JP2021031172A - Double container and manufacturing method of double container - Google Patents

Abstract

To provide a double container which can surely secure an airway reaching between a barrel body area of a barrel part and a storage part passing between a shoulder area of the barrel part with a low stretching ratio in a peripheral direction and the storage part from an outside air inlet provided at a mouth part, and a manufacturing method of the double container.SOLUTION: A double container 1 has an outer layer body 10 including an outer mouth part 11 and a barrel part 12, and an inner layer body 20 including an inner mouth part 21 and a storage part 22. A mouth part 31 composed of the outer mouth part 11 and the inner mouth part 21 has an outside air inlet 13 communicating between the outer layer body 10 and the inner layer body 20. The barrel part 12 has a shoulder region 12a extending between a lower end 11d of the outer mouth part 11 and an apex 14a of a curved part 14 projecting toward an outer surface closest to the lower end 11d in a vertical cross section. A stretching ratio in a peripheral direction of the shoulder region 12a is 1.70 or less. A rib 15 extending in a vertical direction is provided at least in the shoulder region 12a. The inner layer body 20 has an outward ridge 23 extending in the vertical direction through a portion of height corresponding to an upper end of the rib 15.SELECTED DRAWING: Figure 2

Description

The present invention relates to a double container and a method for manufacturing a double container.

A preform assembly that incorporates the inner preform inside the outer preform as a container for storing food seasonings such as soy sauce, cosmetics such as beverages and lotions, and toiletries such as shampoo, conditioner, and liquid soap. Was blow-molded and arranged inside an outer layer and an outer layer having a tubular outer mouth and a bottomed tubular body that was connected to the outer mouth and had a larger diameter than the outer mouth. A double container formed in a double structure having an inner layer portion connected to the inner mouth portion and an inner layer body having a volume-reducing deformable accommodating portion that is detachably laminated on the inner surface of the body portion is known. (See, for example, Patent Document 1).

The double container is used, for example, as a squeeze-type pouring container combined with a pouring cap equipped with a check valve or a container with a pump combined with a pump. In this case, the content liquid can be poured out by squeezing (squeezing) the body of the outer layer body or operating the pump, while the outside air provided on the outer layer body is provided after the content liquid is poured out. By introducing the outside air between the outer layer body and the inner layer body from the introduction port, it is possible to restore only the outer layer body to the original shape while reducing the volume and deforming the accommodating portion of the inner layer body. Therefore, according to the double container, the content liquid contained in the accommodating portion of the inner layer body can be discharged to the outside without replacing the outside air, so that the content liquid contained inside the inner layer body can be discharged to the outside. It is possible to reduce the contact of the outside air with the content liquid and suppress the deterioration and deterioration of the content liquid.

JP-A-2017-178434

However, in a double container formed by blow molding a preform assembly in which the inner preform is incorporated inside the outer preform, as in the conventional double container, the space between the outer layer body and the inner layer body is formed. If the outside air introduction port for introducing outside air is provided in the mouth portion composed of the outside port portion and the inside port portion, the outside air introduction port passes between the shoulder area of the body portion and the accommodating portion of the body portion. It was not possible to secure the airway between the body area and the containment part, and after pouring out the contents, the outside air was not introduced between the body area and the containment part, and the volume reduction deformation of the containment part was maintained. It tends not to be done or the restoration of the outer layer is hindered. In particular, this tendency was remarkable when the circumferential stretching ratio of the shoulder region was a low stretching ratio of 1.70 or less.

The present invention has been made in view of such a problem, and an object of the present invention is to pass from an outside air introduction port provided in the mouth portion to a shoulder region having a low circumferential extension ratio of the body portion and a storage portion. It is an object of the present invention to provide a double container and a method for manufacturing a double container that ensure that an airway leading between a body area of the body and a housing portion is secured.

The double container of the present invention has an outer layer body including a tubular outer mouth portion, a bottomed tubular body portion connected to the outer mouth portion and a diameter larger than that of the outer mouth portion, and a tubular inner portion. It has a mouth portion and an inner layer body including a volume-reducing and deformable accommodating portion that is connected to the inner mouth portion and is detachably laminated on the inner surface of the body portion. The mouth portion composed of the inner mouth portion arranged inside has an outside air introduction port communicating between the outer layer body and the inner layer body, and the body portion has the outer mouth portion in a vertical cross section. Has a shoulder region extending between the lower end of the shoulder region and the apex of the curved portion that protrudes toward the outer surface closest to the lower end, the circumferential extension ratio of the shoulder region is 1.70 or less, and the body portion moves up and down. It has ribs extending in the direction, and the inner layer body has outward ridges extending in the vertical direction through a portion having a height corresponding to the upper end of the ribs.

In the above configuration, the double container of the present invention preferably terminates the outward ridge at a height corresponding to the upper part of the shoulder region.

