Composite preform, composite container and manufacturing method thereof, and plastic bottle

Abstract

To provide a composite preform, a composite container and a manufacturing method thereof, and a plastic bottle, which are capable of clearly displaying discolored parts.SOLUTION: A composite container 10A comprises a container body 10 and a plastic member 40 provided in close contact with an outside of the container body 10 without being bonded. The plastic member 40 includes a temperature indicating material, and the plastic member 40 has a discolored portion 43 where the temperature indicating material has changed color.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a composite preform, a composite container and a method for manufacturing the same, and a plastic bottle.

Background Art

[0002] Recently, plastic bottles have become widespread as bottles for containing content liquids such as foods and drinks, and such plastic bottles contain content liquids. A plastic bottle is manufactured by inserting a preform into a mold and performing biaxial stretch blow molding.

[0003] 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, or a blend material is used to form a container shape. However, in the conventional biaxial stretch blow molding method, it is common to simply form a preform into a container shape. Therefore, when imparting various functions and characteristics (such as barrier properties and heat retention properties) to a container, the means are limited, for example, by changing the material constituting the preform.

[0004] In contrast, the applicant has proposed, in Patent Document 1, a composite container capable of imparting various functions and characteristics to a container.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present embodiment provides a composite preform, a composite container and a method for manufacturing the same, and a plastic bottle that can clearly display a discolored portion.

Means for Solving the Problems

[0007] Embodiments of the present disclosure relate to the following [1] to

[10] .

[0008] [1] A composite container including a container body and a plastic member provided in close contact with the outside of the container body without being adhered thereto, the plastic member containing a temperature indicating material, and the plastic member having a discolored portion where the temperature indicating material has changed color.

[0009] [2] The composite container according to [1], wherein the temperature indicating material changes color when heated to a predetermined temperature of 60° C. or higher and maintains the changed color when returned to a predetermined temperature of 0° C. or higher and less than 60° C.

[0010] [3] The composite container according to [1] or [2], wherein the plastic member has an unchanged portion where the temperature indicating material has not changed color.

[0011] [4] A composite preform including a preform and a plastic member provided in close contact with the outside of the preform without being adhered thereto, the plastic member containing a temperature indicating material, and the temperature indicating material changing color when heated to a predetermined temperature of 60° C. or higher and maintaining the changed color when returned to a predetermined temperature of 0° C. or higher and less than 60° C.

[0012] [5] A method for manufacturing a composite preform, the method including: preparing a plastic member containing a temperature indicating material; preparing a preform; and providing the plastic member in close contact with the outside of the preform without adhering it, wherein the temperature indicating material changes color when heated to a predetermined temperature of 60° C. or higher and maintains the changed color when returned to a predetermined temperature of 0° C. or higher and less than 60° C.

[0013] [6] A step of preparing a plastic member containing a temperature indicating material, a step of preparing a preform, a step of closely providing the plastic member on the outside of the preform without adhesion, a step of heating the preform and the plastic member and inserting them into a blow molding die, a step of expanding the preform and the plastic member integrally by performing blow molding on the preform and the plastic member in the blow molding die, and a step of discoloring the temperature indicating material by heating a part of the plastic member. A method for manufacturing a composite container comprising the steps of:

[0014] [7] The temperature indicating material according to [6], which discolors when heated to a predetermined temperature of 60 ° C or higher and maintains the discolored color when returned to a predetermined temperature of 0 ° C or higher and less than 60 ° C. Method for manufacturing a composite container.

[0015] [8] A plastic bottle containing a temperature indicating material, comprising a mouth portion, a neck portion, a shoulder portion, a body portion, and a bottom portion, wherein the plastic bottle has a discolored portion where the temperature indicating material has discolored. Plastic bottle.

[0016] [9] The plastic bottle according to [8], comprising an inner layer and an outer layer disposed outside the inner layer, wherein the inner layer or the outer layer includes the discolored portion.

[0017]

[10] The preform according to [8], wherein the plastic bottle is single-layer.

Effect of the Invention

[0018] According to the embodiment of the present disclosure, the discolored portion can be clearly displayed.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and easier understanding, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are appropriately changed and exaggerated from those of the actual object.

[0021] (First Embodiment) The first embodiment will be described with reference to FIGS. 1 to 6. FIGS. 1 to 6 are diagrams showing the first embodiment. In the following figures, the same parts are denoted by the same reference numerals, and some detailed descriptions may be omitted.

[0022] (Configuration of Composite Container) First, with reference to FIGS. 1 and 2, an overview of the composite container according to this embodiment will be described. In this specification, "upper" and "lower" refer to the upper and lower sides, respectively, in the state where the composite container 10A is upright (FIG. 1).

[0023] The composite container 10A shown in FIGS. 1 and 2 is obtained by performing biaxial stretch blow molding on a composite preform 70 (see FIG. 4) using a blow molding die 50, as will be described later. The composite container 10A is obtained by expanding the preform 10a of the composite preform 70 and the plastic member 40a integrally.

[0024] The composite container 10A includes a container body 10 and a plastic member 40. The container body 10 is made of a plastic material and is located inside. The plastic member 40 is provided in close contact with the outside of the container body 10 without being adhered.

[0025] Among these, the container body 10 includes a mouth portion 11, a neck portion 13, a shoulder portion 12, a body portion 20, and a bottom portion 30. The neck portion 13 is located below the mouth portion 11. The shoulder portion 12 is located below the neck portion 13. The body portion 20 is located below the shoulder portion 12. The bottom portion 30 is located below the body portion 20.

[0026] The plastic member 40 is adhered in a state of being thinly extended on the outer surface of the container body 10. The plastic member 40 is attached to the container body 10 in a state where it does not easily move or rotate.

[0027] Next, the container body 10 will be described in detail. As described above, the container body 10 has a mouth portion 11, a neck portion 13, a shoulder portion 12, a body portion 20, and a bottom portion 30.

[0028] Among these, the mouth portion 11 has a threaded portion 14 and a flange portion 17. The threaded portion 14 is screwed onto a cap (not shown). The flange portion 17 is provided below the threaded portion 14. The flange portion 17 protrudes laterally from the peripheral wall of the mouth portion 11. Note that the shape of the mouth portion 11 may be a conventionally known shape. When the container body 10 is filled with contents such as a content liquid and a cap (not shown) is screwed onto the mouth portion 11, a composite container containing the contents is produced.

[0029] The neck portion 13 is located between the flange portion 17 and the shoulder portion 12. The neck portion 13 has a substantially cylindrical shape with a substantially uniform diameter. The shoulder portion 12 is located between the neck portion 13 and the body portion 20. The shoulder portion 12 has a shape in which the diameter gradually increases from the neck portion 13 side toward the body portion 20 side (a shape in which the area gradually increases in a horizontal cross-section).

