Note: Descriptions are shown in the official language in which they were submitted.
1
DUAL CONTAINER
BACKGROUND OF THE INVENTION
Field of the Invention
[0001]
The present invention relates to a dual container. Priority is claimed on
Japanese Patent Application No. 2021-160790, filed September 30, 2021, the
content of
which is incorporated herein by reference.
Description of Related Art
[0002]
In the related art, for example, as disclosed in Japanese Unexamined Patent
Application, First Publication No. 2019-131256, a dual container is known. The
dual
container includes an inner container deformed to reduce its volume according
to
reduction in accommodated contents, and an outer container in which the inner
container
is inserted and which is elastically deformable. In the dual container, a
mouth portion, a
shoulder portion, a drum portion, and a bottom portion are arranged in
sequence from top
to bottom in a bottle axis direction, and an outside air introduction hole
configured to
introduce outside air is provided between the outer container and the inner
container
according to reduction in contents.
[0003]
However, in the dual container in the related art, there is room for
improvement
in increasing a restoring force of the outer container without impeding smooth
peeling of
the inner container from an inner surface of the outer container.
[0004]
Date Recue/Date Received 2022-09-27
2
In consideration of the above-mentioned circumstances, the present invention
is
directed to providing a dual container capable of increasing a restoring force
of an outer
container without impeding smooth peeling of an inner container from an inner
surface of
the outer container.
SUMMARY OF THE INVENTION
[0005]
A first aspect of the present invention is a dual container including: an
inner
container deformed to reduce a volume according to reduction of accommodated
contents; and an outer container in which the inner container is inserted and
which is
elastically deformable. In the dual container, a mouth portion, a shoulder
portion, a
drum portion, and a bottom portion are arranged in sequence from top to bottom
in a
bottle axis direction, an outside air introduction hole configured to
introduce outside air
between the outer container and the inner container according to reduction of
contents is
provided, a circumferential groove recessed inward in a radial direction and
extending in
a circumferential direction is formed in the drum portion, and a longitudinal
convex
portion configured to disconnect the circumferential groove in the
circumferential
direction is provided on an inner surface of the circumferential groove.
[0006]
The circumferential groove is formed in the drum portion. Accordingly,
rigidity of the drum portion of the outer container can be increased, and
after the drum
portion is squeezed inward in the radial direction by applying an external
force to the
drum portion, the drum portion of the outer container can be smoothly restored
when the
external force (i.e., pressing force) is released.
Date Recue/Date Received 2022-09-27
3
The longitudinal convex portion configured to disconnect the circumferential
groove in the circumferential direction is formed on the inner surface of the
circumferential groove. Accordingly, the outside air introduced between the
inner
container and the outer container from the outside air introduction hole can
easily pass
through the longitudinal convex portion in the upward/downward direction, and
the inner
container can easily peel off from the inner surface of the outer container in
the
circumferential groove from the longitudinal convex portion as an origin.
Accordingly,
the inner container including the portion in which the circumferential groove
is formed
can smoothly peel off from the inner surface of the outer container according
to reduction
of the accommodated contents.
[0007]
A second aspect of the present invention is the dual container according to
the
above-mentioned first aspect. In the dual container, an outer surface of the
longitudinal
convex portion, the outer surface facing outward in the radial direction, is
continuous
with an outer circumferential surface of each portion of the dual container,
the portion
being continuous with the circumferential groove in the upward/downward
direction,
with no step difference in the upward/downward direction.
[0008]
The outer surface of the longitudinal convex portion facing outward in the
radial
direction is continuous with the outer circumferential surface of each portion
continuous
with the circumferential groove of the dual container in the upward/downward
direction
with no step difference in the upward/downward direction. Accordingly, the
outside air
introduced between the inner container and the outer container from the
outside air
introduction hole can reliably pass through the longitudinal convex portion in
the
upward/downward direction.
