JP7078484B2 - Manufacturing method of molded products - Google Patents

Description

The present invention relates to a method for producing a molded product including a transparent portion and a method for producing a composite resin molded product using the molded product containing the transparent portion obtained by the above-mentioned manufacturing method.

Inventions of transparent molded products used for various purposes using polyamide resins, polyamide elastomers, etc. are known (Patent Documents 1 to 10). Injection molding is generally used as a method for manufacturing these molded products.

Special Table 2017-510677 Japanese Patent No. 5937814 Japanese Patent No. 5677840 Japanese Patent No. 5681911 Japanese Patent No. 5725730 Japanese Patent No. 58088887 Japanese Patent No. 5384334 Japanese Patent No. 5384508 Japanese Patent No. 4416073 Special Table 2009-54087 Gazette

The present invention provides a method for producing a molded product containing a transparent portion from a base sheet made of a polyamide resin by applying a vacuum forming method or a pressure molding method, and a method for producing a composite resin molded product using the above-mentioned manufacturing method. The task is to do.

The present invention is a method for manufacturing a molded product including a portion in which a base sheet made of a polyamide resin is molded.
The polyamide resin constituting the substrate sheet made of the polyamide resin has a crystal melting temperature (Tm1) and a crystallization temperature (Tc1).
The first step of heating the substrate sheet made of the polyamide resin at a temperature of Tm1-10 ° C. or higher,
Then, it has a second step of vacuum forming or compressed air forming in a state where a base sheet made of a polyamide resin heated at the above temperature is placed in a mold adjusted to Tc1-50 ° C. or lower.
Provided is a method for producing a molded product, wherein the haze of the obtained molded product is 50% or less.

Further, in the present invention, after manufacturing a molded product by the above-mentioned manufacturing method,
Provided is a method for producing a composite resin molded product, which comprises insert molding using the obtained molded product and a polyurethane resin to obtain a composite resin molded product composed of the molded product and the polyurethane resin.

Since the molded product obtained by the production method of the present invention contains a portion transparent to the naked eye having a haze value of 50% or less, the colored or patterned portion is clear and enhances the aesthetic appearance. be able to. Therefore, it is possible to increase the product value when applied to various uses.

<Manufacturing method of molded products including transparent parts>
The method for producing a molded product of the present invention is characterized by including a step of applying a vacuum forming method or a pressure molding method when producing a molded product containing a transparent portion formed by a base sheet made of a polyamide resin sheet. be. Hereinafter, the steps will be described separately.
Further, the method for manufacturing a molded product of the present invention includes an embodiment of manufacturing using a single sheet and an embodiment of manufacturing using a plurality of sheets.
The thickness of the sheet in the present invention is adjusted according to the intended use, and includes a film.

(Manufacturing method of molded products using a single sheet)
In the first step, a substrate sheet made of a polyamide resin (a crystallized opaque polyamide resin sheet) is heated at a temperature of Tm1-10 ° C. or higher to melt the crystals, and the substrate sheet made of a transparent polyamide resin is used. To.
The polyamide resin used in the first step is preferably selected from polyamide 6, polyamide 66, polyamide 12 and a mixture thereof, and among these, polyamide 12 is more preferable.
The polyamide resin can be made into a desired color after molding by blending various colorants (pigments and the like). In addition, a known resin additive can be added to the polyamide resin in order to impart properties according to the intended use to the molded product.
The size and shape of the base sheet made of the polyamide resin used in the first step are not particularly limited, and those having a thickness of, for example, 0.3 to 1.2 mm can be used.

Tm1 is the crystal melting temperature of the polyamide resin constituting the base sheet made of the polyamide resin.
The upper limit of the heating temperature in the first step is preferably Tm1 + 50 ° C.
The heating method in the first step is not particularly limited, and for example, heating can be performed in a heating furnace or the like using a heat source such as an infrared heater.