[0030] The body portion 20 has a cylindrical shape with a substantially uniform diameter as a whole. The body portion 20 may have a polygonal cylindrical shape such as a square cylindrical shape or an octagonal cylindrical shape. Alternatively, the body portion 20 may have a cylindrical shape with a non-uniform horizontal cross-section from top to bottom. In the present embodiment, the body portion 20 has no irregularities and has a substantially flat surface, but is not limited thereto. For example, irregularities such as panels or grooves may be formed on the body portion 20.

[0031] The bottom portion 30 has a concave portion 31 and a grounding portion 32. The concave portion 31 is located at the center of the bottom portion 30. The grounding portion 32 is provided around the concave portion 31. The grounding portion 32 contacts the placement surface when the composite container 10A is placed on the placement surface. Note that the shape of the bottom portion 30 is not particularly limited either, and may have a conventionally known bottom shape (for example, a petaloid bottom shape or a round bottom shape).

[0032] Also, the thickness of the container body 10 in the body portion 20 is not limited to this, but can be thinned to about 50 μm or more and 250 μm or less, for example. Further, regarding the weight of the container body 10, it is not limited to this, but can be 10 g or more and 20 g or less. By thinning the wall thickness of the container body 10 in this way, the weight reduction of the container body 10 can be achieved.

[0033] Such a container body 10 can be produced by biaxially stretching and blow molding a preform 10a (described later) produced by injection molding a synthetic resin material. As the material of the container body 10, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate). The container body 10 may be colored in colors such as red, blue, yellow, green, brown, black, and white. Considering the ease of recycling, the container body 10 is preferably colorless and transparent. Also, the above-mentioned various resins may be blended and used. Further, in order to enhance the barrier property of the container, a vapor deposition 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.

[0034] The container body 10 can also be formed as a multilayer molded bottle of two or more layers. That is, the container body 10 may be formed as a multilayer bottle having a gas barrier property. This multilayer bottle can be obtained by blow molding after producing a preform 10a composed of three or more layers by injection molding. The preform 10a composed of three or more layers may contain, 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) as an intermediate layer. Note that as the intermediate layer, a resin obtained by blending the above-mentioned various resins may be used.

[0035] By mixing an inert gas (nitrogen gas, argon gas) into the melt of the thermoplastic resin, a foamed preform having a cell diameter of 0.5 μm or more and 100 μm or less is formed, and the container body 10 may be produced by blow molding this foamed preform. Since such a container body 10 incorporates foamed cells, the light-shielding property of the entire container body 10 can be enhanced.

[0036] The container body 10 may be, for example, a bottle having a filling capacity of 100 ml or more and 2000 ml or less. Alternatively, the container body 10 may be a large bottle having a filling capacity of, for example, 10 L or more and 60 L or less.

[0037] 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 being subjected to biaxial stretch blow molding together with the preform 10a.

[0038] The plastic member 40 is attached without being adhered to the outer surface of the container body 10. The plastic member 40 is closely adhered so as not to move or rotate with respect to the container body 10. 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. The plastic member 40 has a substantially circular horizontal cross section.

[0039] In this case, the plastic member 40 is provided so as to cover the neck portion 13, the shoulder portion 12, the body portion 20, and the bottom portion 30 of the container body 10, excluding the mouth portion 11. Thereby, desired functions and characteristics can be imparted to the neck portion 13, the shoulder portion 12, the body portion 20, and the bottom portion 30 of the container body 10.

[0040] Note that the plastic member 40 may be provided in the entire area or a partial area of the container body 10 other than the mouth portion 11. For example, the plastic member 40 may be provided so as to cover the entire shoulder portion 12, body portion 20, and bottom portion 30 of the container body 10 excluding the mouth portion 11 and the neck portion 13. Alternatively, the plastic member 40 may be provided so as to cover the shoulder portion 12, body portion 20, and bottom portion 30 of the container body 10 excluding the mouth portion 11, the neck portion 13, and the central portion of the bottom portion 30.

[0041] Since the plastic member 40 is not welded or adhered to the container body 10, it can be peeled off and removed from the container body 10. Specifically, for example, the plastic member 40 can be cut off using a blade or the like, or a cutting line (not shown) can be provided in advance on the plastic member 40, and the plastic member 40 can be peeled off along this cutting line. Thereby, the plastic member 40 can be separated and removed from the container body 10.

[0042] Such a plastic member 40 may not have an effect of shrinking with respect to the preform 10a, or may have an effect of shrinking.

[0043] When the plastic member 40 has an effect of shrinking with respect to the preform 10a, the plastic member (outer shrinkage member) 40a is provided outside the preform 10a. The plastic member 40 is obtained by being heated integrally with the preform 10a and subjected to biaxial stretch blow molding.

[0044] As the resin that is the main component of the plastic member 40, for example, 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, ionomer resin, diallyl phthalate resin, fluororesin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene-1, polyisoprene, polychloroprene, ethylene propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluororubber, nylon 6, nylon 6,6, aromatic polyamide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, U polymer, liquid crystal polymer, modified polyphenylene ether, polyether ketone, polyether ether ketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene sulfide, polyether sulfone, silicone resin, polyurethane, phenol resin, urea resin, polyethylene oxide, polypropylene oxide, polyacetal, epoxy resin, etc. can be mentioned. Among these, it is preferable to use thermoplastic non-elastic resins such as polyethylene (PE) such as low-density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc. Also, those of their blend materials, multilayer structures, and partial multilayer structures may be used. Furthermore, in the range where the properties of the plastic member 40 are not impaired, various additives may be added in addition to the resin that is the main component. As additives, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, yarn friction reducers, slip agents, mold release agents, antioxidants, ion exchangers, and coloring pigments can be added. Also, by mixing an inert gas (nitrogen gas, argon gas) into the melt of the thermoplastic resin, a foamed member having a cell diameter of 0.5 μm or more and 100 μm or less is used, and by molding this foamed preform, the light-shielding property can be enhanced.In this specification, the "main component resin" means a resin contained in an amount exceeding 50% by mass, preferably exceeding 70% by mass, based on the total mass of the object.

[0045] The resin that is the main component of the plastic member 40 may be made of a material having an ultraviolet barrier property that blocks ultraviolet rays. In this case, without using a multilayer preform or a preform containing a blend material as the preform 10a, the ultraviolet barrier property of the composite container 10A can be enhanced, and deterioration of the content liquid due to ultraviolet rays can be prevented. Examples of such materials include blend materials, or materials obtained by adding a light-shielding resin to PET, PE, or PP. Further, a foamed member having a cell diameter of 0.5 μm or more and 100 μm or less, which is produced by mixing an inert gas (nitrogen gas, argon gas) into a melt of a thermoplastic resin, may be used.

