Composite preform and method of manufacturing the same, composite container, and method of manufacturing the same, preform, and plastic bottle

Abstract

To provide a composite preform and a method of manufacturing the same, a composite container and a method of manufacturing the same, a preform, and a plastic bottle, which are capable of efficiently heating a preform during blow molding.SOLUTION: A composite preform 70 comprises a preform 10a and a plastic member 40a provided in close contact with an outside of the preform 10a without being bonded. The plastic member 40a includes a temperature indicating material.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] Recently, plastic bottles have become common as bottles for containing content liquids such as food and beverages, 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. For this reason, 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 present applicant has proposed a composite container capable of imparting various functions and characteristics to a container in Patent Document 1.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The composite container disclosed in Patent Document 1 is manufactured by heating a composite preform with near-infrared rays and then blow-molding it. However, when the color of the plastic member is a highly light-shielding color such as black, only the outer plastic member is heated, and it is difficult to efficiently heat the inner preform.

[0007] This embodiment provides a composite preform, a method for manufacturing the same, a composite container, a method for manufacturing the same, a preform, and a plastic bottle that can efficiently heat the preform during blow molding.

Means for Solving the Problems

[0008] The embodiments of the present disclosure relate to the following [1] to

[16] .

[0009] [1] A composite preform comprising a preform and a plastic member provided in close contact without being adhered to the outside of the preform, wherein the plastic member contains a temperature indicating material.

[0010] [2] The plastic member has a light transmittance of 0% or more and 10% or less at a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C, and the plastic member has a light transmittance of 60% or more and 100% or less at a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. The composite preform according to [1].

[0011] [3] The visible light transmittance of the plastic member is 0% or more and 10% or less at any temperature below 60°C. The composite preform according to [1] or [2].

[0012] [4] A composite container comprising a container body and a plastic member provided in close contact without being adhered to the outside of the container body, wherein the plastic member contains a temperature indicating material.

[0013] [5] The plastic member has a light transmittance of 0% or more and 20% or less at any temperature below 60°C for light with a wavelength of 800 nm or more and 2500 nm or less, and the plastic member has a light transmittance of 70% or more and 100% or less at any temperature of 60°C or more for light with a wavelength of 800 nm or more and 2500 nm or less, the composite container according to [4].

[0014] [6] The visible light transmittance of the plastic member is 0% or more and 20% or less at any temperature below 60°C, the composite container according to [4] or [5].

[0015] [7] 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 closely providing the plastic member outside the preform without adhesion, a method for manufacturing a composite preform.

[0016] [8] A step of preparing the composite preform according to any one of [1] to [3], a step of heating the composite preform and inserting it into a blow molding die, and a step of performing blow molding on the composite preform in the blow molding die to expand the preform and the plastic member of the composite preform integrally, a method for manufacturing a composite container.

[0017] [9] A preform having a mouth part, a body part, and a bottom part, and containing a temperature indicating material, a preform.

[0018]

[10] The preform includes an inner layer and an outer layer disposed outside the inner layer, and the inner layer or the outer layer contains the temperature indicating material, the preform according to [9].

[0019]

[11] The inner layer or the outer layer has a light transmittance of 0% or more and 10% or less at any temperature below 60°C for light with a wavelength of 800 nm or more and 2500 nm or less, and the inner layer or the outer layer has a light transmittance of 60% or more and 100% or less at any temperature of 60°C or more for light with a wavelength of 800 nm or more and 2500 nm or less, the preform according to

[10] .

[0020]

[12] The temperature indicating material is included in the whole of the preform, the preform according to [9].

[0021]

[13] A plastic bottle including a mouth portion, a neck portion, a shoulder portion, a body portion, and a bottom portion, and containing a temperature indicating material.

[0022]

[14] The plastic bottle includes an inner layer and an outer layer disposed outside the inner layer, and the inner layer or the outer layer contains the temperature indicating material, the plastic bottle according to

[13] .

[0023]

[15] The inner layer or the outer layer has a light transmittance of 0% or more and 20% or less at any temperature below 60°C for light with a wavelength of 800 nm or more and 2500 nm or less, and the inner layer or the outer layer has a light transmittance of 70% or more and 100% or less at any temperature of 60°C or more for light with a wavelength of 800 nm or more and 2500 nm or less, the plastic bottle according to

[14] .

[0024]

[16] The temperature indicating material is included in the whole of the plastic bottle, the plastic bottle according to

[13] .

Advantages of the Invention

[0025] According to the embodiments of the present disclosure, the preform can be efficiently heated during blow molding.

Brief Description of the Drawings

[0026]

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

BEST MODE FOR CARRYING OUT THE INVENTION

[0027] 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 easy understanding, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are appropriately changed and exaggerated from those of the actual object.