In the second step, after that, a base sheet made of a transparent polyamide resin heated at the above temperature is vacuum formed or placed in a mold adjusted to Tc1-50 ° C or lower, preferably Tc1-80 ° C or lower. Vacuum forming.
Tc1 is the crystallization temperature of the polyamide resin constituting the base sheet made of the polyamide resin.
By vacuum forming or pneumatic forming in this way, the base sheet made of a transparent polyamide resin in a heated state is adhered to a mold adjusted to Tc1-50 ° C. or lower (preferably Tc1-80 ° C. or lower). It will be cooled rapidly.
By quenching in this way, the growth of the polyamide resin crystals is suppressed, and it is possible to mold the polyamide resin into a desired shape while maintaining high transparency.

The vacuum forming method is a known molding method, and for example, plug-assist molding, air slip molding, and the like can be applied.
In the plus assist molding, the base sheet made of the polyamide resin heated in the first step is vacuum-sucked in a state of being in contact with the concave mold, and at the same time, the concave mold is pressed from above with a plug (auxiliary mold) for molding. The method. In the plus assist molding method, the temperature of the concave mold is adjusted to Tc1-50 ° C. or lower.
In air slip molding, a base sheet made of polyamide resin heated in the first step is inflated with compressed air, a convex mold is pushed up from below, and vacuum suction is performed to form a base sheet made of polyamide resin into a convex mold. It is a method of molding by bringing the two into close contact with each other. In the air slip molding method, the temperature of the convex mold is adjusted to Tc1-50 ° C. or lower.
The compressed air forming method is a known forming method, and is a method in which pressure is applied instead of vacuum forming in vacuum forming.
The vacuum forming method and the vacuum forming method are single-shot vacuum forming (single-shot vacuum forming) using a base sheet made of one polyamide resin, and continuous vacuum forming using a long base sheet made of polyamide resin (continuous). Any molding method (pneumatic molding) may be used.

The molded product obtained by the above-mentioned first step and second step treatment has a haze of 50% or less, preferably a haze of 40% or less, and more preferably a haze of 30% or less. It is a thing.
Then, the obtained molded product is trimmed so as to have a desired shape and used.
As described above, since the molded product obtained by the production method of the present invention has a small haze value, it is transparent to the naked eye, has good coloring property, and can be colored to a desired color. Therefore, it is preferable because the product value when made into a product is increased. Since the injection-molded product of the polyamide resin has a poor haze value, it is inferior in colorability.
Further, the obtained molded product can be printed with a desired pattern or the like. The pattern can be a colored pattern.

(Manufacturing method of molded product using multiple sheets-1)
A base sheet made of a transparent polyamide resin in a heated state obtained in the same manner as in the first step of the method for manufacturing a molded product using a single sheet described above, and whether it is colored or has a pattern printed on it. Alternatively, in the mold in the same manner as in the second step of the method for manufacturing a molded product using a single sheet described above, using a laminated product of another thermoplastic resin sheet colored and having a pattern printed on it. Vacuum forming or pressure forming in the state of being put in.
At this time, the portion in contact with the mold is arranged so as to be a base sheet made of a transparent polyamide resin in a heated state, and vacuum forming or compressed air forming is performed.
In the molded product thus obtained, a portion on which the base sheet made of the polyamide resin was molded (a portion having a haze of 50% or less) and a thermoplastic resin sheet having a pattern or the like were molded. It is a molded product with a two-layer structure.
In the obtained molded product, the pattern of the portion where the thermoplastic resin sheet is molded can be seen through the portion where the base sheet made of a transparent polyamide resin is molded, and the base made of the polyamide resin can be seen. The part where the material sheet is molded functions as a protective sheet.
The thermoplastic resin sheet is preferably one selected from polyamide 6, polyamide 66, polyamide 12 and a mixture thereof, and among these, the one made of polyamide 12 is more preferable.

