JP2021127157A - Composite container and manufacturing method of composite container, and composite preform and manufacturing method of composite reform - Google Patents

Abstract

To provide a composite container having high oxygen barrier property and recyclability, and capable of reducing the amount of use of a resin material.SOLUTION: A composite container 10A of the present invention is a composite container including a container body 10 having a single-layer structure and a plastic member 40 provided in close contact with the outside of the container body. The container body and the plastic member are integrally obtained by blow molding, and the weight of the container body is 7 g to 15 g. The oxygen permeability of the container body is 0.100 cc/pkg/day/0.21 atm or more. The container body contains a polyethylene terephthalate. The plastic member comprises at least an oxygen barrier layer containing an oxygen barrier resin. The thickness of the plastic member at the position where the horizontal cross-sectional area of the composite container is maximum is 5 μm or more and 30 μm or less. The oxygen permeability of the composite container is 0.060 cc/pkg/day/0.21 atm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite container and a method for producing the composite container, and a composite preform used for manufacturing the composite container and a method for manufacturing the composite preform.

Plastic containers are widely used as containers for storing soft drinks and seasonings, and are excellent in oxygen barrier properties, mechanical properties, chemical stability, transparency, heat resistance, etc., and are inexpensive. Therefore, polyesters such as polyethylene terephthalate are often used for making plastic containers.

By the way, depending on the contents to be contained, it is required that the plastic container has a high oxygen barrier property due to oxidation due to the invasion of oxygen into the container.
For the purpose of improving the oxygen barrier property of the plastic container, the weight of the resin material such as polyethylene terephthalate contained in the plastic container is increased, or an oxygen barrier layer containing the oxygen barrier resin is provided as an intermediate layer in the plastic container. (See Patent Document 1).

However, in recent years, environmental conservation awareness has been rapidly increasing, and there is a demand for reducing the amount of resin materials used such as polyester. Against this background, there is a demand for reducing the amount of resin materials used in plastic containers. There is.
In addition, there is a strong demand for recycling of used plastic containers, and it is difficult for the above-mentioned containers composed of different materials to have an oxygen barrier layer as an intermediate layer to be peeled off from layer to layer after recovery. In some cases, there was a need to improve its recyclability.

Japanese Unexamined Patent Publication No. 2003-3349906

The present invention has been made in view of the above problems, and the problem to be solved is to provide a composite container having high oxygen barrier properties and recyclability, and capable of reducing the amount of resin material used. It is to be.
Another object to be solved by the present invention is to provide a composite preform used for producing the container, a method for producing the container, and a method for producing the composite preform.

The composite container of the present invention includes a container body having a single-layer structure and a container body.
A composite container provided with a plastic member provided in close contact with the outside of the container body without welding and adhesion.
The container body and the plastic member are integrally obtained by blow molding.
The weight of the container body is 7 g to 15 g, and the weight of the container body is 7 g to 15 g.
The oxygen permeability of the container body is 0.100 cc / pkg / day / 0.21 atm or more.
The container body contains polyethylene terephthalate as a main component.
The plastic member includes at least an oxygen barrier layer containing an oxygen barrier resin.
The thickness of the plastic member at the position where the horizontal cross-sectional area of the composite container is maximum is 5 μm or more and 30 μm or less.
The oxygen permeability of the composite container is 0.060 cc / pkg / day / 0.21 atm or less.

In one embodiment, the weight of the plastic member is 0.8-2.0 g.

In one embodiment, the plastic member comprises a first resin layer in contact with the container body, an oxygen barrier layer, and a second resin layer.

In one embodiment, the first resin layer and the second resin layer contain polyolefin.

In one embodiment, the container body comprises a mouth, neck, shoulders, body and bottom.
The plastic member is provided so as to cover the neck portion, the shoulder portion, the body portion, and a part of the bottom portion of the container body.

In one embodiment, the plastic member is heat shrinkable.

In one embodiment, the density of the container body is 1 g / cm ³ or more, and the density of the plastic member is less than ^{1 g / cm 3.}

In one embodiment, the total weight of the resin material contained in the composite container is 7.8 to 17 g.

The composite preform of the present invention is a composite preform for producing the above-mentioned composite container.
Preform and
It is characterized by including a plastic member provided in close contact with the outside of the preform without being welded and adhered.

The method for manufacturing a composite container of the present invention is the above-mentioned method for manufacturing a composite container.
The process of preparing the composite preform and
The step of heating the composite preform and
It is characterized by including a step of integrally expanding the preform and the plastic member by performing blow molding on the composite preform after heating in a blow molding die.

In one embodiment, the step of preparing the composite preform is
The process of preparing the preform and
The process of preparing the plastic member and
The step of heating the preform and
After heating the preform, the step of fitting the preform from one end of the plastic member is included.

The method for producing a composite preform of the present invention is the above-mentioned method for producing a composite preform.
The process of preparing the preform and
The process of preparing the plastic member and
It is characterized by including a step of fitting the preform from one end of the plastic member.

According to the present invention, it is possible to provide a composite container having a high oxygen barrier property without increasing the amount of the resin material used. In addition, the composite container has high recyclability.
Further, according to the present invention, it is possible to provide a composite preform used for producing the container, a method for producing the container, and a method for producing the composite preform.

FIG. 1 is a partial vertical sectional view of the composite container 10A of the present invention. FIG. 2 is a horizontal sectional view (FIG. II-II sectional view of FIG. 1) showing the composite container 10A of the present invention. FIG. 3 is a partial vertical sectional view of the composite preform 70 of the present invention in one embodiment. FIG. 4 is a perspective view showing various plastic members 40a. FIG. 5 is a schematic view showing an embodiment of a method for manufacturing the composite container 10A. FIG. 6 is a schematic view showing an embodiment of a method for manufacturing the plastic member 40a. FIG. 7 is a schematic view showing an embodiment of a method for manufacturing the plastic member 40a.

