CN111225856B

CN111225856B - Double-layer container

Info

Publication number: CN111225856B
Application number: CN201880067778.0A
Authority: CN
Inventors: 铃木正人; 千叶润一; 佐佐木正昭
Original assignee: Yoshino Kogyosho Co Ltd
Current assignee: Yoshino Kogyosho Co Ltd
Priority date: 2017-10-31
Filing date: 2018-08-10
Publication date: 2022-02-25
Anticipated expiration: 2038-08-10
Also published as: CN111225856A; WO2019087515A1

Abstract

The present invention provides a double container, which is a blow molding inner preform (60) combined with the preform assembly (40) inside the outer preform (50) and is formed into a double structure of an outer layer body (10) having an outer mouth part (11) and a main body part (13) connected with the outer mouth part (11) through a shoulder part (12), and an inner layer body (20) having an inner mouth part (21) arranged inside the outer mouth part (11) and a containing part (22) which is arranged on the inner surface of the main body part (13) and can be stripped and freely deformed with reduced volume, wherein the double container (1) is provided with an external gas inlet (14) for introducing external gas and a plurality of longitudinal ribs (30) which are arranged on the inner surface of the outer layer body (10) or the outer surface of the inner layer body (20) in parallel at intervals along the circumferential direction and respectively extend from the outer mouth part (11) to the shoulder part (12) or from the inner mouth part (21) to the containing part (22), at least one longitudinal rib (30) is opposed to the external air introduction port (14).

Description

Double-layer container

Technical Field

The present invention relates to a synthetic resin double container having a double-layer structure of an outer layer body and an inner layer body.

Background

As a container for containing food seasonings such as soy sauce, beverages, cosmetics such as toilet water, and washing products such as shampoo and/or hair conditioner, and hand sanitizer as a content liquid, there is known a container formed by blow molding a preform assembly in which an inner preform formed by injection molding is assembled inside an outer preform formed by injection molding, the preform assembly being formed into a synthetic resin double-layer container having a double-layer structure of an outer layer body and an inner layer body (for example, see patent document 1), the outer layer body having a cylindrical outer mouth portion and a bottomed cylindrical body portion connected to the outer mouth portion via a shoulder portion, the inner layer body having a cylindrical inner mouth portion disposed inside the outer mouth portion and a receiving portion which is detachably laminated on an inner surface of the body portion and is deformable to a reduced volume.

The double container is used as, for example, a squeeze-type discharge container combined with a discharge cap having a check valve, or a container with a pump combined with a pump. In this case, the content liquid can be discharged to the outside by pressing (compressing) the main body of the outer layer body or operating the pump, and after the content liquid is discharged, the external air can be introduced between the inner layer body and the outer layer body from the external air inlet provided in the outer layer body, whereby only the outer layer body can be restored to the original shape in a state where the accommodation portion of the inner layer body is deformed to reduce the volume. Therefore, according to the double container, since the content liquid stored in the storage portion of the inner layer body can be discharged to the outside without replacing the content liquid with the outside air, contact between the content liquid stored in the inner portion of the inner layer body and the outside air can be reduced, and deterioration, or the like of the content liquid can be suppressed.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-178434

Disclosure of Invention

Technical problem

However, in a double container formed by blow molding a preform assembly in which an inner preform is assembled inside an outer preform, as in the conventional double container described above, if an external air inlet port for introducing external air between the inner layer and the outer layer is provided in the outer mouth portion of the outer layer, there are problems as follows: it is difficult to secure an air passage from the external air inlet toward the space between the shoulder portion and the receiving portion, and after the content liquid is discharged, the external air may not pass through the space between the shoulder portion and the receiving portion and be introduced between the main body portion and the receiving portion, and the receiving portion may be deformed so as not to reduce the volume.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a double container capable of reliably securing a gas passage from an external air inlet provided in an outer opening portion to a space between a main body and a housing portion.

Technical scheme

A double container according to the present invention is a double container made of a synthetic resin having a double structure of an outer layer body and an inner layer body by blow molding a preform assembly in which an inner preform formed by injection molding is combined with an inner preform formed by injection molding, the outer layer body including a cylindrical outer mouth portion and a bottomed cylindrical body portion connected to the outer mouth portion via a shoulder portion, the inner layer body including a cylindrical inner mouth portion disposed inside the outer mouth portion and a receiving portion which is detachably laminated on an inner surface of the body portion and is deformable to a reduced volume, the double container comprising: an external air inlet for introducing external air between the outer layer body and the inner layer body; and a plurality of longitudinal ribs that are provided in parallel at intervals in a circumferential direction on an inner surface of the outer layer body or an outer surface of the inner layer body, and that extend from the outer opening portion across the shoulder portion or from the inner opening portion across the receiving portion, respectively, wherein at least one of the longitudinal ribs faces the external air inlet.

In the double container according to the present invention, in addition to the above configuration, the external air inlet is preferably a through hole provided in the outer opening portion and penetrating the outer opening portion.

In the double container according to the present invention, in addition to the above configuration, it is preferable that the outside air introduction ports are provided on both sides of the axial center of the outer opening portion, the plurality of longitudinal ribs face the outside air introduction port on one side, and the plurality of longitudinal ribs face the outside air introduction port on the other side.

