Tubular container and method for producing same

Provided is a tubular container capable of improving extractability of contents inside the container. The tubular container includes: a trunk portion having a tubular shape one end of which is closed, the trunk portion being formed by using a film member containing a resin material, and being capable of storing contents therein; and a spout portion attached to the other end of the trunk portion, and capable of closing the other end of the trunk portion. On a peripheral portion of the spout portion, the other end of the trunk portion is attached to a surface, of the spout portion, on a side opposite to the one end of the trunk portion.

BACKGROUND

Field

The present invention relates to a tubular container and a method for producing the same.

Description of the Related Art

Tubular containers capable of being filled with pharmaceutical products, cosmetic products, foods, etc., and packaging these contents, have been known. A tubular container generally includes: a tubular trunk portion having one end being closed and the other end being opened; and a spout portion (also called a shoulder portion) attached to the open end of the trunk portion by welding or the like. The spout portion is formed in a tapered shape in which the outer diameter decreases with an increasing distance from the open end of the trunk portion. An opening through which the contents can be taken out is formed in a part, of the spout portion, on the side opposite to the trunk portion, and a user of the tubular container can discharge the contents from the opening by squeezing the trunk portion (see Japanese Laid-Open Patent Publication No. 2016-199280).

Furthermore, in the tubular container disclosed in Japanese Laid-Open Patent Publication No. 2016-199280, a highly rigid trunk portion is formed by using a film member that is formed of a resin, has a thickness of about 200 μm to 400 μm, and has a relatively high elastic modulus (high stiffness). Therefore, when the trunk portion returns to its original shape after the contents have been discharged from the squeezed and deformed trunk portion, a phenomenon called “air back”, i.e., inflow of air into the trunk portion, occurs. When squeezing out the contents again, the inflow air is pushed together with the trunk portion, so that the contents are pushed out from the spout portion by the pressure of the inflow air.

Meanwhile, Japanese Laid-Open Patent Publication No. 2002-19814 discloses a spout portion that includes a flange portion, a spouting tube portion, a sealing plate portion that closes the spouting tube portion, and a pull ring (grip) provided in the sealing plate portion. The spout is attached to a spout attachment hole formed at the top of a packaging container (paper container for liquid) together with a cap attached so as to cover the spouting tube portion. In this spout, a gas barrier film is insert-molded in the flange portion in order to enhance gas barrier performance of the packaging container.

SUMMARY

An object of the present invention is to provide a tubular container that can improve dischargeability of the contents inside the container.

One aspect of the present invention is a tubular container including: a trunk portion having a tubular shape one end of which is closed, the trunk portion being formed by using a film member containing a resin material, and being capable of storing contents therein; and a spout portion attached to the other end of the trunk portion, and capable of closing the other end of the trunk portion. On a peripheral portion of the spout portion, the other end of the trunk portion is attached to a surface, of the spout portion, on a side opposite to the one end of the trunk portion.

DETAILED DESCRIPTION

First Embodiment

According to the present embodiment, it is possible to provide a tubular container that can inhibit the contents from remaining inside the container.

A tubular container1100according to a first embodiment of the present invention will be described with reference to the drawings. The tubular container1100includes a trunk portion110one end of which is closed, and a spout portion120attached to the other end of the trunk portion110. The tubular container1100further includes, for example, a hinge cap130to be attached to the spout portion120.

FIG.1shows a front view and a side view of the tubular container1100.FIG.2shows a plan view of the spout portion120and a cross-sectional view cut along a B-B′ line.FIG.3is an enlarged cross-sectional view, cut along an A-A line inFIG.1, of the spout portion120and its vicinity to which the hinge cap130is attached.FIG.1shows, for convenience sake, the spout portion120to which the hinge cap130is not attached.

The trunk portion110is a tubular member that is formed of a soft material, has a closed bottom portion111at one end thereof, and is able to store contents (not shown) therein. For example, the trunk portion110can be formed as follows. That is, after a film (also referred to as “film member”) is shaped like a tube, opposed parts of the film at the bottom portion111are adhered to each other, and opposed parts of the film at the edges along the longitudinal direction of the trunk portion110are adhered to each other. The film adhering method is not particularly limited. For example, a method of forming adhesive layers containing polyethylene on the film, and heat-sealing these layers, can be adopted.

The spout portion120is a member that is attached to a top portion112located at the other end of the trunk portion110and is able to close the top portion112of the trunk portion110. The spout portion120includes a plate-shaped closing portion121orthogonal to the longitudinal direction of the trunk portion110. As shown inFIG.2, the closing portion121has a circular-plate shape, for example. The shape of the closing portion121is not limited as long as it is a plate shape, and may be an ellipse, an elongated circle, a polygon, or any other shape. The material of the spout portion120is not particularly limited, but a resin material such as low-density polyethylene can be preferably used. The spout portion120having the plate-shaped closing portion121can reduce the material to be used, as compared to the tapered spout portion according to the conventional art.

The closing portion121has, for example, an annular half cut122at substantially the center thereof, and a pull ring123inside the half cut122. Since the closing portion121has the half cut122and the pull ring123, a user of the tubular container1100can remove a part of the closing portion121along the half cut122by pulling the pull ring123, thereby forming an opening, in the closing portion121, through which the contents can be taken out. Instead of providing the half cut122and the pull ring123, an opening for taking out the contents may be formed in the closing portion121in advance.

As shown inFIGS.1and3, the top portion112of the trunk portion110is, at an edge (peripheral portion) of the closing portion121, adhered to a surface, of the closing portion121, on the side opposite to the bottom portion111of the trunk portion110. The method of adhering the trunk portion110and the closing portion121is not particularly limited. For example, a method of forming an adhesive layer containing polyethylene on an innermost layer of the film, forming the spout portion120using a material containing polyethylene, and heat-sealing them, can be adopted.

The hinge cap130is a member that is attached to the spout portion120and enables closing and opening of an opening formed in the spout portion120. The hinge cap130includes: a tubular fixing portion131that is attached and fixed to the spout portion120and has a hole131afor spouting; and a cap132pivotally attached to the fixing portion131via a hinge133. As shown inFIG.3, the hole131aof the fixing portion131is formed such that, in a planar view, the center thereof overlaps the center of the opening formed in the spout portion120. Therefore, the opening formed in the spout portion120is closed and opened when the cap132closes and opens the hole131aof the fixing portion131. The material of the hinge cap130is not particularly limited, but a resin material such as polypropylene, polyethylene, or low-density polyethylene can be used.

The structure for fixing the hinge cap130to the spout portion120is not particularly limited. For example, as shown inFIG.3, a tubular engagement wall is provided to each of the hinge cap130and the closing portion121, and the engagement walls are fitted and fixed to each other.

As shown inFIG.3, the inner circumferential diameter of the hole131afor spouting formed in the fixing portion131of the hinge cap130is preferably greater than the diameter of the half cut122and the outer diameter of the pull ring123. Thus, when an opening is formed in the closing portion121by use of the pull ring123, the pull ring123can be easily picked up from the outside of the hole131aof the fixing portion131, and the removed part of the closing portion121can be taken out through the hole131a. Therefore, the opening can be easily formed in the spout portion120without removing the hinge cap130from the spout portion120.

As shown inFIGS.1and3, a ring portion at an upper end of the pull ring123may be formed such that at least a part thereof is located outward of the hole131aof the fixing portion131. This allows the pull ring123to be picked up more easily as compared to the case where the ring portion is located inward of the hole131a. Thus, an opening can be formed in the spout portion120more easily.

The structure for realizing closing and opening of the opening formed in the spout portion120is not limited to the hinge cap130. For example, a structure including: a cylindrical member provided on the spout portion120and having an outer thread, and a cap having an inner thread fittable to the outer thread, may be adopted.

FIG.4is a cross-sectional view showing the state of the tubular container1100when a small amount of contents remaining in the trunk portion110is taken out.

In the tubular container1100, the spout portion120includes the plate-shaped closing portion121orthogonal to the longitudinal direction of the trunk portion110, and the top portion112of the trunk portion110is, at the edge of the closing portion121, adhered to the surface, of the closing portion121, on the side opposite to the bottom portion111of the trunk portion110. Therefore, as shown inFIG.4, when the trunk portion110is bent at the edge of the closing portion121with a finger or the like, a small amount of contents remaining in the trunk portion110can be pushed toward the periphery of the opening of the spout portion120while being sandwiched by the inner-side surface of the closing portion121and the inner surface of the trunk portion110.

Since the closing portion121of the spout portion120has a plate shape, a space that allows the contents to remain therein is not present on the inner side of the closing portion121, in contrast to the tapered spout portion according to the conventional art. Therefore, the contents pushed toward the periphery of the opening of the spout portion120can be squeezed out from the opening without being remained inside the trunk portion110and the spout portion120. As a result, remaining of the contents inside the container can be inhibited.

In the tubular container1100, as described above, remaining of the contents can be inhibited by squeezing out the contents while bending the trunk portion110. Therefore, the trunk portion110is preferably formed of a film having a low rigidity (less stiff) that allows the trunk portion110to be easily bent. Regarding the cap, the aforementioned hinge cap130allows a reduction in rigidity, against distortion, that is required of the trunk portion110to be held by hand when the cap is opened, as compared to the cap that is thread-engaged with the closing portion and turned to be opened. Therefore, a film having a low rigidity can be used.

Second Embodiment

According to the present embodiment, it is possible to provide a tubular container that inhibits smooth discharge of the contents after unsealing from being impeded by the gas barrier film, while ensuring sealing property and gas barrier property before unsealing for the first time.

A tubular container according to a second embodiment of the present invention will be described with reference to the drawings. In the following description, the same or corresponding components between the embodiments and modifications are designated by the same reference characters, and the description thereof is omitted.

A tubular container2100according to a second embodiment of the present invention includes a trunk portion210one end of which is closed, and a spout portion220attached to the other end of the trunk portion210.FIG.5is a front view of the tubular container2100.

The trunk portion210is a tubular member that is formed of a lamination member including a gas barrier layer214, has a closed bottom portion211located at one end thereof, and is able to store contents (not shown) therein. For example, the trunk portion210can be formed as follows. That is, after a film (lamination film) including the gas barrier layer214is shaped like a tube, opposed parts of the film at the bottom portion211are adhered to each other, and opposed parts of the film at the edges along the longitudinal direction (the up-down direction of the sheet ofFIG.5) of the trunk portion210are adhered to each other. The film adhering method is not particularly limited. For example, a method of providing the film with adhesive layers containing polyethylene, and heat-sealing these layers, can be adopted. The material of the gas barrier layer214is not particularly limited as long as it is a film member having gas barrier property. For example, aluminum foil or a resin film containing EVOH resin or the like can be used.