(Composite container 10A)
As shown in FIG. 1, the composite container 10A of the present invention includes a container body 10 and a plastic member 40 provided in close contact with the outside of the container body 10 without being welded or adhered.
In the present invention, the fact that the plastic member 40 is not adhered to the container body 10 means that the plastic member 40 is not provided on the outside of the container body 10 via an adhesive.
In the present invention, the container body and the plastic member are integrally obtained by blow molding, and therefore have high adhesion. Therefore, the oxygen barrier property of the plastic member 40 is effectively exhibited even though the plastic member 40 is not adhered, and the invasion of oxygen into the container body 10 can be effectively prevented.
Further, since the plastic member 40 is provided in close contact with the container body 10 without being welded and adhered, these can be separately collected and recycled after use.

The oxygen permeability of the composite container 10A of the present invention is 0.060 cc / pkg · day · 0.21 atm or less.
The oxygen permeability is preferably 0.050 cc / pkg / day / 0.21 atm or less, and more preferably 0.040 cc / pkg / day / 0.21 atm or less.
In the present invention, in accordance with the JIS K 7126 isobaric method, an oxygen permeability measuring device (for example, manufactured by MOCON, trade name: OX-TRAN 2/20) is used under the conditions of 23 ° C. and 90% humidity RH. It is a value to be measured.

The total weight of the resin material contained in 10A of the composite container is preferably 7.8 to 17 g.
When the content of the container body 10 is 180 to 450 mL, the total weight of the resin material contained in the composite container 10A is preferably 7.8 to 12 g. When the content of the container body 10 is 450 to 700 mL, the total weight of the resin material contained in the composite container 10A is preferably 8.8 to 17 g. Thereby, the amount of the resin material used can be effectively reduced while maintaining the oxygen barrier property and the mechanical strength of the composite container 10A.

In the composite container 10A, it is preferable that the density of the container body 10 is 1 g / cm ³ or more and the density of the plastic member 40 ^{is less than 1 g / cm 3.} More preferably, the density of the container body 10 is 1.3 g / cm ³ or more, and the density of the plastic member 40 is less than ^{1 g / cm 3.}
With such a configuration, when the composite container 10A recovered after use is crushed into flakes and impregnated in water, the flakes of the container body 10 sink and the flakes of the plastic member 40 float. , These can be easily separated and recovered (separated and recovered in water).

(Container body 10)
The container body 10 included in the composite container 10A of the present invention contains polyethylene terephthalate as a main component, its weight is 7 g to 15 g, and its oxygen permeability is 0.100 cc / pkg · day · 0.21 atm or more. Is. The container body 10 having such a structure includes a thin body portion having a thickness of about 100 μm.
The composite container 10A of the present invention includes a plastic member 40 having a high oxygen barrier property in close contact with the outside of the container body 10, contains polyethylene terephthalate as a main component, and has a weight of 7 g to 15 g. The oxygen permeability is 0.100 cc / pkg · day · 0.21 atm or more, and even when the thin container body 10 is used, it has high oxygen permeability. Then, by making the container body 10 such a thin structure, the amount of the resin material used can be effectively reduced.

From the viewpoint of reducing the amount of the resin material used, when the container body 10 has an internal volume of 180 to 450 mL, its weight is preferably 7 to 11.2 g. When the container body 10 has an internal volume of 450 to 700 mL, its weight is preferably 8.0 to 16.2 g.

In the composite container 10A of the present invention, the container body 10 has a single-layer structure. As a result, the container body 10 can be collected from the composite container 10A and recycled.

The thickness of the container body 10 at the position where the horizontal cross-sectional area of the composite container 10A of the present invention is maximized is preferably 50 μm or more and 150 μm or less, and more preferably 80 μm or more and 125 μm or less. As a result, the amount of the resin material used can be reduced while maintaining the mechanical strength of the container body 10.
When there are a plurality of locations having the maximum horizontal cross-sectional area in the composite container 10A, the "thickness of the container body 10 at the locations having the maximum horizontal cross-sectional area" means the average thickness thereof. do.

The container body 10 included in the composite container 10A of the present invention is characterized by containing polyethylene terephthalate as a main component.
In the present invention, "containing as a main component" means that the content in the container body 10 exceeds 90% by mass.
Further, in the present invention, polyethylene terephthalate includes polyethylene terephthalate obtained by using a mechanical recycling method, a chemical recycling method, or the like, and also includes a blend material with petroleum-derived polyethylene terephthalate.

The content of polyethylene terephthalate is preferably 90% by mass or more, more preferably 95% by mass or more, and further preferably 99% by mass or more. As a result, the recyclability of the container body 10 after collection can be improved.
The recycling method is not particularly limited, and examples thereof include conventionally known methods such as a mechanical recycling method and a chemical recycling method.

The container body 10 may contain a resin material other than polyethylene terephthalate as long as the characteristics of the present invention are not impaired. As the resin material, polyester, polyamide, polyolefin, vinyl resin, (meth) acrylic other than polyethylene terephthalate may be contained. Examples thereof include resins, imide resins, cellulose resins, styrene resins, polycarbonates, and ionomer resins thereof.
Further, the container body 10 can contain various additives as long as the characteristics of the present invention are not impaired. Additives include, for example, colorants such as pigments and dyes, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, etc. Examples thereof include slip agents, mold release agents, antioxidants, ion exchangers, dispersants, and ultraviolet absorbers.
Further, the container body 10 may contain various colorants, but from the viewpoint of recycling suitability, it is preferable that the container body 10 does not contain a colorant and is colorless and transparent.

Next, an embodiment of the structure of the container body 10 will be described, but the present invention is not limited thereto.
In one embodiment, as shown in FIG. 1, the container body 10 is connected to the mouth portion 11 and the neck portion 13 provided below the mouth portion 11 and to the neck portion 13. It is provided with a shoulder portion 12 provided below, a body portion 20 provided below the shoulder portion 12 so as to be connected to the shoulder portion 12, and a bottom portion 30 provided below the body portion 20 so as to be connected to the body portion 20. ing.

In one embodiment, the mouth portion 11 has a screw portion 14 screwed to a cap (not shown) and a flange portion 17 provided below the screw portion 14. The shape of the mouth portion 11 may be a conventionally known shape, or may be a plugging method other than the screwing method. The cap may be a metal cap as well as a plastic cap.