In the double container according to the present invention, in addition to the above-described configuration, it is preferable that the plurality of longitudinal ribs be arranged in parallel at equal intervals in the circumferential direction over the entire circumference of the inner surface of the outer layer body or the entire circumference of the outer surface of the inner layer body.

In the double container of the present invention, in addition to the above configuration, it is preferable that the outer layer member and the inner layer member are made of polyethylene terephthalate.

In the double container of the present invention, in addition to the above configuration, it is preferable that the longitudinal rib is provided on the outer surface of the inner body.

In the double container according to the present invention, in addition to the above-described configuration, the longitudinal rib is preferably provided on an inner surface of the outer layer body.

In the double container according to the present invention, preferably, in addition to the above-described configuration, the body portion is elastically deformable by being pressed.

In the double container according to the present invention, in addition to the above configuration, a neck ring is preferably provided on an outer peripheral surface of the outer mouth portion on the shoulder side of the external air introduction port.

In the double container according to the present invention, in addition to the above configuration, it is preferable that at least the longitudinal ribs other than the pair of longitudinal ribs located at both ends in the circumferential direction among the plurality of longitudinal ribs provided corresponding to the external air introduction port include notch portions that notch the longitudinal ribs, respectively.

Technical effects

According to the present invention, it is possible to provide a double container capable of reliably securing a gas passage from an external air inlet provided in an outer opening portion to a space between a main body portion and a housing portion.

Drawings

Fig. 1 is a half sectional view of a double container as one embodiment of the present invention.

Fig. 2 is a sectional view taken along line a-a in fig. 1.

Fig. 3 is an enlarged sectional view showing the outer mouth portion and the inner mouth portion in an enlarged manner.

Fig. 4 is a sectional view showing a state where the preform assembly is disposed in a mold for blow molding.

Fig. 5 is a sectional view showing a state where the preform assembly is molded into a double container by biaxial stretch blow molding.

Fig. 6 (a) is a half sectional view showing a modification of the inner mouth portion shown in fig. 1, and fig. 6 (B) is a sectional view taken along line B-B of fig. 6 (a).

Fig. 7 is a half sectional view showing another modification of the inner mouth portion shown in fig. 1.

Fig. 8 (a) is a half sectional view showing main components of a modification of the double container shown in fig. 1, and fig. 8 (b) is a sectional view taken along line C-C of fig. 8 (a).

Fig. 9 (a) is a half sectional view showing a modification of the longitudinal rib shown in fig. 1, and fig. 9 (b) is a sectional view taken along line D-D of fig. 9 (a).

Description of the symbols

1 double-layer container

10 outer layer body

11 outer mouth part

11a external thread

11b neck ring

11c reduced diameter portion

12 shoulder part

13 main body part

13a bottom part

14 external air inlet

20 inner layer body

21 inner mouth part

22 housing part

23 gap

24 expanding part

25 flange part

30 longitudinal rib

30a cut part

31 ventilation path

40 preform assembly

50 outer preform

51 outer mouth part

51a external thread

51b neck ring

52 external air inlet

53 extension part

60 inner preform

61 inner opening part

62 diameter expanding part

63 flange part

64 extension part

65 longitudinal rib

70 mould

70a die cavity

Detailed Description

Hereinafter, the present invention will be described more specifically by way of examples with reference to the accompanying drawings.

A double container 1 shown in fig. 1, which is an embodiment of the present invention, is a synthetic resin container called a delamination container or a delamination container (a delamination container), and has a double-layer structure including an outer layer body 10 and an inner layer body 20. Hereinafter, a case where the double container 1 is used as a squeeze discharge container for containing a cosmetic as a content liquid will be described.

The outer layer body 10 is a part constituting a housing of the double container 1, and has a bottle shape including an outer mouth portion 11, a shoulder portion 12, and a body portion 13.

As shown in fig. 2, the outer mouth portion 11 is cylindrical. As shown in fig. 1, a male screw 11a is integrally provided on the outer peripheral surface of the outer mouth portion 11, and a discharge cap (not shown) having a discharge port can be attached to the outer mouth portion 11 by screwing the male screw 11 a.

The outer mouth portion 11 may be provided with an annular protrusion instead of the male screw 11a, and may be attached to the discharge cap by being engaged with the discharge cap in a snap-fit manner by a plug.

The outer port portion 11 is provided with a pair of outside air introduction ports 14. The pair of outside air introduction ports 14 are disposed symmetrically to each other on both sides of the axial center of the outer port portion 11, and each is formed in a long hole shape extending in the circumferential direction so as to penetrate through the outer port portion 11 in the radial direction. The external air inlet 14 communicates between the outer cover 10 and the inner cover 20, and external air can be introduced between the outer cover 10 and the inner cover 20 through the external air inlet 14.

A neck ring 11b is integrally provided on the outer peripheral surface of the outer mouth portion 11 on the shoulder portion 12 side of the external air introduction port 14. The neck ring 11b is formed in a flange shape extending over the entire circumference of the outer mouth portion 11, and projects radially outward from the outer circumferential surface of the outer mouth portion 11.