The method for producing a double container of the present invention includes an outer preform having a tubular outer mouth portion and an extending portion connected to the outer opening portion, and a tubular inner opening portion and an extending portion connected to the inner opening portion. The inner preform is formed with the outer preform and the inner preform is provided with outward ridges extending in the vertical direction, and the inner preform is incorporated inside the outer preform to form the outer mouth portion and the inner side of the outer mouth portion. A preform forming step of forming a preform assembly having an outside air inlet that communicates between the outer preform and the inner preform by the mouth portion composed of the inner mouth portion arranged in the above. By blow-molding the preform assembly with a ridge or recess extending in the vertical direction by a mold provided on the cavity forming surface, the preform assembly is connected to the outer opening portion and the outer opening portion, and is more than the outer opening portion. An outer layer body having an enlarged bottomed tubular body portion, and a volume-reducing and deformable accommodating portion connected to the inner mouth portion and the inner mouth portion and laminated on the inner surface of the body portion so as to be peelable. The outer layer body is provided, the outside air introduction port communicates between the outer layer body and the inner layer body, and the body portion is the lower end of the outer port portion and the outer surface side closest to the lower end in the vertical cross section. It has a shoulder region extending from the apex of the curved portion protruding into the shoulder region, the circumferential extension ratio of the shoulder region is 1.70 or less, and the body portion is formed on the convex or concave portion of the cavity forming surface. It is characterized by having a corresponding rib and having a blow forming step of forming a double container in which the outward ridge extends in the vertical direction through a portion having a height corresponding to the upper end of the rib.

In the above configuration, the method for producing a double container of the present invention forms the double container in which the outward ridges are terminated at a height corresponding to the upper part of the shoulder region in the blow molding step. Is preferable.

According to the present invention, an airway from an outside air introduction port provided in the mouth portion, passing between the shoulder region of the body portion having a low circumferential extension ratio and the accommodating portion, and reaching between the body body region of the body portion and the accommodating portion. It is possible to provide a double container and a method for manufacturing a double container that can surely secure the above.

It is a half sectional view of the double container which is one Embodiment of this invention. It is a semi-cross-sectional view which shows the main part of the double container shown in FIG. It is a half cross-sectional view of the preform assembly blow-molded into the double container shown in FIG. FIG. 3 is a cross-sectional view showing a state in which the preform assembly shown in FIG. 3 is arranged in a mold for blow molding. FIG. 5 is a cross-sectional view showing a state in which the preform assembly is formed into a double container by biaxial stretching blow molding from the state shown in FIG.

Hereinafter, an embodiment of the present invention will be illustrated and described with reference to the drawings.

The double container 1 according to the embodiment of the present invention shown in FIG. 1 is made of synthetic resin, which is also called a laminated peeling container or a delamination container (derami container), and has an outer layer body 10 and an inner layer body 20. It has a double structure. The double container 1 can be formed by biaxially stretching blow molding the preform assembly 40 shown in FIG. Hereinafter, a case where the double container 1 is used as a squeeze-type pouring container for containing a liquid such as a cosmetic or a food seasoning as a content will be described.

As shown in FIG. 1, the outer layer body 10 is a portion constituting the outer shell of the double container 1, and has a bottle shape including an outer mouth portion 11 and a body portion 12.

As shown in FIG. 2, the outer opening portion 11 has a cylindrical shape centered on the central axis O. A male screw 11a is integrally provided on the outer peripheral surface of the outer mouth portion 11, so that a pouring cap (not shown) having a spout can be screwed to the male screw 11a and attached to the outer mouth portion 11. It has become.

The vertical direction means a direction along the central axis O, the upper direction means a direction from the body portion 12 to the outer mouth portion 11, and the lower direction means the opposite direction. The radial direction means a direction orthogonal to the central axis O, and the circumferential direction means a direction orbiting the central axis O. The vertical cross section means a cross section including the central axis O, and the cross section means a cross section perpendicular to the central axis O.

The outer opening portion 11 may be provided with an annular protrusion instead of the male screw 11a, and may be attached by engaging the injection cap in an undercut shape with a stopper.

The outer port portion 11 is provided with a pair of outside air introduction ports 13. The pair of outside air introduction ports 13 are arranged symmetrically on both sides of the outer port portion 11 with the axial center of the outer port portion 11 in between, and are formed in an elongated hole shape extending in the circumferential direction and penetrate the outer port portion 11 in the radial direction. .. That is, each outside air introduction port 13 is composed of a through hole penetrating the outside port portion 11. Each outside air introduction port 13 communicates between the outer layer body 10 and the inner layer body 20, and outside air can be introduced between the outer layer body 10 and the inner layer body 20 through the outside air introduction port 13. The outside air introduction port 13 is not limited to the elongated hole shape, and can be appropriately designed to have a perfect circular shape or the like.