The spout portion220is a member that is attached to a top portion212located at the other end of the trunk portion210and is able to close the top portion212of the trunk portion210. The spout portion220includes, for example, a plate-shaped closing portion221orthogonal to the longitudinal direction of the trunk portion210. As shown inFIG.6, the closing portion221has, for example, a circular-plate shape in a planar view. The shape of the closing portion221is not particularly limited, and may be an ellipse, an elongated circle, a polygon, or any other shape. The material of the spout portion220is not particularly limited, but a resin material such as straight-chain low-density polyethylene or low-density polyethylene can be preferably used. The spout portion220having the plate-shaped closing portion221can reduce the material to be used, as compared to the tapered spout portion according to the conventional art. The closing portion221may not necessarily have the plate shape orthogonal to the longitudinal direction of the trunk portion210, and may have any shape as long as a half cut222and a gas barrier film225described later can be formed. The closing portion221may have a tapered shape having a shoulder portion the outer diameter of which decreases with an increasing distance from the top portion212.

The closing portion221includes: an annular half cut222formed at substantially the center thereof; a pick-up portion223extending from an inner side of the half cut222toward a side opposite to the bottom portion211of the trunk portion210; a tubular peripheral wall224disposed outside the half cut222and extending toward a side opposite to the bottom portion211of the trunk portion210; and a gas barrier film225.

The pick-up portion223is, for example, a pull ring including: a support portion223aextending from the closing portion221; and a ring portion223bthat is provided at an end, of the support portion223a, on the side opposite to the spout portion220, and allows the user to insert a finger therein. Since the closing portion221includes the half cut222and the pick-up portion223, when the user of the tubular container2100pulls the pick-up portion223with a predetermined force, the user can remove a to-be-opened portion221a(an area surrounded by the half cut222), which is a part of the closing portion221, along the half cut222together with the gas barrier film225, thereby forming an opening, in the closing portion221, through which the contents can be taken out. As described above, in the tubular container2100, the other end of the trunk portion210is closed by the spout portion220, and a part of the closing portion221is removed to form an opening in the spout portion220when the tubular container2100is unsealed for the first time. Therefore, sealing property before unsealing for the first time can be ensured. A weakened line corresponding to the shape of the half cut222may be formed in the gas barrier film225to facilitate removal of the to-be-opened portion221a.

The pick-up portion223is not limited to a pull ring, and may have any shape as long as the user can remove a part of the closing portion221by pulling the same. For example, the pick-up portion223may be a plate-shaped pick-up margin extending from the closing portion221.

The peripheral wall224is provided for attaching a cap (not shown) that closes the opening formed in the spout portion220. The peripheral wall224may have a thread or an engagement claw for fixing the cap.

The gas barrier film225is a film provided on a surface, of the spout portion220, facing the inside of the tubular container2100, in order to impart gas barrier property to a predetermined area of the spout portion220. The material of the gas barrier film225is not particularly limited as long as it is a film member having gas barrier property and removable along the half cut222together with a part of the closing portion221as described later. For example, aluminum foil, an EVOH resin, or the like can be used. The method of providing the spout portion220with the gas barrier film225is as follows, for example. That is, the gas barrier film225may be heat-sealed to the molded spout portion220, or the gas barrier film225may be integrally molded (insert-molded) with the spout portion220. The edge (end face) of the gas barrier film225may be exposed, or may be covered with the closing portion221as shown inFIG.5. Covering the edge of the gas barrier film225with the closing portion221inhibits occurrence of delamination from the edge of the gas barrier film225.

As shown inFIG.5andFIG.6, the inner peripheral surface of the trunk portion210near the top portion212is adhered to the surface, of the closing portion221, on the side opposite to the bottom portion211of the trunk portion210, over the entire periphery, at a peripheral portion221bthat is an edge around the to-be-opened portion221aof the closing portion221. The method of adhering the trunk portion210and the closing portion221is not particularly limited. For example, a method of disposing an adhesive layer containing polyethylene on an innermost layer of the film, forming the spout portion220using a material containing polyethylene, and heat-sealing them, may be adopted.

At this time, it is assumed that: an area, of the peripheral portion221b, to which the inner peripheral surface near the top portion is adhered is a first area; an area, of the surface of the spout portion220facing the inside of the tubular container2100, where the gas barrier film225is disposed is a second area; and an area over the entire periphery of the peripheral portion221bof the spout portion220is a third area. Then, the trunk portion210is adhered to the closing portion221of the spout portion220so as to satisfy the following conditions. That is, the trunk portion210is adhered and attached to the spout portion220such that the first area and the second area overlap each other, as viewed from a normal direction in the third area. Specifically, in the case of the tubular container2100, since the closing portion221has a plate shape orthogonal to the longitudinal direction of the trunk portion210, the trunk portion210is adhered and attached to the closing portion221of the spout portion220such that, in a planar view, the gas barrier layer214and the gas barrier film225overlap each other as shown in FIG.5.

Thus, in the tubular container2100in which the trunk portion210is attached to the spout portion220, the gas barrier layer214and the gas barrier film225overlap each other as viewed from the normal direction at each position on the peripheral portion of the closing portion221. Therefore, an area having no gas barrier property is absent, thereby realizing high gas barrier property. Thus, the trunk portion210and the spout portion220ensure gas barrier property and sealing property before unsealing for the first time (before formation of an opening in the spout portion220).

FIG.6is a cross-sectional view of the spout portion220when a part of the closing portion221is removed along the half cut222to form an opening in the closing portion221. As shown inFIG.6, when the pick-up portion223is pulled with a predetermined force, the to-be-opened portion221a, which is a part of the closing portion221, is removed along the half cut222together with the gas barrier film225, thereby forming an opening in the closing portion221. Thus, the gas barrier film225is prevented from remaining in the opening, thereby inhibiting the gas barrier film225from impeding smooth discharge of the contents.

FIG.7is a front view of a tubular container2101according to a modification of the second embodiment of the present invention. This tubular container2101is different from the tubular container2100in that the tubular container2101does not include the pick-up portion223and the peripheral wall224. Since the tubular container2101does not include the pick-up portion223, an opening can be formed by pushing the to-be-opened portion221atoward the inside of the trunk portion210.

The user may perform the work of pushing the to-be-opened portion221ainward with a finger or the like, a pointed jig or the like, or a tubular member such as a straw through which the contents can be taken out. Meanwhile, for example, the tubular container2101may be housed in a rigid container in which the tubular container2101can be erected, and the to-be-opened portion221amay be pushed inward by using a suction device such as a pump dispenser to suck the contents.

Also in the tubular container2101, since the trunk portion210is adhered such that the gas barrier layer214and the gas barrier film225overlap each other, sealing property and gas barrier property before the first unsealing can be ensured. In addition, since a part of the closing portion221can be removed along the half cut222, the gas barrier film225is prevented from remaining in the opening, thereby inhibiting the gas barrier film225from impeding smooth discharge of the contents.

Third Embodiment

According to the present embodiment, it is possible to provide a tubular container that can achieve both hermetical sealing before unsealing for the first time and hermetical sealing after resealing.

A tubular container3100according to a third embodiment of the present invention includes a trunk portion310one end of which is closed, a spout portion320attached to the other end of the trunk portion310, and a cap330attached to the spout portion320.FIG.8shows a front view and a side view of the tubular container3100.FIG.9shows a plan view of the spout portion320and a cross-sectional view cut along a D-D′ line.FIG.10is an enlarged cross-sectional view, cut along a C-C line inFIG.8, of the spout portion320to which the cap330is attached.FIG.8shows, for convenience sake, the spout portion320to which the cap330is not attached.

The trunk portion310is a tubular member that is formed of a soft material, has a closed bottom portion311located at one end thereof, and is able to store contents (not shown) therein. For example, the trunk portion310can be formed as follows. That is, after a film is shaped like a tube, opposed parts of the film at the bottom portion311are adhered to each other, and opposed parts of the film at the edges along the longitudinal direction (the up-down direction of the sheet ofFIG.8) of the trunk portion310are adhered to each other. The film adhering method is not particularly limited. For example, a method of providing the film with adhesive layers containing polyethylene, and heat-sealing these layers, can be adopted.

The spout portion320is a member that is attached to a top portion312located at the other end of the trunk portion310and is able to close the top portion312of the trunk portion310. The spout portion320includes, for example, a plate-shaped closing portion321orthogonal to the longitudinal direction of the trunk portion310. As shown inFIG.9, the closing portion321has, for example, a circular-plate shape in a planar view. The shape of the closing portion321is not particularly limited, and may be an ellipse, an elongated circle, a polygon, or any other shape. The material of the spout portion320is not particularly limited, but a resin material such as straight-chain low-density polyethylene or low-density polyethylene can be preferably used. The spout portion320having the plate-shaped closing portion321can reduce the material to be used, as compared to the tapered spout portion according to the conventional art. The closing portion321may not necessarily have the plate shape orthogonal to the longitudinal direction of the trunk portion310, and may have any shape as long as a half cut322, a pick-up portion323, and a peripheral wall324described later can be formed. The closing portion321may have a tapered shape having a shoulder portion the outer diameter of which decreases with an increasing distance from the top portion312of the trunk portion310.

The closing portion321includes: an annular half cut322formed at substantially the center thereof; a pick-up portion323extending from an inner side of the half cut322toward a side opposite to the bottom portion311of the trunk portion310; and a tubular peripheral wall324disposed outside the half cut322and extending toward the side opposite to the bottom portion311of the trunk portion310.

The pick-up portion323is, for example, a pull ring including: a support portion323aextending from the closing portion321; and a ring portion323bthat is provided at an end, of the support portion323a, on the side opposite to the spout portion320, and allows the user to insert a finger therein. Since the closing portion321includes the half cut322and the pick-up portion323, when the user of the tubular container3100pulls the pick-up portion323with a predetermined force, the user can remove a part of the closing portion321along the half cut322, thereby forming an opening, in the closing portion321, through which the contents can be taken out. As described above, in the tubular container3100, the other end of the trunk portion310is closed by the spout portion320, and a part of the closing portion321is removed to form an opening in the spout portion320when the tubular container3100is unsealed for the first time. Thus, the tubular container3100can be hermetically sealed before unsealing for the first time.

The pick-up portion323is not limited to a pull ring, and may have any shape as long as the user can remove a part of the closing portion321by pulling the same. For example, the pick-up portion323may be a plate-shaped pick-up margin extending from the closing portion321.

As shown inFIGS.8and10, at an edge (peripheral portion) of the closing portion321, the top portion312of the trunk portion310is adhered to a surface, of the closing portion321, on the side opposite to the bottom portion311of the trunk portion310. The method of adhering the trunk portion310and the closing portion321is not particularly limited. For example, a method of forming an adhesive layer containing polyethylene on an innermost layer of the film, forming the spout portion320using a material containing polyethylene, and heat-sealing them, may be adopted.