The shoulder portion 12 is integrally connected to the lower end of the outer mouth portion 11 and projects radially outward with respect to the outer mouth portion 11.

The body portion 13 is formed in a bottomed cylindrical shape, and is integrally connected to an outer peripheral end of the shoulder portion 12 at an upper end thereof. That is, the body 13 is connected to the outer mouth portion 11 via the shoulder 12. The cross-sectional shape of the body 13 may be circular, elliptical, or substantially rectangular.

The main body portion 13 is flexible, can be depressed by being pressed (compressed) to be elastically deformed, and can be restored to its original shape by itself from the depressed state by the elastic force. When the double container 1 is used as a squeeze discharge container by adopting a configuration in which the body portion 13 is elastically deformable by squeezing, the discharge operation of the content liquid can be easily performed, and the outer layer body 10 is easily restored to the original shape after the content liquid is discharged, so that the external air is reliably introduced between the outer layer body 10 and the inner layer body 20 through the external air introduction port 14, and the double container 1 can reliably function.

The bottom portion 13a at the lower end of the body portion 13 has a shape recessed inside the annular outer peripheral edge, and the double container 1 can be arranged in an upright posture by bringing the bottom portion 13a into contact with the ground.

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

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

The inner body 20 has an inner mouth portion 21 and a housing portion 22.

As shown in fig. 2, the inner port portion 21 is formed in a cylindrical shape having a smaller diameter than the outer port portion 11, and is disposed coaxially with the outer port portion 11 inside the outer port portion 11. A gap 23 having a predetermined interval is provided between the inner peripheral surface of the outer mouth portion 11 and the outer peripheral surface of the inner mouth portion 21.

As shown in fig. 3, the expanded diameter portion 24 is integrally provided at the upper end of the inner mouth portion 21, and the outer peripheral surface of the expanded diameter portion 24 is brought into contact with the inner peripheral surface of the outer mouth portion 11 over the entire periphery, whereby the gap 23 between the outer mouth portion 11 and the inner mouth portion 21 is closed to the outside at the outer mouth portion 11 and even at the upper end portion of the inner mouth portion 21. A flange portion 25 extending radially outward is integrally provided at the upper end of the enlarged diameter portion 24, and the inner port portion 21 is positioned in the axial direction with respect to the outer port portion 11 by bringing the flange portion 25 into contact with the upper end of the outer port portion 11.

As shown in fig. 1, the housing portion 22 is formed in a bag shape thinner than the main body portion 13, and the housing portion 22 is integrally connected to the lower end of the inner opening portion 21 and is detachably laminated on the inner surface of the main body portion 13. The inside of the containing section 22 becomes a containing space for the content liquid, and the content liquid can be filled through the inner opening 21 and the content liquid contained in the containing section 22 can be discharged to the outside through the inner opening 21. The containing portion 22 can be deformed to reduce its volume (deformed to reduce its internal volume) while being peeled off from the inner surface of the main body portion 13 in accordance with the discharge of the content liquid. At this time, by introducing the external air from the external air inlet port 14 into the space between the outer layer body 10 and the inner layer body 20, only the main body portion 13 is restored to the original shape, and the housing portion 22 can be easily peeled off from the inner surface of the main body portion 13, thereby reducing the volumetric deformation.

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

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

In order to secure a passage for the external air from the external air inlet 14 to the space between the main body 13 and the housing portion 22, a plurality of vertical ribs 30 are integrally provided on the outer surface of the inner body 20.

In the present embodiment, as shown in fig. 2, on the outer surface of the inner layer 20, five longitudinal ribs 30 are provided in parallel with equal intervals in the circumferential direction in a predetermined range in the circumferential direction around the one external air introduction port 14, and five longitudinal ribs 30 are provided in parallel with equal intervals in the circumferential direction in a predetermined range in the circumferential direction around the other external air introduction port 14. Of the five longitudinal ribs 30 provided in a predetermined range in the circumferential direction around the one external air introduction port 14, three longitudinal ribs 30 other than the two longitudinal ribs 30 at both ends face the one external air introduction port 14, respectively, and of the five longitudinal ribs 30 provided in a predetermined range in the circumferential direction around the other external air introduction port 14, three longitudinal ribs 30 other than the two longitudinal ribs 30 at both ends face the other external air introduction port 14, respectively. The longitudinal rib 30 in the middle in the circumferential direction among the five longitudinal ribs 30 is disposed so as to vertically straddle the external air introduction port 14 at the circumferential center position of the corresponding external air introduction port 14.

Each longitudinal rib 30 protrudes radially outward from the outer surface of the inner layer 20 and extends in the axial direction from the inner opening 21 across the receiving portion 22. That is, each longitudinal rib 30 extends from a position facing the external air introduction port 14 beyond the neck ring 11b and is bent radially outward to a position reaching the shoulder portion 12. At the shoulder portion 12, the height at which the longitudinal ribs 30 protrude from the outer surface of the inner layer body 20 gradually decreases. The radially outward projecting end of each longitudinal rib 30 is formed in a slightly circular shape, and faces the inner peripheral surface of the outer mouth portion 11 at a slight interval in the portion of the inner mouth portion 21, and abuts against the inner surface of the shoulder portion 12 in the portion of the receiving portion 22. The upper end side of each longitudinal rib 30 reaches the enlarged diameter portion 24 and is connected to the enlarged diameter portion 24.