Date Recue/Date Received 2022-09-27
4
[0009]
A third aspect of the present invention is the dual container according to the
above-mentioned first or second aspect. In the dual container, at least a
lower portion of
the drum portion extends further outward in the radial direction as it goes
downward, and
the circumferential groove is provided in the lower portion of the drum
portion.
[0010]
At least the lower portion of the drum portion extends outward in the radial
direction as it goes downward, and the circumferential groove is provided in
the lower
portion where it is difficult for the outer container to be restored after
squeeze
.. deformation. Accordingly, rigidity of the lower portion of the drum portion
of the outer
container can be increased, and the lower portion of the drum portion of the
outer
container can be easily restored after squeeze deformation.
Since the longitudinal convex portion is formed on the inner surface of the
circumferential groove, smooth peeling of the inner container from the inner
surface of
the outer container in the lower portion of the drum portion can be secured.
[0011]
According to the present invention, it is possible to increase a restoring
force of
the outer container without impeding smooth peeling of the inner container
from the
inner surface of the outer container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012]
FIG. 1 is a side view including a partial longitudinal cross section when a
dual
container shown as an embodiment is seen from an outer side in a radial
direction.
Date Recue/Date Received 2022-09-27
5
DETAILED DESCRIPTION OF THE INVENTION
[0013]
Hereinafter, a dual container according to an embodiment will be described
with
reference to the accompanying drawings.
As shown in FIG. 1, a dual container 1 according to the embodiment includes an
inner container 12 deformed to reduce a volume according to reduction in
accommodated
contents, and an outer container 11 in which the inner container 12 is
inserted and which
is elastically deformable. An outer surface of the inner container 12 is
provided on an
inner surface of the outer container 11 to be separable therefrom. In an
example shown,
.. the inner container 12 is highly flexible and is stacked on the inner
surface of the outer
container 11 so that it can be peeled off.
Further, a gap may be provided between the inner surface of the outer
container
11 and the outer surface of the inner container 12.
[0014]
The dual container 1 is formed by integrally blow-molding an outer preform and
an inner preform in a state in which the inner preform configured to form the
inner
container 12 is fitted into the outer preform configured to form the outer
container 11.
That is, the dual container 1 is a biaxial stretching blow container.
[0015]
Materials of the inner container 12 and the outer container 11 are synthetic
resin
materials, which may be the same material or may be different materials. As an
example of the synthetic resin material, for example, polyethylene
terephthalate (i.e.,
PET), polypropylene (i.e., PP), polyethylene (i.e., PE), nylon (i.e.,
polyamide), and
ethylene-vinyl alcohol copolymer (i.e., EVOH), or the like, may be
exemplified.
Date Recue/Date Received 2022-09-27
6
In the example shown, each of the inner container 12 and the outer container
11
is formed of polyethylene terephthalate (i.e., PET).
[0016]
The dual container 1 includes a mouth portion 13, a shoulder portion 15, a
drum
.. portion 16 and a bottom portion 14. The mouth portion 13, the shoulder
portion 15, the
drum portion 16 and the bottom portion 14 are disposed coaxially with a common
axis in
sequence.
Hereinafter, the common axis is referred to as a bottle axis 0, a side of the
mouth portion 13 of the dual container 1 along the bottle axis 0 is referred
to as an upper
side, and a side of the bottom portion 14 of the dual container 1 is referred
to as a lower
side. A direction crossing the bottle axis 0 when seen in a bottle axis 0
direction (i.e.,
an upward/downward direction) is referred to as a radial direction, and a
direction around
the bottle axis 0 is referred to as a circumferential direction.
[0017]
The mouth portion 13 of the dual container 1 is configured by stacking a mouth
portion of the inner container 12 and a mouth portion of the outer container
11. The
shoulder portion 15 of the dual container 1 is configured by stacking a
shoulder portion
of the inner container 12 and a shoulder portion of the outer container 11.
The drum
portion 16 of the dual container 1 is configured by stacking a drum portion of
the inner
container 12 and a drum portion of the outer container 11. The bottom portion
14 of the
dual container 1 is configured by stacking a bottom portion of the inner
container 12 and
a bottom portion of the outer container 11.
