JP2020026299A - Composite container, manufacturing method for composite container, and blow molding die - Google Patents

Abstract

To provide a composite container which can improve appearance of the composite container and improve a design, and a manufacturing method for the composite container.SOLUTION: A composite container 10A includes a container body 10 and a plastic member 40 provided in close contact with an outside of the container body 10. The composite container is provided a structural color display part 23 having a fine uneven shape and exhibiting a structural color, on an outer surface of the plastic member 40.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a composite container, a method for manufacturing the composite container, and a blow mold.

  Recently, plastic bottles for storing content liquids such as food and drink have become popular, and such plastic bottles store the content liquid.

  A plastic bottle containing such a content liquid is manufactured by inserting a preform into a mold and performing biaxial stretch blow molding.

  By the way, in the conventional biaxial stretch blow molding method, for example, a preform containing a single layer material such as PET or PP, a multilayer material, a blend material, or the like is used to mold the container into a container shape. However, in the conventional biaxial stretch blow molding method, it is common to simply mold the preform into a container shape. For this reason, when giving various functions and characteristics (barrier property, heat insulation property, etc.) to the container, the means for changing the material of the preform is limited, for example. In particular, it is difficult to provide different functions and characteristics depending on the parts of the container (for example, the trunk and the bottom).

  On the other hand, the present applicant has proposed a composite container capable of imparting various functions and characteristics to the container in Patent Document 1.

JP-A-2005-128858

  On the other hand, in manufacturing such a composite container, it is required to improve the appearance of the composite container and improve the design.

  The present invention has been made in view of the above points, and has an object to provide a composite container and a method for manufacturing the composite container, which can improve the appearance of the composite container and improve the design. I do.

  A composite container according to one embodiment includes a container main body and a plastic member provided in close contact with the outside of the container main body, and has a structure in which the outer surface of the plastic member has a fine uneven shape and a structural color. A color display section is provided.

  In the composite container according to one embodiment, the structural color display section may present a structural color based on a diffraction grating.

  In the composite container according to one embodiment, a pitch of the fine unevenness may be not less than 0.8 μm and not more than 3.0 μm.

  In the composite container according to one embodiment, the fine unevenness of the structural color display portion may be a shape transferred from a surface shape of a blow mold for molding the composite container.

  In the composite container according to one embodiment, the fine unevenness of the structural color display portion may be a shape transferred from a transfer sheet attached to a blow mold for molding the composite container.

  The method for manufacturing a composite container according to one embodiment includes a step of preparing a preform, a step of providing a plastic member outside the preform, a step of preparing a blow mold, and a step of preparing the preform and the plastic. By blow molding the formed member in the blow mold, the step of expanding the preform and the plastic member integrally, and the step of expanding the preform and the plastic member integrally, The surface shape of the blow molding die is transferred, and a structural color display portion including a fine uneven shape and exhibiting a structural color is formed on the outer surface of the plastic member after the blow molding.

  A method for manufacturing a composite container according to one embodiment is a method for manufacturing a composite container, comprising the steps of: preparing a preform; providing a plastic member on the outside of the preform; A step of preparing a molding die; and a step of blow-molding the preform and the plastic member in the blow molding die to expand the preform and the plastic member integrally. In the step of integrally expanding the reform and the plastic member, the surface shape of the transfer sheet adhered to the blow molding die is transferred, and the outer surface of the plastic member after blow molding has a fine irregular shape. A structural color display portion exhibiting a color is formed.

  The blow molding die according to one embodiment is a blow molding die for producing a composite container having a container body and a plastic member provided in close contact with the outside of the container body, wherein the outer surface of the plastic member is In addition, a surface shape portion for forming a structural color display portion having a structural color including fine irregularities is provided.

  The blow molding mold according to one embodiment is a blow molding mold for producing a composite container having a container body and a plastic member provided in close contact with the outside of the container body, wherein the mold body, the mold A transfer sheet adhered to the inner surface of the main body and having a surface shape for forming a structural color display portion having a structural color including fine irregularities on the outer surface of the plastic member.

  According to the present disclosure, it is possible to improve the appearance of the composite container and improve the design.

FIG. 1 is a partial vertical sectional view showing a composite container according to an embodiment. FIG. 2 is a horizontal cross-sectional view (a cross-sectional view taken along the line II-II in FIG. 1) illustrating the composite container according to the embodiment. FIG. 3 is a schematic diagram showing a fine uneven shape of a structural color display section of the composite container according to one embodiment. FIG. 4 is a partial vertical sectional view showing a composite preform according to one embodiment. FIG. 5 is a horizontal cross-sectional view (a cross-sectional view taken along line VV of FIG. 4) showing the composite preform according to one embodiment. FIGS. 6A to 6D are perspective views showing various plastic members. 7A to 7F are schematic diagrams illustrating a method for manufacturing a composite container using a blow mold according to one embodiment. FIG. 8 is a cross-sectional view illustrating a transfer sheet of a blow molding die according to a modification of the embodiment. 9A to 9C are schematic diagrams illustrating a method of manufacturing a composite container using a blow mold according to a modification of the embodiment.