[0046] The resin that is the main component of the plastic member 40 may be made of a material with higher cold insulation or heat insulation properties (a material with low thermal conductivity) than the plastic material that constitutes the container body 10 (preform 10a). In this case, without increasing the thickness of the container body 10 itself, it becomes possible to make it difficult for the temperature of the content liquid to be transmitted to the surface of the composite container 10A. As a result, the cold insulation or heat insulation properties of the composite container 10A are enhanced. Also, 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 materials include foamed polyurethane, polystyrene, PE (polyethylene), PP (polypropylene), phenolic resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin, etc. It is preferable to mix hollow particles into the resin material containing these resins. The average particle diameter of the hollow particles is preferably 1 μm or more and 200 μm or less, and more preferably 5 μm or more and 80 μm or less. Note that the "average particle diameter" means the volume average particle diameter, and it is measured using a particle size distribution and particle diameter distribution measuring device (nanotrack particle size distribution measuring device, manufactured by Nikkiso Co., Ltd.). Also, the hollow particles may be organic hollow particles composed of resin or the like, or inorganic hollow particles composed of glass or the like, but organic hollow particles are preferable because of their excellent dispersibility. Examples of the resin that constitutes the organic hollow particles include styrene-based resins such as crosslinked styrene-acrylic resins, (meth)acrylic-based resins such as acrylonitrile-acrylic resins, phenolic resins, fluorine-based resins, polyamide-based resins, polyimide-based resins, polycarbonate-based resins, polyether-based resins, etc. Also, commercially available hollow particles such as Rohm and Haas HP-1055, Rohm and Haas HP-91, Rohm and Haas OP-84J, Rohm and Haas Ultra, Rohm and Haas SE, Rohm and Haas ST (manufactured by Rohm and Haas Co.), Nippon Zeon MH-5055 (manufactured by Nippon Zeon Co., Ltd.), SX8782, SX866 (manufactured by JSR Corporation) can also be used. The content of the hollow particles is preferably 0.01 part by mass or more and 50 parts by mass or less, and more preferably 1 part by mass or more and 20 parts by mass or less, based on 100 parts by mass of the resin material contained in the plastic member 40.

[0047] Also, the resin that is the main component of 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, without changing the material of the container body 10, the user can easily grip the composite container 10A.

[0048] The plastic member 40 includes the resin that is the main component described above and a temperature indicating material. The temperature indicating material may also be referred to as a thermochromic material. The temperature indicating material is preferably uniformly contained throughout the plastic member 40. The temperature indicating material may be contained in an amount of more than 0% by mass and 20% by mass or less, or may be contained in an amount of 1% by mass or more and 10% by mass or less with respect to the total mass of the plastic member 40.

[0049] The plastic member 40 containing the temperature indicating material exhibits a first color in a non-heated or non-thermally heated state, and exhibits a second color when heated or thermally heated. In other words, the plastic member 40 does not change color in a non-heated or non-thermally heated state, and changes color when heated or thermally heated. Specifically, the plastic member 40 does not change color and exhibits the first color at a predetermined temperature of 0°C or more and less than 60°C. The plastic member 40 may exhibit the first color throughout the temperature range of 0°C or more and less than 60°C, or may exhibit the first color only in a part of the temperature range of 0°C or more and less than 60°C. When the plastic member 40 rises to a predetermined temperature of 60°C or more, it changes color and exhibits the second color. However, due to problems with the heat resistance of the material, it is desirable to cause the color change at a predetermined temperature of 60°C or more and 150°C or less. The plastic member 40 may exhibit the second color throughout the temperature range of 60°C or more, or may exhibit the second color only in a part of the temperature range of 60°C or more. Incidentally, even when the plastic member 40 returns from the state of having changed color at a predetermined temperature of 60°C or more to a temperature of 0°C or more and less than 60°C, particularly room temperature of 5°C or more and 35°C or less, it maintains the changed color state (second color).

[0050] The temperature indicating material may contain temperature indicating agent microcapsules. The temperature indicating agent microcapsules have, for example, a structure in which a temperature indicating agent composed of an electron-donating coloring dye, an electron-accepting color developer, and a polar organic compound as a core substance is coated with a wall film. The temperature indicating material changes color reversibly or irreversibly with the set critical temperature as the boundary. The irreversible type of temperature indicating material changes to a second color when the temperature exceeds the critical temperature, and then does not return to the original color (the first color) even when the temperature becomes lower than the critical temperature and returns to normal temperature.

[0051] The reversible type of temperature indicating material changes to a second color when the temperature exceeds the critical temperature, and then returns to the original color (the first color) when the temperature becomes lower than the critical temperature and returns to normal temperature. The temperature indicating material of the present embodiment is preferably of the irreversible type described above. When the temperature indicating material is heated or warmed and changes color, the color change start temperature is the critical temperature. The critical temperature may be 40°C or higher and 60°C or lower. In addition, the temperature indicating material may return to the first color when it reaches a temperature sufficiently lower than normal temperature. This temperature may be, for example, -50°C or higher and -20°C or lower.

[0052] Examples of the material constituting the temperature indicating material include temperature indicating materials such as cholesteric liquid crystals, spiiran compounds, and metal salt compounds as temperature indicating pigments, and those whose color changes by utilizing solid-phase reactions, thermal decomposition, dehydration, electron transfer between electron donors and acceptors, changes in crystal structure, etc.

[0053] When the temperature indicating material has not changed color, the plastic member 40 may be colored in any first color such as red, blue, yellow, green, brown, white, black, gray, silver, etc. Alternatively, the first color may be colorless (transparent). When the temperature indicating material has changed color, the plastic member 40 may be colored in any second color such as red, blue, yellow, green, brown, white, black, gray, silver, etc. The second color may be colorless (transparent). The first color is preferably different from the second color.

[0054] As shown in Fig. 1, the plastic member 40 has a discolored portion 43 colored in a second color. The discolored portion 43 may be formed by heating a part of the plastic member 40 after blow molding. The discolored portion 43 may be obtained by discoloring a temperature indicating material present in a part of the plastic member 40 to the second color. The portion of the plastic member 40 other than the discolored portion 43 is an unchanged portion 44 where the temperature indicating material has not discolored. The unchanged portion 44 exhibits the first color.

[0055] The discolored portion 43 may be formed throughout the entire thickness direction of the plastic member 40. The discolored portion 43 is not formed on the container body 10.

[0056] The discolored portion 43 may be formed by the heat of laser light. The discolored portion 43 may be obtained by partially discoloring the temperature indicating material of the plastic member 40 by applying external energy by laser light. The wavelength of the laser light may be, for example, 355 nm or more and 10600 nm or less. As an example, UV laser light with a wavelength of 355 nm may be used.

[0057] The discolored portion 43 may be a portion that gives a decorative or design appearance on the plastic member 40. The discolored portion 43 may be formed over the entire outer surface of the plastic member 40, or may be formed on a part of the outer surface of the plastic member 40. The heating for forming the discolored portion 43 is performed on the plastic member 40 after biaxial stretch blow molding. Alternatively, the heating for forming the discolored portion 43 may be performed on the plastic member 40a before biaxial stretch blow molding.