In the following description, both the inner container 12 and the outer
container
11 have the same form unless the context clearly indicates otherwise.
[0018]
Date Recue/Date Received 2022-09-27
7
A size of the dual container 1 in the bottle axis 0 direction is, for example,
115
mm or more and 220 mm or less. An inner capacity of the dual container 1 is,
for
example, 150 ml or more and 600 ml or less. In the example shown, a size of
the dual
container 1 in the bottle axis 0 direction is about 150 mm, and an inner
capacity of the
dual container 1 is 200 ml.
[0019]
The mouth portion 13 of the dual container 1 is formed in a cylindrical shape
extending upward from an upper end portion of the shoulder portion 15.
A flange portion protruding outward in the radial direction and extending
continuously throughout the entire length in the circumferential direction is
formed on an
upper end portion of the mouth portion of the inner container 12. The flange
portion is
placed on an upper end opening edge of the mouth portion of the outer
container 11.
[0020]
A locking protrusion 18 to which a cap (that is not shown) is locked, a sealed
protrusion 19 onto which an outer circumferential portion of the cap (that is
not shown) is
fitted, and a neck ring 20 are formed on an outer circumferential surface of
the mouth
portion of the outer container 11 in sequence from top to bottom.
The locking protrusion 18, the sealed protrusion 19, and the neck ring 20
protrude outward from the mouth portion of the outer container 11 in the
radial direction,
and extend continuously throughout the entire length in the circumferential
direction. A
gap (i.e., a space) between the outer circumferential surface of the sealed
protrusion 19
and the inner circumferential surface of the outer circumferential portion of
the cap (that
is not shown) is air-tightly sealed. An outer diameter of the neck ring 20 is
greater than
an outer diameter of the sealed protrusion 19.
Date Recue/Date Received 2022-09-27
8
Further, the cap may be threaded onto the mouth portion of the outer container
11. The neck ring 20 may not be provided.
[0021]
An outside air introduction hole 17 configured to introduce outside air into a
space with the inner container 12 is provided above the shoulder portion 15
according to
the reduction in contents. In the example shown, the outside air introduction
hole 17 is
formed in the mouth portion of the outer container 11. The outside air
introduction hole
17 are located on the outermost side of the sealed protrusion 19 in the radial
direction,
and located above a sealing surface continuously extending throughout the
entire length
in the circumferential direction.
Further, a forming position of the outside air introduction hole 17 is not
limited
to the mouth portion of the outer container 11. A forming position of the
outside air
introduction hole 17 may be, for example, the drum portion, the shoulder
portion, or the
bottom portion, other than the mouth portion, of the outer container 11, and
may be a
space between the upper end opening edge of the mouth portion of the outer
container 11
and the lower surface of the flange portion of the mouth portion of the inner
container 12,
or the like.
[0022]
The shoulder portion 15 extends further outward in the radial direction as it
goes
downward from the lower end portion of the mouth portion 13.
At least a lower portion of the drum portion 16 extends outward in the radial
direction as it goes downward. In the example shown, an upper portion of the
drum
portion 16 extends almost straight in the bottle axis 0 direction. A portion
of the lower
portion of the drum portion 16 except a lower end portion 16a exhibits a
curved shape
that is recessed inward in the radial direction when seen from an outer side
in the radial
Date Recue/Date Received 2022-09-27
9
direction. The lower end portion 16a of the drum portion 16 exhibits a curved
shape
protruding outward in the radial direction when seen from an outer side in the
radial
direction. An outer circumferential surface of the lower end portion 16a of
the drum
portion 16 is a maximum outer diameter portion having a largest outer diameter
in the
dual container 1. The outer diameter of the maximum outer diameter portion is,
for
example, 58 mm or more and 74 mm or less. In the example shown, an outer
diameter
of the maximum outer diameter portion of the dual container 1 is about 62 mm.