The neck portion 13 is located between the flange portion 17 and the shoulder portion 12, and has a substantially cylindrical shape having a substantially uniform diameter. Further, the shoulder portion 12 is located between the neck portion 13 and the body portion 20, and has a shape in which the diameter gradually increases from the neck portion 13 side to the body portion 20 side.

Further, the body portion 20 has a cylindrical shape having a substantially uniform diameter as a whole. However, the present invention is not limited to this, and the body portion 20 may have a polygonal tubular shape such as a quadrangular tubular shape or an octagonal tubular shape. Alternatively, the body portion 20 may have a tubular shape having a non-uniform horizontal cross section from the upper side to the lower side. Further, in the present embodiment, the body portion 20 is not formed with irregularities and has a substantially flat surface, but the present invention is not limited to this. For example, the body portion 20 may have irregularities such as panels or grooves.

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

In one embodiment, the container body 10 can be manufactured by biaxially stretching blow molding a preform 10a, which will be described later, together with a plastic member 40a.

In one embodiment, the container body 10 may be provided with a vapor-deposited film such as a diamond-like carbon film or a silicon oxide thin film on the inner surface thereof in order to enhance the oxygen barrier property of the container.

(Plastic member 40)
The composite container 10A includes a plastic member 40 provided in close contact with the outside of the container body 10 without being welded and adhered. Since the plastic member 40 is provided in close contact with the container body 10 without being welded or adhered, the plastic member 40 and the container body 10 are separated from the used composite container 10A. Can be collected in, and each of these can be recycled.
As a method of separating (peeling) the plastic member 40 from the container body 10, for example, the plastic member 40 is cut off using a knife or the like, or a cutting line is provided in advance on the plastic member 40 and along the cutting line. The plastic member 40 can be peeled off.
In another embodiment, the composite container 10A is crushed into flakes and then immersed in water or hot water to utilize the difference in density between the plastic member 40 and the container body 10, and the heat-shrinkable plastic member. 40 can be separated and recovered. Further, as will be described later, when the heat-shrinkable plastic member 40 has heat-shrinkability, it can be easily peeled off from the container body 10 in hot water.

The thickness of the plastic member 40 at the position where the horizontal cross-sectional area of the composite container 10A of the present invention is maximized is 5 μm or more and 30 μm or less. Preferably, the thickness is 8 μm or more and 25 μm or less, and more preferably, the thickness is 10 μm or more and 22 μm or less.
By having the plastic member 40 having such a configuration, it is possible to achieve both the oxygen barrier property of the composite container 10A and the reduction of the amount of the resin material used.
In the composite container 10A, when there are a plurality of places where the horizontal cross-sectional area is the maximum, the "thickness of the plastic member 40 at the places where the horizontal cross-sectional area is the maximum" is the average thickness. means.

The plastic member 40 may have a single-layer structure or a multi-layer structure.

In one embodiment, the plastic member 40 (40a) can be heat shrinkable. Since the plastic member 40 (40a) has heat shrinkage, the plastic member 40a expands in diameter while shrinking with respect to the preform 10a during blow molding, and the container body is expanded. It is possible to prevent bubbles from being generated between the 10 and the heat-shrinkable plastic member 40, and it is possible to obtain a composite container 10A having a good appearance. In addition, the above-mentioned separation and recovery in hot water becomes easy.

The plastic member 40 included in the composite container 10A of the present invention includes at least an oxygen barrier layer containing an oxygen barrier resin.
Examples of the oxygen barrier resin include polyamides such as metachilen adipamide (MXD-6), nylon 6, nylon 6,6 and nylon 6 / nylon 6,6 copolymers, ethylene-vinyl acetate copolymers, and the like. Ethylene-vinyl alcohol copolymer (EVOH), polyglucol (PGA), polyvinylidene chloride copolymer (PVDC), polyacrylonitrile, polyvinyl alcohol (PVA), polytetrafluoroethylene (PTFE), and styrene-isobutylene-styrene. Examples include copolymers.
Among these, metachilen adipamide (MXD-6), ethylene-vinyl alcohol copolymer (EVOH), polyglucol (PGA), and polyvinyl alcohol (PVA) are preferable, but oxygen barrier property and moldability are particularly preferable. From this point of view, an ethylene-vinyl alcohol copolymer (EVOH) is preferable.
The oxygen barrier layer may contain two or more kinds of oxygen barrier resins.

The content of the oxygen barrier resin in the oxygen barrier layer is preferably 80% by mass or more, and more preferably 95% by mass or more.

The oxygen barrier layer may contain a resin material other than the oxygen barrier resin (for example, polyethylene, polypropylene, etc.), the above-mentioned additives, and colorants as long as the characteristics of the present invention are not impaired.

The thickness of the oxygen barrier layer at the portion where the horizontal cross-sectional area of the composite container 10A of the present invention is maximized is preferably 0.5 μm or more and 20 μm or less, and more preferably 1 μm or more and 15 μm or less.
By setting the thickness of the oxygen barrier layer to 0.5 μm or more, the oxygen barrier property can be further improved. Further, by setting the average thickness of the oxygen barrier layer to 20 μm or less, the amount of the resin material used can be further reduced.

Hereinafter, an embodiment in the case where the plastic member 40 has a multi-layer structure will be described.
In one embodiment, the plastic member 40 includes a first resin layer in contact with the container body 10, an oxygen barrier layer, and a second resin layer.
Further, in one embodiment, the plastic member 40 may include an adhesive layer between the first resin layer and the oxygen barrier layer, and between the oxygen barrier layer and the second resin layer.
The constituent materials, thicknesses, and additives contained in the first resin layer and the second resin layer may be the same or different.

The first resin layer and the second resin layer contain at least one resin material. Examples of the resin material include polyester, polyamide, polyolefin, vinyl resin, (meth) acrylic resin, imide resin, cellulose resin, styrene resin, polycarbonate, and ionomer resins thereof.
Among these, polyolefin is preferable, and polyethylene or polypropylene is preferable from the viewpoint of moldability, transparency, cost and the like.