(Manufacturing method of molded product using multiple sheets-2)
A base sheet made of a transparent polyamide resin in a heated state obtained in the same manner as in the first step of the method for manufacturing a molded product using a single sheet described above, and a first laminated sheet made of a polyamide resin sheet and a metal layer. In the same manner as in the second step of the method for manufacturing a molded product using the single sheet described above, the laminated product is vacuum-molded or pneumatically molded in a state of being placed in a mold.
At this time, the portion in contact with the mold becomes a base sheet made of a transparent polyamide resin in a heated state, and the metal layer of the first laminated sheet is arranged so as to be an intermediate layer, and vacuum forming or vacuum forming is performed.
The first laminated sheet is one in which a metal layer is laminated on one surface of a polyamide resin sheet, and the metal layer is preferably a thin-film film formed by thin-film deposition. The thin-film film can also be colored in one color or two or more colors.
Examples of those forming the metal layer (deposited film) include metals such as aluminum, silver, gold, titanium, nickel, copper, chromium, tin and indium, and metal oxides such as alumina and silica.

The molded product thus obtained has a three-layer structure consisting of a portion in which the base sheet made of the polyamide resin is molded (a portion having a haze of 50% or less) and a portion in which the first laminated sheet is molded. , The intermediate layer is a molded product made of a metal layer.
In the obtained molded product, the metal layer of the intermediate layer can be seen through the portion where the base sheet made of transparent polyamide resin is molded, and the portion where the base sheet made of polyamide resin is molded. Is demonstrating the function of the protective sheet.
It is preferable because the metal layer forming the intermediate layer of the molded product receives light (natural light or artificial light) and shines brilliantly, so that the aesthetic appearance can be further improved.

(Manufacturing method of molded product using multiple sheets-3)
The method for manufacturing a molded product using a plurality of sheets-3 is a thermoplastic polyurethane sheet (base material) / instead of the first laminated sheet used in the above-mentioned manufacturing method-2 for a molded product using a plurality of sheets. This is a manufacturing method using a second laminated sheet made of a metal layer. If necessary, the second laminated sheet may have a three-layer structure of a thermoplastic polyurethane sheet / a metal layer / a thermoplastic polyurethane sheet.

As the thermoplastic polyurethane used in the second laminated sheet, for example, a commercially available product such as the trade name "Higres" (manufactured by Seadam Co., Ltd.) can be used.
The thermoplastic polyurethane sheet (base material) has fine irregularities formed by embossing or the like.
The metal layer used in the second laminated sheet is formed by a method of forming a metal thin film on the surface of a thermoplastic polyurethane sheet (base material) by vapor deposition, a method of attaching a metal foil with an acrylic or urethane adhesive, or the like. It is a thing.
As the adhesive, a dry laminate adhesive that sounds from the combination of the ester polyurethane "TM-595" (main agent) manufactured by Toyo Morton Co., Ltd. and the curing agent (trade names "CAT-10L," CAT-RT85 "" is used. Can be used.
As the metal forming the metal layer, those selected from aluminum, silver, copper, chromium, tin, nickel, silicon oxide and zinc sulfide are preferable.

The molded product thus obtained has a three-layer structure consisting of a portion in which a base sheet made of the polyamide resin is molded (a portion having a haze of 50% or less) and a portion in which a second laminated sheet is molded. The intermediate layer is a molded product made of a metal layer.
In the obtained molded product, the metal layer of the intermediate layer can be seen through the portion where the base sheet made of transparent polyamide resin is molded, and the portion where the base sheet made of polyamide resin is molded. Is demonstrating the function of the protective sheet.
It is preferable to use the second laminated sheet because it is diffusely reflected when exposed to light (natural light or artificial light) to shine in various colors (for example, rainbow colors) and give an aesthetic appearance.