The cap330is a member that is attached to the spout portion320and enables closing and opening of an opening formed in the spout portion320. For example, the cap330is a hinge cap including: a tubular fixing portion331that can be attached and fixed to the spout portion320; and a lid332pivotally attached to the fixing portion331via a hinge333. The material of the cap330is not particularly limited, but a resin material such as polypropylene, polyethylene, or low-density polyethylene can be used. The fixing portion331, the lid332, and the hinge333can be integrally molded, for example.

The fixing portion331includes: a top plate331a; a hole331bformed in the top plate331ato take out the contents; a first tubular inner ring331cdisposed on a surface, of the top plate331a, on the side opposed to the spout portion320so as to surround the hole331b; a contact ring331dannually protruding from the top plate331aon the outer peripheral side of the first inner ring331c; and a second inner ring331edisposed on a surface, of the top plate331a, on the side opposed to the lid332so as to surround the hole331b. The contents taken out from the opening of the spout portion320can be taken out from the tubular container3100through the hole331b. The contact ring331dand the second inner ring331eare not essential.

As shown inFIG.10, the first inner ring331cis formed in a tubular shape so that it can be closely fitted to the inner peripheral surface of the peripheral wall324while being attached to the spout portion320. The contact ring331dis disposed in contact with an edge, of the peripheral wall324, on the side opposite to the bottom portion311of the trunk portion310while being attached to the spout portion320. The second inner ring331eis formed such that an inner ring332cof the lid332can be closely fitted to the outer peripheral surface thereof while the lid332closes the hole331bas described later. The first inner ring331c, the contact ring331d, and the second inner ring331eare formed such that the center axes thereof are aligned. The second inner ring331emay be formed such that the inner ring332cof the lid332can be closely fitted to the inner peripheral surface thereof.

In the tubular container3100, for example, the first inner ring331cand the second inner ring331eof the fixing portion331have the center axes aligned with each other, and have the same outer circumferential diameter and the same inner circumferential diameter, as shown inFIG.10. However, the first inner ring331cand the second inner ring331emay have different outer circumferential diameters and different inner circumferential diameters as long as the center axes thereof are aligned with each other. Specifically, the outer circumferential diameter and the inner circumferential diameter of the second inner ring331emay be greater than those of the first inner ring331c.

As shown inFIG.10, the hole331bof the fixing portion331is formed such that, in a planar view, the center thereof is aligned with the center of the opening formed in the spout portion320. Therefore, as described later, the opening formed in the spout portion320can be closed and opened when the lid332closes and opens the hole331bof the fixing portion331.

The structure for fixing the fixing portion331to the spout portion320is not particularly limited. For example, as shown inFIG.10, an engagement claw protruding outward is disposed at the tip of the peripheral wall324while the cap330is provided with a tubular engagement wall331fhaving, at the tip thereof, an engagement claw protruding inward. The engagement wall331fis fitted to the peripheral wall324, and the engagement claws of the peripheral wall324and the engagement wall331fare fitted to each other, thereby fixing the fixing portion331to the spout portion320.

The lid332is a member that can be pivoted via the hinge333to cover and close the hole331bof the fixing portion331as shown inFIG.10. The lid332is composed of a peripheral wall332a, a top plate332b, and a tubular inner ring332c. The inner ring332cis disposed on the surface, at the inner peripheral side, of the top plate332bso as to be closely fitted to the outer peripheral surface of the second inner ring331eof the fixing portion331in the state where the lid332closes the hole331bas shown inFIG.10.

As described above, in the tubular container3100, the cap330is provided with the first inner ring331cthat is closely fitted to the inner peripheral surface of the peripheral wall324of the spout portion320. Therefore, even after formation of an opening in the spout portion320, when the cap330is attached to the spout portion320, the opening of the spout portion320can be hermetically resealed by the peripheral wall324and the first inner ring331c. That is, in the tubular container3100, since the closing portion321of the spout portion320used for hermetical sealing before unsealing for the first time, and the adhered portion between the first inner ring331cand the peripheral wall324used for hermetical sealing after unsealing are located at different positions, these members are prevented from interfering with each other. Thus, it is possible to achieve both hermetical sealing before unsealing for the first time, and hermetical sealing after resealing.

The tubular container3100is provided with the contact ring331dthat is in contact with the edge, of the peripheral wall324, on the side opposite to the bottom portion311of the trunk portion310, while being attached to the spout portion320. Therefore, when the tubular container3100is resealed, the opening of the spout portion320can be hermetically sealed more reliably by the peripheral wall324and the contact ring331d.

Moreover, the tubular container3100is provided with the second inner ring331eand the inner ring332cof the lid332that are closely fitted to each other while the lid332closes the hole331b. Therefore, when the tubular container3100is resealed, the opening of the spout portion320can be hermetically sealed more reliably by the second inner ring331eand the inner ring332c.

Moreover, in the tubular container3100, the contents are not likely to enter the area surrounded by the peripheral wall324before unsealing for the first time. Therefore, it is not necessary to impart gas barrier property to the peripheral wall324, and the adsorption amount of contents to the resin forming the peripheral wall324can be reduced.

As shown inFIG.10, the inner circumferential diameter of the hole331bfor spouting provided in the fixing portion331of the cap330is preferably greater than the outer diameter of the half cut322and the outer diameter of the ring portion323bof the pick-up portion323. Thus, when an opening is formed in the closing portion321by use of the pick-up portion323, the ring portion323bcan be easily picked up from the outside of the hole331bof the fixing portion331, and a removed part of the closing portion321can be easily taken out through the hole331b. Therefore, the opening of the spout portion320can be easily formed without removing the cap330from the spout portion320.

Furthermore, as shown inFIGS.8and10, the pick-up portion323may be formed such that at least a part thereof is located outward of the top plate331aof the fixing portion331. This allows the pick-up portion323to be picked up more easily as compared to the case where the ring portion is located inward of the hole331b. Thus, an opening can be formed in the spout portion320more easily.

The structure of the cap is not limited to a hinge cap as long as the cap is provided with an inner ring that can be closely fitted to the inner peripheral surface of the peripheral wall324while the cap is attached to the spout portion320. For example,FIG.11shows a cap330′ of a tubular container3101according to a modification. The cap330′ is a screw cap that can be attached to the peripheral wall324in a thread-fitted manner. The cap330′ may include: an inner thread330bfittable to an outer thread324aformed at the outer peripheral surface of the peripheral wall324; an inner ring330cthat is hanging from a top plate330aand is closely fitted to the inner peripheral surface of the peripheral wall324when the cap330′ is attached to the spout portion320; and a contact ring330dthat is in contact with an edge, of the peripheral wall324, on the side opposite to the trunk portion310.

Also in the tubular container3101, when the pick-up portion323is pulled with a predetermined force, a part of the closing portion321is removed along the half cut322and thereby an opening is formed. In addition, as shown inFIG.11, when the cap330′ is attached to the spout portion320with the inner thread330bbeing fitted to the outer thread324a, the inner ring330cis closely fitted to the inner peripheral surface of the peripheral wall324. Since hermetical sealing can be reliably achieved even after resealing, it is possible to achieve both hermetical sealing before unsealing for the first time, and hermetical sealing after resealing.

Fourth Embodiment

According to the present embodiment, it is possible to provide: a spout portion that has a high degree of freedom in choosing materials while having gas barrier property and that can be produced at reduced cost; and a tubular container using the spout portion.

A packaging container4100according to a fourth embodiment of the present invention is a tubular container including a container body420corresponding to the trunk portion described in the other embodiments, and a spout portion410. The spout portion410includes a spouting tube portion411, a flange portion412, and a cap seal413.FIG.12is an exploded perspective view of the spout portion410, andFIG.13is a vertical cross-sectional view of the spout portion410. The spout portion410is attached to the container body420when being used, as described later.

The spouting tube portion411is a tubular member serving as a spouting port when the contents stored in the container body are taken out. As described later, a cap (not shown) for resealing after unsealing of the spout portion410by removing the cap seal413, may be attached to the spouting tube portion411. For example, the spouting tube portion411has, at an outer peripheral surface thereof, a thread411ato which the cap can be attached in a thread-engaged manner. The method of attaching the cap is not limited to the thread engagement. For example, fitting or the like may be adopted. If resealing is not intended, a cap need not be attached to the spouting tube portion411.

The flange portion412is a member for attaching the spout portion410to the container body by welding. The flange portion412is formed extending outward from one end of the spouting tube portion411. The flange portion412has, at a surface thereof, a projection412acalled an energy director. When ultrasonic welding is adopted, the projection412aconcentrates ultrasonic vibration to realize stable welding. The flange portion412has a circular plate shape, for example. However, as long as it extends outward from one end of the spouting tube portion411, the flange portion412may have a tapered shape the outer diameter of which increases with an increasing distance from the other end of the spouting tube portion411in the axial direction.

The spouting tube portion411and the flange portion412are integrally formed by vacuum molding, vacuum/pressure molding, blow molding, or the like using a film-shaped first laminate414. The first laminate414includes a first sealant layer414aserving as an outer layer of the spouting tube portion411, and a first gas barrier layer414bhaving gas barrier property. The first laminate414can be formed by using a co-extrusion process or a heat lamination process, for example.

The first sealant layer414ais formed by using, for example, polyethylene (PE), polyethylene terephthalate (PET) having heat sealability, cyclic polyolefin, EVOH sealant, or the like. The first gas barrier layer14bis formed by using, for example, a transparent vapor-deposited film, aluminum foil, EVOH, or the like. The transparent vapor-deposited film is formed by vapor-depositing a thin layer of a metal such as aluminum, or a metal oxide such as alumina or silicon oxide, on a stretched or unstretched film of a plastic such as PET or nylon (NY).

According to a function required of the spout portion410, the first laminate414may further include a layer formed by using polypropylene (PP), cyclic olefin polymer (COP), cyclic olefin copolymer (COC), or the like, in addition to the first sealant layer414aand the first gas barrier layer414b.

The cap seal413is a film member that is welded to the other end of the spouting tube portion411to close an opening at the other end of the spouting tube portion411.

The cap seal413is formed by cutting a film-shaped second laminate415into a predetermined shape corresponding to the other end of the spouting tube portion11. The second laminate415includes a second sealant layer415athat can be welded to the first sealant layer414a, and a second gas barrier layer415bhaving gas barrier property. When the second sealant layer415ais welded to the first sealant layer414a, the cap seal413is fixed to the other end of the spouting tube portion411. The second laminate415can be formed by using a co-extrusion process or a heat lamination process, for example.