[0028] (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. In the following figures, the case where the plastic member 40a (40) does not transmit near-infrared rays is shown in gray, and the case where the plastic member 40a (40) transmits near-infrared rays is shown in white.

[0029] (Configuration of the composite container) First, with reference to FIGS. 1 and 2, the outline of the composite container according to the present 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 standing upright (FIG. 1).

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Among these, the mouth portion 11 has a screw portion 14 and a flange portion 17. The screw portion 14 is screwed onto a cap (not shown). The flange portion 17 is provided below the screw 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.

[0036] 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).

[0037] 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 above downward. 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.

[0038] The bottom portion 30 has a recess 31 and a grounding portion 32. The recess 31 is located at the center of the bottom portion 30. The grounding portion 32 is provided around the recess 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 it may have a conventionally known bottom shape (for example, a petaloid bottom shape or a round bottom shape).

[0039] Also, the thickness of the container body 10 in the body portion 20 is not limited thereto, but can be thinned to about 50 μm or more and 250 μm or less, for example. Further, the weight of the container body 10 is not limited thereto, 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 of the container body 10 can be reduced.

[0040] Such a container body 10 can be produced by biaxially stretching and blow molding a preform 10a (described later) manufactured 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, white, etc. 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.

[0041] 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.

[0042] 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 molded, 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.

[0043] The container body 10 may be, for example, a bottle with a filling volume of 100 ml or more and 2000 ml or less. Alternatively, the container body 10 may be a large bottle with a filling volume of, for example, 10 L or more and 60 L or less.

[0044] 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 will be 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Examples of the resin that is the main component 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, 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. 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), and polyethylene naphthalate (PEN). Also, blend materials, multi-layer structures, and partially multi-layer structures thereof may be used. Further, in the range where the characteristics of the plastic member 40 are not impaired, various additives may be added in addition to the resin as the main component. Examples of the additives include 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. 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 "resin as the main component" means a resin contained in an amount exceeding 50% by mass, preferably exceeding 70% by mass, based on the total mass of the object.

[0052] The resin as 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.

[0053] 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. Thereby, the cold insulation or heat insulation property of the composite container 10A is 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 preferred for reasons of excellent dispersibility. Examples of the resin that constitutes the organic hollow particles include styrene resins such as crosslinked styrene-acrylic resins, (meth)acrylic 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' Rohpake HP-1055, Rohpake HP-91, Rohpake OP-84J, Rohpake Ultra, Rohpake SE, Rohpake ST, Zeon's Nipol MH-5055, JSR's SX8782, SX866 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 with respect to 100 parts by mass of the resin material contained in the plastic member 40.

[0054] 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.

[0055] The plastic member 40 includes the resin that is the main component described above and a temperature indicating material. The temperature indicating material may 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, preferably 1% by mass or more and 10% by mass or less, based on the total mass of the plastic member 40.

[0056] The plastic member 40 containing the temperature indicating material does not transmit near-infrared rays at normal temperature and transmits near-infrared rays when heated or warmed. Specifically, the plastic member 40 may have a light transmittance of 50% or less, preferably 30% or less, and more preferably 20% or less, for light having a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. In addition, the plastic member 40 preferably has a light transmittance of 0% or more and 20% or less for the entire range of light having a wavelength of 800 nm or more and 2500 nm or less in the entire temperature range of 5°C or more and 35°C or less. The plastic member 40 may have a light transmittance of 0% or more for light having a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. The light transmittance being X% or more and Y% or less at any temperature below 60°C means that the light transmittance is X% or more and Y% or less at a specific (one) temperature below 60°C, and it is not necessarily the case that the light transmittance is X% or more and Y% or less in the entire temperature range below 60°C.

[0057] Further, the plastic member 40 may have a light transmittance of 70% or more, preferably 80% or more, at any temperature of 60°C or higher for light rays with wavelengths ranging from 800 nm to 2500 nm. The plastic member 40 may have a light transmittance of 100% or less at any temperature of 60°C or higher for light rays with wavelengths ranging from 800 nm to 2500 nm. Preferably, the plastic member 40 has a light transmittance of 80% or more and 100% or less for the entire range of light rays with wavelengths ranging from 800 nm to 2500 nm over the entire temperature range of 90°C or higher and 130°C or lower. The light transmittance of the plastic member 40 for light rays with wavelengths ranging from 800 nm to 2500 nm is measured using a spectrophotometer (Ultraviolet-Visible-Infrared Spectrophotometer: V-670 manufactured by JASCO Corporation). When the light transmittance is X% or more and Y% or less at any temperature of 60°C or higher, it means that the light transmittance is X% or more and Y% or less at a specific (one) temperature of 60°C or higher, and it is not necessarily the case that the light transmittance is X% or more and Y% or less over the entire temperature range of 60°C or higher.