By providing the plurality of longitudinal ribs 30 facing the external air introduction port 14, a ventilation path 31 is formed between the outer sheet 10 and the inner sheet 20 from the external air introduction port 14 beyond the neck ring 11b to a portion between the shoulder 12 and the receiving portion 22. In the present embodiment, since three vertical ribs 30 are opposed to each external air introduction port 14, two ventilation paths 31 between the three vertical ribs 30 are formed for each external air introduction port 14. Each ventilation path 31 extends from the external air inlet 14 to a portion between the shoulder 12 and the housing portion 22 beyond the bent portion between the outer mouth portion 11 and the shoulder 12 (the bent portion between the inner mouth portion 21 and the housing portion 22).

The double container 1 having such a structure can be configured as a squeeze container by attaching a discharge cap to the outer mouth portion 11. In this case, as the discharge cover, for example, a cover body having a structure including an external air check valve that allows the external air to be introduced into the external air introduction port 14 and prevents the external air from flowing out from the external air introduction port 14 to the outside, and a content liquid check valve that allows the content liquid to be discharged and prevents the external air from flowing back into the inside of the housing portion 22 can be used.

In the double container 1 configured as a squeeze container, when the main body 13 of the outer layer body 10 is squeezed, the containing portion 22 is deformed to reduce its volume, and the content liquid is pushed out from the discharge cap and discharged to the outside. When the squeezing is released after the content liquid is discharged, the main body 13 is restored to the 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 the external air is introduced between the outer layer body 10 and the inner layer body 20 from the external air inlet 14, and only the main body 13 is restored to the original shape while the accommodating portion 22 is deformed to reduce the volume. Accordingly, since the content liquid stored in the storage portion 22 can be discharged without replacing the content liquid with the outside air, contact between the content liquid stored in the storage portion 22 and the outside air can be reduced, and deterioration and/or deterioration thereof can be suppressed.

Here, in the double container 1 of the present embodiment, the plurality of longitudinal ribs 30 extending from the inner opening 21 across the receiving portions 22 are provided in parallel at intervals in the circumferential direction on the outer surface of the inner body 20, and thereby the ventilation path 31 extending from the external air introduction port 14 to the portion between the shoulder 12 and the receiving portion 22 beyond the bent portion between the outer opening 11 and the shoulder 12 (the bent portion between the inner opening 21 and the receiving portion 22) is provided between the outer body 10 and the inner body 20. Accordingly, when the pressed body portion 13 is restored to the original shape, the external air introduced from the external air introduction port 14 to the portion between the outer mouth portion 11 and the inner mouth portion 21 can be reliably guided to the portion between the shoulder portion 12 and the housing portion 22 through the ventilation path 31 beyond the bent portion between the outer mouth portion 11 and the shoulder portion 12. That is, in the configuration in which the shoulder portion 12 is provided between the outer mouth portion 11 and the body portion 13, the inner layer 20 may be less likely to peel off from the outer layer body 10 at the bent portion between the outer mouth portion 11 and the shoulder portion 12, and it may be difficult to secure the air passage from the external air inlet port 14 provided in the outer mouth portion 11 to the portion between the shoulder portion 12 and the housing portion 22, but in the double container 1 of the present embodiment, by providing the longitudinal ribs 30, even in the configuration in which the shoulder portion 12 is provided between the outer mouth portion 11 and the body portion 13, the air passage can be reliably secured from the external air inlet port 14 to the portion between the shoulder portion 12 and the housing portion 22. Therefore, by reliably peeling the housing portion 22 from the inner surface of the outer layer body 10 at the shoulder portion 12 and by performing the peeling, a gas passage for the external air can be reliably secured so as to reach between the main body portion 13 and the housing portion 22 from the external air introduction port 14. Further, when the pressed main body portion 13 is restored to the original shape, the external air can be reliably introduced between the main body portion 13 and the housing portion 22 from the external air inlet 14 provided in the outer port portion 11, and therefore the housing portion 22 can be reliably peeled off from the inner surface of the outer layer body 10 in accordance with the discharge of the content liquid, and the volume deformation can be reduced. Further, since the storage section 22 can be deformed to be reliably reduced in volume in accordance with the discharge of the content liquid, the introduction of the outside air into the storage section 22 can be reliably prevented.

In addition, in the present embodiment, since the external air inlets 14 are provided on both sides across the axial center of the outer port portion 11, and the plurality of vertical ribs 30 are provided corresponding to the respective external air inlets 14, the housing portion 22 is peeled from the main body portion 13 from both the left and right sides across the axial center, and the volume deformation of the housing portion 22 can be reduced while the housing portion 22 is peeled from the inner surface of the outer layer body 10 more reliably as the content liquid is discharged. On the other hand, in the case of adopting a structure in which only one outside air introduction port 14 is provided in the opening 11, the following problems occur: since the storage portion 22 is peeled off from the body portion 13 only from one side with the axis therebetween and only one side of the storage portion 22 is narrowed, the balance of the center of gravity of the double container 1 is deteriorated.