The second sealant layer415acan be welded to the first sealant layer414a, and therefore is typically formed by using the same material as the first sealant layer414a. However, the second sealant layer415amay be formed by using a material different from that of the first sealant layer414aas long as it can be welded to the first sealant layer414a. For example, the second sealant layer415amay be formed by using PE, PET having heat sealability, cyclic polyolefin, EVOH sealant, or the like. Meanwhile, the second gas barrier layer415bis formed by using, for example, a transparent vapor-deposited film, aluminum foil, EVOH, or the like. The transparent vapor-deposited film is formed by vapor-depositing a thin layer of a metal such as aluminum, or a metal oxide such as alumina or silicon oxide, on a stretched or unstretched film of a plastic such as PET or nylon.

According to a function required of the spout portion410, the second laminate415may further include a layer formed by using PP, COP, COC, or the like, in addition to the second sealant layer415aand the first gas barrier layer414b.

Unsealing of the spout portion410may be performed by partially or completely removing the cap seal413from the spouting tube portion411, or by breaking through the cap seal413to partially form a hole.

As described above, the spout portion410formed by using the first laminate414including the first gas barrier layer414band the second laminate415including the second gas barrier layer415b, has excellent gas barrier property. In addition, since a limitation regarding setting of strength, i.e., “being tearable”, is not imparted to the first laminate414and the second laminate415, the degree of freedom in choosing materials usable for producing the spout portion410is increased. Therefore, a spout portion410, which can be suitably used for a packaging container to be subjected to sterilization treatment (retort sterilization, boil sterilization) using hot water, can be produced by using, for example, PP having high heat resistance for the first laminate414and second laminate415.

Moreover, the first laminate414and the second laminate415can be produced by using a co-extrusion process, a heat lamination process, or the like, and the spouting tube portion411and the flange portion412can be produced by using vacuum molding, vacuum/pressure molding, blow molding, or the like. In this case, the spout portion410does not require complicated molds and processes as used in producing the spout portion of Japanese Laid-Open Patent Publication No. 2002-19814, and therefore can be produced at low cost.

Moreover, when the spout portion410is covered with the cap for resealing, the space between the spout portion410and the cap is narrower than that in the spout portion having a space for housing a pull ring as disclosed in Japanese Laid-Open Patent Publication No. 2002-19814. Therefore, even when the spout portion410is subjected to sterilization treatment using hot water, the degree of expansion/contraction of air remaining in the space can be reduced. Thus, deformation of the spouting tube portion411is inhibited. Moreover, the water used for the treatment is inhibited from entering the space through the gap between the cap and the spout portion410.

Next, a packaging container4100including a spout portion410will be described. The packaging container4100includes a spout portion410according to the above embodiment, and a container body420.FIG.14is a vertical cross-sectional view of the packaging container4100.

The container body420is formed by using a film-shaped third laminate423, for example. The container body420is a tubular member, one end of which is closed, including a top portion421and a bottom portion422. The third laminate423includes a third sealant layer423athat can be welded to the first sealant layer414a, and a third gas barrier layer423bhaving gas barrier property.

The spout portion410is attached to the top portion421by welding the third sealant layer423ato the first sealant layer414a. The bottom portion422is formed by welding opposed third sealant layers423a. As shown inFIG.14, in the packaging container4100, welding is performed in the state where the top portion421of the container body420covers the first sealant layer414aas an outer layer of the spout portion410, and the third sealant layer423aas an inner layer of the third laminate423is in contact with the first sealant layer414a. As long as the sealant layers respectively included in the spout portion410and the container body420can be in contact with each other, the layer configurations and the attachment manner are not limited

Like the second sealant layer415a, the third sealant layer423amay be formed by using the same material as the first sealant layer414a, or may be formed by using, for example, PE, PET having heat sealability, cyclic polyolefin, EVOH sealant, or the like. Meanwhile, the third gas barrier layer423bmay be formed by using, for example, a transparent vapor-deposited film, aluminum foil, EVOH, or the like. The transparent vapor-deposited film is formed by vapor-depositing a thin layer of a metal such as aluminum, or a metal oxide such as alumina or silicon oxide, on a stretched or unstretched film of a plastic such as PET or nylon.

As described above, both the spout portion410and the container body420forming the packaging container4100include the gas barrier layer having gas barrier property. This enables the entire packaging container4100to have excellent gas barrier property.

Next, a spout portion410aused in a packaging container according to a modification of the fourth embodiment of the present invention will be described. The spout portion410ais different from the spout portion410in that the flange portion412of the spout portion410aincludes a protection portion416, that the spouting tube portion411includes a protection portion417, and that the first sealant layer414ais provided as both an innermost layer and an outermost layer of the spouting tube portion411and the flange portion412. Like the spout portion410, the spout portion410ais attached to the container body420when being used.FIG.15is a vertical cross-sectional view showing the spout portion410aand a part of a production process thereof. Specifically, an upper part ofFIG.15shows a method of forming the protection portions416,417, and a lower part ofFIG.15shows a completed spout portion410a. For convenience sake,FIG.15shows the spout portion410ato which the cap seal413is not attached.

The protection portions416,417are provided for covering and protecting the cross section of the first laminate414. More specifically, the protection portions416,417are provided for inhibiting the contents from permeating the interface of each layer from the cross section of the first laminate414.

FIG.15shows cross-sectional views illustrating an example of a formation method for the protection portions416,417. As shown in the upper part ofFIG.15, for example, each of the protection portions416,417is formed such that an area of a predetermined width including the cross section of the first laminate414is folded back. After having been folded back, the cross section may be pressed and heated as shown by a black arrow. Thus, the innermost first sealant layer414aand the outermost first sealant layer414aare welded to each other. As a result, as shown in the lower part ofFIG.15, the cross section of the first laminate414is covered and protected by the first sealant layer414a.

In the above description, the spout portion410ais provided with both of the protection portions416,417. However, the spout portion410amay be provided with only one of the protection portions416,417. As long as the cross section of the first laminate414can be satisfactorily covered with the first sealant layer414a, the first sealant layer414aneed not be provided as both the innermost layer and the outermost layer, and the formation method for the protection portions416,417is not limited.

Like the spout portion410, the spout portion410ais attached to the top portion421of the container body420by welding the third sealant layer423ato the first sealant layer414aas the outermost layer.

Spout portions according to Examples and spout portions according to Reference Examples were produced, and gas barrier properties thereof were measured.

EXAMPLES

As spout portions according to Examples, spout portions410according to the embodiment shown inFIGS.12and13were produced. The layer configuration of the first laminate414and the thicknesses of the respective layers were, in order from the outside, a first sealant layer414abeing 0.1 to 2.0 mm thick, and a first gas barrier layer414bbeing 0.001 to 0.2 mm thick. The layer configuration of the second laminate415and the thicknesses of the respective layers were, in order from the outside, a second sealant layer415abeing 0.01 to 0.2 mm thick, and a second gas barrier layer415bbeing 0.001 to 0.2 mm thick. The dimensions of the respective portions of the spout portion410were as follows. That is, the spouting tube portion411had an outer peripheral diameter of 3 to 50 mm and a height of 3 to 50 mm, the flange portion412had an outer peripheral diameter of 8 to 65 mm, and the cap seal413had an outer peripheral diameter of 3 to 50 mm. For each of these dimensions, a plurality of values including a maximum value and a minimum value within the aforementioned range were prepared, and a plurality of spout portions410were produced for every combination of the values.

Spout portions according to Reference Examples, which were identical to the spout portions according to Examples except that the first laminate414and the second laminate415included no barrier layer, were produced.

For each of the spout portions, oxygen permeability was measured under conditions of 25° C. and 65% RH. A MOCON method was used as a measurement method.

The oxygen permeabilities of the spout portions according to Examples were not greater than 3 cc/m2/day/atm. Meanwhile, the oxygen permeabilities of the spout portions according to Reference Examples were 2,000 cc/m2/day/atm. With the measurement results, it was confirmed that the spout portion according to the present embodiment has gas barrier property.

Fifth Embodiment

According to the present embodiment, it is possible to provide a tubular container that can suppress an increase in the thickness of the film to inhibit the contents from remaining inside the trunk portion, while allowing application of decoration or functionality to the film.

A tubular container5100according to a fifth embodiment of the present invention will be described with reference to the drawings. The tubular container5100includes a trunk portion510one end of which is closed, and a spout portion520attached to the other end of the trunk portion510. The tubular container5100further includes, for example, a cap530to be attached to the spout portion520.

FIG.16shows a front view and a side view of the tubular container5100.FIG.17shows a cross-sectional view of the trunk portion510cut along an E-E′ line, and an enlarged view of a major part of the trunk portion510.FIG.16shows, for convenience sake, the spout portion520to which the cap530is not attached.

The trunk portion510is a tubular member that has a closed bottom portion511at one end thereof, and is able to store contents (not shown) therein. The trunk portion510can be formed as follows. That is, a rectangular lamination film514, which has an adhesive layer514acontaining an adhesive material as an innermost layer, is shaped like a tube. Then, opposed parts of the lamination film514at the bottom portion511are adhered to each other, and opposed parts of the lamination film514at the edges along the longitudinal direction of the trunk portion510are adhered to each other. As shown inFIGS.16and17, a joint portion513is formed by making parts of the adhesive layer514aat the edges along the longitudinal direction of the trunk portion510face each other, and adhering the facing parts. The joint portion513has a band shape extending along the longitudinal direction on the surface of a tubular portion of the trunk portion510.

As shown inFIGS.16and17, in the tubular container5100, the joint portion513is formed extending outward from the surface of the tubular portion of the trunk portion510. However, the joint portion513may be adhesively fixed to the surface of the tubular portion. Specifically, as shown in a cross-sectional view ofFIG.18, at a position where the joint portion513is in contact with the tubular portion of the trunk portion510, the joint portion513may be bent along the surface of the trunk portion510and adhered to the surface of the trunk portion510. Therefore, when the user holds and uses the tubular container5100, the joint portion513extending from the surface of the trunk portion510is prevented from touching the hand or the like and hindering the use.

The method of adhering the joint portion513to the surface of the trunk portion510is not particularly limited. For example, heat-seal welding using an adhesive material such as polyethylene or heat-sealable polyethylene terephthalate partially laminated on the surfaces of the joint portion513and the trunk portion510, may be adopted. Alternatively, an adhesion process using a hot-melt adhesive or a heat-seal varnish partially laminated on the surface of at least one of the joint portion513and the trunk portion510, may be adopted.