[0058] The thermochromic material may contain thermochromic microcapsules. The thermochromic microcapsules have, for example, a structure in which a thermochromic agent composed of an electron-donating coloring dye, an electron-accepting developer, and a polar organic compound is used as the core substance and coated with a wall film. The thermochromic material changes color reversibly or irreversibly at the set critical temperature. In the case of an irreversible type of thermochromic material, when the temperature exceeds the critical temperature, the color changes and the light transmittance increases, and thereafter, even when the temperature drops below the critical temperature and returns to normal temperature, the original light transmittance is not restored.

[0059] In the case of a reversible type of thermochromic material, when the temperature exceeds the critical temperature, the light transmittance increases, and thereafter, when the temperature drops below the critical temperature and returns to normal temperature, the original light transmittance is restored. The thermochromic material of the present embodiment is preferably of the reversible type described above. When the thermochromic material is heated and the light transmittance increases, the starting temperature of the increase is the critical temperature, and the critical temperature may be 40°C or higher and 70°C or lower.

[0060] As materials constituting the temperature-indicating material, for example, temperature-indicating materials such as cholesteric liquid crystals, spiran compounds, and metal salt compounds are used as temperature-indicating pigments, and those whose color changes by utilizing solid-phase reaction, thermal decomposition, dehydration, electron transfer between electron donors and acceptors, change in crystal structure, etc. can be mentioned.

[0061] In the present embodiment, the plastic member 40 may be colored in a highly light-shielding color such as black, gray, or silver at any temperature below 60°C. Specifically, the transmittance of visible light of the plastic member 40 may be 0% or more and 30% or less, preferably 0% or more and 20% or less, and more preferably 5% or more and 20% or less at any temperature below 60°C. Here, the transmittance of visible light means the transmittance of light having a wavelength of 400 nm or more and 700 nm or less. Alternatively, the plastic member 40 may be colored in a color such as red, blue, yellow, green, brown, or white at any temperature below 60°C.

[0062] In the present embodiment, the plastic member 40 may transmit visible light at any temperature of 60°C or more. Specifically, the transmittance of visible light of the plastic member 40 may be 60% or more and 90% or less, preferably 70% or more and 80% or less at any temperature of 60°C or more. The transmittance of visible light is measured using a spectrophotometer (ultraviolet-visible-infrared spectrophotometer: V-670 manufactured by JASCO Corporation).

[0063] Also, the thickness of the plastic member 40 is not limited to this, but can be, for example, about 5 μm or more and 500 μm or less when attached to the container body 10.

[0064] (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.

[0065] 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.

[0066] 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.

[0067] The plastic member 40a is attached without being adhered to the outer surface of the preform 10a. 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.

[0068] 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.

[0069] 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.

[0070] When the plastic member 40a has a shrinking effect, the plastic member 40a may be used, for example, when an external effect (such as heat) is applied, it shrinks (such as heat shrinkage) with respect to the preform 10a. Alternatively, the plastic member 40a may itself have shrinkability or elasticity and be capable of shrinking without applying an external effect.

[0071] 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.

[0072] The plastic member 40a contains a thermochromic material. The plastic member 40a containing a thermochromic material does not transmit near-infrared rays at normal temperature and transmits near-infrared rays when heated or warmed. Specifically, the plastic member 40a may have a light transmittance of 40% or less, preferably 10% or less, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. The plastic member 40a may have a light transmittance of 0% or more for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. Also, the plastic member 40a may have a light transmittance of 60% or more, preferably 70% or more, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. The plastic member 40a may have a light transmittance of 100% or less for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. In addition, the composition of the thermochromic material is as described above.

[0073] Next, the shape of the plastic member 40a will be described.

[0074] 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 joints. 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 can 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.

[0075] 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 joints. 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.

[0076] 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 joints.

[0077] As shown in Fig. 5(d), the plastic member 40a may have a circular tube shape as a whole and may have a cylindrical body portion 41. This plastic member 40a has no joints.

[0078] (Method for manufacturing composite preform and composite container) Next, with reference to Figs. 6(a) to 6(f), a method for manufacturing the composite container 10A (blow molding method) according to the present embodiment will be described.

[0079] First, prepare a preform 10a made of a plastic material (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 preform generally used in the past may be used.

[0080] Next, provide a plastic member 40a so as to surround the outside of the preform 10a (see Fig. 6(b)). The plastic member 40a is closely attached to the outside of the preform 10a without being adhered. 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 be closely attached to the outer surface of the preform 10a.