The double container 1 having the above-described structure can be formed by biaxially stretch blow molding a synthetic resin preform assembly 40 shown in fig. 4.

The preform assembly 40 has a two-layer structure in which the inner preform 60 made of synthetic resin for forming the inner layer body 20 is assembled to the inner side of the outer preform 50 made of synthetic resin for forming the outer layer body 10.

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, as in the outer layer body 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 port portion 51 is formed in a cylindrical shape, and the male screw 51a is integrally provided on the outer peripheral surface thereof, and the pair of outside air inlet ports 52, which are formed in a long hole shape extending in the circumferential direction and penetrate the outer port portion 51 in the radial direction, are provided symmetrically with each other on both sides across the axial center of the outer port portion 51. Further, a substantially tubular extension 53 having a hemispherical bottom is integrally provided at the lower end of the outer mouth portion 51. The thickness of the extension 53 is thicker than that of the outer mouth portion 51. A collar 51b having a flange shape is integrally provided between the outer mouth portion 51 and the extension portion 53.

The inner preform 60 is formed into a predetermined shape corresponding to the inner layer body 20 by injection molding the same synthetic resin material as the inner layer body 20 using a mold. In the present embodiment, the inner preform 60 is made of polyethylene terephthalate as in the case of the inner layer body 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 port portion 61 is formed in a cylindrical shape having a smaller diameter than the outer port portion 51, and is disposed coaxially with the outer port portion 51 inside the outer port portion 51. An enlarged diameter portion 62 is integrally provided at the upper end of the inner port portion 61, and the upper end portion of the gap between the outer port portion 51 and the inner port portion 61 is closed with respect to the outside by bringing the outer peripheral surface of the enlarged diameter portion 62 into contact with the inner peripheral surface of the outer port portion 51 over the entire circumference. A flange portion 63 extending radially outward is integrally provided at the upper end of the enlarged diameter portion 62, and the inner port portion 61 is positioned in the axial direction with respect to the outer port portion 51 by the flange portion 63 coming into contact with the upper end of the outer port portion 51. An extension 64 having a substantially tubular shape with a hemispherical bottom is integrally provided at the lower end of the inner mouth portion 61. The outer diameter of the extension 64 is smaller than the outer diameter of the inner mouth portion 61. A gap is provided between the outer peripheral surface of the extending portion 64 and the inner peripheral surface of the extending portion 53, so that the outer peripheral surface of the extending portion 64 and the inner peripheral surface of the extending portion 53 are not scratched when the inner preform 60 is assembled inside the outer preform 50.

The outer surface of the inner preform 60 is provided with a plurality of longitudinal ribs 65 corresponding to the plurality of longitudinal ribs 30. That is, five longitudinal ribs 65 are provided in parallel with equal intervals in the circumferential direction in a predetermined range in the circumferential direction around the one external air introduction port 52 on the outer surface of the inner preform 60, and five longitudinal ribs 65 are provided in parallel with equal intervals in the circumferential direction in a predetermined range in the circumferential direction around the other external air introduction port 52. Of the five longitudinal ribs 65 provided in a predetermined range in the circumferential direction around the one outside air introduction port 52, three longitudinal ribs 65 other than the two longitudinal ribs 65 at both ends face the one outside air introduction port 52, respectively, and of the five longitudinal ribs 65 provided in a predetermined range in the circumferential direction around the other outside air introduction port 52, three longitudinal ribs 65 other than the two longitudinal ribs 65 at both ends face the other outside air introduction port 52, respectively. The longitudinal rib 65 in the middle in the circumferential direction among the five longitudinal ribs 65 is disposed so as to vertically straddle the external air introduction port 52 at the circumferential center position of the corresponding external air introduction port 52.

Each longitudinal rib 65 protrudes from the outer surface of the inner preform 60 toward the radially outer side and extends straight in the axial direction from the inner mouth portion 61 beyond the neck ring 51b to the extension portion 64. Although the plurality of longitudinal ribs 65 are each substantially the same shape as the longitudinal rib 30 of the inner layer body 20, they are different in that a portion extending to the extension portion 64 does not extend radially outward but extends downward along the extension portion 64, and gradually decreases in height at which the inner preform 60 projects from the outer surface beyond the lower side of the neck ring 51 b.

The inner preform 60 is positioned and assembled with respect to the outer preform 50 in the circumferential direction (the rotational direction about the axis) such that the three longitudinal ribs 65 provided on one side of the inner mouth portion 61 face the one external air inlet 52 and the three longitudinal ribs 65 provided on the other side of the inner mouth portion 61 face the other external air inlet 52. Although details are not shown in order to facilitate this positioning, the inner preform 60 may be positioned in the circumferential direction with respect to the outer preform 50 by engaging the concave portion or the convex portion provided in the flange portion 63 with the convex portion or the concave portion provided at the upper end of the outer mouth portion 51.