The molded product containing the base sheet made of the polyamide resin obtained by the production method of the present invention includes the following first to fourth embodiments.
The molded product of the first embodiment is made of only a base sheet made of a polyamide resin, and the haze of the molded product is 50% or less.
The molded product of the second embodiment has a two-layer structure including a molded portion of a base sheet made of a polyamide resin and a molded portion of another thermoplastic resin sheet (preferably a polyamide resin sheet), and is made of a polyamide resin. The haze of the molded portion of the base sheet is 50% or less. Other thermoplastic resin sheets are colored or printed with patterns.
The molded product of the third embodiment has a three-layer structure including a molded portion of a base sheet made of a polyamide resin and a molded portion of a first laminated sheet (a laminated sheet made of a polyamide resin sheet and a metal foil), and has a polyamide structure. The haze of the molded portion of the base sheet made of resin is 50% or less. The metal leaf may be colored or printed with a pattern.
The molded product of the fourth embodiment comprises a molded portion of a base sheet made of a polyamide resin and a molded portion of a second laminated sheet (a laminated sheet composed of a polyurethane layer having irregularities and a metal layer formed on the uneven surface). It has a three-layer structure, and the haze of the molded portion of the base sheet made of a polyamide resin is 50% or less. The metal layer may be colored or printed with a pattern.
The molded products of the first to fourth embodiments obtained by the manufacturing method of the present invention are cases for communication terminal devices such as mobile phones (smartphones) and tablet terminal devices, and various exhibits (for example, for window displays). ), Decorative products used at events, containers for various products (excluding those for communication terminal devices), or parts of the containers (for example, container inlays, container inner lids, container covers), and the like.

<Manufacturing method of composite resin molded products>
The method for producing a composite resin molded product of the present invention is a method using a molded product (molded product according to the first to fourth embodiments) obtained by the manufacturing method using the above-mentioned vacuum forming method.
In the first step, the molded product of the first embodiment to the fourth embodiment is manufactured by the manufacturing method using the vacuum forming method described above.
Then, in the second step, insert molding is performed using the molded product obtained in the first step and the polyurethane resin to obtain a composite resin molded product composed of the molded product and the polyurethane resin.
By blending various colorants (pigments and the like) in the polyurethane resin to be used, the portion made of the polyurethane resin can be made to have a desired color after molding. In addition, a known resin additive can be added to the polyurethane resin in order to impart properties according to the intended use.

The insert molding method is a method of injection molding a polyurethane resin in a state where the molded products of the first to fourth embodiments are placed in a desired mold, and the obtained composite resin molded product can be any of the following. The form is preferable, but the form is not limited to these forms.
(I) A form in which a part of the part where the base sheet made of the polyamide resin is molded has a haze of 50% or less is covered with the polyurethane resin and the rest is exposed. (II) The base sheet made of the polyamide resin. A form in which a portion having a haze of 50% or less is laminated with a polyurethane resin. In addition, when the polyamide 12 is used as the polyamide resin, the adhesiveness with the polyurethane resin is particularly good, so what kind of form is used? It is preferable because the adhesive portion is hard to peel off and the durability is improved even when the setting is made.

The composite resin molded product obtained by the production method of the present invention can be used as all or part of the sole of spike shoes used in various competitions.
When used as spike shoes, a transparent molded product made of polyamide resin becomes the sole, and the polyurethane resin part becomes the pin (spike pin) in the sole, and also corresponds to the sole part and the heel part. The portion or the like can be formed of a polyurethane resin.
At this time, the transparent molded product made of polyamide resin can have the sole transparent or colored in a desired color, and the pin made of polyurethane resin can be colored in a desired color, and the sole and pin can be colored. May be the same color or different colors.
In addition, the weight can be reduced as compared with the case where the whole is molded from polyurethane resin, and the durability is also excellent.
As spike shoes, it can be used for various sports spike shoes such as soccer, rugby, grand hockey, American football, and golf.

Examples 1 to 3 (molded articles of the first embodiment) and Comparative Examples 1 to 7.
(First step)
A substrate sheet of polyamide 12 (length 200 mm, width 200 mm, thickness 0.5 mm) was prepared. The Tm1 of the polyamide 12 was 177 ° C, and the Tc1 was 149 ° C.
In addition, Tm1 and Tc1 were measured under the following conditions.
Measuring equipment: Hitachi High-Tech Science Corporation X-DSC7000
Measurement conditions: Nitrogen atmosphere 20 ° C → 260 ° C Increase in temperature at 10 ° C / min 260 ° C → -10 ° C Decrease in temperature at 10 ° C / min Put this sheet in an infrared heating furnace and heat it to the sheet with the temperature shown in Table 1. Got

(Second step)
The base sheet heated in the first step was placed in a mold adjusted to the temperature shown in Table 1 and vacuum formed to obtain a vacuum formed product having a haze value shown in Table 1.