[0081] The plastic member 40a contains a temperature indicating material. The plastic member 40a does not transmit near-infrared rays at normal temperature. Specifically, the plastic member 40a may have a light transmittance of 0% or more and 40% or less, preferably 0% or more and 10% or less, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. Also, the plastic member 40a does not have to transmit visible light at normal temperature. In this case, the plastic member 40a is in a colored state when viewed with the naked eye.

[0082] In this way, the composite preform 70 shown in Figs. 3 and 4 is obtained. The composite preform 70 has the preform 10a and the plastic member 40a closely attached to the outside of the preform 10a without being adhered.

[0083] In this manner, the plastic member 40a is closely attached to the outside of the preform 10a in advance to produce the composite preform 70. Thereby, it becomes possible to carry out a series of steps for producing the composite preform 70 (Figs. 6(a), (b)) and a series of steps for producing the composite container 10A by blow molding (Figs. 6(c) to (f)) at separate locations (such as factories).

[0084] 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 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 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.

[0085] The plastic member 40a containing the temperature indicating material becomes in a state of transmitting near-infrared rays when heated. Specifically, when the plastic member 40a is heated and reaches the critical temperature, the light transmittance begins to increase. This critical temperature may be 40°C or higher and 70°C or lower. When the plastic member 40a reaches a temperature of 90°C or higher and 130°C or lower, the light transmittance of light with a wavelength of 800 nm or longer and 2500 nm or shorter may be 60% or higher and 100% or lower, and preferably 70% or higher and 100% or lower. For this reason, the near-infrared rays from the heating device 51 pass through the plastic member 40a and reach the preform 10a. Thereby, the temperature of the preform 10a can be efficiently increased without being blocked by the plastic member 40a. Also, the plastic member 40a may transmit visible light at any temperature of 60°C or higher. In this case, the plastic member 40a exhibits a transparent appearance when viewed with the naked eye at any temperature of 60°C or higher.

[0086] Subsequently, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 (see FIG. 6(d)).

[0087] The composite container 10A is formed using this blow molding die 50. In this case, the blow molding die 50 consists of a pair of body dies 50a and 50b that are divided from each other and a bottom die 50c (see Fig. 6(d)). In Fig. 6(d), between the pair of body dies 50a and 50b are 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.

[0088] Next, as shown in Fig. 6(e), after the bottom die 50c is lowered, 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 press-fitted into the preform 10a, and biaxial stretch blow molding is performed on the composite preform 70.

[0089] As a result, the container body 10 is obtained from the preform 10a within the blow molding die 50. During this time, the body dies 50a and 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. As a result, 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.

[0090] After that, the temperature of the plastic member 40 decreases within the blow molding die 50. The plastic member 40 containing the temperature indicating material becomes in a state of no longer transmitting near-infrared rays again by being cooled to near room temperature. Specifically, when the plastic member 40 is cooled and reaches an arbitrary temperature less than 60°C, the light transmittance of light with a wavelength of 800 nm or more and 2500 nm or less is 0% or more and 20% or less. Also, the plastic member 40 may transmit visible light at room temperature. In this case, the plastic member 40 exhibits a colored appearance at an arbitrary temperature less than 60°C.

[0091] Thereafter, as shown in FIG. 6(f), the pair of body molds 50a and 50b and the bottom mold 50c are separated from each other, and the composite container 10A is taken out from the blow molding mold 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.

[0092] In the present embodiment, as described above, when the plastic member 40a reaches an arbitrary temperature of 60° C. or higher, the light transmittance of light having a wavelength of 800 nm or more and 2500 nm or less is 70% or more. Therefore, the near-infrared rays from the heating device 51 pass through the plastic member 40a and reach the preform 10a. Thereby, the temperature of the preform 10a can be efficiently increased without being blocked by the plastic member 40a.

[0093] Further, the plastic member 40a may have a light transmittance of 0% or more and 40% or less, preferably 0% or more and 10% or less, for light having a wavelength of 800 nm or more and 2500 nm or less at an arbitrary temperature below 60° C. Further, the plastic member 40a may have a light transmittance of 0% or more and 20% or less for light having a wavelength of 400 nm or more and 700 nm or less at an arbitrary temperature below 60° C. In this case, at normal temperature, the appearance of the plastic member 40a can be colored in a highly light-shielding color.

[0094] 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.

[0095] Further, according to the present embodiment, when manufacturing the composite container 10A, a general blow molding device 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 no need to prepare new molding equipment for molding the preform 10a.

[0096] (Modification example of the method for manufacturing a composite container) Next, a modified example of the manufacturing method (blow molding method) of the composite container 10A according to the present embodiment will be described with reference to FIGS. 7(a) to 7(h). The modified example shown in FIGS. 7(a) to 7(h) has the effect that the plastic member 40a shrinks with respect to the preform 10a, and other configurations are substantially the same as those shown in FIGS. 6(a) to 6(f). In FIGS. 7(a) to 7(h), the same parts as those in FIGS. 6(a) to 6(f) are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0097] First, a preform 10a made of a plastic material is prepared (see FIG. 7(a)).