The preform assembly 40 thus configured is subjected to biaxial stretch blow molding, whereby the double container 1 shown in fig. 1 can be manufactured.

As shown in fig. 4, in the biaxial stretch blow molding of the preform assembly 40, the preform assembly 40 is placed in a blow mold 70 constituting a blow molding device such that the outer mouth portion 51 and the inner mouth portion 61 protrude from the cavity 70a, the neck ring 51b is supported on the upper surface of the mold 70, and the extension portion 53 and the extension portion 64 are located inside the cavity 70a, and in this state, a pressurized medium such as pressurized air or pressurized liquid is supplied from a supply device not shown into the preform assembly 40. As a result, as shown in fig. 5, the

extension portions

53 and 64 of the preform assembly 40 can be blow molded into a shape along the inner surface of the cavity 70a, and the double container 1 can be formed.

Thus, the double container 1 having the above-described structure can be easily manufactured by biaxially stretch blow molding the preform assembly 40 in which the inner preform 60 formed by injection molding is assembled inside the outer preform 50 formed by injection molding.

Further, in the double container 1 of the present embodiment, the external air introduction ports 14 are provided on both sides across the axial center of the external mouth portion 11, and the plurality of longitudinal ribs 30 corresponding to the external air introduction ports 14 are provided only in the predetermined range in the circumferential direction around each external air introduction port 14, so that the inner preform 60 for forming the double container 1 can be configured to have the plurality of longitudinal ribs 65 only on both sides across the axial center of the internal mouth portion 61, and the inner preform 60 can be easily formed at low cost by injection molding using a split mold.

In the double container 1 of the present embodiment, since the plurality of longitudinal ribs 30 are provided on the outer surface of the inner layer 20, the degree of freedom in design regarding the shape and/or the number of the longitudinal ribs 30 can be increased.

Fig. 6 (a) is a half sectional view showing a modification of the inner mouth portion shown in fig. 1, and fig. 6 (B) is a sectional view taken along the line B-B in fig. 6 (a). Fig. 7 is a half sectional view showing another modification of the inner mouth portion shown in fig. 1. Fig. 8 (a) is a half sectional view showing main components of a modification of the double container shown in fig. 1, and fig. 8 (b) is a sectional view taken along line C-C in fig. 8 (a). Fig. 9 (a) is a half sectional view showing a modification of the longitudinal rib shown in fig. 1, and fig. 9 (b) is a sectional view taken along line D-D in fig. 9 (a). In fig. 6 to 9, the same reference numerals are given to the components corresponding to the above components. In fig. 6 and 7, the outer layer body 10 is shown by a two-dot chain line for ease of understanding.

In the double container 1 shown in fig. 1 to 3, in the configuration in which the external air introduction ports 14 are provided on both sides across the axial center of the outer mouth portion 11, the plurality of longitudinal ribs 30 corresponding to the external air introduction ports 14 are provided only in the predetermined range in the circumferential direction around each external air introduction port 14, but as shown in fig. 6, a configuration in which the plurality of longitudinal ribs 30 are provided in parallel at equal intervals in the circumferential direction over the entire circumference of the outer surface of the inner body 20 may be adopted. In the case of the structure in which the plurality of vertical ribs 30 are arranged in parallel at equal intervals in the circumferential direction over the entire circumference of the outer surface of the inner body 20, since the vertical ribs 30 face the external air introduction port 14 regardless of the circumferential position (the rotational direction position centered on the axial center) of the inner mouth portion 21 with respect to the outer mouth portion 11, there is no need to position the inner mouth portion 21 with respect to the outer mouth portion 11 in the circumferential direction (the rotational direction centered on the axial center), and the double container 1 can be easily manufactured.

In the double container 1 shown in fig. 1 to 3, the plurality of longitudinal ribs 30 are formed so as to extend to the vicinity of the upper end of the inner body 20 in continuous with the enlarged diameter portion 24 of the inner mouth portion 21, but may be formed so as to extend only toward the shoulder portion 12 side from the outer position with the position facing the outside air introduction port 14 as a starting point, as shown in fig. 7.

In the double container 1 shown in fig. 1 to 3, a plurality of longitudinal ribs 30 are provided on the outer surface of the inner layer 20, but as shown in fig. 8, a plurality of longitudinal ribs 30 may be provided on the inner surface of the outer layer 10. In the illustrated embodiment, five longitudinal ribs 30 having a triangular cross-sectional shape with acute angles at the tip end are provided on the inner surface of the outer layer 10. Each longitudinal rib 30 protrudes radially inward from the inner surface of the outer layer body 10, and extends in the axial direction from the outer mouth portion 11 across the shoulder portion 12. That is, each longitudinal rib 30 extends from a position facing the external air introduction port 14 beyond the neck ring 11b, bends outward in the radial direction, and reaches the shoulder portion 12. At the shoulder portion 12, the height at which the longitudinal ribs 30 protrude from the inner surface of the outer layer body 10 gradually decreases. The upper end side of each longitudinal rib 30 extends to the vicinity of the upper end of the outer mouth portion 11 facing the enlarged diameter portion 24.