A seal ring 11b is integrally provided on the outer peripheral surface of the outer port portion 11 below the pair of outside air introduction ports 13. The seal ring 11b has a flange shape extending over the entire circumference of the outer opening portion 11, and projects outward from the outer peripheral surface of the outer opening portion 11 in the radial direction. The seal ring 11b can form an annular seal portion with the ejection cap attached to the outer port portion 11.

A neck ring 11c is integrally provided on the outer peripheral surface of the outer opening portion 11 below the seal ring 11b. The neck ring 11c has a flange shape extending over the entire circumference of the outer opening portion 11, and projects outward from the outer peripheral surface of the outer opening portion 11 in the radial direction. The neck ring 11c is provided slightly above the lower end of the outer opening portion 11. That is, in the present embodiment, a cylindrical non-stretched portion that is not substantially stretched during biaxial stretching blow molding is provided directly below the neck ring 11c, and the lower end of the outer opening portion 11 is provided at this non-stretched portion. It constitutes 11d. By providing the non-stretched portion directly under the neck ring 11c in this way, the neck ring 11c can be prevented from being affected by stretching. The lower end 11d of the outer opening portion 11 may be formed by the neck ring 11c without providing such a non-stretched portion.

As shown in FIG. 1, the body portion 12 is formed in a bottomed tubular shape that is connected to the outer opening portion 11 and has a diameter larger than that of the outer opening portion 11. The cross-sectional shape of the body portion 12 may be circular, oval or substantially rectangular.

The body portion 12 has a shoulder region 12a connected to the outer mouth portion 11 and a body body region 12b connected to the shoulder region 12a.

The shoulder region 12a is a region extending between the lower end 11d of the outer opening portion 11 and the apex 14a of the curved portion 14 projecting toward the outer surface closest to the lower end 11d in the vertical cross section. In other words, the shoulder region 12a is a region extending from the lower end 11d of the outer opening portion 11 to the apex 14a of the curved portion 14. The apex 14a of the curved portion 14 means a point where the curvature is maximum at the curved portion 14, or a point at the center of an arc portion where the curvature is maximum at the curved portion 14.

The circumferential stretch ratio (HSR: Hop Stretch Ratio) of the shoulder region 12a is set to 1.70 or less. That is, the circumferential extension ratio at the apex 14a of the curved portion 14 which is the lower end of the shoulder region 12a is set to 1.70 or less. In the present embodiment, the circumferential extension ratio at the lower end of the shoulder region 12a is 1.68. In the present application, the circumferential extension ratio at the lower end of the shoulder region 12a means a value obtained by dividing the peripheral length of the outer surface of the lower end of the shoulder region 12a by the peripheral length of the outer surface of the lower end 11d of the outer opening portion 11. When each rib 15 described later is provided so as to pass through the lower end of the shoulder region 12a as shown, the circumferential extension ratio at the lower end of the shoulder region 12a is the ratio of the rib 15 on the outer surface of the lower end of the shoulder region 12a. It is a value obtained by dividing the peripheral length along the shape by the peripheral length of the outer surface of the lower end 11d of the outer opening portion 11.

The body body region 12b is a region located below the apex 14a of the curved portion 14 in the vertical cross section. The body region 12b has flexibility and can be elastically deformed and dented by being squeezed (squeezed), and can be restored to its original shape from the dented state by elastic force. .. By making the body body region 12b elastically deformable by squeeze, it is possible to easily perform the content liquid pouring operation when the double container 1 is used as a squeeze type pouring container. At the same time, the outer layer body 10 is easily restored to its original shape after the content liquid is poured so that the outside air is surely introduced through the pair of outside air introduction ports 13 between the outer layer body 10 and the inner layer body 20. The function as the double container 1 can be surely exhibited. The lower end of the body body region 12b has a concave shape inside the outer peripheral edge of the annulus, and the double container 1 can be arranged in an upright posture by grounding the outer peripheral edge.

The upper part of the body area 12b is suppressed to the same diameter as the lower end of the shoulder area 12a, and the diameter gradually expands from the lower end of the upper part of the body area 12b to the central part in the vertical direction of the body area 12b. The diameter of the lower half of the main body region 12b is substantially constant, but the shape of the body region 12b is not limited to this.

In the present embodiment, the outer layer body 10 is made of polyethylene terephthalate (PET). By making the outer layer body 10 made of polyethylene terephthalate, the double container 1 can be made a lightweight and highly transparent container.

The material of the outer layer body 10 is not limited to polyethylene terephthalate, for example, polyester resin, polyolefin resin, nylon resin, polycarbonate resin (PC resin), cycloolefin copolymer resin (COC resin), cycloolefin polymer resin (COP resin). Other synthetic resin materials such as these can also be used.