  Hereinafter, an embodiment will be described with reference to the drawings. 1 to 7 are views showing an embodiment. Each figure shown below is schematically shown. Therefore, the size and shape of each part are exaggerated as appropriate to facilitate understanding. Further, the present invention can be appropriately changed and implemented without departing from the technical idea. In the following drawings, the same portions are denoted by the same reference numerals, and a detailed description thereof may be partially omitted. Further, the numerical values such as the dimensions of each member and the material names described in this specification are merely examples of the embodiment, and are not limited thereto, and can be appropriately selected and used. In this specification, terms specifying shapes and geometric conditions, such as terms such as parallel, orthogonal, and vertical, include not only strictly meaning but also substantially the same state.

Structure of the composite container First, referring to FIG. 1 and FIG. 2, an outline of the composite container according to the present embodiment.
In this specification, “upper” and “lower” refer to upper and lower sides in a state where the composite container 10A is erected (FIG. 1), respectively.

  1 and 2, a composite preform 70 (see FIGS. 4 and 5) including a preform 10a and a plastic member 40a using a blow mold 50, as described later. This is obtained by expanding the preform 10a of the composite preform 70 and the plastic member 40a integrally by performing axial stretch blow molding.

  Such a composite container 10A includes a container body 10 made of a plastic material located inside, and a plastic member 40 provided in close contact with the outside of the container body 10.

  The container body 10 includes a mouth portion 11, a neck portion 13 provided below the mouth portion 11, a shoulder portion 12 provided below the neck portion 13, a body portion 20 provided below the shoulder portion 12, and a body portion. And a bottom part 30 provided below the part 20.

  On the other hand, the plastic member 40 is closely attached to the outer surface of the container main body 10 in a state of being thinly extended, and is attached to the container main body 10 without being easily moved or rotated.

  Next, the container body 10 will be described in detail. The container body 10 has the mouth 11, the neck 13, the shoulder 12, the trunk 20, and the bottom 30 as described above.

  The opening 11 has a screw portion 14 screwed to a cap (not shown) and a flange portion 17 provided below the screw portion 14. Note that the shape of the mouth portion 11 may be a conventionally known shape. The container body 10 is filled with a content such as a content liquid, and a cap (not shown) is screwed into the mouth portion 11 to produce a content-containing composite container.

  The neck portion 13 is located between the flange portion 17 and the shoulder portion 12 and has a substantially cylindrical shape having a substantially uniform diameter. The shoulder portion 12 is located between the neck portion 13 and the trunk portion 20 and has a shape whose diameter gradually increases from the neck portion 13 side to the trunk portion 20 side (the area gradually increases in a horizontal cross section). Shape).

  The body 20 has a cylindrical shape having a substantially uniform diameter as a whole. However, the present invention is not limited to this, and the body 20 may have a polygonal cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape. Alternatively, the body 20 may have a tubular shape having a horizontal cross section that is not uniform from above to below. On the outer surface of the body portion 20, irregularities other than the structural color display portion 23 described later, for example, irregularities such as a reduced pressure absorption panel or a groove may be formed.

  On the other hand, the bottom portion 30 has a concave portion 31 located at the center and a ground portion 32 provided around the concave portion 31. The shape of the bottom 30 is not particularly limited, and may have a conventionally known bottom shape (for example, a petaloid bottom shape or a round bottom shape).

  The thickness of the container body 10 in the body 20 is not limited to this, but can be reduced to, for example, about 50 μm or more and 250 μm or less. Further, the weight of the container body 10 is not limited to this, but can be 10 g or more and 20 g or less. By reducing the thickness of the container body 10 in this way, the weight of the container body 10 can be reduced.

  Such a container body 10 can be manufactured by biaxially stretch blow molding a preform 10a (described later) manufactured by injection molding a synthetic resin material. It is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate) as a material of the container body 10. The container body 10 may be colored in a color such as red, blue, yellow, green, brown, black, or white, but is preferably colorless and transparent in consideration of ease of recycling. Further, the various resins described above may be blended and used. Further, a vapor-deposited film such as a diamond-like carbon film or a silicon oxide thin film may be formed on the inner surface of the container body 10 in order to enhance the barrier properties of the container.

  Further, the container body 10 can be formed as a multilayer molded bottle having two or more layers. That is, by injection molding, for example, a resin having a gas barrier property such as MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer), or PEN (polyethylene naphthalate) (intermediate layer). After injection molding of a preform 10a having three or more layers, a multi-layer bottle having gas barrier properties may be formed by blow molding. As the intermediate layer, a resin obtained by blending the above various resins may be used.