Further,
the drum portion 16 may extend outward in the radial direction as it goes
downward from
above throughout the entire length in the bottle axis 0 direction. Among the
lower
portion of the drum portion 16, the lower end portion 16a of the drum portion
16 and the
lower portion of the drum portion 16, the portions except the lower end
portion 16a may
extend in a linear shape or may extend in a curved shape when seen from an
outer side in
the radial direction.
The bottom portion 14 is formed in a cylindrical shape with a bottom. An
outer circumferential portion 14b of the bottom portion 14 extends inward in
the radial
direction as it goes downward. The bottom portion 14 exhibits a circular shape
through
the entire length in the bottle axis 0 direction when seen in a lateral cross-
sectional view
perpendicular to the bottle axis 0.
[0023]
At least the drum portion of the outer container 11 is able to be squeezed
(i.e.,
elastically deformed), and the inner container 12 is deflated according to the
squeeze
deformation of the outer container 11. The drum portion 16, the shoulder
portion 15
and the bottom portion 14 are continuous with each other in the bottle axis 0
direction
with no step difference.
[0024]
Date Recue/Date Received 2022-09-27
10
The drum portion 16 and the shoulder portion 15 are configured as a plurality
of
surface portions 31 are continuous with each other via comer portions 32 in
the
circumferential direction. In the example shown, the drum portion 16 and the
shoulder
portion 15 exhibit a regular hexagonal shape when seen in a lateral cross-
sectional view.
Further, the shoulder portion 15 may exhibit, for example, a circular shape,
an elliptical
shape, or the like, when seen in a lateral cross-sectional view.
[0025]
The surface portions 31 exhibit a curved shape protruding outward in the
radial
direction when seen in a lateral cross-sectional view perpendicular to the
bottle axis 0.
Further, the surface portions 31 may exhibit a linear shape when seen in a
lateral cross-
sectional view.
The corner portions 32 are formed in a ridge shape extending in the bottle
axis 0
direction when seen from an outer side in the radial direction. Further, the
corner
portions 32 may be formed in a belt shape having a width in the
circumferential direction
and extending in the bottle axis 0 direction when seen from an outer side in
the radial
direction.
[0026]
Each of the comer portions 32 has a first longitudinal convex rib 33 extending
in
the bottle axis 0 direction when seen from an outer side in the radial
direction. Further,
.. the first longitudinal convex rib 33 may not be provided.
[0027]
The first longitudinal convex rib 33 is separately formed in each of the
plurality
of comer portions 32. The first longitudinal convex rib 33 extends straight in
the bottle
axis 0 direction when seen from an outer side in the radial direction. A width
of the
first longitudinal convex rib 33 is greater than a width of the comer portion
32. The
Date Recue/Date Received 2022-09-27
11
first longitudinal convex rib 33 is formed integrally from a connecting
portion
(hereinafter, referred to as a lower end portion) 13a of the mouth portion 13
to the
shoulder portion 15 to a central portion of the drum portion 16 in the bottle
axis 0
direction via the shoulder portion 15. That is, an upper end portion off the
first
longitudinal convex rib 33 is located at the lower end portion 13a of the
mouth portion
13, and a lower end portion of the first longitudinal convex rib 33 is located
at a central
portion of the drum portion 16 in the bottle axis 0 direction.
[0028]
Here, the lower end portion 13a of the mouth portion 13 is a boundary portion
located below the neck ring 20 and extending during blow molding. An upper gap
is
provided between the outer container 11 and the inner container 12 in the
lower end
portion 13a of the mouth portion 13. The upper gap is provided intermittently
throughout the entire length in the circumferential direction. The upper gap
is provided
even in a state before the dual container 1 becomes a biaxial stretching blow
container,
i.e., a state in which the inner preform configured to form the inner
container 12 is fitted
into the outer preform configured to form the outer container 11. Further, a
configuration in which a plurality of longitudinal ribs are formed on an outer
circumferential surface of an upper portion of the inner preform at intervals
in the
circumferential direction, and an upper gap is provided intermittently by the
plurality of
longitudinal ribs throughout the entire length in the circumferential
direction may be
employed. The upper gap may extend continuously throughout the entire length
in the
circumferential direction.