The inner layer body 20 has an inner opening portion 21 and an accommodating portion 22 integrally connected to the lower end of the inner opening portion 21.

As shown in FIG. 2, the inner opening portion 21 has a stepped cylindrical shape, and is arranged coaxially with the outer opening portion 11 inside the outer opening portion 11. The inner opening portion 21 has an annular flange 21a placed on the upper end of the outer opening portion 11, a cylindrical upper cylinder 21b that hangs down from the inner peripheral edge of the flange 21a and is in contact with the inner surface of the outer opening portion 11, and an upper cylinder 21b. It has a conical inclined cylinder 21c whose diameter is reduced downward from the lower end of the cylinder 21b, and a cylindrical lower cylinder 21d hanging from the lower end of the inclined cylinder 21c. The upper end of the inclined cylinder 21c is located above the upper ends of the pair of outside air introduction ports 13. A gap 30 at a predetermined interval is provided between the inner peripheral surface of the outer opening portion 11 and the outer peripheral surface of the lower cylinder 21d.

The outer peripheral surface of the upper cylinder 21b abuts on the inner peripheral surface of the outer mouth portion 11 over the entire circumference, so that the gap 30 between the outer mouth portion 11 and the lower cylinder 21d is formed by the outer mouth portion 11 or the inner mouth portion. The upper end portion of 21 is closed to the outside. When the flange 21a comes into contact with the upper end of the outer opening portion 11, the inner opening portion 21 is positioned in the vertical direction with respect to the outer opening portion 11.

The mouth portion 31 of the double container 1 is formed by the outer mouth portion 11 and the inner mouth portion 21 arranged inside the outer mouth portion 11, and the outside air introduction port 13 provided in the mouth portion 31 is the outer layer body 10. It communicates with the inner layer 20.

As shown in FIGS. 1 to 2, the accommodating portion 22 is connected to the lower end 21e of the lower cylinder 21d of the inner opening portion 21, that is, the lower end 21e of the inner opening portion 21, and is detachably laminated on the inner surface of the body portion 12. There is. The lower end 21e of the inner opening portion 21 means a portion having a height corresponding to the lower end 11d of the outer opening portion 11. In addition, the "peeling" in the present application is not only when the outer layer body 10 and the inner layer body 20 are separated from the adhesive state or the pseudo-adhesive state where the adhesive force hardly intervenes, but also when the outer layer body 10 and the outer layer body 10 are separated from the adhesive state where the adhesive force does not intervene. It also includes the case where the inner layer 20 is separated from the inner layer 20.

The portion of the accommodating portion 22 except for the vicinity of the upper end is formed to be thinner than the body portion 12, and extends along the inner surface of the body portion 12b of the body portion 12. The inside of the accommodating portion 22 is a storage space for the content liquid, and the content liquid can be filled in the accommodating portion 22 through the inner mouth portion 21 and the content liquid stored in the accommodating portion 22 through the inner mouth portion 21. Can be dispensed to the outside. The accommodating portion 22 can be deformed (deformed so as to reduce the internal volume) while being peeled from the inner surface of the body portion 12 as the content liquid is poured out. At this time, by introducing outside air between the outer layer body 10 and the inner layer body 20 from the pair of outside air introduction ports 13, only the body portion 12 is restored to the original shape, and the accommodating portion 22 is the inner surface of the body portion 12. It can be peeled off from the body and deformed to reduce its volume.

In the present embodiment, the inner layer 20 is made of polyethylene terephthalate. By making the inner layer 20 made of polyethylene terephthalate, the double container 1 can be made a lightweight and highly transparent container.

The material of the inner layer 20 is not limited to polyethylene terephthalate, and for example, polyester resin, polyolefin resin, nylon resin, polycarbonate resin (PC resin), cycloolefin copolymer resin (COC resin), cycloolefin polymer resin (COP resin). , Other synthetic resin materials such as ethylene-vinyl alcohol copolymer resin (EVOH resin) can also be adopted. When an ethylene-vinyl alcohol copolymer resin is used as the material of the inner layer body 20, an ethylene-vinyl alcohol copolymer resin having an appropriate ethylene content can be adopted in consideration of barrier properties and flexibility. Further, the inner layer body 20 may have a multi-layer structure in which a barrier layer such as an MX nylon resin layer is provided between a pair of polyethylene terephthalate layers, for example, in order to secure the barrier property.

A plurality of outward ridges 23 extending in the vertical direction are provided on the outer surface of the inner layer 20 in order to facilitate securing an airway for the outside air directed from the pair of outside air introduction ports 13 to the body portion 12 and the accommodating portion 22. It is provided integrally.

In the present embodiment, eight plate-shaped outward ridges 23 are provided side by side on the outer surface of the lower cylinder 21d at equal intervals in the circumferential direction. The number of outward ridges 23 is not limited to eight and can be changed as appropriate. Further, the eight outward ridges 23 have the same shape and size as each other, but the present invention is not limited to this.