[0058] The unchanged portion 44 is located in the region of the plastic member 40 other than the discolored portion 43. The unchanged portion 44 exhibits the color (first color) of the temperature indicating material before discoloration without being subjected to the heat of laser light. The unchanged portion 44 is adjacent to the discolored portion 43. The unchanged portion 44 may exist so as to surround the periphery of the discolored portion 43. The area of the unchanged portion 44 may be larger than the area of the discolored portion 43.

[0059] By providing the discolored portion 43 on the plastic member 40, images and characters can be displayed on the composite container 10A without separately attaching a label or the like to the container body 10 after blow molding. One or more discolored portions 43 may be provided. As the items to be displayed on the discolored portion 43, in addition to patterns and product names, character information such as the name of the content liquid, the manufacturer, and the raw material name may also be used.

[0060] Another printing layer may be formed on the plastic member 40. When another printing layer is formed, the other printing layer may be formed by a printing method such as an inkjet method, a gravure printing method, an offset printing method, or a flexographic printing method. The ink used for printing is not limited. When forming a printing layer on the plastic member 40a before blow molding, it is preferable to use an ink with high stretchability so that the printing layer is clearly displayed even after being stretched by biaxial stretch blow molding. Examples of such an ink with high stretchability include UV curable ink and EB curable ink.

[0061] 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.

[0062] (Configuration of the composite preform) Next, the configuration of the composite preform according to the present embodiment will be described with reference to FIGS. 3 and 4.

[0063] As shown in FIGS. 3 and 4, 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.

[0064] The preform 10a includes a mouth portion 11a, a body portion 20a, and a bottom portion 30a. The mouth portion 11a corresponds to the mouth portion 11 of the container body 10 described above and has substantially the same shape as the mouth portion 11. The body portion 20a is connected to the mouth portion 11a, and the bottom portion 30a is connected to the body portion 20a. The body portion 20a corresponds to the neck portion 13, the shoulder portion 12, and the body portion 20 of the container body 10 described above and has a substantially cylindrical shape. The bottom portion 30a corresponds to the bottom portion 30 of the container body 10 described above and has a substantially hemispherical shape.

[0065] The plastic member 40a is attached to the outer surface of the preform 10a without being adhered. The plastic member 40a is in close contact with the preform 10a so as not to move or rotate with respect to the preform 10a, or is in close contact with the preform 10a to such an extent that it does not fall 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.

[0066] In this case, the plastic member 40a covers the entire body portion 20a and the entire bottom portion 30a. Note that the plastic member 40a may be provided over the entire area or a partial area other than the mouth portion 11a. For example, the plastic member 40a may cover the entire body portion 20a and the bottom portion 30a excluding the portion corresponding to the neck portion 13 of the container body 10 and the mouth portion 11a. Alternatively, the plastic member 40a may cover the body portion 20a excluding the bottom portion 30.

[0067] Such a plastic member 40a may not have an effect of shrinking with respect to the preform 10a, or may have an effect of shrinking.

[0068] When the plastic member 40a has an effect of shrinking, for example, a plastic member 40a that shrinks (e.g., thermally shrinks) with respect to the preform 10a when an external action (e.g., heat) is applied may be used. Alternatively, the plastic member 40a may itself have shrinkability or elasticity and be capable of shrinking without applying an external action.

[0069] As the plastic member 40a, for example, a direct blow tube produced by direct blow molding, a sheet molding tube produced by sheet molding, an extrusion tube produced by extrusion molding, an injection molding tube produced by injection molding, an inflation molding tube produced by inflation molding, etc. can be used. The method of molding the plastic member 40a is not limited to this, and molding methods other than the above may be used.

[0070] The plastic member 40a contains a thermochromic material. The plastic member 40a containing a thermochromic material changes color from the first color to the second color when heated to a predetermined temperature of 60°C or higher. The plastic member 40a maintains the discolored color (the second color) even when returned to a predetermined temperature of 0°C or higher and less than 60°C. In addition, the constitution of the thermochromic material is as described above.

[0071] As shown in FIG. 3, the entire plastic member 40a is an unchanged color portion 44 where the thermochromic material has not changed color. That is, the discolored portion 43 described above is formed with respect to the plastic member 40 after biaxial stretch blow molding. However, it is not limited to this, and a discolored portion 43, which is a portion where the thermochromic material has changed color, may exist in the plastic member 40a. That is, the discolored portion 43 may be formed in the plastic member 40a before biaxial stretch blow molding (see FIGS. 5(c) and (d)).

[0072] Next, the shape of the plastic member 40a will be described.

[0073] As shown in Fig. 5(a), the plastic member 40a may have a bottomed cylindrical shape as a whole, and may have a cylindrical (tubular) body portion 41 and a bottom portion 42 connected to the body portion 41. This plastic member 40a has no joint. No discolored portion 43 is formed on the outer surface of the plastic member 40a. 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 can be imparted not only to the body portion 20 of the composite container 10A but also to the bottom portion 30. Such plastic members 40a may include, for example, the direct blow tube, sheet forming tube, and injection molding tube described above. The bottom portion 42 may be closed by thermocompression bonding the end of the tubular plastic member.

[0074] As shown in Fig. 5(b), the plastic member 40a may have a circular tube shape (bottomless cylindrical shape) as a whole and may have a cylindrical (tubular) body portion 41. This plastic member 40a has no joint. No discolored portion 43 is formed on the outer surface of the plastic member 40a. In this case, as the plastic member 40a, for example, the blow tube, extrusion tube, inflation molding tube, and sheet forming tube described above can be used.

[0075] As shown in Fig. 5(c), the plastic member 40a may have a bottomed cylindrical shape as a whole, and may have a cylindrical body portion 41 and a bottom portion 42 connected to the body portion 41. This plastic member 40a has no joint. A discolored portion 43 is formed on the outer surface of the plastic member 40a. That is, the discolored portion 43 is formed on the plastic member 40a before blow molding.

[0076] As shown in Fig. 5(d), the plastic member 40a may have a generally circular tube shape as a whole and may have a cylindrical body portion 41. This plastic member 40a has no joint. A discolored portion 43 is formed on the outer surface of the plastic member 40a. That is, the discolored portion 43 is formed with respect to the plastic member 40a before blow molding.

[0077] (Method for manufacturing composite preform and composite container) Next, with reference to Figs. 6(a) to (f) and Fig. 7, a method for manufacturing the composite container 10A (blow molding method) according to the present embodiment will be described.

[0078] First, a preform 10a made of a plastic material is prepared (see Fig. 6(a)). In this case, for example, an injection molding machine (not shown) may be used to produce the preform 10a by an injection molding method. As the preform 10a, a conventionally generally used preform may be used.

[0079] Next, a plastic member 40a is provided so as to surround the outside of the preform 10a (see Fig. 6(b)). The plastic member 40a is brought into close contact without being adhered to the outside of the preform 10a. At this time, the plastic member 40a having an inner diameter equal to or slightly smaller than the outer diameter of the preform 10a may be pushed against the preform 10a to bring it into close contact with the outer surface of the preform 10a.