[0029]
In the first longitudinal convex rib 33, a protrusion height of the portion
located
between both end portions in the bottle axis 0 direction is equal to the
entire length in the
Date Recue/Date Received 2022-09-27
12
bottle axis 0 direction, and a protrusion height of both end portions in the
bottle axis 0
direction is decreased outward in the bottle axis 0 direction (i.e., an outer
side of the dual
container 1 in the bottle axis 0 direction). In the first longitudinal convex
rib 33, a
width of the portion located between both end portions in the bottle axis 0
direction is
equal to the entire length in the bottle axis 0 direction, and a width of both
end portions
in the bottle axis 0 direction is decreased outward in the bottle axis 0
direction (i.e., an
outer side of the dual container 1 in the bottle axis 0 direction). The first
longitudinal
convex rib 33 exhibits a convex curved shape when seen in a lateral cross-
sectional view.
[0030]
In the shoulder portion 15, a longitudinal groove 34 extending in the bottle
axis
0 direction when seen from an outer side in the radial direction is formed in
the portion
located between the first longitudinal convex ribs 33 neighboring in the
circumferential
direction. Further, the longitudinal groove 34 may not be provided.
[0031]
The longitudinal groove 34 extends straight in the bottle axis 0 direction
when
seen from an outer side in the radial direction. An upper end portion of the
longitudinal
groove 34 is located below the lower end portion 13a of the mouth portion 13.
The
longitudinal groove 34 is formed integrally from the upper end portion of the
shoulder
portion 15 to the upper end portion of the drum portion 16. Further, the
longitudinal
groove 34 may be formed only in the shoulder portion 15. A width of the
longitudinal
groove 34 is greater than a width of the first longitudinal convex rib 33.
Further, the
width of the longitudinal groove 34 may be smaller than the width of the first
longitudinal convex rib 33.
[0032]
Date Recue/Date Received 2022-09-27
13
In the longitudinal groove 34, a depth of the portion located between both end
portions in the bottle axis 0 direction is equal to the entire length in the
bottle axis 0
direction, and a depth of both end portions in the bottle axis 0 direction
becomes
shallower outward in the bottle axis 0 direction (i.e., an outer side of the
dual container 1
in the bottle axis 0 direction). In the longitudinal groove 34, a width of the
portion
located between both end portions in the bottle axis 0 direction is equal to
the entire
length in the bottle axis 0 direction, and a width of both end portions in the
bottle axis 0
direction becomes narrower outward in the bottle axis 0 direction (i.e., an
outer side of
the dual container 1 in the bottle axis 0 direction). The plurality of
longitudinal
grooves 34 are formed in the surface portions 31 at intervals in the
circumferential
direction. The one longitudinal groove 34 is formed in a central portion of
the surface
portion 31 in the circumferential direction. The inner surface of the
longitudinal groove
34 exhibits a concave curved shape the when seen in a lateral cross-sectional
view.
[0033]
A second longitudinal convex rib 35 extending in the bottle axis 0 direction
when seen from an outer side in the radial direction is formed between the
first
longitudinal convex ribs 33 neighboring in the circumferential direction.
Further, the
second longitudinal convex rib 35 may not be provided.
[0034]
The second longitudinal convex rib 35 extends straight in the bottle axis 0
direction when seen from an outer side in the radial direction. The second
longitudinal
convex rib 35 is formed integrally with the shoulder portion 15 and the drum
portion 16.
A length of the second longitudinal convex rib 35 is smaller than a length of
the first
longitudinal convex rib 33. A lower end portion of the second longitudinal
convex rib
35 is located below the lower end portion of the longitudinal groove 34 and
above the
Date Recue/Date Received 2022-09-27
14
lower end portion of first longitudinal convex rib 33. Positions of upper end
portions of
the second longitudinal convex rib 35 and the first longitudinal convex rib 33
in the
bottle axis 0 direction are the same as each other.