Each outward ridge 23 projects in the radial direction from the outer surface of the inner layer body 20 and extends in the vertical direction from the inner opening portion 21 across the accommodating portion 22. That is, each outward ridge 23 extends in the vertical direction through a portion having a height corresponding to the lower end 11d of the outer opening portion 11. Further, each outward ridge 23 is provided below the pair of outside air introduction ports 13, but is not limited to this, and may extend to the height of the pair of outside air introduction ports 13 or a pair. It may extend above the outside air introduction port 13. Each outward ridge 23 terminates at a height portion corresponding to the upper part of the shoulder region 12a. The height of protrusion of the inner layer body 20 of each outward ridge 23 from the outer surface gradually decreases downward at the lower part of the outward ridge 23, but is not limited to this. Further, each outward ridge 23 extends continuously along the vertical direction, but the present invention is not limited to this, and for example, it may extend in a direction inclined with respect to the vertical direction, or intermittently in the vertical direction. And may be extended. The outward ridges 23 project from the outer surface of the inner layer 20 along the radial direction, but the present invention is not limited to this, and each outward ridge 23 may project in a direction inclined with respect to the radial direction.

By providing the plurality of outward ridges 23, the gap 30 between the outer opening portion 11 and the lower cylinder 21d can be surely secured. The number of outward ridges 23 is not limited to a plurality.

As shown in FIG. 2, in order to facilitate securing an air passage for outside air directed from the pair of outside air introduction ports 13 to the body body region 12b of the body portion 12 and the accommodating portion 22, the body portion 12 of the outer layer body 10 is easily secured. Is provided with a plurality of ribs 15 extending in the vertical direction.

In the present embodiment, 18 ribs 15 are provided side by side in the shoulder region 12a of the outer layer body 10 at equal intervals in the circumferential direction. The number of ribs 15 is not limited to this, and can be changed as appropriate. Further, the 18 ribs 15 have the same shape and size as each other, but the ribs 15 are not limited to this. Each rib 15 extends from the upper end of the shoulder region 12a through the apex 14a of the curved portion 14 which is the lower end of the shoulder region 12a to the upper part of the body body region 12b. Each rib 15 extends continuously along the radial direction in the top view, but is not limited to this. For example, each rib 15 may extend in a direction inclined with respect to the radial direction in the top view, or may extend in a direction inclined with respect to the radial direction in the top view. It may extend intermittently in the radial direction.

Each rib 15 is a concave rib formed by bending the body portion 12 so as to locally project inside the container so as to form a concave shape when viewed from the outside of the container. Each rib 15 may be a convex rib formed by bending the body portion 12 so as to locally project to the outside of the container so as to form a convex shape when viewed from the outside of the container. The rib 15 means a portion formed by bending the body portion 12 so as to locally project inside or outside the container. Each rib 15 has a U-shaped cross-sectional shape in which the width gradually narrows inward in the radial direction in the cross section over substantially the entire length. The cross-sectional shape of the rib 15 is not limited to this, and can be changed as appropriate. The inner layer 20 is also stretched by biaxial stretching blow molding so as to follow the shape of the rib 15.

By providing the plurality of ribs 15, it is possible to prevent the accommodating portion 22 from being detached from the inner surface of the outer layer body 10 and then reattaching to the inner surface of the outer layer body 10 at each of the rib 15 portions in the body portion 12. The airway in the body 12 can be secured more reliably. The number of ribs 15 is not limited to a plurality.

The double container 1 having such a configuration can be configured as a squeeze container by attaching a pouring cap to the outer port portion 11. In this case, the injection caps include, for example, a check valve for outside air that allows the introduction of outside air into the pair of outside air introduction ports 13 and prevents the outflow of outside air from the pair of outside air introduction ports 13 to the outside. A structure provided with a check valve for the content liquid, which allows the pouring of the content liquid and prevents the backflow of the outside air into the inside of the accommodating portion 22, can be used.

In the double container 1 configured as a squeeze container, when the body portion 12 of the outer layer body 10 is squeezed (squeezed), the capacity of the accommodating portion 22 is reduced and deformed, and the content liquid is pushed out from the pouring cap and poured to the outside. Is issued. When the squeeze is released after the content liquid is poured out, the body portion 12 is restored to its original shape, and the accommodating portion 22 of the inner layer body 20 is peeled off from the inner surface of the outer layer body 10 and a pair of outside air inlets 13 are separated. The outside air is introduced between the outer layer body 10 and the inner layer body 20, and only the body portion 12 is restored to its original shape while the accommodating portion 22 is reduced in volume and deformed. As a result, the content liquid contained in the accommodating portion 22 can be poured out without being replaced with the outside air, so that the contact of the outside air with the content liquid contained in the accommodating portion 22 can be reduced to prevent deterioration and deterioration thereof. It can be suppressed.