[0080] In this way, the composite preform 70 shown in Figs. 3 and 4 is obtained. The composite preform 70 has a preform 10a and a plastic member 40a that is brought into close contact without being adhered to the outside of the preform 10a.

[0081] In this way, the plastic member 40a is adhered to the outside of the preform 10a in advance to produce the composite preform 70. As a result, it becomes possible to perform a series of steps for producing the composite preform 70 (Figs. 6(a) and (b)) and a series of steps for producing the composite container 10A by blow molding (Figs. 6(c) to (f) and Fig. 7) at separate locations (such as a factory).

[0082] Next, the composite preform 70 is heated by the heating device 51 (see Fig. 6(c)). The heating device 51 may be a near-infrared irradiation device that irradiates near-infrared rays. At this time, the composite preform 70 is heated evenly in the circumferential direction by the heating device 51 while rotating with the mouth portion 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. Note that the heating temperature refers to the surface temperature of the plastic member 40a during heating.

[0083] Subsequently, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 (see Fig. 6(d)).

[0084] The composite container 10A is formed using this blow molding die 50. In this case, the blow molding die 50 includes a pair of body dies 50a and 50b that are split from each other and a bottom die 50c (see Fig. 6(d)). In Fig. 6(d), the space between the pair of body dies 50a and 50b is open to each other, and the bottom die 50c is raised upward. In this state, the composite preform 70 is inserted between the pair of body dies 50a and 50b.

[0085] Next, as shown in Fig. 6(e), after the bottom die 50c descends, the pair of body dies 50a and 50b are closed, and a blow molding die 50 sealed by the pair of body dies 50a and 50b and the bottom die 50c is formed. Next, air is pressed into the preform 10a, and biaxial stretch blow molding is performed on the composite preform 70.

[0086] As a result, the container body 10 is obtained from the preform 10a within the blow molding die 50. During this process, the body dies 50a, 50b are heated to 30°C to 80°C, and the bottom die 50c is cooled to 5°C to 25°C. At this time, within the blow molding die 50, the preform 10a of the composite preform 70 and the plastic member 40a expand integrally. Thereby, the preform 10a and the plastic member 40a are integrally shaped into a shape corresponding to the inner surface of the blow molding die 50. In this way, the container body 10 and the plastic member 40 provided on the outer surface of the container body 10 are obtained.

[0087] Thereafter, as shown in FIG. 6(f), the pair of body dies 50a, 50b and the bottom die 50c separate from each other, and the composite container 10A is taken out from within the blow molding die 50. The composite container 10A includes the container body 10 and the plastic member 40. In this way, the composite container 10A shown in FIGS. 1 and 2 is obtained.

[0088] The plastic member 40 of the composite container 10A contains a thermochromic material. The plastic member 40 has a first color. The plastic member 40 changes color from the first color to a second color when heated, and maintains the second color even when returned to normal temperature thereafter. Specifically, the plastic member 40 changes color when heated to a predetermined temperature of 60°C or higher. Also, the plastic member 40 maintains the changed color when returned to a temperature of 0°C or higher and less than 60°C.

[0089] Thereafter, as shown in FIG. 7, a discolored portion 43 is provided on the expanded plastic member 40. Specifically, by irradiating the outer surface of the plastic member 40 with laser light, a part of the plastic member 40 is heated and discolored to form the discolored portion 43. At this time, the laser light is irradiated from a laser light irradiation device 58. The laser light scans the outer surface of the plastic member 40 to discolor a part of the plastic member 40, thereby generating a predetermined image or character. The irradiated laser light does not substantially reach the container body 10.

[0090] As described above, the plastic member 40 contains a thermochromic material. The laser beam heats the thermochromic material contained in the plastic member 40. As a result, the thermochromic material changes color, and a discolored portion 43 is formed. When the plastic member 40 containing the thermochromic material is heated, a part of it changes to a second color. Specifically, when the plastic member 40 is heated and reaches the critical temperature, the color begins to change. This critical temperature may be a predetermined temperature of 60°C or higher. When the plastic member 40a reaches a predetermined temperature of 60°C or higher, it changes color from the first color to the second color. The portion of the plastic member 40 that is not irradiated with the laser beam maintains the first color and becomes an unchanged portion 44.

[0091] Thereby, a vivid discolored portion 43 can be formed on the plastic member 40 using a laser beam. By appropriately adjusting the thermochromic material contained in the plastic member 40, various colors can be adopted as the combination of the second color of the discolored portion 43 and the first color of the unchanged portion 44.

[0092] Thereafter, the temperature of the plastic member 40 decreases. The heated portion of the plastic member 40 containing the thermochromic material is cooled to near room temperature. At this time, the color of the discolored portion 43 does not return to the first color again.

[0093] In FIG. 7, a discolored portion 43 is provided for the composite container 10A before filling the content liquid. Not limited to this, a discolored portion 43 may be provided for the composite container 10A after filling the content liquid and closing it with a cap (not shown).

[0094] Thus, according to the present embodiment, the plastic member 40 of the composite container 10A contains a thermochromic material, and the plastic member 40 has a discolored portion 43 where the thermochromic material has changed color. Thereby, a distinctively colored discolored portion 43 can be displayed on the composite container 10A, enhancing the designability of the composite container 10A.

[0095] Also, the temperature indicating material of the plastic member 40 changes color when heated to a predetermined temperature of 60°C or higher, and maintains the changed color when the temperature returns to a temperature of 0°C or higher and less than 60°C. Therefore, even when the temperature of the plastic member 40 returns to normal temperature, there is no possibility that the discolored portion 43 will return to its original color (the first color).

[0096] Further, according to the present embodiment, since the plastic member 40 can be separated and removed from the container body 10, the colorless and transparent container body 10 can be recycled in the same manner as in the prior art.

[0097] Also, according to the present embodiment, when manufacturing the composite container 10A, a general blow molding apparatus can be used as it is, so there is no need to prepare new molding equipment for manufacturing the composite container 10A. Further, since the plastic member 40a is provided outside the preform 10a, there is also no need to prepare new molding equipment for molding the preform 10a.

[0098] (Modification example of the manufacturing method of the composite container) Next, with reference to FIGS. 8(a) to (h), a modification example of the manufacturing method (blow molding method) of the composite container 10A according to the present embodiment will be described. The modification example shown in FIGS. 8(a) to (h) has an effect that the plastic member 40a contracts with respect to the preform 10a, and other configurations are substantially the same as those shown in FIGS. 6(a) to (f). In FIGS. 8(a) to (h), the same parts as those in FIGS. 6(a) to (f) are denoted by the same reference numerals, and detailed description thereof is omitted.

[0099] First, a preform 10a made of a plastic material is prepared (see FIG. 8(a)).

[0100] Next, a plastic member 40a is prepared, and the plastic member 40a containing a temperature indicating material is gently inserted outside the preform 10a (see FIG. 8(b)).