  In addition, by mixing an inert gas (nitrogen gas, argon gas) with a melt of the thermoplastic resin, a foamed preform having a foamed cell diameter of 0.5 μm or more and 100 μm or less is formed, and this foamed preform is blow molded. By doing so, the container body 10 may be manufactured. Since such a container body 10 has a built-in foam cell, the light shielding property of the entire container body 10 can be enhanced.

  Such a container body 10 may be composed of, for example, a bottle having a full filling capacity of 100 ml or more and 2000 ml or less. Alternatively, the container body 10 may be a large bottle having a full filling capacity of, for example, 10 L or more and 60 L or less.

  Next, the plastic member 40 will be described. The plastic member 40 (40a) is provided so as to surround the outside of the preform 10a as described later, and is obtained by being closely adhered to the outside of the preform 10a and then biaxially stretch blow-molded together with the preform 10a. It is a thing.

  The plastic member 40 is attached to the outer surface of the container main body 10 without being adhered thereto, and is in close contact with the container main body 10 so as not to move or rotate. The plastic member 40 is thinly stretched on the outer surface of the container body 10 to cover the container body 10. Further, as shown in FIG. 2, the plastic member 40 is provided over the entire circumferential direction so as to surround the container body 10, and has a substantially circular horizontal cross section.

  In this case, the plastic member 40 is provided so as to cover the neck 13, the shoulder 12, the trunk 20, and the bottom 30, excluding the mouth 11, of the container body 10. Thereby, desired functions and characteristics can be given to the neck portion 13, the shoulder portion 12, the trunk portion 20, and the bottom portion 30 of the container body 10.

  Note that the plastic member 40 may be provided in the entire or a part of the container body 10 other than the mouth 11. For example, the plastic member 40 may be provided so as to cover the entirety of the shoulder 12, the trunk 20, and the bottom 30 of the container body 10 except for the mouth 11 and the neck 13. Alternatively, the plastic member 40 may be provided so as to cover the shoulder 12, the trunk 20, and the bottom 30 of the container main body 10 except for the mouth 11, the neck 13, and the center of the bottom 30.

  Since the plastic member 40 is not welded or adhered to the container main body 10, it can be removed from the container main body 10 by being peeled off. Specifically, for example, the plastic member 40 is cut off using a cutting tool or the like, or a cutting line (not shown) is provided in advance on the plastic member 40, and the plastic member 40 is peeled off along the cutting line. it can. Thereby, the plastic member 40 can be separated and removed from the container body 10.

  Such a plastic member 40 may have no function of contracting the preform 10a or may have a function of contracting.

  When the plastic member 40 has a function of contracting with respect to the preform 10a, the plastic member (outside contraction member) 40 is provided outside the preform 10a, and is heated integrally with the preform 10a. It is obtained by biaxial stretch blow molding.

By the way, in the present embodiment, on the outer surface of the plastic member 40, there is provided a structural color display portion 23 (shaded portion in FIG. 1) which has a fine uneven shape and exhibits a structural color. The fine uneven shape of the structural color display portion 23 is a shape transferred from the surface shape of the blow mold 50 for molding the composite container 10A. When the structural color display section 23 presents a structural color, various colors can be visually recognized depending on the viewing angle of the composite container 10A. For this reason, the design of the composite container 10A can be improved. In addition, when the plastic member 40 is colored, or when the plastic member 40 forms a display portion having a pearl color or the like, it is general to knead a pigment or dye into the resin material. On the other hand, in the present embodiment,
On the outer surface of the plastic member 40, there is provided a structural color display portion 23 having a fine uneven shape and exhibiting a structural color. For this reason, since ink that deteriorates due to ultraviolet rays or the like is not used, the design can be maintained for a long period of time as compared with, for example, a case where printing is performed on the outer surface of the plastic member 40. Further, in the composite container 10A according to the present embodiment, the plastic member 40 may be separated and removed from the container main body 10, and the colorless and transparent container main body 10 may be recycled. On the other hand, in the present embodiment, since the structural color can be presented by the structural color display portion 23 without adding a pigment or a dye to the plastic member 40, the recyclability of the container body 10 is improved. Can be. In the present specification, the term “structural color” is not a special dye, but a color that is generated by an optical phenomenon based on a physical structure such as light diffraction, refraction, interference or scattering caused by a fine structure. Say.