Here, since the double container 1 of the present embodiment has a special shape in which the shoulder region 12a has a low circumferential stretching ratio of 1.70 or less, the shoulder region 12a from the pair of outside air introduction ports 13 It is more difficult than usual to secure an airway that passes between the and the accommodating portion 22 and reaches between the body body region 12b and the accommodating portion 22.

However, in the double container 1 of the present embodiment, as described above, the upper end of each rib 15 is located at the upper end of the shoulder region 12a, and the lower end of each outward ridge 23 is the upper portion of the shoulder region 12a. It is located at the height corresponding to. That is, in the double container 1 of the present embodiment, each outward ridge 23 extends in the vertical direction through a portion having a height corresponding to the upper ends of the plurality of ribs 15. Therefore, the gap 30 between the outer opening portion 11 and the lower cylinder 21d secured by the plurality of outward ridges 23 is suppressed from re-adhesion after the outer layer body 10 and the inner layer body 20 are separated to secure the airway. Since it can be connected to the upper ends of the plurality of ribs 15, the portion between the pair of outside air introduction ports 13 to the outer port 11 and the inner port 21 when the squeeze body 12 is restored to its original shape. The outside air introduced into the body can be reliably guided to the portion between the body body region 12b and the accommodating portion 22.

As long as each outward ridge 23 extends in the vertical direction through a portion having a height corresponding to the upper ends of the plurality of ribs 15, the upper end of each rib 15 extends to the upper end of the shoulder region 12a. The lower end of each outward ridge 23 is not limited to a portion having a height corresponding to the upper part of the shoulder region 12a. For example, the upper end of each rib 15 may be located below the upper end of the shoulder region 12a, and the lower end of each outward ridge 23 may be below the portion of height corresponding to the upper portion of the shoulder region 12a. May be located at. However, from the viewpoint of moldability of the inner layer 20 at the time of blow molding, it is preferable that the lower end of each outward ridge 23 is located at a height corresponding to the upper part of the shoulder region 12a, and therefore each of them. The upper end of the rib 15 is preferably located above the shoulder region 12a. Further, it is preferable that each rib 15 extends from the upper part of the shoulder region 12a to at least the upper part of the body body region 12b.

As shown in FIG. 3, the preform assembly 40 is a synthetic resin inner preform 60 for forming the inner layer 20 inside the synthetic resin outer preform 50 for forming the outer layer 10. It has a double structure that incorporates.

The outer preform 50 is formed into a predetermined shape corresponding to the outer layer body 10 by injection molding the same synthetic resin material as the outer layer body 10 using a mold. In the present embodiment, the outer preform 50 is made of polyethylene terephthalate like the outer layer 10.

The outer preform 50 has an outer mouth portion 51 having the same shape as the outer mouth portion 11 of the outer layer body 10. That is, the outer mouth portion 51 is formed in a cylindrical shape, and male threads 51a are integrally provided on the outer peripheral surface thereof, and each is formed in an elongated hole shape extending in the circumferential direction to penetrate the outer mouth portion 51 in the radial direction. The outside air introduction port 52 is provided symmetrically on both sides of the outer port portion 51 with the axis of the outer port portion 51 in between. Further, at the lower end of the outer opening portion 51, a substantially test tubular extending portion 53 having a hemispherical bottom portion is integrally provided. The thickness of the stretched portion 53 is thicker than that of the outer opening portion 51. A seal ring 51b and a neck ring 51c are integrally provided on the outer opening portion 51.

The inner preform 60 is formed into a predetermined shape corresponding to the inner layer 20 by injection molding the same synthetic resin material as the inner layer 20 using a mold. In the present embodiment, the inner preform 60 is made of polyethylene terephthalate like the inner layer 20.

The inner preform 60 has an inner mouth portion 61 having the same shape as the inner mouth portion 21 of the inner layer body 20. That is, the inner opening portion 61 has a stepped cylindrical shape, and is arranged coaxially with the outer opening portion 51 inside the outer opening portion 51. The inner opening 61 includes an annular flange 61a placed on the upper end of the outer opening 51, a cylindrical upper cylinder 61b that hangs down from the inner peripheral edge of the flange 61a and is in contact with the inner surface of the outer opening 51, and an upper cylinder 61b. It has a conical inclined cylinder 61c whose diameter is reduced downward from the lower end of the cylinder 61b, and a cylindrical lower cylinder 61d hanging from the lower end of the inclined cylinder 61c. When the outer peripheral surface of the upper cylinder 61b comes into contact with the inner peripheral surface of the outer mouth portion 51 over the entire circumference, the upper end portion of the gap 70 between the outer mouth portion 51 and the lower cylinder 61d is closed to the outside. ing. When the flange 61a comes into contact with the upper end of the outer opening portion 51, the inner opening portion 61 is positioned in the vertical direction with respect to the outer opening portion 51. At the lower end of the inner opening portion 61, a substantially test tubular extending portion 62 having a hemispherical bottom portion is integrally provided. The outer diameter of the stretched portion 62 is smaller than the outer diameter of the inner opening portion 61. A gap is provided between the outer peripheral surface of the stretched portion 62 and the inner peripheral surface of the stretched portion 53, and when the inner preform 60 is incorporated into the outer preform 50, the outer peripheral surface of the stretched portion 62 and the stretched portion 53 are provided. It is designed so that it will not be scratched on the inner peripheral surface of the.