[0101] Next, the preform 10a and the plastic member 40a are heated by the first heating device 55 (see FIG. 8(c)). At this time, the heating temperature of the preform 10a and the plastic member 40a may be, for example, 50°C to 100°C. When the plastic member 40a is heated, the plastic member 40a thermally contracts and adheres closely to the outside of the preform 10a.

[0102] In this way, a composite preform 70 having the preform 10a and the plastic member 40a adhered closely to the outside of the preform 10a is obtained (see FIG. 8(d)).

[0103] In this manner, the plastic member 40a is heated and adhered closely to the outside of the preform 10a in advance using the first heating device 55 to produce the composite preform 70. Thereby, a series of steps for producing the composite preform 70 (FIGS. 8(a) to (d)) and a series of steps for producing the composite container 10A by blow molding (FIGS. 8(e) to (h)) can be carried out at separate locations (such as factories).

[0104] Next, the composite preform 70 is heated by the second heating device 51 (see FIG. 8(e)). The second heating device 51 may be a near-infrared irradiation device that irradiates near-infrared rays. At this time, the composite preform 70 is heated evenly in the circumferential direction by the second heating device 51 while rotating with the mouth portion 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.

[0105] Subsequently, the composite preform 70 heated by the second heating device 51 is sent to the blow molding die 50 (see FIG. 8(f)).

[0106] The composite preform 70 is molded using the blow molding die 50 in substantially the same manner as shown in FIGS. 6(d) to (f) (see FIGS. 8(f) to (h)).

[0107] In this way, a composite container 10A is obtained, which includes a container body 10 and a plastic member 40 provided on the outer surface of the container body 10.

[0108] After that, in the same manner as shown in FIG. 7, a discolored portion 43 is provided on the plastic member 40. Specifically, by irradiating the outer surface of the plastic member 40 with laser light, a part of the plastic member 40 is heated and discolored to form the discolored portion 43.

[0109] (Second Embodiment) Next, a second embodiment will be described with reference to FIGS. 9 to 11. FIGS. 9 to 11 are diagrams showing the second embodiment. The second embodiment shown in FIGS. 9 to 11 mainly differs in that the plastic bottle and the preform are multilayered and the plastic bottle and the preform contain a temperature indicating material, and other configurations are substantially the same as those of the first embodiment described above. In FIGS. 9 to 11, the same parts as those in the first embodiment shown in FIGS. 1 to 8 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0110] (Configuration of Plastic Bottle) FIG. 9 is a diagram showing a plastic bottle 10B according to the present embodiment. As shown in FIG. 9, the plastic bottle 10B includes a mouth portion 11, a neck portion 13 connected to the mouth portion 11, a shoulder portion 12 connected to the neck portion 13, a body portion 20 connected to the shoulder portion 12, and a bottom portion 30 connected to the body portion 20.

[0111] In the present embodiment, the plastic bottle 10B includes an inner layer 18 and an outer layer 19 disposed outside the inner layer 18. The inner layer 18 and the outer layer 19 are integrally formed by being welded or adhered to each other.

[0112] Next, the outer layer 19 of the plastic bottle 10B will be described. The body 20 of the plastic bottle 10B includes the outer layer 19. In the example shown in FIG. 9, the shoulder 12, the body 20, and the bottom 30 of the plastic bottle 10B include the outer layer 19. As shown in FIG. 9, the outer layer 19 is provided from the upper end of the shoulder 12 to the bottom 30. Although not shown, the outer layer 19 may be provided from the neck 13 to the bottom 30. The outer layer 19 covers a part of the outer surface of the inner layer 18. When the outer layer 19 contains a temperature indicating material, the outer layer 19 is preferably provided at a location that stretches during blow molding. Specifically, the outer layer 19 is preferably provided at least on the shoulder 12, the body 20, and the bottom 30.

[0113] As the resin of the main component of the outer layer 19, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate).

[0114] The outer layer 19 contains a temperature indicating material. The temperature indicating material is preferably uniformly contained throughout the outer layer 19. The outer layer 19 exhibits a first color when not heated or warmed, and exhibits a second color when heated or warmed. In other words, the outer layer 19 does not change color when not heated or warmed, and changes color when heated or warmed. Specifically, the outer layer 19 does not change color and exhibits the first color at a predetermined temperature of 0°C or more and less than 60°C. The outer layer 19 changes color and exhibits the second color when it rises to a predetermined temperature of 60°C or more. However, due to the heat resistance problem of the material, it is desirable to change the color at a predetermined temperature of 60°C or more and 150°C or less. Even when the outer layer 19 returns from the state of changing color at a predetermined temperature of 60°C or more to a temperature of 0°C or more and less than 60°C, particularly room temperature of 5°C or more and 35°C or less, the state of changing color (the second color) is maintained. In addition, the configuration of the temperature indicating material may be the same as that of the temperature indicating material contained in the above-described plastic member 40.

[0115] The outer layer 19 has a discoloring portion 43 colored in a second color. The discoloring portion 43 may be formed by heating a part of the plastic member 40 after blow molding. The discoloring portion 43 may be formed by discoloring a temperature indicating material existing in a part of the plastic member 40 into the second color. The portion of the plastic member 40 other than the discoloring portion 43 is an unchanged portion 44 where the temperature indicating material has not discolored. The unchanged portion 44 exhibits the first color.

[0116] The thickness (radial distance) of the outer layer 19 at the shoulder 12 gradually decreases from the lower end side to the upper end side at least in a part of the shoulder 12. The thickness (radial distance) of the outer layer 19 is preferably 0.02 mm or more and 0.48 mm or less, and more preferably 0.05 mm or more and 0.4 mm or less in any region of the body portion 20 of the plastic bottle 10B.

[0117] Next, the inner layer 18 of the plastic bottle 10B will be described. The shoulder 12 and the body portion 20 of the plastic bottle 10B include the inner layer 18. In the example shown in FIG. 9, the mouth portion 11, the shoulder 12, the body portion 20, and the bottom portion 30 include the inner layer 18. As shown in FIG. 1, the inner layer 18 is provided from the upper end of the mouth portion 11 to the bottom portion 30. The inner layer 18 does not contain a temperature indicating material.

[0118] The thickness (radial distance) of the inner layer 18 is preferably 0.02 mm or more and 0.48 mm or less, and more preferably 0.05 mm or more and 0.4 mm or less in any region of the body portion 20. As the material of the inner layer 18, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate). The inner layer 18 may be colored in colors such as red, blue, yellow, green, brown, black, white, etc. Considering the ease of recycling, the inner layer 18 is preferably colorless and transparent. Also, the above-mentioned various resins may be blended and used. Further, in order to enhance the barrier property of the container, a vapor deposition film such as a diamond-like carbon film or a silicon oxide thin film may be formed on the inner surface of the inner layer 18.

[0119] Note that the inner layer 18 may contain a temperature indicating material, and the outer layer 19 may not contain a temperature indicating material. Alternatively, the plastic bottle 10B may include three or more resin layers, and at least one of these layers may contain a temperature indicating material.