The first resin layer and the second resin layer may contain the above-mentioned additives and colorants as long as the characteristics of the present invention are not impaired.
The colorant is preferably selected and used as appropriate according to the contents to be filled in the container body 10, and when the container body 10 is filled with beer, the colorant cuts visible light having a wavelength of 400 nm to 500 nm. It is preferable to use a brownish colorant that can be used.
In addition, light-reflecting pigments such as titanium white, aluminum powder, mica powder, zinc sulfide, zinc oxide, calcium carbonate, kaolin, and talc, and light-absorbing pigments such as carbon black, ceramic black, and bone black are used as colorants. You may.

The thickness of the first resin layer and the second resin layer at the portion where the horizontal cross-sectional area of the composite container 10A of the present invention is maximized is preferably 3 μm or more and 12 μm or less, and preferably 5 μm or more and 10 μm or less. More preferred.

The adhesive layer can be formed by a conventionally known adhesive, for example, a polyvinyl acetate adhesive, a polyacrylic acid ester adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, and a cellulose adhesive. , Polyester adhesive, Polyamide adhesive, Polygon adhesive, Amino resin adhesive, Phenolic resin adhesive, Epoxy adhesive, Polyurethane adhesive, Rubber adhesive, Silicone adhesive, etc. Be done.

The thickness of the adhesive layer at the portion where the horizontal cross-sectional area of the composite container 10A of the present invention is maximized is preferably 0.5 μm or more and 7 μm or less, and more preferably 1 μm or more and 5 μm or less.

From the viewpoint of reducing the amount of the resin material used, the weight of the plastic member 40 is preferably 0.8 to 2.0 g.
When the container body 10 has an internal volume of 180 to 450 mL, the weight of the plastic member 40 is preferably 0.8 to 1.5 g. When the container body 10 has an internal volume of 450 to 700 mL, the weight of the plastic member 40 is preferably 1.0 to 2.0 g.

Next, an embodiment of the structure of the plastic member 40 will be described, but the present invention is not limited thereto.
The plastic member 40 is provided in the entire area or a partial area thereof except for the mouth portion 11 of the container body 10.
In one embodiment, the plastic member 40 is provided so as to cover the body 20 of the container body 10.
Further, in one embodiment, the plastic member 40 is provided so as to cover the shoulder portion 12 and the body portion 20 of the container body 10 (see FIG. 1).
Further, in one embodiment, the plastic member 40 is provided so as to cover the shoulder portion 12, the body portion 20, and a part of the bottom portion 30 of the container body 10. At this time, the plastic member 40 may cover the entire bottom portion 30, but from the viewpoint of oxygen barrier property and ease of manufacture, the plastic member 40 is provided so as to cover a part of the bottom portion. Is preferable. Specifically, it is preferable that the plastic member 40 is provided so as to cover at least up to the bottom 30 ground contact portion 32.

The composite container 10A may include two or more plastic members 40.

The surface of the plastic member 40 may be printed. The image formed by printing is not particularly limited, such as patterns and characters. From the viewpoint of not being affected by the color tone of the plastic member, it is preferable that the printing is provided on the surface side of the composite container of the plastic member 40. Further, the printing method may be a known printing method, or may be an inkjet, a flexo, a pad, a silk screen, a laser, a gravure, a thermal transfer, an offset, a hot stamp, a cold stamp, or the like.
Further, the plastic member 40 may be provided with a primer layer or an adhesive layer on the surface thereof. Thereby, the printability on the plastic member 40 can be improved.
Further, a surface coat layer made of a protective varnish or the like may be provided on the surface of the printed plastic member 40.

(label)
In one embodiment, the composite container 10A of the present invention may include a label provided to surround the outside of the container body 10 and / or the heat shrinkable plastic member 40.
Examples of the label include a shrink label, a stretch label, a roll label, a tack label, a paper label, or a label suspended from the neck 13 of the composite container 10A with a string or the like (hereinafter, referred to as a “hanging label” in some cases). And so on. Among these, it is preferable to use a shrink label or a roll label because of high productivity.

(Composite preform 70)
The composite preform 70 is used for producing the composite container 10A, and in one embodiment, as shown in FIG. 3, the composite preform 70 is welded to the preform 10a and to the outside of the preform 10a. It is provided with a plastic member 40a provided in close contact with each other without being adhered.
The composite container 10A shown in FIG. 1 can be obtained by subjecting the composite preform 70 to biaxial stretch blow molding and expanding the preform 10a and the plastic member 40a constituting the composite preform 70 as a unit. can.

(Preform 10a)
As shown in FIG. 3, the preform 10a includes a mouth portion 11a, a body portion 20a connected to the mouth portion 11a, and a bottom portion 30a connected to the body portion 20a. Of these, 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. Further, 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, but may have a substantially conical shape or a substantially rectangular shape previously known.

The preform 10a can be produced by using a conventionally known method, and examples thereof include injection molding (injection), compression molding (compression), and injection compression molding (injection-compression).

(Plastic member 40a)
In one embodiment, as shown in FIG. 4A, the plastic member 40a has a bottomed cylindrical shape and has a cylindrical body 41 and a bottom 42 connected to the body 41.
Further, in one embodiment, as shown in FIG. 4B, the plastic member 40a has a bottomless cylindrical shape as a whole and has a cylindrical body portion 41.
Further, in one embodiment, as shown in FIG. 4C, the plastic member 40a has a bottomless cylindrical shape formed by forming a film into a tubular shape and laminating its ends.
As shown in FIGS. 4 (b) and 4 (c), when the plastic member 40a has a bottomless cylindrical shape, one end thereof can be heat-bonded to form a bottom portion.