  The structural color display section 23 according to the present embodiment presents a structural color by the diffraction grating. When the structural color display section 23 presents a structural color based on the diffraction grating, it is difficult to manufacture a similar product, so that the reliability of the product can be improved and the aesthetics of the composite container 10A can be improved. Such a fine uneven shape of the structural color display section 23 may be a regular uneven pattern having a periodic structure, or an irregular uneven pattern that changes continuously. In the example shown in FIG. 3, the fine unevenness has a wavy uneven pattern having a periodic structure. The pitch P (interval between adjacent concave portions) of the fine unevenness may be, for example, 0.8 μm or more and 3.0 μm or less. By setting the pitch P of the fine unevenness to 0.8 μm or more, the shapeability during blow molding can be improved, and high diffraction efficiency can be exhibited for a specific wavelength in the visible region. Further, by setting the height H of the fine unevenness to 3.0 μm or less, the structural color display section 23 can effectively exhibit the structural color, and has a high diffraction efficiency for a specific wavelength in the visible region. Can be shown. The height H (difference between the most protruded part and the most depressed part) of the fine unevenness may be, for example, 0.5 μm or more and 10 μm or less. By setting the height H of the fine unevenness to 0.5 μm or more, the shapeability during blow molding can be improved. Further, by setting the height H of the fine unevenness to 10 μm or less, the structural color display section 23 can effectively exhibit the structural color. The uneven pattern of the fine uneven shape is arbitrary, and may be, for example, a sawtooth shape or a rectangular shape.

  The structural color display portion 23 may be formed on the entire outer surface or only a part of the outer surface of the plastic member 40 located on the body portion 20. Further, the structural color display section 23 is not limited to the body section 20 and may be formed on a part or the entirety of the plastic member 40 located on the shoulder section 12, the neck section 13 and / or the bottom section 30.

  Examples of the plastic member 40 include polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, poly-4-methylpentene-1, polystyrene, AS resin, ABS resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, Polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, diallyl phthalate resin, fluorine resin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene-1, polyisoprene, polychloroprene, Ethylene propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluoro rubber, nylon 6, nylon 6,6, aromatic polyamide, polycarbonate , Poly (ethylene terephthalate), poly (butylene terephthalate), poly (ethylene naphthalene), U polymer, liquid crystal polymer, modified polyphenylene ether, polyether ketone, polyether ether ketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene sulfide, poly Examples thereof include ether sulfone, silicone resin, polyurethane, phenol resin, urea resin, polyethylene oxide, polypropylene oxide, polyacetal, and epoxy resin. Among them, it is preferable to use a thermoplastic inelastic resin such as polyethylene (PE) such as low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). Further, a blend material, a multilayer structure, or a partial multilayer structure thereof may be used. Furthermore, various additives other than the main component resin may be added to the material of the plastic member 40 as long as the properties are not impaired. Examples of additives include a plasticizer, an ultraviolet stabilizer, a coloring inhibitor, a matting agent, a deodorant, a flame retardant, a weathering agent, an antistatic agent, a yarn friction reducing agent, a slip agent, a release agent, An oxidizing agent, an ion exchange agent, a coloring pigment, and the like can be added. Further, by mixing an inert gas (nitrogen gas, argon gas) with a melt of the thermoplastic resin, a foamed member having a foamed cell diameter of 0.5 μm or more and 100 μm or less is used, and the foamed preform is molded. Thereby, the light shielding property can be improved.

  The plastic member 40 may be made of a material having a light-barrier property for blocking invisible light such as ultraviolet light. In this case, without using a multilayer preform or a preform containing a blend material as the preform 10a, the light barrier property of the composite container 10A can be enhanced, and the deterioration of the content liquid due to ultraviolet rays or the like can be prevented. As such a material, a blended material or a material obtained by adding a light-shielding resin to PET, PE, or PP can be considered. Further, a foamed member having a foam cell diameter of 0.5 μm or more and 100 μm or less produced by mixing an inert gas (nitrogen gas, argon gas) with a melt of a thermoplastic resin may be used.

  The plastic member 40 may be made of a material (a material with low thermal conductivity) having a higher heat insulating property or heat insulating property than the plastic material forming the container body 10 (preform 10a). In this case, it is possible to make it difficult for the temperature of the content liquid to be transmitted to the surface of the composite container 10A without increasing the thickness of the container body 10 itself. Thereby, the coolness or heat retention of the composite container 10A is enhanced. Further, when the user grips the composite container 10A, it is prevented that the composite container 10A becomes difficult to hold due to being too cold or too hot. Examples of such a material include foamed polyurethane, polystyrene, PE (polyethylene), PP (polypropylene), phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, and melamine resin. It is preferable to mix hollow particles with a resin material containing these resins. The average particle diameter of the hollow particles is preferably from 1 μm to 200 μm, more preferably from 5 μm to 80 μm. The “average particle diameter” means a volume average particle diameter, and is measured by a known method using a particle size distribution / particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device, manufactured by Nikkiso Co., Ltd.). can do. The hollow particles may be organic hollow particles composed of a resin or the like, or may be inorganic hollow particles composed of a glass or the like. Hollow particles are preferred. Examples of the resin constituting the organic hollow particles include a styrene resin such as a crosslinked styrene-acryl resin, a (meth) acryl resin such as an acrylonitrile-acryl resin, a phenol resin, a fluorine resin, a polyamide resin, and a polyimide. Resin, polycarbonate resin, polyether resin and the like. In addition, Ropeike HP-1055, Ropeke HP-91, Ropeke OP-84J, Ropeke Ultra, Ropeke SE, Ropeke ST (manufactured by Rohm and Haas Co., Ltd.), Nipol MH-5055 (manufactured by Nippon Zeon Co., Ltd.), SX8782 And SX866 (manufactured by JSR Corporation) can also be used. The content of the hollow particles is preferably 0.01 to 50 parts by mass, and more preferably 1 to 20 parts by mass, based on 100 parts by mass of the resin material contained in the plastic member 40. More preferably, there is.