The layer configuration of the lamination film514is not limited as long as the lamination film514includes the adhesive layer514aas an innermost layer. For example, the lamination film514may be formed by laminating, from the adhesive layer514aside, a polyethylene layer (50 μm), an aluminum foil layer (15 μm), an ink layer, and a polyethylene terephthalate layer (12 μm). Since the polyethylene terephthalate layer is disposed as an outermost layer, the outermost layer is less likely to be damaged and is more lustrous as compared to the case where a polyethylene layer is disposed as an outermost layer of the trunk portion510. A paper layer may be disposed as an outermost layer of the lamination film514. In this case, the texture of the trunk portion510can be enhanced, and the amount of resin can be reduced. Moreover, according to a function required of the tubular container5100, a layer implementing the function may be further added as appropriate.

The material and the adhering method of the adhesive layer514aof the lamination film514are not particularly limited, but heat sealing using polyethylene or polypropylene is simple and therefore preferable.

The spout portion520is a member that is attached to a top portion512located at the other end of the trunk portion510and is able to close the top portion512of the trunk portion510. For example, the spout portion520includes: a tapered portion521which is attached to the top portion512of the trunk portion510, and the outer diameter of which decreases with an increasing distance from the trunk portion510; and a cylindrical portion522contiguous to the tapered portion521. An outer thread522ais formed at the outer peripheral surface of the cylindrical portion522, and an opening of the cylindrical portion522can be closed when the cap530is thread-fitted to the outer thread522a. The material of the spout portion520is not particularly limited, but a resin material such as low-density polyethylene can be preferably used.

As shown inFIG.16, at an edge (peripheral portion) of the tapered portion521, the top portion512of the trunk portion510is adhered to the surface, of the tapered portion521, on the side opposite to the one end of the trunk portion510. The method of adhering the trunk portion510and the spout portion520is not particularly limited, but heat sealing may be adopted, for example.

The cap530is a member that is attached to the spout portion520and enables closing and opening of an opening formed in the cylindrical portion522. For example, the cap530includes a cylindrical side wall531, and a top plate532that covers one end of the side wall531. An inner thread531aengageable with the outer thread522aof the cylindrical portion522is formed at the inner peripheral surface of the side wall531. The material of the cap530is not particularly limited, but a resin material such as polypropylene, polyethylene, or low-density polyethylene can be used.

The configurations of the spout portion520and the cap530are not limited to the present embodiment. For example, the cap530may be a hinge cap including a fixing portion attachable to the spout portion520, and a cap portion pivotally attached to the fixing portion via a hinge.

As described above, in the tubular container5100, an adhesive layer is not provided as an outermost layer, and the parts of the adhesive layer514aas an innermost layer at the edges of the lamination film514are made to face each other to form the joint portion513, whereby the trunk portion510is formed into a tubular shape. Therefore, the rigidity of the trunk portion510formed by using the lamination film514is inhibited from increasing, and the trunk portion510can be squeezed more easily to discharge the contents. As a result, the contents are inhibited from remaining in the trunk portion510.

Moreover, the lamination film514need not be provided with an adhesive layer as an outermost layer, and therefore has less limitation on the layer configuration. Thus, materials can be selected with a high degree of freedom according to required decorations and functions.

Since the rigidity of the trunk portion510is inhibited from increasing, the “air back” phenomenon, i.e., back flow of the contents into the trunk portion510when the load for squeezing the trunk portion510is released and thereby the trunk portion510is restored to the original shape, is less likely to occur. Therefore, it is not necessary to make the contents easy to be squeezed out by, for example, storing the tubular container5100upside down so as to gather the contents to the periphery of the spout portion520. Thus, the contents can be easily squeezed out regardless of the position of the contents.

Moreover, since the trunk portion510is formed in a tubular shape by forming the joint portion513, the tubular container5100can be produced by using a packaging bag producing apparatus for pillow packaging bags, stick packaging bags, or the like without using a molding apparatus dedicated to laminated tubes.

First Modification

FIG.19shows a partial front view and a partial side view of a tubular container5200according to a first modification of the fifth embodiment. The tubular container5200is obtained by providing the tubular container5100with tabs515.

As shown inFIG.19, the joint portion513of the tubular container5200has tabs515extending from the end parts of the adhered lamination films514. The tabs515are not adhered to each other. For example, a pair of tabs515is provided.

When the user holds the tabs515and applies force in directions (directions indicated by black arrows inFIG.19) of opening the joint portion513, the user can separate the joint portion513. Therefore, when the residual amount of contents becomes small along with the use of the tubular container5200and it is difficult to squeeze out the contents, the user can separate the joint portion513by using the tabs515to open the trunk portion510. Thus, the contents attached on the inner surface of the trunk portion510can be taken out, thereby further preventing the contents from remaining in the trunk portion510.

The joint portion513having the tabs515may also be adhered to the trunk portion510together with the tabs515, as described above.

Second Modification

FIG.20shows a partial front view and a partial side view of a tubular container5300according to a second modification of the fifth embodiment. The tubular container5300is obtained by providing the tubular container5100with notches516.

As shown inFIG.20, the joint portion513of the tubular container5300has notches516at the end parts of the joined lamination films514. For example, the joint portion513has two notches516at a predetermined interval. Each notch516is a cutout as shown inFIG.20, but may just be a cut. The number of the notches516is not limited as long as the notches516enable breakage of the lamination film514as described later.

When the user holds the joint portion513and applies force in the circumferential direction of the trunk portion510, the user can break the lamination film514of the trunk portion510from the notches516. Therefore, when the residual amount of contents becomes small along with the use of the tubular container5300and it is difficult to squeeze out the contents, the user can tear the trunk portion510by using the notches516and take out the contents attached on the inner surface of the trunk portion510. Thus, the contents can be further prevented from remaining in the trunk portion510.

The joint portion513having the notches516may also be adhered to the trunk portion510, as described above.

Third Modification

A tubular container5400according to a third modification of the fifth embodiment of the present invention will be described with reference to the drawings. Differences from the tubular container5100will be mainly described. The tubular container5400includes a trunk portion510one end of which is closed, and a spout portion520aattached to the other end of the trunk portion510. Like the tubular container5100, the tubular container5400may further include a cap530to be attached to the spout portion520a.FIG.21shows a front view and a side view of the tubular container5400, andFIG.22shows a side view of the spout portion520a.

The tubular container5400is different from the tubular container5100in the shape of the spout portion520a, as shown inFIGS.21and22. Specifically, the spout portion520ahas, instead of the tapered portion521of the spout portion520, a plate-shaped closing portion521aorthogonal to the longitudinal direction of the trunk portion510. At an edge of the closing portion521a, the other end of the trunk portion510is adhered to a surface, of the closing portion521a, on the side opposite to the one end of the trunk portion510.

FIG.23is a cross-sectional view illustrating the state of the tubular container5400when a small amount of contents remaining in the trunk portion510is taken out. In the tubular container5400, the spout portion520aincludes the plate-shaped closing portion521aorthogonal to the longitudinal direction of the trunk portion510, and the top portion512of the trunk portion510is, at the edge of the closing portion521a, adhered to the surface, of the closing portion521a, on the side opposite to the bottom portion511of the trunk portion510. Therefore, as shown inFIG.23, when the trunk portion510ais bent at the edge of the closing portion521awith a finger or the like, a small amount of contents remaining in the trunk portion510is pushed toward the periphery of the opening of the spout portion520awhile being sandwiched by the inner-side surface of the closing portion521aand the inner surface of the trunk portion510.

Moreover, the closing portion521aof the spout portion520ahas a plate shape, and therefore does not have a space that allows the contents to remain on the inner side, in contrast to the tapered spout portion. Therefore, the contents pushed toward the periphery of the opening of the spout portion520acan be squeezed out from the opening without being remained inside the trunk portion510and the spout portion520a. As a result, remaining of the contents inside the container can be inhibited.

Therefore, according to the tubular container5400in which the spout portion520ais attached to the trunk portion510provided with the joint portion513that prevents remaining of the contents, remaining of the contents can be further inhibited.

The trunk portion510of the tubular container5400may be provided with the tabs515or the notches516.

Fourth Modification

A tubular container5500according to a fourth modification of the fifth embodiment of the present invention will be described with reference to the drawings. Differences from the tubular container5100will be mainly described. The tubular container5500includes a trunk portion510aone end of which is closed, and a spout portion520attached to the other end of the trunk portion510a. Like the tubular container5100, the tubular container5500may further include a cap530to be attached to the spout portion520.FIG.24shows a front view and a side view of the tubular container5500, andFIG.25shows a cross-sectional view of the trunk portion510acut along an F-F′ line.

The tubular container5500is different from the tubular container5100in that the trunk portion510ahas two joint portions513as shown inFIGS.24and25. Specifically, the trunk portion510ais formed such that innermost layers at the edges of two lamination films514are made to face each other and are adhered to each other, thereby providing two joint portions513.

The two lamination films514forming the trunk portion510amay have the same layer configuration or different layer configurations as long as each film514includes the adhesive layer514aas an innermost layer. When the two lamination films514forming the trunk portion510ahave different layer configurations, various functions can be imparted to the tubular container5500. Hereinafter, specific examples of layer configurations of the lamination film514and functions achieved by using the lamination films514of the respective layer configurations, will be described. The layer configurations described below are merely examples. The layer configurations of the two lamination films514are not limited as long as the effects of the specific examples below can be achieved, and more layers may be added as appropriate.

Specific Example 1

In a tubular container5500according to Specific Example 1, one of the two lamination films514forming the trunk portion510ahas a low rigidity such that the contents are easily discharged by squeezing a part of the trunk portion510a, while the other lamination film514has a certain rigidity such that the shape of the trunk portion510ais kept even when the residual amount of contents is small.

The layer configurations of the two lamination films514used in the tubular container5500according to Specific Example 1 are as follows. For example, one of the lamination films514includes polyethylene terephthalate (PET) (12 μm), nylon (NY) (15 μm), and polyethylene (PE) (100 μm) while the other lamination film514includes PET (24 μm), NY (25 μm), and PE (100 μm), in order from the outer side of the trunk portion510a. Alternatively, one of them may include PET (12 pin), NY (15 μm), and PE (100 μm) while the other may include PE (20 μm), paper (200 g/m2), and PE (100 μm), in order from the outer side of the trunk portion510a.

Specific Example 2

In the tubular container5500according to Specific Example 2, the other one of the two lamination films514forming the trunk portion510ahas minute irregularities at the surface thereof. This allows the tubular container5500to change the texture at a part of the surface of the trunk portion510(i.e., between the one and the other lamination films514). Thus, the tubular container5500is interesting, is tactually distinguishable from other containers, and has high designability, that is, the appearance of the trunk portion510abeing partially changed at the surface thereof.

The layer configurations of the two lamination films514used in the tubular container5500according to Specific Example 2 are as follows. For example, one of them includes PET (12 μm), NY (15 μm), and PE (100 μm) while the other includes PET (12 μm) embossed at the outer surface, NY (15 μm), and PE (100 μm), in order from the outer side of the trunk portion510a. Alternatively, one of them may include PET (12 μm), NY (15 μm), and PE (100 μm) while the other may include a textile (woven fabric or cloth) or a nonwoven fabric, a gas barrier layer, and PE (100 μm), in order from the outer side of the trunk portion510a. The gas barrier layer may not necessarily be provided.