[0098] Next, a plastic member 40a is prepared, and a plastic member 40a containing a temperature indicating material is gently inserted outside the preform 10a (see FIG. 7(b)).

[0099] Next, the preform 10a and the plastic member 40a are heated by a first heating device 55 (see FIG. 7(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 to the outside of the preform 10a. At this time, the plastic member 40a may be in a state of transmitting near-infrared rays. Specifically, the plastic member 40a may have a light transmittance of 70% or more for light rays having a wavelength of 800 nm or more and 2500 nm or less.

[0100] In this way, a composite preform 70 having a preform 10a and a plastic member 40a adhered to the outside of the preform 10a is obtained (see FIG. 7(d)). When the plastic member 40a is cooled to near room temperature, it becomes a state of not transmitting near-infrared rays. Specifically, when the plastic member 40a is cooled and reaches an arbitrary temperature below 60°C, the light transmittance for light rays having a wavelength of 800 nm or more and 2500 nm or less becomes 0% or more and 10% or less.

[0101] In this way, the plastic member 40a is heated and adhered to the outside of the preform 10a in advance using the first heating device 55 to produce the composite preform 70. As a result, a series of steps for producing the composite preform 70 (Figs. 7(a) to (d)) and a series of steps for producing the composite container 10A by blow molding (Figs. 7(e) to (h)) can be carried out at separate locations (such as factories).

[0102] Next, the composite preform 70 is heated by the second heating device 51 (see Fig. 7(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.

[0103] The plastic member 40a containing the temperature indicating material becomes in a state of transmitting near-infrared rays when heated. Specifically, when the plastic member 40a is heated and reaches the critical temperature, the light transmittance begins to increase. This critical temperature may be 40°C or higher and 70°C or lower. When the plastic member 40a reaches a temperature of 90°C or higher and 130°C or lower, the light transmittance of light with a wavelength of 800 nm or longer and 2500 nm or shorter becomes 70% or higher and 100% or lower. For this reason, the near-infrared rays from the second heating device 51 pass through the plastic member 40a and reach the preform 10a. As a result, the temperature of the preform 10a can be efficiently increased without being blocked by the plastic member 40a. Also, the plastic member 40a may transmit visible light at any temperature of 60°C or higher. In this case, the plastic member 40a exhibits a transparent appearance at any temperature of 60°C or higher.

[0104] Subsequently, the composite preform 70 heated by the second heating device 51 is sent to the blow molding die 50 (see Fig. 7(f)).

[0105] The composite preform 70 is formed using the blow molding die 50 in substantially the same manner as shown in FIGS. 6(d) to (f) (see FIGS. 7(f) to (h)).

[0106] Thereafter, the temperature of the plastic member 40 decreases within the blow molding die 50. The plastic member 40 containing the temperature indicating material becomes in a state of no longer transmitting near-infrared rays again when cooled to room temperature. Specifically, when the plastic member 40 is cooled and reaches an arbitrary temperature less than 60°C, the light transmittance of light with a wavelength of 800 nm or more and 2500 nm or less is 0% or more and 20% or less. Also, the plastic member 40 may transmit visible light at room temperature. In this case, the plastic member 40 exhibits a colored appearance at an arbitrary temperature less than 60°C.

[0107] 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.

[0108] (Second Embodiment) Next, a second embodiment will be described with reference to FIGS. 8 to 10. FIGS. 8 to 10 are diagrams showing the second embodiment. The second embodiment shown in FIGS. 8 to 10 is mainly different 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. 8 to 10, the same parts as those in the first embodiment shown in FIGS. 1 to 7 are denoted by the same reference numerals and detailed descriptions thereof are omitted. In the following figures, the case where the outer layer 19 is in a state of not transmitting near-infrared rays is shown in gray, and the case where the outer layer 19 is in a state of transmitting near-infrared rays is shown in white.

[0109] (Configuration of Plastic Bottle) FIG. 8 is a view showing a plastic bottle 10B according to the present embodiment. As shown in FIG. 8, 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.

[0110] 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.

[0111] Next, the outer layer 19 of the plastic bottle 10B will be described. The body portion 20 of the plastic bottle 10B includes the outer layer 19. In the example shown in FIG. 8, the shoulder portion 12, the body portion 20, and the bottom portion 30 of the plastic bottle 10B include the outer layer 19. As shown in FIG. 8, the outer layer 19 is provided from the upper end of the shoulder portion 12 to the bottom portion 30. Although not shown, the outer layer 19 may be provided from the neck portion 13 to the bottom portion 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 portion that stretches during blow molding. Specifically, the outer layer 19 is preferably provided at least on the shoulder portion 12, the body portion 20, and the bottom portion 30.