[0035]
A protrusion height of the second longitudinal convex rib 35 is equal to a
protrusion height of the first longitudinal convex rib 33. Further, the
protrusion heights
of the second longitudinal convex rib 35 and the first longitudinal convex rib
33 may be
different from each other. A width of the second longitudinal convex rib 35 is
smaller
than a width of the first longitudinal convex rib 33. Further, the width of
the second
longitudinal convex rib 35 may be greater than the width of the first
longitudinal convex
rib 33.
[0036]
In the second longitudinal convex rib 35, a protrusion height of the portion
located between both end portions in the bottle axis 0 direction is equal to
the entire
length in the bottle axis 0 direction, and a protrusion height of both end
portions in the
bottle axis 0 direction is decreased outward in the bottle axis 0 direction
(i.e., an outer
side of the dual container 1 in the bottle axis 0 direction). In the second
longitudinal
convex rib 35, a width of the portion between both end portions in the bottle
axis 0
direction is equal to the entire length in the bottle axis 0 direction, and a
width of both
end portions in the bottle axis 0 direction is narrowed outward in the bottle
axis 0
direction (i.e., an outer side of the dual container 1 in the bottle axis 0
direction). The
second longitudinal convex rib 35 exhibits a convex curved shape when seen in
a lateral
cross-sectional view.
[0037]
Date Recue/Date Received 2022-09-27
15
The longitudinal groove 34 and the second longitudinal convex rib 35 are
provided on the surface portions 31 alternately in the circumferential
direction. At least
one of the plurality of longitudinal grooves 34 provided in the surface
portion 31 is
provided between the first longitudinal convex rib 33 and the second
longitudinal convex
rib 35 neighboring in the circumferential direction. The first longitudinal
convex rib 33,
the longitudinal groove 34 and the second longitudinal convex rib 35 are
provided
continuously in the circumferential direction.
Further, the first longitudinal convex rib 33 and the second longitudinal
convex
rib 35 may be adjacent to each other in the circumferential direction with no
interposition
of the longitudinal groove 34. The first longitudinal convex rib 33, the
longitudinal
groove 34, and the second longitudinal convex rib 35 may be provided at
intervals in the
circumferential direction.
[0038]
Here, in the embodiment, a circumferential groove 21 recessed inward in the
radial direction and extending in the circumferential direction is formed in
the drum
portion 16. An inner surface of the circumferential groove 21 exhibits a
curved shape
recessed inward in the radial direction when seen in a longitudinal cross-
sectional view in
the bottle axis 0 direction. A longitudinal convex portion 22 configured to
disconnect
the circumferential groove 21 in the circumferential direction is formed on
the inner
surface of the circumferential groove 21. The plurality of longitudinal convex
portions
22 are provided at intervals in the circumferential direction. The plurality
of
longitudinal convex portions 22 are provided in the circumferential groove 21
at intervals
throughout the entire length in the circumferential direction. The
longitudinal convex
portion 22 is formed in a rectangular parallelepiped shape elongated in the
bottle axis 0
direction.
Date Recue/Date Received 2022-09-27
16
[0039]
In the example shown, the circumferential groove 21 is provided in a lower
portion of the drum portion 16. The circumferential groove 21 is provided in
the lower
end portion 16a of the drum portion 16. The circumferential groove 21 is
provided in
the lower end portion 16a of the drum portion 16 throughout the entire length
in the
bottle axis 0 direction.
[0040]
The longitudinal convex portion 22 is defined by an outer surface facing
outward in the radial direction, and a pair of side surfaces that connect both
end portions
of the outer surface in the circumferential direction to an inner surface of
the
circumferential groove 21. Side surfaces of the longitudinal convex portion 22
extend
in a direction in which they are separated from each other in the
circumferential direction
as they go inward in the radial direction. The outer surface of the
longitudinal convex
portion 22 is continuous with an outer circumferential surface of each portion
continuous
with the circumferential groove 21 of the dual container 1 in the bottle axis
0 direction
with no step difference in the bottle axis 0 direction. The upper end portion
of the outer
surface of the longitudinal convex portion 22 is continuous with the outer
circumferential
surface of the drum portion 16 with no step difference, and the lower end
portion of the
outer surface of the longitudinal convex portion 22 is continuous with the
outer
circumferential surface of the outer circumferential portion 14b of the bottom
portion 14
with no step difference.