On the outer surface of the inner preform 60, a plurality of outward ridges 63 corresponding to the plurality of outward ridges 23 are provided. That is, on the outer surface of the lower cylinder 21d of the inner preform 60, eight plate-shaped outward ridges 63 are provided side by side at equal intervals in the circumferential direction. Each outward ridge 63 projects radially from the outer surface of the inner preform 60 and extends continuously along the vertical direction from the inner opening 61 across the extending portion 62. That is, each outward ridge 63 extends in the vertical direction through the lower end 61e of the inner opening 61, which is a portion having a height corresponding to the lower end 51d of the outer opening 51. Further, each outward ridge 63 is provided below the pair of outside air introduction ports 52. The height of protrusion of the inner preform 60 of each outward ridge 63 from the outer surface gradually decreases downward at the lower part of the outward ridge 63.

The mouth portion 71 of the preform assembly 40 is composed of the outer mouth portion 51 and the inner mouth portion 61 arranged inside the outer mouth portion 51, and the outside air introduction port 52 provided in the mouth portion 71 is an outer preform. It communicates between 50 and the inner preform 60.

The double container 1 shown in FIG. 1 can be manufactured, for example, by the following procedure (a method for manufacturing a double container according to an embodiment of the present invention).

The method for manufacturing a double container according to the present embodiment includes a preform forming step and a blow molding step. The method for manufacturing a double container according to the present embodiment can also be applied to the case of manufacturing a double container other than the double container 1 shown in FIG.

In the preform forming step, first, the outer preform 50 and the inner preform 60 are formed, respectively. As described above, the outer preform 50 includes a cylindrical outer mouth portion 51 and an extension portion 53 connected to the outer mouth portion 51, and a through hole for forming the outside air introduction port 52 is provided in the outer mouth portion 51. It is provided. Further, as described above, the inner preform 60 includes a cylindrical inner opening portion 61 and an extending portion 62 connected to the inner opening portion 61, and an outward ridge 63 extending in the vertical direction is provided on the outer surface. It is a thing. Then, the inner preform 60 is incorporated inside the outer preform 50, and the outside air introduction port 52 communicating between the outer preform 50 and the inner preform 60 is inside the outer port 51 and the outer port 51. The preform assembly 40 provided in the mouth portion 71 composed of the arranged inner mouth portion 61 is formed.

When the preform forming step is completed, the blow molding step is performed. In the blow molding step, first, as shown in FIG. 4, the preform assembly 40 heated to a stretchable temperature is placed in a mold 80 for blow molding, with a mouth portion 71 protruding from the cavity 80a and a neck ring. The preform assembly 40 is set so that the 51c is supported on the upper surface of the mold 80 and the stretched portions 53 and 62 are located inside the cavity 80a. Here, the cavity forming surface 80b of the mold 80 is provided with a plurality of ridges 81 extending in the vertical direction having a shape corresponding to the outer surface shape of the rib 15. Then, with the preform assembly 40 set in this way, a pressurized medium such as pressurized air or pressurized liquid is supplied to the inside of the preform assembly 40 from a supply device (not shown). As a result, as shown in FIG. 5, the stretched portions 53 and 62 of the preform assembly 40 can be biaxially stretched and blow molded into a shape along the inner surface of the cavity forming surface 80b to form the double container 1. it can.

In the present embodiment, since the mold 80 having the above-mentioned protrusions 81 is used for the biaxial stretching blow molding, the double container 1 having a plurality of ribs 15 can be formed. When the rib 15 is provided in a convex rib shape instead of a concave rib shape, the cavity forming surface 80b of the mold 80 may be provided with a concave groove having a shape corresponding to the outer surface shape of the rib 15 instead of the convex rib 81. Good.

It goes without saying that the present invention is not limited to the above-described embodiment and can be variously modified without departing from the gist thereof.

In the above embodiment, the outer port portion 11 is provided with a pair of outside air introduction ports 13, but at least one outside air introduction port 13 may be provided.