Specific Example 3

In a tubular container5500according to Specific Example 3, one of the two lamination films514forming the trunk portion510ahas been subjected to printing, while the other lamination film514has been subjected to vapor deposition of aluminum. Thus, the tubular container5500has high designability, that is, the print being exhibited by the metallic luster.

The layer configurations of the two lamination films514used in the tubular container5500according to Specific Example 3 are as follows. For example, one of them includes PET (12 μm), NY (15 μm), and PE (100 μm) while the other includes aluminum-deposited PET (VM-PET) (12 μm), NY (15 μm), and PE (100 μm), in order from the outer side of the trunk portion510a. The other lamination film514can be subjected to printing.

Specific Example 4

In a tubular container5500according to Specific Example 4, the other one of the two lamination films514forming the trunk portion510ahas air permeability. Thus, the tubular container5500inhibits the inner air pressure from increasing to a predetermined value or more. Moreover, the tubular container5500, after filled with contents, allows the contents to be externally subjected to gas sterilization.

The layer configurations of the two lamination films514used in the tubular container5500according to Specific Example 4 are as follows. For example, one of them includes PET (12 μm), NY (15 μm), and PE (100 μm) while the other is a sheet member (160 μm) having air permeability. As the sheet member having air permeability, Tyvek (registered trademark) can be used, for example.

In the tubular container5500, the two joint portions513are provided at opposed positions in the circumferential direction of the trunk portion510a, for example. The two joint portions513provided at the opposed positions in the circumferential direction of the trunk portion510aallow the tubular container5500to appear larger than that in the case of one joint portion513, thereby enhancing designability.

As shown inFIG.26, the two joint portions513may be provided at positions not opposed to each other in the circumferential direction of the trunk portion510a. The number of the joint portions513provided in the trunk portion510ais not limited to two, and may be three or more. Also in this case, the trunk portion510ais formed such that the innermost layers at the edges of the three or more lamination films514are made to face each other and are adhered to each other. The lamination films514may have the same layer configuration or different layer configurations. Moreover, the joint portions513may be adhesively fixed to the surface of the trunk portion510a.

The tubular container5500in which the spout portion520is attached to the other end of the trunk portion510ahas been described above. However, the tubular container5500may include the spout portion520aaccording to the third modification, instead of the spout portion520. Moreover, the trunk portion510amay include the tabs515or the notches516. Moreover, any of the trunk portions510and510aused in the tubular containers5100to5500according to the fifth embodiment can be attached to any of the spout portions of the tubular containers according to the first to fourth embodiments.

Tubular containers according to Example and Reference Example were produced, and the amounts of remaining contents were compared and evaluated.

EXAMPLE

As a tubular container according to Example, a tubular container5100was produced. The layer configuration of a lamination film was, from the innermost layer side, a polyethylene layer (50 μm) and a polyethylene terephthalate layer (12 μm).

Reference Example

As a tubular container according to Reference Example, a tubular container in which only the layer configuration of the lamination film was changed from that of Example, was produced. The layer configuration of the lamination film was, from the innermost layer side, a polyethylene layer (100 μm), an EVOH layer (20 μm), and a polyethylene layer (100 μm).

After each of the produced tubular containers was filled with mustard paste, the mustard paste was squeezed out with the same load, and the amount of mustard paste remaining in each trunk portion was measured.

As a result, in the tubular container according to Reference Example, gaps were formed at folded lines, of the lamination film, located at the opposed ends in the width direction of the trunk portion, and the contents remained in these spaces. On the other hand, in the tubular container according to Example, gaps were hardly formed at the opposed ends in the width direction of the trunk portion, and therefore, the amount of remaining contents was very small. Moreover, in the tubular container according to Example, when a part of the trunk portion was inserted into the tapered portion of the spout portion, even the contents remaining inside the tapered portion could be squeezed out. However, in the tubular container according to Reference Example, since the rigidity of the trunk portion was high, the contents remaining inside the tapered portion could not be squeezed out.

As a result, the amount of contents remaining in the tubular container according to Example was half the amount of contents remaining in the tubular container according to Reference Example. Thus, it was confirmed that the tubular container according to Example inhibited the contents from remaining inside the trunk portion.

Sixth Embodiment

According to the present embodiment, it is possible to provide a tubular container that does not require highly accurate alignment for welding of the trunk portion to the spout portion, and therefore can be easily produced.

A tubular container6100according to a sixth embodiment of the present invention will be described with reference to the drawings. The tubular container6100includes a trunk portion610having a closed bottom portion611at one end thereof, and a spout portion620attached by welding to a top portion612at the other end of the trunk portion610. The tubular container6100is typically used with a cap (not shown) being attached to the spout portion620.

FIG.27shows a front view of the tubular container6100.FIG.28shows a plan view ((a) ofFIG.28) and a cross-sectional view ((b) ofFIG.28) of a major part, cut along a G-G′ line.

The trunk portion610is a tubular member that is formed of a soft material, has the closed bottom portion611, and is able to store contents (not shown) therein. In order to attach the spout portion620to the top portion612of the trunk portion610by welding, the trunk portion610is formed so as to contain a material that can be welded to at least an inner peripheral surface of the top portion612.

The trunk portion610can be formed by using a film, for example. More specifically, after a film is shaped like a tube, parts of the film at the bottom portion611are adhered to each other, and parts of the film at the edges along the longitudinal direction of the trunk portion610are adhered to each other. The film adhering method is not particularly limited. For example, heat sealing, bonding using a tap, or the like can be adopted. When adhering the parts of the film at the edges along the longitudinal direction of the trunk portion610, this adhesion may be performed such that the edges of an innermost layer of the film are made to face each other and adhered (butt-seam sealing), such that the innermost layer and an outermost layer of the film are made to face each other and adhered (envelope-like sealing), or such that the end parts of the film are made to abut on each other. The trunk portion610includes, for example, a joint portion613formed by making the edges of the innermost layer of the film face each other, and adhering the edges.

The spout portion620is a member that is attached to the top portion612and is able to close the top portion612of the trunk portion610. The spout portion620includes a discharge portion621for discharging the contents stored in the trunk portion610, and a peripheral portion622formed around the discharge portion621. As shown inFIG.27, the discharge portion621is a cylindrical member, for example. However, the shape of the discharge portion621is not limited as long as it can discharge the contents, and may be merely an opening. The peripheral portion622has a circular plate shape, for example. However, the shape of the peripheral portion622is not limited as long as the top portion612can be attached to the spout portion620, and may be an ellipse, an elongated circle, a polygon, or any other shape. Alternatively, the peripheral portion622may have a tapered shape the outer diameter of which decreases with an increasing distance from the top portion612. The material of the spout portion620is not particularly limited, but a material that can be welded to a weldable material on the inner peripheral surface of the trunk portion610is preferable. For example, a resin material such as low-density polyethylene can be used.

The spout portion620further includes, inside the discharge portion621, a partition wall623in which an annular half cut is formed, and a pull ring624attached to the partition wall623, for example. Therefore, when the user of the tubular container6100pulls the pull ring624to remove a part of the partition wall623along the half cut, an opening for taking out the contents is formed in the partition wall623.

As shown in (b) ofFIG.28, in a first area that is an area over the entire circumference of a surface on the outer side of the tubular container6100, the inner peripheral surface near the top portion612of the folded trunk portion610is welded to the peripheral portion622of the spout portion620. In addition, in the tubular container6100, for example, the top portion612includes a plurality of pleated parts612aformed by folding back the top portion612such that opposed parts of the inner peripheral surface of the trunk portion610abut on each other.

The number of the pleated parts612ais appropriately adjustable according to the shape of the peripheral portion622, the thickness of the film forming the trunk portion610, or the like. In the tubular container6100, for example, 16 pleated parts612aare provided. From the viewpoint of designability, strength of a processing machine for forming pleated parts612a, and the like, the number of the pleated parts612ais preferably not less than 3 and not greater than 60, and more preferably, not less than 3 and not greater than 36.

The interval of the pleated parts612ain the peripheral portion622is appropriately adjustable according to the shape of the peripheral portion622, the thickness of the film forming the trunk portion610, or the like. When the peripheral portion622has a shape, such as an ellipse, the curvature radius of which varies over the circumferential direction of the trunk portion610, the pleated parts612amay be arranged such that, for example, the interval of the pleated parts612ais reduced in an area where the curvature radius is small while the interval of the pleated parts612ais increased in an area where the curvature radius is great. In the tubular container6100, since the peripheral portion622has a circular shape, the pleated parts612aare arranged at equal intervals over the circumferential direction of the trunk portion610, for example. Since the interval of the pleated parts612ais varied according to the curvature radius of the peripheral portion622, the top portion612can be folded along the edge of the peripheral portion622. The folded part of the top portion612need not completely abut on the edge of the peripheral portion622. However, in order to increase the connection strength between the trunk portion610and the spout portion620, the edge of the peripheral portion622is preferably inscribed in the folded part of the top portion612, as viewed in the longitudinal direction of the trunk portion610.

Next, an example of a method of welding the top portion612to the peripheral portion622will be described with reference toFIG.29.FIG.29shows a plan view and a cross-sectional view of a major part, illustrating a process of welding the trunk portion610of the tubular container6100to the peripheral portion622.

Firstly, the spout portion620is inserted near the top portion612of the trunk portion610in the tubular shape, the bottom portion611of which is not yet closed. Thereafter, the top portion612is folded toward an upper side of the peripheral portion622by using a processing machine having claws corresponding to the number of the pleated parts612a. InFIG.29, (a) shows a plan view of the tubular container6100and a cross-sectional view of the top portion612and its vicinity, in the state where the top portion612is folded toward the upper side of the peripheral portion622.

As shown in (a) ofFIG.29, the folded top portion612includes alternating contact parts612band non-contact parts612cover the circumferential direction of the trunk portion610. Each contact part612bis in contact with the peripheral portion622while each non-contact part612cis not in contact with the peripheral portion622and protrudes outward from the tubular container6100. In the tubular container6100, the top portion612is folded such that the width of the contact part612bin the circumferential direction of the trunk portion610is wider than the width of the non-contact part612cin the circumferential direction.