[0112] 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).

[0113] 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 does not transmit near-infrared rays at normal temperature, but transmits near-infrared rays when heated or warmed. Specifically, the outer layer 19 may have a light transmittance of 0% or more and 30% or less, preferably 0% or more and 20% or less, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. In addition, it is preferable that the outer layer 19 has a light transmittance of 0% or more and 20% or less for the entire range of wavelengths from 800 nm to 2500 nm over the entire temperature range of 5°C or more and 35°C or less.

[0114] The outer layer 19 may have a light transmittance of 70% or more and 100% or less, preferably 80% or more and 100% or less, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. In addition, it is preferable that the outer layer 19 has a light transmittance of 80% or more and 100% or less for the entire range of wavelengths from 800 nm to 2500 nm over the entire temperature range of 90°C or more and 130°C or less. In addition, the composition 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 may be colored in a highly light-shielding color such as black, gray, or silver at any temperature below 60°C. Specifically, the visible light transmittance of the outer layer 19 may be 0% or more and 20% or less, preferably 5% or more and 20% or less, at any temperature below 60°C. Alternatively, the outer layer 19 may be colored in a color such as red, blue, yellow, green, brown, or white at any temperature below 60°C.

[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 at least 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, more preferably 0.05 mm or more and 0.4 mm or less, in any region of the body 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 20 of the plastic bottle 10B include the inner layer 18. In the example shown in FIG. 8, the mouth portion 11, the shoulder 12, the body 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, more preferably 0.05 mm or more and 0.4 mm or less, in any region of the body 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), or PC (polycarbonate). The inner layer 18 may be colored in colors such as red, blue, yellow, green, brown, black, white, etc. Considering 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 while the outer layer 19 does not. 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 the preform) FIG. 9 is a view showing the preform 10b according to the present embodiment. As shown in FIG. 9, 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. 9, the body portion 20a and the bottom portion 30a of the preform 10b include the outer layer 19. As shown in FIG. 9, 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 does not transmit near-infrared rays at normal temperature and transmits near-infrared rays when heated or warmed. Specifically, the outer layer 19 may have a light transmittance of 0% or more and 40% or less, preferably 0% or more and 10% or less, for light having a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. The outer layer 19 may have a light transmittance of 60% or more and 100% or less, preferably 70% or more and 100% or less, for light having a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. In addition, the configuration of the outer layer 19 is the same as that of the outer layer 19 of the plastic bottle 10B described above.

[0125] 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. 9, the mouth portion 11a, the body portion 20a, and the bottom portion 30a include the inner layer 18. As shown in FIG. 9, 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.

[0126] The preform 10b can be produced, for example, by a two-layer (multi-layer) molding method, an in-mold molding method, or the like. Also, the inner layer 18 may contain a temperature indicating material while the outer layer 19 does 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.

[0127] 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.

[0128] (Manufacturing method of plastic bottle) Next, a method for manufacturing the plastic bottle 10B using the preform 10b according to the present embodiment will be described.

[0129] First, the preform 10b shown in FIG. 9 is prepared (FIG. 10(a)).

[0130] Next, the preform 10b is heated by a heating device 51 (FIG. 10(b)). The heating device 51 may be a near-infrared irradiation device that irradiates near-infrared rays. At this time, the preform 10b 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 10b in the heating step may be, for example, 90°C to 130°C.

[0131] The outer layer 19 of the preform 10b containing the thermochromic material becomes in a state of transmitting near-infrared rays when heated. Specifically, when the outer layer 19 reaches a temperature of 90°C or higher and 130°C or lower, the light transmittance of light rays with a wavelength of 800 nm or longer and 2500 nm or shorter may be 60% or higher and 100% or lower, and preferably 70% or higher and 100% or lower. For this reason, the near-infrared rays from the heating device 51 pass through the outer layer 19 and reach the inner layer 18. Thereby, the temperature of the inner layer 18 can be efficiently increased without being blocked by the outer layer 19. Further, the outer layer 19 may transmit visible light at any temperature of 60°C or higher. In this case, the outer layer 19 of the preform 10b exhibits a transparent appearance at any temperature of 60°C or higher.