Thus, even if the configuration is adopted in which the plurality of longitudinal ribs 30 are provided on the inner surface of the outer cover 10, the ventilation path 31 is formed between the outer cover 10 and the inner cover 20 from the external air introduction port 14 beyond the neck ring 11b to the portion between the shoulder 12 and the housing portion 22, and the air passage for the external air can be reliably secured from the external air introduction port 14 to the portion between the main body 13 and the housing portion 22.

As shown in fig. 8 (b), the portion of the inner peripheral surface of the outer mouth portion 11 where the longitudinal rib 30 is not provided may be formed as a reduced diameter portion 11c which abuts against the outer peripheral surface of the inner mouth portion 21 so as not to generate the gap 23 shown in fig. 2. By providing the reduced diameter portion 11c, when the preform assembly 40 is biaxially stretch blow molded to form the double container 1, the outer mouth portion 51 of the outer preform 50 can be prevented from being deformed into an elliptical cross section and the gap 23 can be prevented from being narrowed, and the outer mouth portion 11 can be maintained in a circular shape. Although not shown in detail, in the embodiment shown in fig. 2, a diameter-enlarged portion corresponding to the reduced diameter portion 11c may be provided on the outer peripheral surface of the inner mouth portion 21 so as to fill the gap 23. In the case where the reduced diameter portion 11c and the enlarged diameter portion corresponding to the reduced diameter portion 11c are provided, the ventilation path 31 is formed in a groove shape on the inner peripheral surface of the outer mouth portion 11 and the outer peripheral surface of the inner mouth portion 21.

Even when the plurality of longitudinal ribs 30 are provided on the inner surface of the outer layer body 10, the plurality of longitudinal ribs 30 can be arranged in parallel at equal intervals in the circumferential direction over the entire circumference of the inner surface of the outer layer body 10, and the longitudinal ribs 30 can be formed in a shape extending from a position facing the external air introduction port 14 to only the shoulder portion 12 side from the position.

In the above embodiment, the longitudinal ribs 30 other than the pair of longitudinal ribs 30 located at both ends in the circumferential direction among the plurality of longitudinal ribs 30 provided corresponding to one external air introduction port 14 may be provided with the notch portions 30a that notch the longitudinal ribs 30. Fig. 9 shows a case where a plurality of (six) longitudinal ribs 30 provided on the outer peripheral surface of the inner port portion 21 corresponding to the respective external air introduction ports 14 are each provided with a notch portion 30 a.

In the case shown in fig. 9, the cutout portion 30a is formed in a substantially rectangular groove shape that radially cuts out the respective longitudinal ribs 30 from the root portion facing the radially outer side of the outer circumferential surface toward the radially inner port portion 21 side at the middle portion (portion shifted downward with respect to the outside air introduction port 14) in the vertical direction (longitudinal direction) thereof. The notch 30a reaches the outer peripheral surface of the inner mouth portion 21, and the vertical rib 30 is cut vertically by the notch 30 a.

Thus, by adopting a configuration in which at least the longitudinal ribs 30 other than the pair of longitudinal ribs 30 located at both ends in the circumferential direction among the plurality of longitudinal ribs 30 provided corresponding to the one external air introduction port 14 are provided with the notch portions 30a that notch the respective longitudinal ribs 30, even if the inner mouth portion 21 is fixed by being displaced in the circumferential direction from the standard position with respect to the outer mouth portion 11, and the central longitudinal rib 30 among the three longitudinal ribs 30 provided on the one external air introduction port 14 side is opposed to the external air introduction port 14 at the end portion in the circumferential direction of the external air introduction port 14, it is possible to reliably guide the external air introduced from the external air introduction port 14 to the ventilation path 31 on the one side to the ventilation path 31 on the other side shielded by the longitudinal ribs 30 through the notch portions 30a when the pressed main body portion 13 is restored to the original shape. This allows the outside air to be reliably introduced between the main body 13 and the housing portion 22 through the two ventilation paths 31.

Note that, although fig. 9 shows a case where three longitudinal ribs 30 are provided corresponding to one external air introduction port 14, the number of longitudinal ribs 30 provided corresponding to one external air introduction port 14 can be variously changed as long as the cutout portions 30a are provided in at least the longitudinal ribs 30 other than the pair of longitudinal ribs 30 disposed at both ends in the circumferential direction among the plurality of longitudinal ribs 30 provided corresponding to one external air introduction port 14.

Further, as shown in the present embodiment, in the case of adopting a configuration in which all of the plurality of longitudinal ribs 30 are provided with the notch portions 30a, not only is the outside air introduced from the outside air introduction port 14 into the ventilation path 31 when the pressed body portion 13 is restored to the original shape reliably guided between the body portion 13 and the housing portion 22 through all of the ventilation paths 31, but also the outside air introduced into the ventilation path 31 can be supplied to the region other than the ventilation path 31 except for the gap 23 between the outer mouth portion 11 and the inner mouth portion 21 through the notch portions 30 a. This allows external air to be reliably guided between the main body 13 and the housing portion 22 through the ventilation path 31, and also allows the housing portion 22 to be easily peeled off from the inner surface of the outer layer body 10 at the portion of the shoulder portion 12 where the ventilation path 31 is not provided.