Next, the entirety of the top portion612is heated and pressed by a ring-shaped thermocompression means630from above. InFIG.29, (b) shows a plan view of the tubular container6100and a cross-sectional view of the top portion612and its vicinity, in the state where the top portion612is heated and pressed by the thermocompression means630. Thus, the contact parts612bare welded to the peripheral portion622. Meanwhile, when the non-contact parts612care pressed by the thermocompression means630, at least a part of each non-contact part612cis folded back such that opposed parts of the inner peripheral surface of the trunk portion610abut on each other, resulting in two pleated parts612ain which opposed parts of the inner peripheral surface are welded to each other. A part of the non-contact part612cin which opposed parts of the inner peripheral surface of the trunk portion610do not abut on each other (i.e., a part that is not formed into a pleated part612a) may be welded to the peripheral portion622. As a specific welding method using the thermocompression means630, hot-plate pressing, ultrasonic sealing, high-frequency sealing, impulse sealing, or the like can be adopted.

First Modification

The configuration of the top portion612when being adhered to the peripheral portion622is not limited to the above configuration as long as the top portion612includes the contact parts612band the non-contact parts612c. For example, the top portion612may be folded such that the width of each non-contact part612cin the circumferential direction of the trunk portion610is wider than the width of each contact part612bin the circumferential direction.FIG.30shows plan views and cross-sectional views of a major part, illustrating a process of welding the trunk portion610to the peripheral portion622in a tubular container6200according to a modification in which the width of each non-contact part612cin the circumferential direction of the trunk portion610is wider than the width of each contact part612bin the circumferential direction. InFIG.30, (a) shows a state where the top portion612is folded toward an upper side of the peripheral portion622, and (b) shows a state where the top portion612is heated and pressed by the thermocompression means630.

As shown in (b) ofFIG.30, in the tubular container6200, each contact part612bis welded to the peripheral portion622by the thermocompression means630, as in the tubular container6100. Meanwhile, each non-contact part612cis at least partially formed into two pleated parts612a, and a part that is not formed in a pleated part612acan be adhered to the peripheral portion622.

As described above, in the tubular containers6100and6200, the trunk portion610and the spout portion620are attached to each other by welding, to the peripheral portion622, the inner peripheral surface near the top portion612, of the trunk portion610, which is folded in the first area. Therefore, welding can be performed in a wider area as compared to the conventional art, and highly accurate alignment is not required for the welding of the trunk portion610to the spout portion620, thereby facilitating the production.

Moreover, in the tubular containers6100and6200, since heat shrinkage is not required during the welding of the trunk portion610and the spout portion620, a material such as aluminum foil that hardly shrinks by heat can be used, thereby increasing the range of material choice, and increasing the degree of freedom in design.

Moreover, since the inner peripheral surface near the top portion612, of the trunk portion610, which is folded in the first area is welded to the peripheral portion622, an angle formed between the peripheral portion622and the trunk portion610can be set to be greater than in the case where welding is performed on a round-chamfered portion by using heat shrinkage. Therefore, the amount of contents remaining inside the spout portion620can be reduced as compared to a spout portion having a tapered shape. Moreover, since the spout portion620does not have a tapered shape, the contents can be easily pushed out by squeezing the trunk portion610until closely contacting with the discharge portion621of the spout portion620.

The spout portion620in which the surface of the peripheral portion622is flat has been described above. However, for example, projections each corresponding to the shape of a pleated part612amay be formed in advance in a place where pleated parts612aare to be provided. In this case, contact parts612band non-contact parts612ccan be formed along the projections, thereby facilitating folding of the top portion612.

Furthermore, cutouts corresponding to pleated parts612amay be formed in advance in a portion to be the top portion612. Thus, formation of pleated parts612athrough heating and compression is facilitated.

Second Modification

FIG.31shows a cross-sectional view of a major part of a tubular container6300according to a modification of the sixth embodiment. A difference between the tubular container6300and the tubular container6100is presence/absence of a gas barrier layer614provided in the trunk portion610and a barrier film625provided in the spout portion620.

As shown inFIG.31, the spout portion620of the tubular container6300includes a second area in which the barrier film625is provided on a surface facing the inside of the tubular container6300. A film forming the trunk portion610includes the gas barrier layer614. The trunk portion610is adhered and attached to the spout portion620such that the first area and the second area overlap each other, as viewed from a normal direction in the third area over the entire circumference of the peripheral portion622of the spout portion620.

Therefore, in the tubular container6300the trunk portion610of which is attached to the spout portion620, an area having no gas barrier property is absent as viewed from the normal direction at each position in the peripheral portion622, thereby realizing high gas barrier property.

The trunk portion610used in any of the tubular containers6100to6300according to the sixth embodiment may be attached to the spout portion of the tubular container according to any of the first to fourth embodiments.

Seventh Embodiment

According to the present embodiment, it is possible to provide a tubular container that can inhibit the contents from remaining inside the container.

A tubular container7100according to a seventh embodiment of the present invention includes a trunk portion710one end of which is closed, and a spout portion720attached to the other end of the trunk portion710.FIG.32shows a front view and a side view of the tubular container7100.FIG.33andFIG.34each are a cross-sectional view of the trunk portion710cut along a K-K′ line.

The trunk portion710is a tubular member having a closed bottom portion711at one end thereof, and includes a storage portion713in which contents can be stored. The trunk portion710is formed by using a film. A thinnest part of the film surrounding the storage portion713has a thickness T1not smaller than 40 μm and not greater than 200 μm, and a thickest part of the film has a thickness T2not greater than twice the thickness T1.

The trunk portion710has, for example, a joint portion714formed by joining the edges of the film to each other. As shown inFIG.33, the joint portion714is formed by making an inner layer and an outer layer face each other at the edges of the film, and joining these layers. The joint portion714is formed extending along the longitudinal direction of the trunk portion710. In the trunk portion710, the thickness T1is the thickness of the film, and the thickness T2is the thickness of the joint portion714.

The joint portion714can be formed by, for example, providing a sealant layer containing polyethylene on a front surface and a rear surface of the film, and heat-sealing these sealant layers. After the heat sealing, the joint portion714may be pressed while being further heated. Thus, the fused sealant layers overflow from the end faces of the film and form a protection layer715at the end faces of the film. When the film is a lamination film, the protection layer715inhibits delamination of the lamination film from the end faces.FIG.34is a cross-sectional view of the trunk portion710having the protection layer715.

The layer configuration of the film used for forming the trunk portion710may be a single-layer film, or a multi-layer film molded by lamination or extrusion The film can be formed by using, but not particularly limited to, a resin material such as polyethylene terephthalate (PET), nylon (NY), or straight-chain (linear) low-density polyethylene (LLDPE), for example. The film member may include a known functional film according to a function required of the trunk portion710. For example, in order to impart gas barrier property to the trunk portion710, a film containing aluminum foil, EVOH resin, or the like may be laminated.

The spout portion720is a member that is attached to the top portion712located on the other end of the trunk portion710and is able to close the top portion712of the trunk portion710. Since the spout portion720is identical to the spout portion120used in the tubular container1100, repeated description is not necessary.

As shown inFIG.32, at an edge of a closing portion721, a top portion712of the trunk portion710is bent along the surface, of the closing portion721, on the side opposite to the bottom portion711of the trunk portion710, and is adhered to the closing portion721. For example, when the trunk portion710is formed of a film having a sealant layer containing polyethylene as an innermost layer while the spout portion720is formed of a material containing polyethylene, the trunk portion710and the closing portion721can be adhered to each other by heat sealing.

Since the thickness T1is not smaller than 40 μm and not greater than 200 μm, a constant strength of the trunk portion710is ensured, and rigidity of the trunk portion710is inhibited from becoming excessively high. In addition, since the thickness T2is not greater than twice the thickness T1, the joint portion714is inhibited from being thicker than the rest of the trunk portion710, thereby inhibiting uneven thickness of the top portion712. Thus, the top portion712can be easily bent along the surface, of the closing portion721, on the side opposite to the bottom portion711, and moreover, joint failure, i.e., partial delamination at the joint portion between the top portion712and the closing portion721due to uneven thickness, can be inhibited. Moreover, degradation of designability caused by the joint portion714swelling on the closing portion721, can be inhibited.

First Modification

Next, a tubular container7101according to a first modification of the seventh embodiment will be described. The tubular container7101includes a trunk portion710aone end of which is closed, and a spout portion720attached to the other end of the trunk portion710a.FIG.35shows a front view of the tubular container7101, andFIG.36is a cross-sectional view of the trunk portion710acut along an L-L′ line.

The tubular container7101is different from the tubular container7100in the method of joining the edges of a film forming the trunk portion710a. Specifically, as shown inFIG.36, the edges of the film of the trunk portion710aare covered with a tape member714awhile the end faces thereof abut on each other. In the trunk portion710a, the tape member714acovers the edges of the film from the inner side of the trunk portion710a, and extends along the longitudinal direction of the trunk portion710a. In the trunk portion710a, a thickness T1is the thickness of the film, and a thickness T2is the thickness in an area where the tape member714acovers the film, i.e., the total thickness of the film and the tape member714a.

The material of the tape member714amay be the same as or different from the material of the film. The tape member714amay be formed by using a lamination film including a functional film such as a gas barrier film according to a required function.

The thickness of the tape member714ais preferably small in order to inhibit the thickness T2from increasing. However, as long as the thicknesses T1and T2are in the aforementioned ranges, the thickness of the tape member714amay be greater than the thickness of the film. The tape member714acan be formed by using, but not particularly limited to, a resin material such as polyethylene or polyethylene terephthalate.

The tape member714amay have an end part protective shape716that covers and protects an end part. InFIG.37, (a) and (b) each show a cross-sectional view of the tape member714acut along a plane orthogonal to the length direction thereof. The tape member714ashown in (a) ofFIG.37has, for example, an end part protective shape716obtained by folding back an end part. Meanwhile, the tape member714ashown in (b) ofFIG.37has, for example, an end part protective shape716covering an end part with a sealant. Since the end part of each tape member714ais covered with the end part protective shape716, delamination of a laminated film from the edge can be inhibited when the film is a lamination film. The tape member714amay cover the edges of the film from the outer side of the trunk portion710a, or from both the outer side and the inner side of the trunk portion710a.

The tubular container7101also can inhibit the contents from remaining inside thereof. Moreover, since the thickness T1of the trunk portion710ais not smaller than 40 μm and not greater than 200 μm and the thickness T2is not greater than twice the thickness T1, occurrence of joint failure and degradation of designability are inhibited.

Second Modification

As long as the thicknesses T1and T2are within the aforementioned ranges, the film of the trunk portion710amay have a predetermined gap between the end parts thereof.FIG.38is a cross-sectional view of the trunk portion710aaccording to a second modification. The trunk portion710aaccording to the second modification has a gap between the end parts. Therefore, for example, if the tape member714ahas air permeability, the internal pressure of the trunk portion710acan be inhibited from increasing to a predetermined pressure or more. Moreover, if the tape member714ais a transparent film, the amount of contents in the trunk portion710acan be visually recognized through the tape member714a.