In one embodiment, as shown in FIG. 3, the plastic member 40a is provided so as to completely cover the body portion 20a included in the preform 10a.
Further, in one embodiment, the plastic member 40a is provided so as to cover a part of the body portion 20a included in the preform 10a (not shown).
Further, in one embodiment, the plastic member 40a is provided so as to cover the body portion 20a included in the preform 10a and a part of the bottom portion 30a (not shown).
Further, in one embodiment, the plastic member 40a is provided so as to completely cover the body portion 20a and the bottom portion 30a included in the preform 10a (not shown).
Two or more plastic members 40a may be provided.

The thickness of the plastic member 40a before blow molding is 200 μm or more and 400 μm or less, and more preferably 250 μm or more and 350 μm or less.
By having the plastic member 40a having such a configuration, it is possible to achieve both the oxygen barrier property of the composite container 10A and the reduction of the amount of the resin material used.

In one embodiment, the plastic member 40a can be heat shrinkable. Since the plastic member 40a has heat shrinkability, the diameter of the container body 10 and the heat shrinkable plastic member 40 are expanded while shrinking with respect to the preform 10a during blow molding. It is possible to prevent bubbles from being generated between the two, and it is possible to obtain a composite container 10A having a good appearance.

As described above, the plastic member 40a may have a single-layer structure or a multi-layer structure.
In one embodiment, the plastic member 40a includes a first resin layer, an oxygen barrier layer, and a second resin layer. Further, in one embodiment, the plastic member 40a may include an adhesive layer between the first resin layer and the oxygen barrier layer, and between the oxygen barrier layer and the second resin layer.
In the plastic member 40a having such a structure, the thickness of the oxygen barrier layer is preferably 10 μm and 50 μm or less. By setting the thickness of the oxygen barrier layer in the plastic member 40a before blow molding to 10 μm or more, the oxygen barrier property can be further improved. Further, by setting the average thickness of the oxygen barrier layer in the plastic member 40a before blow molding to 50 μm or less, the amount of the resin material used can be further reduced, and the density of the entire plastic member is 1 g / g /. It can be less than cm ^3.
The thickness of the first resin layer and the second resin layer is preferably 3 μm or more and 20 μm or less, and more preferably 5 μm or more and 15 μm or less.
The thickness of the adhesive layer is preferably 0.5 μm or more and 15 μm or less, and more preferably 1 μm or more and 10 μm or less.

The surface of the plastic member 40a may be printed. The image formed by printing is not particularly limited, such as patterns and characters. From the viewpoint of not being affected by the color tone of the plastic member, it is preferable that the printing is provided on the surface side of the composite container of the plastic member 40a.
Further, the plastic member 40a may be provided with a primer layer or an adhesive layer on the surface thereof. Thereby, the printability on the plastic member 40a can be improved.
Further, a surface coat layer made of a protective varnish or the like may be provided on the surface of the printed plastic member 40a.

(Manufacturing method of composite container 10A)
The method for producing the composite container 10A according to the present invention is as follows.
The process of preparing the composite preform 70 and
The process of heating the composite preform 70 and
This includes a step of integrally expanding the preform 10a and the plastic member 40a by performing blow molding on the composite preform 70 after heating in the blow molding die.

Hereinafter, the method for producing the composite container 10A of the present invention will be described in more detail based on FIGS. 5A to 5D.

(Step of preparing composite preform 70)
In one embodiment, the step of preparing the composite preform 70 is:
The process of preparing the preform 10a and
The process of preparing the plastic member 40a and
It includes a step of fitting the preform 10a from one end of the plastic member 40a.
When the plastic member 40a has heat shrinkage, the method for producing the composite preform 70 of the present invention may include a step of heat-shrinking the plastic member 40a. When the plastic member 40a has a bottomless cylindrical shape, it may include other steps such as a step of heat-pressing one end of the plastic member 40a.

Further, in one embodiment, the step of preparing the composite preform 70 includes a step of heating the preform 10a before the step of fitting the preform 10a from one end of the plastic member 40a.
This makes it possible to better perform blow molding of the composite preform 70.

(Heating and blow molding process of composite preform 70)
First, the composite preform 70 is heated by the heating device 51 (see FIG. 5A). At this time, it is preferable that the composite preform 70 is uniformly heated in the circumferential direction by the heating device 51 while rotating with the mouth portion 11a facing downward.
The heat source is not particularly limited, and for example, infrared rays, warm air, or the like can be used.

Subsequently, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 (see FIG. 5B).

The composite container 10A is molded using the blow molding die 50. The inner surface of the blow-molded mold 50 may be engraved with a pattern or the like, and the plastic member 40a is pressed against the inner surface of the mold by blow-molding the composite preform 70 in such a mold. Therefore, the pattern is transferred to the surface.

In one embodiment, the blow molding die 50 includes a pair of body molds 50a and 50b that are separated from each other and a bottom mold 50c (see FIG. 5B). In FIG. 5B, the pair of body molds 50a and 50b are open to each other, and the bottom mold 50c is raised upward. In this state, the composite preform 70 is inserted between the pair of body molds 50a and 50b.

Next, after the bottom mold 50c is lowered, the pair of body molds 50a and 50b are closed, and the blow molding mold 50 sealed by the pair of body molds 50a and 50b and the bottom mold 50c is configured. Will be done. Next, air is press-fitted into the preform 10a, and biaxial stretch blow molding is performed on the composite preform 70. As a result, the container body 10 can be obtained from the preform 10a in the blow molding die 50 (see FIG. 5C). During this time, the body molds 50a and 50b are heated, and the bottom mold 50c is cooled. At this time, in the blow molding die 50, the preform 10a of the composite preform 70 and the plastic member 40a are integrally expanded. As a result, the preform 10a and the plastic member 40a are integrally shaped into a shape corresponding to the inner surface of the blow molding die 50.

In this way, the composite container 10A including the container body 10 and the plastic member 40 provided in close contact with the outer surface of the container body 10 without being welded and adhered can be obtained.

Next, as shown in FIG. 5D, 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.