As is clear from the comparison between Examples 1 to 3 and Comparative Examples 1 to 7, the molded product obtained by the production method of the present invention had a small haze value and good colorability.

Example 4 (Manufacturing of resin composite molded product)
A transparent molded product was obtained in the same manner as in Example 2. However, the base sheet of the polyamide 12 used was one containing 1.5% by mass of a pigment (yellowish green pigment). The obtained transparent molded product was beautifully colored in yellowish green.
Next, using a colored transparent molded product and a polyurethane resin (Milactran manufactured by Nippon Miractran Co., Ltd., containing 0.9% by mass of a blue pigment), insert molding was performed under the following conditions to obtain a composite resin molded product.
(Insert molding conditions)
Injection molding machine: Nissei Resin Industry Co., Ltd. PS60E9A
Mold temperature: 40 ° C
Injection pressure: 98MPa (1000kg / cm ² )

The obtained composite resin molded product was in a state where a part of one side of a sheet-shaped transparent molded product (yellowish green) made of polyamide 12 was covered with a polyurethane resin (blue). The contrast between the two colors was vivid, creating a pleasing aesthetic.

Example 5 (molded article of the second embodiment)
In the second step of Example 2, the base sheet heated in the first step of Example 2 and the checkered polyamide 12 sheet are placed in a mold adjusted to the temperature shown in Table 1 (the base sheet is gold). (Bottom side of the mold), vacuum forming was performed to obtain a molded product having a two-layer structure.
In the two-layer structure molded product, the vivid check pattern of the part where the polyamide 12 sheet was molded could be visually confirmed through the part where the base sheet was molded (haze = 24.33%), which gave the appearance. ..

Example 6 (molded article of the third embodiment)
A first laminated sheet having a metal layer made of an aluminum-deposited film formed on the surface of the same polyamide 12 sheet (length 200 mm, width 200 mm, thickness 0.5 mm) as in Examples 1 to 3 was prepared.
In the second step of Example 2, the base sheet and the first laminated sheet heated in the first step of Example 2 are placed in a mold adjusted to the temperature shown in Table 1 (the base sheet is a mold). (Bottom side), vacuum forming was performed to obtain a molded product having a three-layer structure.
In the three-layer structure molded product, the aluminum vapor-deposited film, which is an intermediate layer, could be visually confirmed through the part where the base sheet was molded (haze = 24.33%). The aluminum foil shone when exposed to light, creating an aesthetic appearance.
Further, a molded product having a three-layer structure was similarly obtained by using a partially colored aluminum vapor-deposited film in yellow. The yellow-colored part of the aluminum-deposited film shines golden when exposed to light, giving it an even more aesthetic appearance.

Example 7 (molded article of the fourth embodiment)
A laminated film made of a thermoplastic polyurethane layer / aluminum vapor-deposited layer / thermoplastic polyurethane layer (50 μm / 1 μm / 100 μm) with one side embossed (trade name “Urethane Hologram, manufactured by Murata Gold Foil Co., Ltd.”). I prepared it. Since the aluminum-deposited layer was formed on the embossed surface of the thermoplastic polyurethane layer, fine irregularities were formed.
In the second step of Example 2, the base sheet and the laminated film heated in the first step of Example 2 are placed in a mold adjusted to the temperature shown in Table 1 (the base sheet is on the bottom side of the mold). ), Vacuum forming was performed to obtain a molded product having a three-layer structure.
In the molded product having a three-layer structure, an aluminum-deposited layer in which fine irregularities were formed, which was an intermediate layer, could be visually confirmed through the portion where the base sheet was molded (haze = 24.33%). The uneven aluminum-deposited layer shines rainbow-colored when exposed to light, giving it an even more aesthetic appearance.