  Further, the plastic member 40 may be made of a material that is less slippery than the plastic material constituting the container body 10 (preform 10a). In this case, the user can easily grip the composite container 10A without changing the material of the container body 10.

  The plastic member 40 may be colored red, blue, yellow, green, brown, black, white, or the like, and may be transparent or opaque.

  The thickness of the plastic member 40 is not limited to this, but may be, for example, about 5 μm or more and 500 μm or less when attached to the container body 10.

Configuration of Composite Preform Next, the configuration of the composite preform will be described with reference to FIGS.

  As shown in FIGS. 4 and 5, the composite preform 70 includes a preform 10a made of a plastic material, and a bottomed cylindrical plastic member 40a provided outside the preform 10a.

  The preform 10a includes a mouth 11a, a trunk 20a connected to the mouth 11a, and a bottom 30a connected to the trunk 20a. The mouth 11 a corresponds to the mouth 11 of the container body 10 described above, and has substantially the same shape as the mouth 11. The body 20a corresponds to the neck 13, the shoulder 12, and the body 20 of the container body 10 described above, and has a substantially cylindrical shape. The bottom 30a corresponds to the bottom 30 of the container body 10 described above, and has a substantially hemispherical shape.

  The plastic member 40a is attached to the outer surface of the preform 10a without being adhered thereto, and is adhered to the preform 10a so as not to move or rotate, or to such an extent that the plastic member 40a does not drop by its own weight. . The plastic member 40a is provided over the entire circumferential direction so as to surround the preform 10a, and has a circular horizontal cross section.

  In this case, the plastic member 40a is provided so as to cover the entire region of the container body 10 and the entire region of the bottom portion 30a of the trunk portion 20a.

  The plastic member 40a may be provided in the whole area or a part of the area other than the mouth 11a. Alternatively, the plastic member 40a may be provided so as to cover the trunk 20a except for the bottom 30.

  Such a plastic member 40a may not have a function of contracting to the preform 10a, or may have a function of contracting.

  When the plastic member 40a has a contracting action, the plastic member (outside contracting member) 40a contracts (for example, heat contracts) with the preform 10a when an external action (for example, heat) is applied. ) May be used. Alternatively, the plastic member (outside contraction member) 40a may itself be contractible or elastic, and may be contractable without adding an external action.

  When the plastic member 40a has a heat shrinking action, the lower end of the plastic member 40a (the end opposite to the mouth 11a) is inserted after the cylindrical plastic member 40a is fitted into the preform 10a. May be thermocompression-bonded.

  As the plastic member 40a, for example, a direct blow tube produced by direct blow molding, a sheet molded tube produced by sheet molding, an extruded tube produced by extrusion molding, an injection molded tube produced by injection molding, inflation molding Can be used, but the present invention is not limited to this, and a molding method other than the above may be used.

  The plastic member 40a may be colored red, blue, yellow, green, brown, black, white, or the like, and may be transparent or opaque.

  Next, the shape of the plastic member 40a will be described.

  As shown in FIG. 6A, the plastic member 40 a has a bottomed cylindrical shape as a whole, and may have a cylindrical body 41 and a bottom 42 connected to the body 41. . In this case, since the bottom portion 42 of the plastic member 40a covers the bottom portion 30a of the preform 10a, various functions and characteristics such as barrier properties are imparted to the bottom portion 30 in addition to the body portion 20 of the composite container 10A. Can be. Examples of such a plastic member 40a include the above-described direct blow tube, sheet molding tube, and injection molding tube.

  In addition, as shown in FIG. 6B, the plastic member 40a may have a cylindrical body 41 as a whole in a tubular shape (bottomless cylindrical shape). In this case, as the plastic member 40a, for example, the blow tube, the extrusion tube, the inflation molded tube, and the sheet molded tube described above can be used.

  Further, as shown in FIGS. 6C and 6D, the plastic member 40a may be manufactured by forming a film into a cylindrical shape and bonding the ends thereof. In this case, as shown in FIG. 6C, the plastic member 40a may be formed in a tube shape (bottomless cylindrical shape) having a body portion 41, and as shown in FIG. The bottom portion 42 may be bonded to form a bottomed cylindrical shape.