(Other processes)
The method of the present invention may include a step of printing an image, characters, or the like on the surface of the plastic member 40.
Printing can be performed by, for example, an inkjet method, a gravure printing method, an offset printing method, a flexographic printing method, a thermal transfer method, a silk screen method, a pad method, a hot stamping method, a cold stamping method, or the like. For example, when the inkjet method is used, a UV curable ink is applied to the plastic member 40, UV irradiation is performed on the plastic member 40, and the ink is cured to form a print layer. Further, printing may be performed using a thermal transfer sheet or an intermediate transfer medium.

(Manufacturing method of composite preform 70)
The method for producing the composite preform 70 of the present invention is as follows.
The process of preparing the preform 10a and
The process of preparing the plastic member 40a and
It includes a step of fitting the preform 10a from one end of the plastic member 40a.
When the plastic member 40a has heat shrinkage, the method for producing the composite preform 70 of the present invention may include a step of heat-shrinking the plastic member 40a. When the plastic member 40a has a bottomless cylindrical shape, it may include other steps such as a step of heat-pressing one end of the plastic member 40a.

Hereinafter, each step of the method for producing the composite preform 70 according to the present invention will be described in detail.

(Step of preparing preform 10a)
The preform 10a can be produced by injection molding the above-mentioned resin material or the like using a conventionally known injection molding apparatus.
Alternatively, a commercially available preform 10a may be used.

Further, by mixing an inert gas (nitrogen gas, argon gas) with the melt of the resin material, a foamed preform having a foamed cell diameter of 0.5 to 100 μm is formed, and this foamed preform is blow-molded. The container body 10 may be manufactured according to the above. Since such a container body 10 has a foam cell built-in, it is possible to improve the light-shielding property of the entire container body 10.

(Step of preparing the plastic member 40a)
In one embodiment, the plastic member 40a can be manufactured by molding a resin sheet containing the above-mentioned resin material and the like.
Examples of the molding method include deep drawing molding, or a method of molding a resin sheet into a tube shape and fusing or adhering the end portions thereof.
As the resin sheet, a commercially available product may be used, or the resin sheet can be produced by a conventionally known method. For example, the resin sheet can be produced by extrusion molding using the T-die method or the inflation method.
Further, the multilayer resin sheet for producing the plastic member 40a having a multilayer structure can be obtained by coextrusion molding or by laminating two or more resin sheets via an adhesive.

In one embodiment, the plastic member 40a is a plastic member 40a, as shown in FIG. 6A.
(1) First, the resin material 52 or the like is heated and melted and extruded from the die 53 into a tube shape to form a tubular parison 54.
(2) Next, as shown in FIG. 6B, for example, the tubular parison 54 is sandwiched between the two-divided mold 55.
(3) Next, as shown in FIG. 6C, air is blown into the tubular parison 54 from the blowing nozzle 56, the tubular parison 54 is molded according to the mold 55, cooled, opened, and taken out. It can be produced by sequentially performing (direct blow molding). The plastic member 40a thus obtained has a bottomed cylindrical shape as shown in FIG. 6D.
According to this method, the design of the obtained plastic member 40a can be changed by changing the design of the mold, and the plastic member 40a having high adhesion to the preform 10a can be produced. ..

In one embodiment, the heat-shrinkable plastic member 40a can be produced by the following method.
First, the above-mentioned resin material or the like is heated and melted in an extruder, and the melted resin material or the like is continuously co-extruded from a ring die and cooled to form an unstretched extrusion tube 58 (FIG. FIG. 7 (a)).
One end of the extruded tube is then closed by welding or adhering one end of the unstretched extruded tube.
Further, the extruded tube 58 having one end closed is arranged in a mold 59 having an inner diameter larger than the outer diameter of the extruded tube 58 (see FIG. 7B).
Next, the blow device 60 is arranged (mounted) on the other end of the extrusion tube 58 (see FIG. 7 (c)). At this time, it is preferable that the blow device 60 is brought into close contact with the extrusion tube 58 so that air does not leak between them.
Subsequently, the extrusion tube 58, the mold 59, and the blow device 60 are sent into the heating furnace 61 in this arrangement and heated inside the heating furnace 61 (see FIG. 7D). As the heating furnace 61, a hot air circulation type heating furnace may be used in order to keep the inside thereof at a uniform temperature. Alternatively, the extrusion tube 58, the mold 59 and the blow device 60 may be heated by passing through the heated liquid.
Next, the extrusion tube 58, the mold 59, and the blow device 60 are taken out from the heating furnace 61, and air is blown into the extrusion tube 58 from the blow device 60 to pressure-stretch the inner surface of the extrusion tube 58. As a result, the extrusion tube 58 expands and the diameter is expanded along the inner surface shape of the mold 59 (see FIG. 7E).
Then, the extrusion tube 58 is cooled in cold water while the air is ejected from the blow device 60, and the extrusion tube is taken out from the mold 59 (see FIG. 7 (f)). By cutting this into a desired size, a heat-shrinkable plastic member 40a can be obtained (see FIG. 7 (g)).

Further, in one embodiment, the plastic member 40a can also be obtained by a co-injection molding method. Specifically, first, the above-mentioned resin material or the like is heated and melted, and then co-injected into a mold. The plastic member 40a can also be obtained by cooling this and taking it out of the mold.

(Matching process)
The method of the present invention includes a step of fitting the preform 10a from one end of the plastic member 40a.

(Other processes)
When the plastic member 40a has heat shrinkage, the method for producing the composite preform 70 according to the present invention includes a step of heat-shrinking the plastic member 40a and bringing it into close contact with the preform 10a.
The heating method of the heat-shrinkable plastic member 40a is not particularly limited, and can be appropriately performed by using infrared rays, warm air, or the like.

When the plastic member 40a has a bottomless cylindrical shape as shown in FIGS. 4B and 4C, the method of the present invention may include a step of heat-bonding one end of the plastic member 40a. .. By including such a step, the bottom portion 30a of the preform 10a and, by extension, the bottom portion 30 of the container body 10 after blow molding can be completely covered with the plastic member 40.
Specifically, the length X of the plastic member 40a is made longer than the length Y from the neck 13a to the bottom 30a of the preform 10a, that is, a margin is provided at one end of the plastic member 40a. , The bottom portion can be formed by heat-bonding this margin portion.
The length of the margin portion is preferably 3 mm or more, and more preferably 5 mm or more and 20 mm or less.