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

[0133] The plastic bottle 10B is molded using the blow molding die 50 in substantially the same manner as shown in Figs. 6(d) to (f) (see Figs. 10(c) to (e)). The temperature of the plastic bottle 10B decreases within the blow molding die 50. The outer layer 19 containing the thermochromic material becomes in a state of no longer transmitting near-infrared rays by being cooled to near room temperature. Specifically, when the outer layer 19 is cooled and reaches any temperature below 60°C, the light transmittance of light rays with a wavelength of 800 nm or longer and 2500 nm or shorter becomes 0% or higher and 20% or lower. Further, the outer layer 19 may transmit visible light at room temperature. In this case, the outer layer 19 exhibits a colored appearance at any temperature below 60°C.

[0134] In this way, the plastic bottle 10B shown in Fig. 8 is obtained.

[0135] As described above, according to the present 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 temperature indicating material. The outer layer 19 has a light transmittance of 0% or more and 20% or less for light rays with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C, and a light transmittance of 70% or more and 100% or less for light rays with a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. Therefore, the near-infrared rays from the heating device 51 during blow molding pass through the outer layer 19 and reach the inner layer 18. As a result, the temperature of the inner layer 18 can be efficiently increased without being blocked by the outer layer 19.

[0136] (Third Embodiment) Next, the third embodiment will be described with reference to FIGS. 11 to 13. FIGS. 11 to 13 are diagrams showing the third embodiment. The third embodiment shown in FIGS. 11 to 13 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. 11 to 13, the same parts as those in the first embodiment shown in FIGS. 1 to 7 and the second embodiment shown in FIGS. 8 to 10 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In the following figures, the case where the plastic bottle 10C or the preform 10c does not transmit near-infrared rays is shown in gray, and the case where the plastic bottle 10C or the preform 10c transmits near-infrared rays is shown in white.

[0137] (Configuration of Plastic Bottle) FIG. 11 is a diagram showing the plastic bottle 10C according to the present embodiment. As shown in FIG. 11, 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 that is 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), or PC (polycarbonate).

[0139] The plastic bottle 10C contains the resin of the main component described above and a temperature indicating material. The temperature indicating material is preferably uniformly contained throughout the plastic bottle 10C. The plastic bottle 10C does not transmit near-infrared rays at room temperature, but transmits near-infrared rays when heated or warmed. Specifically, the plastic bottle 10C may have a light transmittance of 0% or more and 40% or less, preferably 10% or less, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. In addition, the plastic bottle 10C preferably has a light transmittance of 20% or less for the entire range of wavelengths of 800 nm or more and 2500 nm or less throughout the temperature range of 5°C or more and 35°C or less. Also, the plastic bottle 10C may have a light transmittance of 70% or more and 100% or less, preferably 80% or more, for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. In addition, the plastic bottle 10C preferably has a light transmittance of 80% or more and 100% or less for the entire range of wavelengths of 800 nm or more and 2500 nm or less throughout the temperature range of 90°C or more and 130°C or less. In addition, the composition of the temperature indicating material may be the same as the temperature indicating material contained in the plastic member 40 described above.

[0140] The plastic bottle 10C may be colored in a highly light-shielding color such as black, gray, or silver at any temperature below 60°C. Specifically, the visible light transmittance of the plastic bottle 10C may be 0% or more and 30% or less, preferably 5% or more and 20% or less, at any temperature below 60°C. Alternatively, the plastic bottle 10C may be colored in a color such as red, blue, yellow, green, brown, or white at any temperature below 60°C.

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

[0142] (Configuration of the preform) FIG. 12 is a view showing a preform 10c according to the present embodiment. As shown in FIG. 12, 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 temperature indicating material. The preform 10c does not transmit near-infrared rays at normal temperature and transmits near-infrared rays when heated or warmed. Specifically, the preform 10c may have a light transmittance of 0% or more and 40% or less, preferably 0% or more and 10% or less, for light having a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. The preform 10c may have a light transmittance of 60% or more and 100% or less, preferably 70% or more and 100% or less, for light having a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more.

[0144] 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.

[0145] (Method for manufacturing a plastic bottle) Next, a method for manufacturing a plastic bottle 10C using the preform 10c according to the present embodiment will be described.

[0146] First, prepare the preform 10c shown in FIG. 12 (FIG. 13(a)).

[0147] Next, the preform 10c is heated by a heating device 51 (Fig. 13(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 process may be, for example, 90°C to 130°C.

[0148] When the preform 10c containing the temperature indicating material is heated, it becomes a state of transmitting near-infrared rays. Specifically, when the preform 10c reaches a temperature of 90°C or higher and 130°C or lower, the light transmittance of light with a wavelength of 800 nm or more and 2500 nm or less is 60% or more and 100% or less. For this reason, the near-infrared rays from the heating device 51 pass through the preform 10c. Thereby, the temperature from the outer surface side to the inner surface side of the preform 10c can be efficiently increased. Also, the preform 10c may transmit visible light at any temperature of 60°C or higher. In this case, the preform 10c exhibits a transparent appearance at any temperature of 60°C or higher.