Manufacturing Method of Composite Preform and Composite Container Next, a manufacturing method (blow molding method) of the composite container 10A according to the present embodiment will be described with reference to FIGS.

  First, a preform 10a made of a plastic material is prepared (see FIG. 7A). In this case, for example, the preform 10a may be manufactured by an injection molding method using an injection molding machine (not shown). Further, as the preform 10a, a preform generally used conventionally may be used.

  Next, by providing a plastic member 40a outside the preform 10a, a composite preform 70 having the preform 10a and the plastic member 40a closely adhered to the outside of the preform 10a is manufactured (FIG. 7 ( b)). In this case, the plastic member 40a has a bottomed cylindrical shape as a whole, and has a cylindrical body 41 and a bottom 42 connected to the body 41.

  At this time, a plastic member 40a having an inner diameter that is the same as or slightly smaller than the outer diameter of the preform 10a may be pressed into the preform 10a to be in close contact with the outer surface of the preform 10a. Alternatively, as described below, a heat-shrinkable plastic member 40a is provided on the outer surface of the preform 10a, and the plastic member 40a is heated to 50 ° C. to 100 ° C. so as to be thermally shrunk so that the outer surface of the preform 10a May be adhered to.

  As described above, the plastic member 40a is brought into close contact with the outside of the preform 10a in advance, and the composite preform 70 is produced, whereby a series of steps for producing the composite preform 70 (FIGS. 7A to 7B). )) And a series of steps (FIGS. 7 (c) to 7 (f)) for producing the composite container 10A by blow molding can be performed at different places (such as factories).

  Next, the composite preform 70 is heated by the heating device 51 (see FIG. 7C). At this time, the composite preform 70 is uniformly heated in the circumferential direction by the heating device 51 while rotating with the mouth 11a facing downward. The heating temperature of the preform 10a and the plastic member 40a in this heating step may be, for example, 90 ° C. to 130 ° C.

  Also, a blow mold 50 is prepared. Then, the composite preform 70 heated by the heating device 51 is sent to a blow mold 50 for producing the composite container 10A (see FIG. 7D).

  The composite container 10A is molded using the blow mold 50. In this case, the blow mold 50 has a surface shape portion 53 (FIGS. 7D to 7F) for forming a structural color display portion 23 having a fine uneven shape and exhibiting a structural color on the outer surface of the plastic member 40. Shaded portion). In the present embodiment, the blow mold 50 includes a mold main body 52 that is a metal mold or a resin mold, and a surface shape portion 53 is provided on the inner surface of the mold main body 52 at a position corresponding to the structural color display portion 23. Is provided. The surface shape portion 53 has an uneven pattern corresponding to the fine uneven shape of the structural color display portion 23. In the present embodiment, a blow mold 50 provided with such a surface shape portion 53 is also provided.

  The mold body 52 includes a pair of body molds 50a and 50b that are divided from each other, and a bottom mold 50c (see FIG. 7D). The inner surface of the mold main body 52 has a shape corresponding to the shoulder 12, neck 13, body 20 and bottom 30 of the composite container 10A. In FIG. 7D, the pair of body molds 50a and 50b are open to each other, and the bottom mold 50c is raised upward. In this state, the composite preform 70 is inserted between the pair of body molds 50a and 50b of the mold body 52.

  Next, as shown in FIG. 7E, after the bottom mold 50c is lowered, the pair of body dies 50a and 50b are closed, and the pair of body dies 50a and 50b of the mold body 52 and the bottom are closed. The mold 50c forms a closed blow molding die 50. Next, air is press-fitted into the preform 10a, and biaxial stretch blow molding is performed on the composite preform 70.

  Thereby, the composite preform 70 is shaped into a shape corresponding to the inner surface of the blow mold 50, and the container body 10 is obtained from the preform 10a in the blow mold 50. During this time, the body molds 50a and 50b are heated to 30 ° C to 80 ° C, and the bottom mold 50c is cooled to 5 ° C to 25 ° C. In the blow mold 50, the surface shape of the blow mold 50 (the mold body 52) is transferred, and the structural color display section including the fine irregularities and showing the structural color is formed on the outer surface of the plastic member 40 after blow molding. 23 are formed. At this time, in the blow mold 50, the preform 10a of the composite preform 70 and the plastic member 40a are integrally expanded. As a result, the preform 10a and the plastic member 40a are integrally formed into a shape corresponding to the inner surface of the blow mold 50.

  In this way, a composite container 10A including the container body 10 and the plastic member 40 provided on the outer surface of the container body 10 is obtained.

  Thereafter, as shown in FIG. 7 (f), the pair of body dies 50a, 50b and the bottom mold 50c of the mold body 52 are separated from each other, and the composite container 10A is taken out from the blow molding mold 50. Thus, the composite container 10A shown in FIGS. 1 and 2 is obtained.