The heat crimping method is not particularly limited, and is not particularly limited as long as it can be crimped by sandwiching a margin heated by infrared rays, warm air, etc. For example, it is made of metal or heat resistant. Resin instruments (hereinafter, sometimes referred to as "crimping instruments") can be used, and they may be combined. The surface of this crimping tool may be flat, or may have an uneven shape in part or in whole.
Further, the crimping tool may have a heating mechanism on its surface. Thereby, the crimping strength of the margin portion 80a can be further increased.

The method of the present invention may include a step of printing an image, characters, or the like on the surface of the plastic member 40a.
Printing can be performed by, for example, an inkjet method, a gravure printing method, an offset printing method, a flexographic printing method, a thermal transfer method, a silk screen method, a pad method, a hot stamping method, a cold stamping method, or the like. For example, when the inkjet method is used, a UV curable ink is applied to the plastic member 40a (40), UV irradiation is performed on the plastic member 40a (40), and the ink is cured to form a print layer. Further, printing may be performed using a thermal transfer sheet or an intermediate transfer medium.
This printing may be applied to the plastic member 40a before being fitted into the preform 10a, or may be applied with the plastic member 40a provided on the outside of the preform 10a.

<Example 1>
Using an injection molding machine, a single-layer preform 10a was prepared using a resin composition containing polyethylene terephthalate.
The weight of the preform 10a was 10.0 g.
The content of polyethylene terephthalate in the preform 10a was 100% by mass.
The density of the preform 10a was 1.335 g / cm ³ .

Propropylene, adhesive polyolefin, and ethylene-vinyl alcohol copolymer were melt-extruded from a ring-shaped die. Next, the inner surface of the extruded tube is pressurized or the outer surface of the tube is negatively pressured from the inner surface, and then the diameter is increased to produce the bottomless cylindrical heat-shrinkable plastic member 40a shown in FIG. 4 (b). bottom.
The plastic member 40a is made of a first resin layer made of polypropylene, an adhesive layer made of adhesive polyolefin, an oxygen barrier layer made of an ethylene-vinyl alcohol copolymer, and an adhesive polyolefin. It includes an adhesive layer composed of an adhesive layer and a second resin layer composed of polypropylene, and the weight thereof is 1.5 g.
The density of the plastic member 40a was 0.998 g / cm ³ .

Then, the preform 10a was manually fitted from one end of the plastic member 40a.

After fitting, the preform 10a and the plastic member 40a were heated using warm air, and the plastic member 40a was heat-shrinked to obtain a composite preform 70.

The composite preform 70 obtained as described above was heated using an infrared heater and conveyed to the blow molding die shown in FIG. 5 (b). In this blow molding mold, the composite preform 70 is blow molded, and the composite container 10A having a capacity of 500 mL is provided with a container body 10 and a plastic member 40a provided so as to completely cover the body 20 thereof. Got

In the composite container 10A after blow molding, the thickness of the container body 10 at the position where the horizontal cross-sectional area was maximum was 86 μm.
In the composite container 10A after blow molding, the thickness of the plastic member 40 at the portion where the horizontal cross-sectional area was maximum was 19 μm.
The oxygen permeability of the container body 10 included in the composite container 10A after blow molding is measured by an oxygen permeability measuring device (for example, manufactured by MOCON, trade name: OX-TRAN 2/20) in accordance with the JIS K 7126 isobaric method. When measured under the conditions of 23 ° C. and 90% humidity RH, it was 0.136 cc / pkg · day · 0.21 atm.
Similarly, when the oxygen permeability of the composite container 10A was measured, it was 0.022 cc / pkg · day · 0.21 atm.
The total weight of the resin material contained in the composite container 10A was 11.5 g.

<Example 2>
A composite container 10A was produced in the same manner as in Example 1 except that the volume of the container body was changed to 600 mL.
In the composite container 10A after blow molding, the thickness of the container body 10 at the position where the horizontal cross-sectional area was maximum was 82 μm.
In the composite container 10A after blow molding, the thickness of the plastic member 40 at the portion where the horizontal cross-sectional area was maximum was 14 μm.
The oxygen permeability of the container body 10 included in the composite container 10A after blow molding is measured by an oxygen permeability measuring device (for example, manufactured by MOCON, trade name: OX-TRAN 2/20) in accordance with the JIS K 7126 isobaric method. When measured under the conditions of 23 ° C. and 90% humidity RH, it was 0.141 cc / pkg · day · 0.21 atm.
Similarly, when the oxygen permeability of the composite container 10A was measured, it was 0.025 cc / pkg · day · 0.21 atm.

<Example 3>
Using an injection molding machine, a single-layer preform 10a was prepared using a resin composition containing polyethylene terephthalate.
The weight of the preform 10a was 7.5 g.
The content of polyethylene terephthalate in the preform 10a was 100% by mass.
The density of the preform 10a was 1.335 g / cm ³ .

Propropylene, adhesive polyolefin, and ethylene-vinyl alcohol copolymer were melt-extruded from a ring-shaped die. Next, the inner surface of the extruded tube is pressurized or the outer surface of the tube is negatively pressured from the inner surface, and then the diameter is increased to produce the bottomless cylindrical heat-shrinkable plastic member 40a shown in FIG. 4 (b). bottom.
The plastic member 40a is made of a first resin layer made of polypropylene, an adhesive layer made of adhesive polyolefin, an oxygen barrier layer made of an ethylene-vinyl alcohol copolymer, and an adhesive polyolefin. It includes an adhesive layer composed of an adhesive layer and a second resin layer composed of polypropylene, and the weight thereof is 0.9 g.
The density of the plastic member 40a was 0.998 g / cm ³ .

Then, the preform 10a was manually fitted from one end of the plastic member 40a.

After fitting, the preform 10a and the plastic member 40a were heated using an infrared heater, and the plastic member 40a was heat-shrinked to obtain a composite preform 70.