[0120] In addition, the configuration of the plastic bottle 10B is the same as the configuration of the container body 10 described above.

[0121] (Configuration of preform) FIG. 10 is a view showing a preform 10b according to the present embodiment. As shown in FIG. 10, the preform 10b includes a mouth portion 11a, a body portion 20a, and a bottom portion 30a. The mouth portion 11a corresponds to the mouth portion 11 of the plastic bottle 10B described above and has substantially the same shape as the mouth portion 11. The body portion 20a is connected to the mouth portion 11a, and the bottom portion 30a is connected to the body portion 20a. The body portion 20a corresponds to the neck portion 13, the shoulder portion 12, and the body portion 20 of the plastic bottle 10B described above and has a substantially cylindrical shape. The bottom portion 30a corresponds to the bottom portion 30 of the container body 10 described above and has a substantially hemispherical shape.

[0122] In the present embodiment, the preform 10b includes an inner layer 18 and an outer layer 19 disposed outside the inner layer 18. The inner layer 18 and the outer layer 19 are integrally formed with each other.

[0123] Next, the outer layer 19 of the preform 10b will be described. The body portion 20a of the preform 10b includes the outer layer 19. In the example shown in FIG. 10, the body portion 20a and the bottom portion 30a of the preform 10b include the outer layer 19. As shown in FIG. 10, the outer layer 19 is provided from the upper end of the body portion 20a to the bottom portion 30a. The outer layer 19 covers a part of the outer surface of the inner layer 18.

[0124] The outer layer 19 contains a temperature indicating material. The outer layer 19 containing the temperature indicating material changes color from the first color to the second color when heated to a predetermined temperature of 60°C or higher. Even when the temperature returns to a temperature of 0°C or higher and less than 60°C, the outer layer 19 maintains the changed color (the second color). In addition, the configuration of the temperature indicating material is as described above.

[0125] Note that the entire outer layer 19 is an unchanged portion 44 where the temperature indicating material has not changed color. That is, the above-described color-changing portion 43 is formed with respect to the outer layer 19 after biaxial stretch blow molding. However, this is not limiting, and a color-changing portion 43, which is a portion where the temperature indicating material has changed color, may exist in the outer layer 19. That is, the color-changing portion 43 may be formed in the outer layer 19 before biaxial stretch blow molding.

[0126] Next, the inner layer 18 of the preform 10b will be described. The body portion 20a of the preform 10b includes the inner layer 18. In the example shown in FIG. 10, the mouth portion 11a, the body portion 20a, and the bottom portion 30a include the inner layer 18. As shown in FIG. 10, the inner layer 18 is provided from the upper end of the mouth portion 11a to the bottom portion 30a. The inner layer 18 does not contain a temperature indicating material. In addition, the configuration of the inner layer 18 is the same as that of the inner layer 18 of the plastic bottle 10B described above.

[0127] The preform 10b can be produced, for example, by a two-layer (multi-layer) molding method, an in-mold molding method, or the like. Further, the inner layer 18 may contain a temperature indicating material and the outer layer 19 may not contain a temperature indicating material. Alternatively, the preform 10b may include three or more resin layers, and at least one of these layers may contain a temperature indicating material.

[0128] In addition, the configuration of the preform 10b may be the same as that of the preform 10a of the composite preform 70 described above.

[0129] (Method for manufacturing a plastic bottle) Next, a method for manufacturing the plastic bottle 10B using the preform 10b according to the present embodiment will be described.

[0130] First, prepare the preform 10b shown in FIG. 10 (FIG. 11(a)).

[0131] Next, the preform 10b is heated by the heating device 51 (FIG. 11(b)). The heating device 51 may be a near-infrared irradiation device that irradiates near-infrared rays. At this time, the preform 10b is evenly heated in the circumferential direction by the heating device 51 while rotating with the mouth portion 11a facing downward. The heating temperature of the preform 10b in the heating process may be, for example, 90°C to 130°C.

[0132] Subsequently, the preform 10b heated by the heating device 51 is sent to the blow molding die 50 (FIG. 11(c)).

[0133] The plastic bottle 10B is formed using the blow molding die 50 in substantially the same manner as shown in FIGS. 6(d) to (f) (see FIGS. 11(c) to (e)). In this way, the plastic bottle 10B shown in FIG. 9 is obtained.

[0134] Thereafter, in the same manner as shown in FIG. 7, a discolored portion 43 is provided in the outer layer 19. Specifically, by irradiating the outer surface of the outer layer 19 with laser light, a part of the outer layer 19 is heated and discolored to form the discolored portion 43.

[0135] As described above, according to this embodiment, the plastic bottle 10B includes an inner layer 18 and an outer layer 19 disposed outside the inner layer 18. The outer layer 19 contains a thermochromic material. The outer layer 19 has a discolored portion 43 where the thermochromic material has changed color. Thereby, a vivid discolored portion 43 can be formed in the outer layer 19 using laser light. By appropriately adjusting the thermochromic material contained in the outer layer 19, various colors can be adopted as the combination of the second color of the discolored portion 43 and the first color of the non-discolored portion 44.

[0136] (Third Embodiment) Next, a third embodiment will be described with reference to FIGS. 12 to 14. FIGS. 12 to 14 are diagrams showing the third embodiment. The third embodiment shown in FIGS. 12 to 14 is mainly different in that the plastic bottle and the preform are single-layer and the plastic bottle and the preform contain a temperature indicating material, and other configurations are substantially the same as those of the first embodiment and the second embodiment described above. In FIGS. 12 to 14, the same parts as those in the first embodiment shown in FIGS. 1 to 8 and the second embodiment shown in FIGS. 9 to 11 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0137] (Configuration of Plastic Bottle) FIG. 12 is a diagram showing a plastic bottle 10C according to the present embodiment. As shown in FIG. 12, the plastic bottle 10C includes a mouth portion 11, a neck portion 13 connected to the mouth portion 11, a shoulder portion 12 connected to the neck portion 13, a body portion 20 connected to the shoulder portion 12, and a bottom portion 30 connected to the body portion 20.

[0138] As the resin of the main component of the plastic bottle 10C, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate).

[0139] The plastic bottle 10C contains the resin of the above-described main component and a thermochromic material. The thermochromic material is preferably uniformly contained throughout the plastic bottle 10C. The plastic bottle 10C exhibits a first color when not heated or warmed, and exhibits a second color when heated or warmed. In other words, the plastic bottle 10C does not change color when not heated or warmed, and changes color when heated or warmed. Specifically, the plastic bottle 10C does not change color and exhibits the first color at a temperature of 5°C or higher and 35°C or lower. The plastic bottle 10C changes color and exhibits the second color when it rises to a predetermined temperature of 60°C or higher. Even when the plastic bottle 10C returns from the state of having changed color at a predetermined temperature of 60°C or higher to the normal temperature of 5°C or higher and 35°C or lower, it maintains the changed color state (second color). In addition, the configuration of the thermochromic material may be the same as the thermochromic material contained in the above-described plastic member 40.