  As described above, according to the present embodiment, on the outer surface of the plastic member 40, the structural color display portion 23 having a fine uneven shape and exhibiting a structural color is provided. Thereby, various colors can be visually recognized depending on the angle at which the composite container 10A is visually recognized. For this reason, the design of the composite container 10A can be improved. In addition, since ink that deteriorates due to ultraviolet rays or the like is not used, the design can be maintained for a long period of time as compared with a case where printing is performed on the outer surface of the plastic member 40, for example.

  Further, according to the present embodiment, blow molding is performed using blow molding die 50 to produce composite container 10A. At this time, the surface shape of the mold body 52 is transferred to the outer surface of the plastic member 40. Thereby, it is possible to easily form the structural color display portion 23 having the fine irregularities on the surface of the composite container 10A.

  Further, according to the present embodiment, since the plastic member 40 can be separated and removed from the container main body 10, the colorless and transparent container main body 10 can be recycled as in the related art.

  Further, according to the present embodiment, it is possible to use, as plastic member 40, a material (eg, polyethylene or polypropylene) having a better shape than the material of container body 10 (eg, polyethylene terephthalate). Therefore, the surface shape of the mold body 52 can be clearly transferred to the plastic member 40 as compared with the case where the surface shape of the mold body 52 is directly transferred to the container body 10. Thereby, a finer (for example, 3 μm or less) uneven shape can be expressed on the surface of the plastic member 40.

  In the above-described embodiment, an example has been described in which the fine unevenness of the structural color display portion 23 is a shape transferred from the surface shape portion 53 provided on the inner surface of the mold body 52. However, the present invention is not limited to this, and the shape of the fine unevenness of the structural color display portion 23 may be a shape transferred from the transfer sheet 60 adhered to the blow mold 50 for forming the composite container 10A.

  In this modification, the blow mold 50 is attached to the inner surface of the mold body 52, and has a surface shape for forming the structural color display portion 23 having a structural color including fine irregularities on the outer surface of the plastic member 40. And a transfer sheet 60 having the same. As shown in FIG. 8, the transfer sheet 60 for blow molding is provided with an adhesive layer 61 to be attached to the mold body 52 of the blow molding die 50, and is disposed on the adhesive layer 61, and is provided on the outer surface of the composite container 10 </ b> A. A transfer layer 62 having a shape to be transferred.

  The adhesive layer 61 may include an adhesive. The pressure-sensitive adhesive is not particularly limited and includes, for example, natural rubber, butyl rubber, polyisoprene, polyisobutylene, polychloroprene, a synthetic rubber resin such as a styrene-butadiene copolymer resin, a silicone resin, and an acrylic resin. Resin, vinyl acetate resin such as polyvinyl acetate, ethylene-vinyl acetate copolymer, urethane resin, acrylonitrile, hydrocarbon resin, alkylphenol resin, rosin, rosin triglyceride, and rosin resin such as hydrogenated rosin can be used. The thickness of the adhesive layer 61 may be, for example, in a range of 5 μm or more and 300 μm or less.

  The adhesive layer 61 can be peeled off from the mold body 52 and can be peeled off manually or mechanically. Even if the adhesive layer 61 remains on the mold body 52, And can be removed by cleaning with alcohol. By removing the adhesive layer 61, the mold main body 52 can be returned to a state before the transfer sheet 60 is attached. In this case, another transfer sheet 60 can be attached to the mold body 52 again.

  As the transfer layer 62, it is preferable to use a material excellent in weather resistance and heat resistance, such as a polyvinyl chloride paper made of a vinyl chloride resin, for example. The thickness of the transfer layer 62 may be, for example, in the range of 10 μm or more and 3000 μm or less, and may be 10 μm or more and 100 μm or less in order to further maintain the bottle shape.

  In addition, on the surface of the transfer layer 62, on the outer surface of the plastic member 40, there is provided a surface shape portion 64 for forming the structural color display portion 23 having a fine uneven shape and exhibiting a structural color. The configuration of the surface shape portion 64 is the same as the surface shape portion 53 of the mold body 52 described above, and a detailed description thereof will be omitted here.

  A release paper 63 is provided on the adhesive layer 61. The release paper 63 is releasably attached to the opposite side of the transfer layer 62 on the adhesive layer 61. By peeling the release paper 63 from the adhesive layer 61 and attaching the adhesive layer 61 to the outer surface of the mold body 52, the transfer layer 62 is directed to the inner surface of the mold body 52. By performing blow molding in this state, the fine irregularities of the transfer layer 62 are transferred to the outer surface of the composite container 10A.

  The release paper 63 has a base material such as high-quality paper, coated paper, impregnated paper, or a plastic film, and a release layer provided on one side of the base material. The release layer is not particularly limited as long as it has a release property, and examples thereof include a silicone resin, an organic resin-modified silicone resin, a fluororesin, an aminoalkyd resin, and a polyester resin. These resins can be used in any of an emulsion type, a solvent type and a solventless type.