The molded product obtained by the manufacturing method of the present invention can be used as a manufacturing material for all or part of the sole of spike shoes.

Claims (11)

It is a method for manufacturing a molded product including a portion in which a base sheet made of a polyamide resin is molded.
The polyamide resin constituting the substrate sheet made of the polyamide resin has a crystal melting temperature (Tm1) and a crystallization temperature (Tc1).
The first step of heating the substrate sheet made of the polyamide resin at a temperature of Tm1-10 ° C to Tm1 + 50 ° C.
Then, it has a second step of vacuum forming or compressed air forming in a state where a base sheet made of a polyamide resin heated at the above temperature is placed in a mold adjusted to Tc1-50 ° C. or lower.
A method for producing a molded product, wherein the haze of the molded portion of the base sheet of the obtained molded product is 50% or less. The second step is the step of vacuum forming or vacuum forming a base sheet made of a polyamide resin heated at the temperature in a mold adjusted to Tc1-80 ° C. or lower, according to claim 1. Manufacturing method of molded products. The molded product according to claim 1 or 2, wherein the base sheet made of the polyamide resin used in the second step is colored, has a pattern printed on it, or is colored and has a pattern printed on it. Manufacturing method. It is a method for manufacturing a molded product including a portion in which a base sheet made of a polyamide resin sheet is molded.
The polyamide resin constituting the substrate sheet made of the polyamide resin has a crystal melting temperature (Tm1) and a crystallization temperature (Tc1).
The first step of heating the substrate sheet made of the polyamide resin at a temperature of Tm1-10 ° C. or higher,
After that, a base sheet made of a polyamide resin heated at the above temperature and another thermoplastic resin sheet that is colored, has a pattern printed on it, or is colored and has a pattern printed on it are laminated. It has a second step of vacuum forming or pressure forming while it is placed in a mold adjusted to Tc1-50 ° C or lower.
A method for producing a molded product, wherein the haze of the portion of the obtained molded product on which the base sheet made of the polyamide resin is molded is 50% or less. It is a method for manufacturing a molded product including a portion in which a base sheet made of a polyamide resin sheet is molded.
The polyamide resin constituting the substrate sheet made of the polyamide resin has a crystal melting temperature (Tm1) and a crystallization temperature (Tc1).
The first step of heating the substrate sheet made of the polyamide resin at a temperature of Tm1-10 ° C. or higher,
Then, a base sheet made of a polyamide resin heated at the above temperature and a laminated sheet made of a polyamide resin sheet and a metal layer were laminated so that the metal layer became an intermediate layer, and the temperature was adjusted to Tc1-50 ° C. or lower. It has a second step of vacuum forming or pressure forming while it is placed in a mold.
A method for producing a molded product, wherein the haze of the portion of the obtained molded product on which the base sheet made of the polyamide resin is molded is 50% or less. The method for manufacturing a molded product according to claim 5, wherein the laminated sheet used in the second step has a thermoplastic polyurethane layer having irregularities on one surface side and a metal layer formed on the uneven surfaces. .. The manufacture of the molded product according to any one of claims 1 to 6, wherein the haze of the molded product of the substrate sheet made of the polyamide resin contained in the obtained molded product is 40% or less. Method. The method for producing a molded product according to any one of claims 1 to 7, wherein the polyamide resin is selected from polyamide 6, polyamide 66, and polyamide 12. The one according to any one of claims 1 to 8, wherein the molded product is used as a case for a communication terminal device, a decorative item, a container (excluding the case for the communication terminal device), or a part of the container. Manufacturing method of molded products. After manufacturing the molded product by the manufacturing method according to any one of claims 1 to 8,
A method for manufacturing a composite resin molded product, which comprises insert molding using the obtained molded product and a polyurethane resin to obtain a composite resin molded product composed of the molded product and the polyurethane resin. The method for manufacturing a composite resin molded product according to claim 10, wherein the composite resin molded product is used as all or part of the sole of spike shoes.