[0140] The plastic bottle 10C has a discolored portion 43 colored in the second color. The discolored portion 43 may be formed by heating a part of the plastic bottle 10C after blow molding. The discolored portion 43 may be a part of the thermochromic material existing in the plastic bottle 10C that has been discolored to the second color. The portion other than the discolored portion 43 of the plastic bottle 10C is an unchanged portion 44 where the thermochromic material has not changed color. The unchanged portion 44 exhibits the first color.

[0141] In addition, the configuration of the plastic bottle 10C may be the same as the configuration of the above-described container body 10.

[0142] (Configuration of preform) FIG. 13 is a view showing the preform 10c according to the present embodiment. As shown in FIG. 13, the preform 10c includes a mouth portion 11a, a body portion 20a, and a bottom portion 30a. The mouth portion 11a corresponds to the mouth portion 11 of the plastic bottle 10C described above and has substantially the same shape as the mouth portion 11. The body portion 20a is connected to the mouth portion 11a, and the bottom portion 30a is connected to the body portion 20a. The body portion 20a corresponds to the neck portion 13, the shoulder portion 12, and the body portion 20 of the plastic bottle 10C described above and has a substantially cylindrical shape. The bottom portion 30a corresponds to the bottom portion 30 of the container body 10 described above and has a substantially hemispherical shape.

[0143] In the present embodiment, the preform 10c contains a thermochromic material. The preform 10c containing the thermochromic material changes color from the first color to the second color when heated to a predetermined temperature of 60° C. or higher. The preform 10c maintains the changed color (second color) even when it is returned to a temperature of 5° C. or higher and 35° C. or lower. In addition, the configuration of the thermochromic material is as described above.

[0144] Note that the entire preform 10c is an unchanged color portion 44 where the thermochromic material has not changed color. That is, the above-described color-changing portion 43 is formed with respect to the plastic bottle 10C after biaxial stretch blow molding. However, the present invention is not limited to this, and a color-changing portion 43, which is a portion where the thermochromic material has changed color, may be present in the preform 10c. That is, the color-changing portion 43 may be formed in the preform 10c before biaxial stretch blow molding.

[0145] In addition, the configuration of the preform 10c may be the same as that of the preform 10a of the composite preform 70 described above.

[0146] (Method for manufacturing a plastic bottle) Next, a method for manufacturing the plastic bottle 10C using the preform 10c according to the present embodiment will be described.

[0147] First, prepare the preform 10c shown in FIG. 13 (FIG. 14(a)).

[0148] Next, the preform 10c is heated by a heating device 51 (Fig. 14(b)). The heating device 51 may be a near-infrared irradiation device that irradiates near-infrared rays. At this time, the preform 10c is heated evenly in the circumferential direction by the heating device 51 while rotating with the mouth portion 11a facing downward. The heating temperature of the preform 10c in the heating step may be, for example, 90°C to 130°C.

[0149] Subsequently, the preform 10c heated by the heating device 51 is sent to a blow molding die 50 (Fig. 14(c)).

[0150] The plastic bottle 10C is molded using the blow molding die 50 in substantially the same manner as shown in Figs. 6(d) to (f) (see Figs. 14(c) to (e)). In this way, the plastic bottle 10C shown in Fig. 12 is obtained.

[0151] Thereafter, a discolored portion 43 is provided on the plastic bottle 10C in the same manner as shown in Fig. 7. Specifically, by irradiating the outer surface of the plastic bottle 10C with laser light, a part of the plastic bottle 10C is heated and discolored to form the discolored portion 43.

[0152] As described above, according to this embodiment, the plastic bottle 10C contains a thermochromic material. The plastic bottle 10C has a discolored portion 43 where the thermochromic material has changed color. Thereby, a vivid discolored portion 43 can be formed on the plastic bottle 10C using laser light. By appropriately adjusting the thermochromic material contained in the plastic bottle 10C, various colors can be adopted as the combination of the second color of the discolored portion 43 and the first color of the non-discolored portion 44.

[0153] The present disclosure is not limited to the above-described embodiments and each modification as they are. At the implementation stage, components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiments and each modification. Some components may be deleted from all the components shown in each embodiment and each modification.

Explanation of Signs

[0154] 10 Container body 10a Preform 10A Composite container 11, 11a Mouth part 12 Shoulder part 13 Neck part 20, 20a Barrel part 30, 30a Bottom part 40, 40a Plastic member 43 Discolored part 44 Non-discolored part 70 Composite preform

Claims

1. In a composite container, a container body, and a plastic member provided in close contact with the outside of the container body without being adhered thereto, the plastic member contains a temperature indicating material, and the plastic member has a discolored portion where the temperature indicating material has changed color, the composite container.

2. The temperature indicating material changes color when heated to a predetermined temperature of 60°C or higher and maintains the changed color when returned to a predetermined temperature of 0°C or higher and less than 60°C. The composite container according to claim 1.

3. The plastic member has an unchanged portion where the temperature indicating material has not changed color. The composite container according to claim 1.

4. In a composite preform, a preform, and a plastic member provided in close contact with the outside of the preform without being adhered thereto, the plastic member contains a temperature indicating material, and the temperature indicating material changes color when heated to a predetermined temperature of 60°C or higher and maintains the changed color when returned to a predetermined temperature of 0°C or higher and less than 60°C. The composite preform.

5. In a method for manufacturing a composite preform, a step of preparing a plastic member containing a temperature indicating material, a step of preparing a preform, and a step of providing the plastic member in close contact with the outside of the preform without adhering it. The method for manufacturing a composite preform, wherein the temperature indicating material changes color when heated to a predetermined temperature of 60°C or higher and maintains the changed color when returned to a predetermined temperature of 0°C or higher and less than 60°C.

6. A step of preparing a plastic member containing a temperature indicating material, The step of preparing a preform; The step of closely providing the plastic member on the outer side of the preform without adhesion; The step of heating the preform and the plastic member and inserting them into a blow molding die; The step of expanding the preform and the plastic member integrally by performing blow molding on the preform and the plastic member in the blow molding die; The step of discoloring the temperature indicating material by heating a part of the plastic member, a manufacturing method of a composite container.

7. The temperature indicating material discolors when heated to a predetermined temperature of 60 °C or higher, and maintains the discolored color when returned to a predetermined temperature of 0 °C or higher and less than 60 °C. The manufacturing method of the composite container according to claim 6.

8. In a plastic bottle containing a temperature indicating material, It includes a mouth part, a neck part, a shoulder part, a body part, and a bottom part, The plastic bottle has a discolored part where the temperature indicating material has discolored.

9. The plastic bottle includes an inner layer and an outer layer disposed outside the inner layer, The inner layer or the outer layer includes the discolored part. The plastic bottle according to claim 8.

10. The plastic bottle is single-layered. The plastic bottle according to claim 8.

Images