  Next, a method of manufacturing the composite container 10A according to the present modification will be described with reference to FIGS.

  First, a plastic member 40a is provided outside the preform 10a by a method shown in FIGS. 7A to 7C, for example, and heated by a heating device 51.

  Subsequently, the preform 10a and the plastic member 40a heated by the heating device 51 are sent to the blow molding die 50 (see FIG. 9A).

  The preform 10a and the plastic member 40a are molded by using the blow mold 50, and the container body 10 and the outer surface of the container body 10 are formed in substantially the same manner as in the above-described cases of FIGS. (See FIGS. 9A to 9C). At this time, the transfer sheet 60 is adhered to the inner surfaces of the pair of body molds 50a and 50b, respectively, and is provided at a position corresponding to the structural color display section 23 described above. Thereby, in the blow mold 50, the surface shape of the transfer sheet 60 is transferred, and the structural color display portion 23 having a structural color including fine irregularities is formed on the outer surface of the plastic member 40 after blow molding. .

  As described above, according to the present modification, the fine unevenness of the structural color display portion 23 is a shape transferred from the transfer sheet 60 adhered to the blow mold 50 for molding the composite container 10A. Also in this case, the surface shape of the transfer sheet 60 adhered to the mold main body 52 is transferred to the outer surface of the plastic member 40, so that the structural color display portion 23 having the fine irregularities on the surface of the composite container 10A. Can be easily formed. Further, the transfer sheet 60 attached to the mold body 52 can be easily peeled off and replaced with another transfer sheet 60. For this reason, it is possible to easily and quickly change the fine irregularities on the surface of the composite container 10A. In this case, since it is not necessary to remanufacture the mold main body 52 itself, the cost and time required for manufacturing the mold main body 52 can be saved. Further, since the transfer sheet 60 can be attached to the existing mold body 52, various desired fine irregularities can be formed on the surface of the composite container 10A while maintaining the overall shape of the existing mold body 52. Can be granted.

  A plurality of constituent elements disclosed in the above-described embodiments and modified examples can be appropriately combined as needed. Alternatively, some components may be deleted from all the components shown in the above-described embodiment and modifications.

DESCRIPTION OF SYMBOLS 10 Container main body 10A Composite container 10a Preform 23 Structural color display part 30, 30a Bottom part 40, 40a Plastic member 50 Blow mold 52 Mold main body 53 Surface shape part 60 Transfer sheet 64 Surface shape part

Claims (9)

In a composite container,
A container body,
A plastic member provided in close contact with the outside of the container body,
A composite container, wherein a structural color display portion having a fine uneven shape and exhibiting a structural color is provided on an outer surface of the plastic member.   The composite container according to claim 1, wherein the structural color display unit displays a structural color based on a diffraction grating.   3. The composite container according to claim 1, wherein a pitch of the fine irregularities is 0.8 μm or more and 3.0 μm or less. 4.   The composite container according to any one of claims 1 to 3, wherein the fine uneven shape of the structural color display portion is a shape transferred from a surface shape of a blow mold for molding the composite container.   The composite according to any one of claims 1 to 3, wherein the fine concave-convex shape of the structural color display portion is a shape transferred from a transfer sheet attached to a blow mold for molding the composite container. container. In the method for manufacturing a composite container,
Preparing a preform;
A step of providing a plastic member outside the preform,
Preparing a blow mold,
Blow molding the preform and the plastic member in the blow mold to inflate the preform and the plastic member integrally,
In the step of integrally expanding the preform and the plastic member, the surface shape of the blow mold is transferred, and the outer surface of the plastic member after blow molding has a structural color including a fine unevenness and a structural color. A method for manufacturing a composite container in which a display unit is formed. In the method for manufacturing a composite container,
Preparing a preform;
A step of providing a plastic member outside the preform,
A step of preparing a blow mold to which a transfer sheet is stuck,
Blow molding the preform and the plastic member in the blow mold to inflate the preform and the plastic member integrally,
In the step of integrally expanding the preform and the plastic member, the surface shape of the transfer sheet adhered to the blow mold is transferred, and the fine irregularities are formed on the outer surface of the plastic member after blow molding. A method for manufacturing a composite container, wherein a structural color display portion having a contained structural color is formed. A blow molding die for producing a composite container having a container body and a plastic member provided in close contact with the outside of the container body,
A blow mold having a surface shape portion for forming a structural color display portion having a structural color including fine irregularities on an outer surface of the plastic member. A blow molding die for producing a composite container having a container body and a plastic member provided in close contact with the outside of the container body,
A mold body,
A transfer sheet adhered to the inner surface of the mold body and having a surface shape for forming a structural color display portion including a fine uneven shape on the outer surface of the plastic member and exhibiting a structural color, and a blow molding die. .