In the above embodiment, the outside air introduction port 13 is provided in the outer port portion 11 and is a through hole that penetrates the outer port portion 11, but the present invention is not limited to this, and for example, the upper end and the inner side of the outer port portion 11 are limited. It can also be configured as a gap provided between the upper end of the mouth portion 21 and the gap 30 to be opened to the outside.

The outer opening portion 11 and the inner opening portion 21 may have a tubular shape other than a cylindrical shape. Further, the outer port portion 11 may be configured not to include the seal ring 11b or the neck ring 11c, or may be configured not to include the seal ring 11b or the neck ring 11c.

The shape of the body portion 12 can also be variously changed as long as the circumferential extension ratio of the shoulder region 12a is 1.70 or less.

In the above-described embodiment, the double container 1 is a squeeze-type pouring container in which a pouring cap having a spout is attached to the outer port 11 and the body 12 is squeezed to pour out the content liquid. However, it is assumed that the body portion 12 has a predetermined rigidity that does not easily squeeze and deform, and the pump-type dispenser is used for a container with a pump attached to the outer port portion 11. You can also do it.

1 Double container 10 Outer layer 11 Outer opening 11a Male screw 11b Seal ring 11c Neck ring 11d Lower end of outer opening 12 Body 12a Shoulder area 12b Body area 13 Outside air introduction port 14 Curved part 14a Curved part apex 15 Rib 20 Inner layer 21 Inner mouth 21a Flange 21b Upper cylinder 21c Inclined cylinder 21d Lower cylinder 21e Lower end of inner mouth 22 Storage 23 Outer ridge 30 Gap 31 Mouth 40 Preform assembly 50 Outer preform 51 Outer mouth 51a Male screw 51b Seal ring 51c Neck ring 51d Lower end of outer mouth 52 Outside air introduction port 53 Extension 60 Inner preform 61 Inner mouth 61a Flange 61b Upper cylinder 61c Inclined cylinder 61d Lower cylinder 61e Lower end of inner mouth 62 Extension 63 Outer Direction Convex 70 Gap 71 Mouth 80 Mold 80a Cavity 80b Cavity forming surface 81 Convex O Central axis

Claims (4)

An outer layer body having a tubular outer mouth portion and a bottomed tubular body portion connected to the outer mouth portion and having a diameter larger than that of the outer mouth portion.
It has an inner layer body including a tubular inner mouth portion and a volume-reducing and deformable accommodating portion that is connected to the inner mouth portion and is detachably laminated on the inner surface of the body portion.
The mouth portion composed of the outer mouth portion and the inner mouth portion arranged inside the outer mouth portion has an outside air introduction port communicating between the outer layer body and the inner layer body.
The body portion has a shoulder region extending between the lower end of the outer mouth portion and the apex of the curved portion protruding toward the outer surface closest to the lower end in the vertical cross section, and the circumferential extension ratio of the shoulder region is high. 1.70 or less,
The body has ribs that extend in the vertical direction.
A double container characterized in that the inner layer has outward ridges extending in the vertical direction through a portion of a height corresponding to the upper end of the rib. The double container according to claim 1, wherein the outward ridges are terminated at a height portion corresponding to the upper part of the shoulder region. An outer preform having a tubular outer mouth portion and an extending portion connected to the outer opening portion, and an outward convex strip having a tubular inner opening portion and an extending portion connected to the inner opening portion and extending in the vertical direction. Each of the inner preforms provided with the above is formed, and the inner preform is incorporated inside the outer preform, and is composed of the outer mouth portion and the inner mouth portion arranged inside the outer mouth portion. A preform forming step of forming a preform assembly having an outside air inlet that communicates between the outer preform and the inner preform.
By blow-molding the preform assembly with ridges or recesses extending in the vertical direction by a mold provided on the cavity forming surface, the preform assembly is connected to the outer opening portion and the outer opening portion, and is more than the outer opening portion. An outer layer body having an enlarged bottomed tubular body portion, and a volume-reducing and deformable accommodating portion connected to the inner mouth portion and the inner mouth portion and laminated on the inner surface of the body portion so as to be peelable. The outer layer body is provided, the outside air introduction port communicates between the outer layer body and the inner layer body, and the body portion is the lower end of the outer port portion and the outer surface side closest to the lower end in the vertical cross section. It has a shoulder region extending between the apex and the apex of the curved portion protruding from the shoulder region, the circumferential extension ratio of the shoulder region is 1.70 or less, and the body portion is formed on the convex or concave portion of the cavity forming surface. A double container having a corresponding rib and having a blow molding step of forming a double container in which the outward ridge extends in the vertical direction through a portion having a height corresponding to the upper end of the rib. Manufacturing method. The method for manufacturing a double container according to claim 3, wherein in the blow molding step, the double container is formed in which the outward ridges are terminated at a portion having a height corresponding to the upper part of the shoulder region.

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