold,
A heating step of fixing the film to the fixed frame and softening by heating in a state where the pressing member of the upper mold is retracted,
During the mold clamping of the upper mold and the lower mold, a primary shaping step of advancing the pressing member and pressing the film at least outside the convex portion to perform primary shaping;
The film is molded by a molding method including a secondary shaping step of secondary shaping of the film at least outside the convex portion of the lower mold clamped by the pressure of the gas introduced from the upper mold side. A film characterized by that.
A lower mold having a convex portion provided with a concave portion on the surface for forming a hole and / or a concave portion in the molded article;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for forming a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing the film between the upper mold and the lower mold,
A heating step of fixing the film to the fixed frame and softening by heating in a state where the pressing member of the upper mold is retracted,
During the mold clamping of the upper mold and the lower mold, a primary shaping step of advancing the pressing member and pressing the film at least outside the convex portion to perform primary shaping;
The film is molded by a molding method including a secondary shaping step of secondary shaping of the film at least outside the convex portion of the lower mold clamped by the pressure of the gas introduced from the upper mold side. A film characterized by that.
The elongation percentage of the second region (end portion) of the film formed on the outside of the convex portion with respect to the first region (thick portion) of the film arranged on the convex portion at the time of molding, The film according to claim 2 or 3, wherein the film is 100% or less.
The film according to claim 2 or 3, wherein the film is a hard coat film having a hard coat layer.
The film according to claim 1, wherein the film is a hard coat film having a surface printed on a surface opposite to the hard coat layer.
A molded article comprising the film according to any one of claims 1 to 6.
A lower mold having a convex portion;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for forming a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing the film between the upper mold and the lower mold,
With the pressing member retracted, a heating step of fixing the film to the fixed frame and heat softening;
During the mold clamping of the upper mold and the lower mold, a primary shaping step of advancing the pressing member and pressing the film at least outside the convex portion to perform primary shaping;
And a secondary shaping step of secondary shaping the film at least outside the convex portion of the lower die clamped by the pressure of the gas introduced from the upper die side. Molding method.
A lower mold having a convex portion provided with a concave portion on the surface for forming a hole and / or a concave portion in the molded article;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding method for forming a film into a predetermined three-dimensional shape using a molding die including a fixing frame for fixing the film between the upper mold and the lower mold,
A heating step of fixing the film to the fixed frame and softening by heating in a state where the pressing member of the upper mold is retracted,
During the mold clamping of the upper mold and the lower mold, a primary shaping step of advancing the pressing member and pressing the film at least outside the convex portion to perform primary shaping;
And a secondary shaping step of secondary shaping the film at least outside the convex portion of the lower die clamped by the pressure of the gas introduced from the upper die side. Molding method.
10. The molding method according to claim 8, wherein the pressing member is advanced to start the primary shaping process and pressurized air is introduced within 1 second to start the secondary shaping process. .
The film forming method according to claim 8 or 9, wherein the gas is pressurized air.
The film forming method according to claim 8 or 9, wherein the film is a hard coat film having a hard coat layer.
13. The method for forming a film according to claim 12, wherein the film is a hard coat film printed on a surface opposite to the hard coat layer.
The film forming method according to claim 8 or 9, wherein, in the primary shaping step, the fixed frame is fitted into the upper mold and the lower mold at the time of mold clamping.
The film according to claim 8 or 9, wherein a gas introduction hole is formed in the upper mold, and gas is introduced from the gas introduction hole to the surface of the film in the secondary shaping step. Molding method.
The film formed by the method according to claim 8 or 9 is a hard coat film in which printing is performed on a surface opposite to the hard coat layer,
A processing step of processing the hard coat film so as to correspond to an injection mold cavity shape;
An insert step of forming a film base by inserting the hard coat film so that the hard coat surface is in contact with the cavity in the cavity of the injection mold;
A molding method comprising: a molding step of molding the molded product by integrating the film base material and the injection molding material by injection molding.
A lower mold having a convex portion;
An upper die provided with a pressing member located outside the convex portion at the time of mold clamping;
A molding die including a fixing frame for fixing a film between the upper die and the lower die.
The molding die according to claim 17, wherein in the lower mold, a concave portion for forming a hole and / or a concave portion in the molded product is provided on the surface.
The molding die according to claim 17, wherein the pressing member has an inner surface substantially similar to the convex portion.
The molding die according to claim 17, wherein a gas introduction hole is formed in the upper die in order to introduce gas into the surface of the film in the secondary shaping step.
The difference in dimension between the inner diameter of the pressing member and the outer diameter of the convex portion is (thickness of the film before forming (mm) × 2) +1 mm to 4 mm. Mold for molding.
The pressing member operates via an air cylinder or a hydraulic cylinder, and a tip cross-sectional shape of the pressing member that presses the film is chamfered and / or rounded, and the primary shaping step and the secondary shaping step The molding die according to claim 17, wherein the molding die is not in contact with a top surface on the convex portion of the film in the shaping step.