Third Modification

Next, a tubular container7102according to a third modification of the seventh embodiment will be described. The tubular container7102includes a trunk portion710bone end of which is closed, and a spout portion720attached to the other end of the trunk portion710b.FIG.39shows a front view of the tubular container7101.FIG.40is a cross-sectional view of the trunk portion710bcut along an M-M′ line.

The tubular container7102is different from the tubular container7100in the method of joining the edges of a film forming the trunk portion710b. Specifically, as shown inFIG.40, the edges of the film of the trunk portion710bare joined to each other such that the end parts of the film are sloped with respect to the film in its flat state, and the sloped end parts are opposed to each other and joined so that the thickness of the trunk portion710bin the circumferential direction is substantially constant. A joint portion714bformed by joining the end parts extends along the longitudinal direction of the trunk portion710b. The end parts of the joint portion714bcan be joined by welding or adhesion. In the trunk portion710, a thickness T1is the thickness of the film, and a thickness T2is the thickness of the Joint portion714. Since the trunk portion710bhas the substantially constant thickness in the circumferential direction as described above, the thickness T1is substantially equal to the thickness T2as shown inFIG.40.

The tubular container7102also can inhibit the contents from remaining inside thereof. Moreover, since the thickness T1of the trunk portion710bis not smaller than 40 μm and not greater than 200 μm and the thickness T2is not greater than twice the thickness T1, occurrence of joint failure and degradation of designability are inhibited.

The method of forming the trunk portion710is not limited to the aforementioned methods, and any method, such as fusing, extrusion molding, or blow molding, may be adopted as long as the method ensures the thicknesses T1and T2of the trunk portion710to be within the aforementioned ranges.

The film member used for the trunk portion in any of the embodiments described above and the modifications thereof may have a loop stiffness value not greater than 600 mN for a loop length of 60 mm in the width direction of the trunk portion.

The loop stiffness value is as follows. That is, a loop is formed by using a film member that is cut into a strip shape of a predetermined size, the loop is pressed by a predetermined amount in the diameter direction, and then the repelling force of the loop is measured. The loop stiffness value is the measured repelling force, and is an index indicating the rigidity of the film. The larger the loop stiffness value is, the higher the rigidity of the film is. The loop stiffness value was measured by using a loop stiffness tester manufactured by Toyo Seiki Co., Ltd., according to the procedure and condition as follows. Firstly, the film member used for the trunk portion was cut into a strip shape having a width of 25 mm and a length of 120 mm. Then, the strip-shaped film was set on the tester such that the longitudinal direction thereof corresponds to the direction of the measurement target, and a loop was formed. At this time, the loop length was 60 mm. Thereafter, a contact plate of the tester was pressed against the formed loop to squeeze the loop, and the repelling force of the loop was measured. The squeezing distance was 20 mm, and the compression rate was 3.5 mm/s.

The rigidity of the formed trunk portion can be reduced by using a material having a small loop stiffness value and a low elasticity as the film member. Therefore, after the trunk portion formed by using the film member having a loop stiffness value not greater than 600 mN is deformed and the contents are squeezed out, restoration of the trunk portion to the original shape can be avoided. Thus, occurrence of air back, i.e., inflow of air into the trunk portion, can be inhibited. As a result, deterioration of quality of the contents due to the inflow air can be inhibited, and the contents can be squeezed out without turning the spout portion upside down, whereby occurrence of abrupt spouting of the contents can be inhibited.

Since the material of the film member contains a resin, the film member can be deformed with a smaller force as compared to the trunk portion formed of a layer mainly composed of a material having high dead hold property. Therefore, even when the contents have high viscosity, the contents can be easily squeezed out. Moreover, generation of minute holes in the film member due to repetitive use can also be inhibited.

Since the loop stiffness value of the film member is reduced to 600 mN or less, the film member can be formed of less material, and the layer configuration of the film member is simplified, thereby reducing the production cost.

Since the elasticity of the film member is low, the trunk portion can be produced by using a bag making machine capable of making bag-shaped packaging containers without using a relatively expensive tubing machine, thereby reducing the production cost.

In this case, the spout portion may be provided with a valve that allows outflow of the contents from the trunk portion, and regulates inflow of air into the trunk portion while the contents do not flow out. Thus, since the loop stiffness value of the trunk portion is not greater than 600 mN, the trunk portion is prevented from being restored to the original shape, and moreover, the valve being closed regulates inflow of air into the trunk portion more reliably, whereby occurrence of air back can be inhibited more reliably. In particular, even when a valve of a simple structure, the backflow checking effect of which is limited, is used, occurrence of air back can be effectively inhibited in the entire tubular container. Therefore, the production cost of the tubular container can be reduced.

The thickness of the film member can be not smaller than 30 μm and not greater than 200 μm, and the loop stiffness value can be not greater than 600 mN for the loop length of 60 mm in the width direction of the trunk portion. Thus, when the contents are squeezed out, the trunk portion can be evenly pressed and squeezed up to the end part thereof to reduce the curvature radius at the end part in the width direction of the trunk portion, thereby inhibiting remaining of the contents. Also in this case, the loop stiffness value is measured according to the aforementioned procedure and condition.

The thickness of the film member can be not smaller than 30 μm and not greater than 200 μm, and the trunk portion may have ruled lines extending in the length direction of the trunk portion, between the other end of the trunk portion and at least one of both ends of the bottom portion11in the width direction. Thus, when the contents are squeezed out, the film member can be bent along the ruled lines. This prevents gaps which cannot be squeezed flat from being formed at the end parts in the width direction of the trunk portion, thereby inhibiting remaining of the contents in such gaps. The ruled lines can be formed by, for example, heating and pressing the trunk portion at a temperature not higher than the fusing point of the material forming the film member.

In the tubular container according to any of the aforementioned embodiments and the modifications thereof, the components such as the spout portion, the trunk portion, and the cap may be formed of a mono-material in order to facilitate recycling. Examples of a usable material include, but not particularly limited to, PP including biaxially stretched polypropylene (OPP) and unstretched polypropylene (CPP). Examples of a layer configuration of a film member used for forming the trunk portion include: OPP (20 μm) with gas barrier property/CPP (80 μm); OPP (20 μm)/OPP (20 μm) with gas barrier property/CPP (80 μm); and OPP (30 μm)/CPP (80 μm). The thickness of each layer can be changed as appropriate according to the capacity of the trunk portion. Moreover, for production of the spout portion, a single PP or a PP blended with a resin having gas barrier property can be used.

As for an example using other materials, there is a film member having gas barrier property and including: a gas barrier lamination that includes a base layer, a first polyvinyl alcohol resin layer, a thin film layer containing Si or Al, and a second polyvinyl alcohol resin layer in this order; and a sealant layer provided on the surface of this gas barrier lamination.

In this case, the second polyvinyl alcohol resin layer may contain a silane compound. The mass ratio of the silane compound may be 0.005 to 0.80 from the viewpoint of maintaining the gas barrier property and the adhesiveness with the thin film layer containing Si or Al.

The thin film layer containing Si or Al may contain at least one of silicon oxide and aluminum oxide. The thin film layer containing Si or Al may contain silicon oxide and aluminum oxide from the viewpoint of transparency and barrier property, and may contain silicon oxide from the viewpoint of improving tensile stretch property during machining. Use of the thin film layer containing Si or Al achieves high barrier property while reducing the thickness.

The thickness of the thin film layer containing Si or Al can be not smaller than 5 nm and not greater than 80 nm. When the thickness is 5 nm or more, sufficient gas barrier property can be achieved. When the thickness is 80 nm or less, cracks are inhibited from being caused by deformation due to the internal stress of the thin film layer, thereby inhibiting reduction in the gas barrier property. If the thickness exceeds 80 nm, the cost is likely to increase due to an increase in the use amount of materials, an increase in time required for film formation, or the like, which is undesirable from an economical viewpoint.

The mass of the first polyvinyl alcohol resin layer per unit area can be not smaller than 0.1 g/m2and not greater than 10 g/m2. When the mass is 0.1 g/m2or more, the surface of the first polyvinyl alcohol resin layer can be formed sufficiently flat even when the flatness of the surface of the base layer is insufficient, whereby a thin film layer containing Si or Al having excellent gas barrier property can be formed on the surface of the first polyvinyl alcohol resin layer. Meanwhile, the mass being 10 g/m2or less is advantageous from the viewpoint of realizing a mono-material tubular container and reducing the material cost.

The roughness Sa of the first polyvinyl alcohol resin layer on the side in contact with the thin film layer containing Si or Al may be 0.2 μm or less. Thus, a thin film layer containing Si or Al, excellent in gas barrier property, can be formed on the surface of the first polyvinyl alcohol resin layer. The roughness Sa means a value measured by using VertScan (manufactured by Ryoka Systems Inc.).

From the viewpoint of achieving excellent oxygen barrier property, the surface of the first polyvinyl alcohol resin layer on the side in contact with the thin film layer containing Si or Al may have a logarithmic decrement not greater than 0.20 at 100° C. and a logarithmic decrement not greater than 0.30 at 125° C., which are measured by using a rigid body pendulum-type physical property tester. The logarithmic decrements can be measured by a rigid body pendulum method (rigid body pendulum-type physical property tester RPT-3000W manufactured by A&D Company, Limited). Measurement is performed using RBP-020 as a pipe edge, under heating from 30° C. to 130° C. with a temperature rise rate of 10° C./min. Measurement is performed at three positions under this condition, and an average value of logarithmic decrements at each of 100° C. and 125° C. is calculated. The smaller logarithmic decrement means that molecules of the resin forming the surface of the measurement target are less likely to move even when subjected to heat.

The base layer may contain at least one selected from the group consisting of polyolefin, polyester, and polyamide.

The base layer of the gas barrier laminate may be formed of a polyolefin resin, the sealant layer may be formed of a polyolefin resin, and the content of the polyolefin resin may be 90% by mass or more with respect to the total mass of the trunk portion. This realizes a mono-material trunk portion.

The base layer may be a propylene monopolymer layer. Use of a propylene monopolymer film (monopolymer layer) as the base layer is advantageous in heat resistance, but is disadvantageous because the surface of the propylene monopolymer film is likely to be veined. Therefore, even when the thin film layer containing Si or Al is directly formed on the surface of the propylene monopolymer film, sufficient barrier property cannot be achieved. Therefore, a polyvinyl alcohol resin layer is interposed between the propylene monopolymer film and the thin film layer containing Si or Al to achieve excellent gas barrier property. Using both the propylene monopolymer film as the base layer and the polypropylene resin film as the sealant layer enables production of a mono-material trunk portion.

The present invention is applicable to packaging containers that can be filled with pharmaceutical products, cosmetic products, foods, etc.