[0041]
As described above, according to the dual container 1 of the embodiment, the
circumferential groove 21 is formed in the drum portion 16. Accordingly,
rigidity of the
drum portion of the outer container 11 can be increased, and after the drum
portion 16 is
Date Recue/Date Received 2022-09-27
17
squeezed inward in the radial direction by applying an external force to the
drum portion
16, the drum portion of the outer container 11 can be smoothly restored when
the external
force (i.e., pressing force) is released.
[0042]
The longitudinal convex portion 22 configured to disconnect the
circumferential
groove 21 in the circumferential direction is formed on the inner surface of
the
circumferential groove 21. Accordingly, the outside air introduced between the
inner
container 12 and the outer container 11 from the outside air introduction hole
17 can
easily pass through the longitudinal convex portion 22 in the bottle axis 0
direction, and
the inner container 12 can easily peel off from the inner surface of the outer
container 11
in the circumferential groove 21 from the longitudinal convex portion 22 as an
origin.
Accordingly, the inner container 12 including the portion where the
circumferential
groove 21 is provided can smoothly peel off from the inner surface of the
outer container
11 according to reduction of the accommodated contents.
[0043]
An outer surface of the longitudinal convex portion 22 facing outward in the
radial direction is continuous with the outer circumferential surface of each
portion of the
circumferential groove 21 of the dual container 1 in the bottle axis 0
direction with no
step difference in the bottle axis 0 direction. Accordingly, the outside air
introduced
between the inner container 12 and the outer container 11 from the outside air
introduction hole 17 can reliably easily pass through the longitudinal convex
portion 22
in the bottle axis 0 direction.
[0044]
At least the lower portion of the drum portion 16 extends outward in the
radial
direction as it goes downward, and the circumferential groove 21 is provided
in the lower
Date Recue/Date Received 2022-09-27
18
portion where the outer container 11 is hard to be restored after squeeze
deformation.
Accordingly, rigidity of the lower portion of the drum portion of the outer
container 11
can be increased, and the lower portion of the drum portion of the outer
container 11 can
be easily restored after squeeze deformation.
Since the longitudinal convex portion 22 is formed on the inner surface of the
circumferential groove 21, smooth peeling of the inner container 12 from the
inner
surface of the outer container 11 in the lower portion of the drum portion 16
can be
secured.
[0045]
Further, the technical scope of the present invention is not limited to the
above-
mentioned embodiment, and various modifications may be made without departing
from
the spirit of the present invention.
[0046]
A step portion may be provided between the outer surface of the longitudinal
.. convex portion 22 and the outer circumferential surface of each portion
continuous with
the circumferential groove 21 of the dual container 1 in the bottle axis 0
direction.
The longitudinal convex portion 22 may be formed in, for example, a cube shape
or the like.
The drum portion 16 may extend straight in the bottle axis 0 direction
throughout the entire length in the bottle axis 0 direction.
[0047]
In addition, the components of the embodiment may be appropriately replaced
with known components and the embodiment and the variants may be appropriately
combined without departing from the spirit of the present invention.
Date Recue/Date Received 2022-09-27
19
While preferred embodiments of the invention have been described and
illustrated above, it should be understood that these are exemplary of the
invention and
are not to be considered as limiting. Additions, omissions, substitutions, and
other
modifications can be made without departing from the spirit or scope of the
present
invention. Accordingly, the invention is not to be considered as being limited
by the
foregoing description, and is only limited by the scope of the appended
claims.
Date Recue/Date Received 2022-09-27