The composite preform 70 obtained as described above was heated using an infrared heater and conveyed to the blow molding die shown in FIG. 5 (b). In this blow molding mold, the composite preform 70 is blow molded, and the composite container 10A having a capacity of 280 mL is provided with a container body 10 and a plastic member 40a provided so as to completely cover the body 20 thereof. Got

In the composite container 10A after blow molding, the thickness of the container body 10 at the position where the horizontal cross-sectional area was maximum was 91 μm.
In the composite container 10A after blow molding, the thickness of the plastic member 40 at the portion where the horizontal cross-sectional area was maximum was 16 μm.
The oxygen permeability of the container body 10 included in the composite container 10A after blow molding is measured by an oxygen permeability measuring device (for example, manufactured by MOCON, trade name: OX-TRAN 2/20) in accordance with the JIS K 7126 isobaric method. When measured under the conditions of 23 ° C. and 90% humidity RH, it was 0.119 cc / pkg · day · 0.21 atm.
Similarly, when the oxygen permeability of the composite container 10A was measured, it was 0.019 cc / pkg · day · 0.21 atm.
The total weight of the resin material contained in the composite container 10A was 8.4 g.

<Comparative example 1>
Using an injection molding machine, a single-layer preform 10a was prepared using a resin composition containing polyethylene terephthalate. The weight of the preform 10a was 38 g, and the thickness thereof was 880 μm. The content of polyethylene terephthalate in the preform 10a was 100% by mass.

The preform 10a was heated using an infrared heater and conveyed to the blow molding die shown in FIG. 5 (b). In this blow molding die, the preform 10a was blow molded to obtain a container having a capacity of 300 mL. The thickness of the container was 880 μm.
The oxygen permeability of the container after blow molding is measured at 23 ° C. using an oxygen permeability measuring device (for example, manufactured by MOCON, trade name: OX-TRAN 2/20) in accordance with the JIS K 7126 isobaric method. When measured under the condition of humidity of 90% RH, it was 0.024 cc / pkg · day · 0.21 atm.
The total weight of the resin material contained in the obtained container was 38 g.

<< Oxygen barrier evaluation >>
The oxygen permeability of the containers obtained in the above Examples and Comparative Examples was measured by using an oxygen permeability measuring device (for example, manufactured by MOCON, trade name: OX-TRAN 2/20) in accordance with the JIS K 7126 isobaric method. It was measured under the conditions of 23 ° C. and 90% humidity RH. The measurement results are summarized in Table 1.

As is clear from the comparison between Example 3 and Comparative Example 1, the composite container produced in Example 3 has a high oxygen barrier property without increasing the amount of the resin material used. ..
Further, the composite container produced in Examples 1 to 3 includes a container main body and a plastic member provided in close contact with the container main body without being welded or adhered, and after use. , The plastic member and the container body can be collected and recycled separately.

10A: Composite container, 10: Container body, 10a: Preform, 11 and 11a: Mouth, 12: Shoulder, 13: Neck, 14: Thread, 17: Flange, 20 and 20a: Body, 30 and 30a: bottom, 31: recess, 32: ground contact, 40: plastic member after blow molding, 40a: plastic member before blow molding, 41a: body, 42a: bottom, 50: blow molding mold, 50a And 50b: Body mold, 50c: Bottom mold, 51: Heating device, 52: Resin material, 53: Die, 54: Tubular parison, 55: Mold, 56: Blow nozzle, 58: Extrusion tube, 59 : Mold, 60: Blow device, 61: Heating furnace, 70: Composite preform,

Claims (12)

A container body with a single-layer structure and
A composite container provided with a plastic member provided in close contact with the outside of the container body without welding and adhesion.
The container body and the plastic member are integrally obtained by blow molding.
The weight of the container body is 7 g to 15 g, and the weight of the container body is 7 g to 15 g.
The oxygen permeability of the container body is 0.100 cc / pkg / day / 0.21 atm or more.
The container body contains polyethylene terephthalate as a main component.
The plastic member includes at least an oxygen barrier layer containing an oxygen barrier resin.
The thickness of the plastic member at the position where the horizontal cross-sectional area of the composite container is maximum is 5 μm or more and 30 μm or less.
A composite container characterized in that the oxygen permeability of the composite container is 0.060 cc / pkg / day / 0.21 atm or less. The composite container according to claim 1, wherein the weight of the plastic member is 0.8 to 2.0 g. The composite container according to claim 1 or 2, wherein the plastic member includes a first resin layer in contact with the container body, the oxygen barrier layer, and a second resin layer. The composite container according to claim 3, wherein the first resin layer and the second resin layer contain polyolefin. The container body comprises a mouth, neck, shoulders, torso and bottom.
The composite container according to any one of claims 1 to 4, wherein the plastic member is provided so as to cover the neck portion, the shoulder portion, the body portion, and a part of the bottom portion of the container body. .. The composite container according to any one of claims 1 to 5, wherein the plastic member has heat shrinkage. The composite container according to any one of claims 1 to 6, wherein the density of the container body is 1 g / cm ³ or more, and the density of the plastic member ^{is less than 1 g / cm 3.} The composite container according to any one of claims 1 to 7, wherein the total weight of the resin material contained in the composite container is 7.8 to 17 g. A composite preform for producing the composite container according to any one of claims 1 to 8.
Preform and
A composite preform comprising the plastic member provided in close contact with the outside of the preform without being welded and adhered. The method for manufacturing a composite container according to any one of claims 1 to 8.
The step of preparing the composite preform according to claim 9 and
The step of heating the composite preform and
A composite container comprising a step of integrally expanding the preform and the plastic member by performing blow molding on the composite preform after heating in a blow molding die. Production method. The step of preparing the composite preform is
The process of preparing the preform and
The process of preparing the plastic member and
The step of heating the preform and
The method for manufacturing a composite container according to claim 10, further comprising a step of fitting the preform from one end of the plastic member after heating the preform. The method for producing a composite preform according to claim 9.
The process of preparing the preform and
The process of preparing the plastic member and
A method for producing a composite preform, which comprises a step of fitting the preform from one end of the plastic member.

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