The notch 30a is not limited to the shape shown in fig. 9, and may be a shape in which the longitudinal rib 30 is notched, and may be a shape that does not reach the outer peripheral surface of the inner mouth portion 21, a semicircular or triangular notch shape, or a notch shape in which the longitudinal rib is axially oriented from the upper end or the lower end thereof. In addition, the position where the cutout portion 30a is provided, and even the height thereof, can be variously changed. Further, the shape of the cutout portions 30a provided in each longitudinal rib 30, and even the positions of the cutouts 30a, can be made different from each other. The longitudinal rib 30 provided on the inner peripheral surface of the outer mouth portion 11 may be configured to include the notch portion 30a, similarly to the above.

The present invention is not limited to the above embodiment, and various changes can be made without departing from the scope of the invention.

For example, in the above embodiment, the pair of external air introduction ports 14 is provided in the outer port portion 11, but at least one external air introduction port 14 may be provided.

In the above embodiment, the external air introduction port 14 is formed as a long hole extending in the circumferential direction, but the shape of the external air introduction port 14 may be variously changed, for example, a circular introduction port.

In the above embodiment, the external air introduction port 14 is a through hole provided in the outer port portion 11 and penetrating the outer port portion 11, but is not limited to this, and may be provided between the upper end of the outer port portion 11 and the upper end of the inner port portion 21 as a gap for opening the ventilation path 31 to the outside.

In the above embodiment, five longitudinal ribs 30 are provided corresponding to each external air introduction port 14, and three of the longitudinal ribs 30 are opposed to the external air introduction port 14, but the present invention is not limited to this, and at least one longitudinal rib 30 may be opposed to the external air introduction port 14, and the number of longitudinal ribs 30 provided corresponding to each external air introduction port 14 and/or the number of longitudinal ribs 30 opposed to the external air introduction port 14 may be arbitrarily set.

Further, the outer mouth portion 11 may be configured without the collar 11 b.

In addition, the shape of the shoulder portion 12 and/or the body portion 13 can also be variously changed.

In the above-described embodiment, the double container 1 is shown as a squeeze type discharge container for attaching a discharge cap having a discharge port to the outer mouth portion 11 and discharging the content liquid by squeezing the body portion 13, but it is also possible to use a double container with a pump container in which the body portion 13 has a predetermined rigidity so as not to be easily deformed by squeezing and a pump type discharge member is attached to the outer mouth portion 11.

Claims

1. A double container, characterized in that a preform assembly formed by combining an inner preform formed by injection molding with an outer preform formed by injection molding is blow molded to form a double container made of a synthetic resin having a double structure of an outer layer body and an inner layer body, the outer layer body includes a cylindrical outer mouth portion and a bottomed cylindrical body portion connected to the outer mouth portion via a shoulder portion, the inner layer body includes a cylindrical inner mouth portion disposed inside the outer mouth portion and a storage portion detachably laminated on an inner surface of the body portion and deformable to reduce a volume,

the double container has:

an external air inlet for introducing external air between the outer layer body and the inner layer body; and

a plurality of longitudinal ribs which are provided in parallel at intervals in the circumferential direction on the inner surface of the outer layer body or the outer surface of the inner layer body, and which extend from the outer opening portion across the shoulder portion or from the inner opening portion across the receiving portion,

the external air inlet is a through hole provided in the outer port and penetrating the outer port,

at least one of the longitudinal ribs is opposed to the external air introduction port,

an outer diameter of a portion of the outer mouth portion where the plurality of longitudinal ribs are provided or a portion of the inner mouth portion where the plurality of longitudinal ribs are provided at a cross section passing through the external air introduction port and perpendicular to an axis is constant over an entire circumference.

2. The double-layered container according to claim 1,

the external air inlet is provided on each of both sides of the axis of the external port,

the plurality of longitudinal ribs face the external air inlet on one side, and the plurality of longitudinal ribs face the external air inlet on the other side.

3. The double-layered container according to claim 1 or 2,

the plurality of longitudinal ribs are arranged in parallel at equal intervals in the circumferential direction over the entire circumference of the inner surface of the outer layer body or the entire circumference of the outer surface of the inner layer body.

4. The double-layered container according to claim 1,

the outer layer body and the inner layer body are made of polyethylene terephthalate respectively.

5. The double-layered container according to claim 1,

the longitudinal ribs are arranged on the outer surface of the inner layer body.

6. The double-layered container according to claim 1,

the longitudinal ribs are disposed on the inner surface of the outer layer body.

7. The double-layered container according to claim 1,

the main body portion is elastically deformable by being pressed.

8. The double-layered container according to claim 1,

a neck ring is provided on an outer peripheral surface of the outer mouth portion on the shoulder side of the external air inlet.

9. The double-layered container according to claim 1,

the longitudinal ribs, at least except for the pair of longitudinal ribs located at both ends in the circumferential direction, of the plurality of longitudinal ribs provided corresponding to the external air introduction port are provided with notch portions that notch the longitudinal ribs, respectively.