[0149] Subsequently, the preform 10c heated by the heating device 51 is sent to a blow molding die 50 (Fig. 13(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. 13(c) to (e)). The temperature of the plastic bottle 10C decreases inside the blow molding die 50. The plastic bottle 10C becomes a state of no longer transmitting near-infrared rays again by being cooled to near room temperature. Specifically, when the plastic bottle 10C is cooled and reaches an arbitrary temperature below 60°C, the light transmittance of light with a wavelength of 800 nm or more and 2500 nm or less is 0% or more and 20% or less. Also, the plastic bottle 10C may transmit visible light at room temperature. In this case, the plastic bottle 10C exhibits a colored appearance at any temperature below 60°C.

[0151] In this way, the plastic bottle 10C shown in FIG. 11 is obtained.

[0152] As described above, according to this embodiment, the preform 10c contains a temperature indicating material. The preform 10c has a light transmittance of 0% or more and 20% or less for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C, and a light transmittance of 70% or more and 100% or less for light with a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or more. Therefore, the near-infrared rays from the heating device 51 reach from the outer surface side to the inner surface side of the preform 10c. As a result, the temperature of the preform 10c can be uniformly and efficiently increased along the thickness direction.

[0153] The present disclosure is not limited to the above-described embodiments and each modification as they are. At the implementation stage, the 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.

Description of Reference Numerals

[0154] 10 Container body 10a Preform 10A Composite container 11, 11a Mouth part 12 Shoulder part 13 Neck part 20, 20a Body part 30, 30a Bottom part 40, 40a Plastic member 70 Composite preform

Claims

1. In a composite preform, a preform, and a plastic member provided in close contact without being adhered to the outside of the preform, wherein the plastic member contains a thermochromic material, the composite preform.

2. The plastic member has a light transmittance of 0% or more and 10% or less at any temperature below 60°C for light with a wavelength of 800 nm or more and 2500 nm or less, and the plastic member has a light transmittance of 60% or more and 100% or less at any temperature of 60°C or more for light with a wavelength of 800 nm or more and 2500 nm or less, the composite preform according to claim 1.

3. The visible light transmittance of the plastic member is 0% or more and 10% or less at any temperature below 60°C, the composite preform according to claim 1.

4. In a composite container, a container body, and a plastic member provided in close contact without being adhered to the outside of the container body, wherein the plastic member contains a thermochromic material, the composite container.

5. The plastic member has a light transmittance of 0% or more and 20% or less at any temperature below 60°C for light with a wavelength of 800 nm or more and 2500 nm or less, and the plastic member has a light transmittance of 70% or more and 100% or less at any temperature of 60°C or more for light with a wavelength of 800 nm or more and 2500 nm or less, the composite container according to claim 4.

6. The visible light transmittance of the plastic member is 0% or more and 20% or less at any temperature below 60°C, the composite container according to claim 4.

7. 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; A method for manufacturing a composite preform, comprising: a step of closely providing the plastic member on the outer side of the preform without adhesion.

8. A step of preparing the composite preform according to claim 1; A step of heating the composite preform and inserting it into a blow molding mold; A method for manufacturing a composite container, comprising: a step of expanding the preform and the plastic member of the composite preform integrally by performing blow molding on the composite preform in the blow molding mold.

9. In the preform, Comprising a mouth part, a body part, and a bottom part; A preform containing a temperature indicating material.

10. The preform includes an inner layer and an outer layer disposed outside the inner layer; The preform according to claim 9, wherein the inner layer or the outer layer contains the temperature indicating material.

11. The inner layer or the outer layer has a light transmittance of 0% or more and 10% or less at a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60 °C; The preform according to claim 10, wherein the inner layer or the outer layer has a light transmittance of 60% or more and 100% or less at a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60 °C or more.

12. The preform according to claim 9, wherein the temperature indicating material is contained throughout the preform.

13. In a plastic bottle, Comprising a mouth part, a neck part, a shoulder part, a body part, and a bottom part; A plastic bottle containing a temperature indicating material.

14. The plastic bottle includes an inner layer and an outer layer disposed outside the inner layer. The plastic bottle according to claim 13, wherein the inner layer or the outer layer contains the temperature indicating material.

15. The inner layer or the outer layer has a light transmittance of 0% or more and 20% or less at a wavelength of 800 nm or more and 2500 nm or less at any temperature below 60°C. The plastic bottle according to claim 14, wherein the inner layer or the outer layer has a light transmittance of 70% or more and 100% or less at a wavelength of 800 nm or more and 2500 nm or less at any temperature of 60°C or higher.

16. The plastic bottle according to claim 13, wherein the temperature indicating material is contained in the whole of the plastic bottle.

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