JP2020152426A - Double structure container - Google Patents

Abstract

To provide a double structure container which allows air to flow in and out of a space between an outer cylindrical container and an inner bag container with extremely simple configuration without formation of an air introduction port at a neck part of the outer cylindrical container.SOLUTION: A double structure container comprises an outer cylindrical container 3, and an inner bag container 5 accommodated in the outer cylindrical container 3. In this double structure container, the outer cylindrical container 3 has an outer cylinder neck part 11, and a shank 15 which is continued to the outer cylinder neck part 11 and is stretch-molded, and the inner bag container 5 has an inner bag neck part 21, and a bag-like part 23 which is continued to the inner bag neck part 21 and is stretch-molded. A ring-shaped projection 43 for fitting fixation to an inner face of the outer cylinder neck part 11 is provided on a lower portion of an outer face of the inner bag neck part 21. The ring-shaped projection 43 has a notch 43a for formation of an air duct, and a small flange 41, which has a diameter smaller than that of the ring-shaped projection 43, extends outward in a horizontal direction at an upper end of the inner bag neck part 21. In the state that the inner bag container 5 is accommodated in the outer cylindrical container 3, the ring-shaped projection 43 of the inner bag neck part 21 is fitted and fixed to the inner face of the outer cylinder neck part 11.SELECTED DRAWING: Figure 2

Description

The present invention relates to a double-structured container including an outer cylinder container and an inner bag container inserted and held in the outer cylinder container.

Conventionally, a double-structured container having a double-structured structure consisting of an inner bag container and an outer cylinder container has been put into practical use as, for example, an airless bottle and a container for storing a seasoning liquid such as soy sauce. Such an airless bottle is used in combination with a cap with a check valve, and is filled in an inner bag container by squeezing and denting the body wall of the bottle, which is an outer cylinder container, from the outside. When the content liquid is discharged from the pouring path formed in the cap and the discharge of the content liquid is completed by stopping the pressing of the body wall of the bottle, the air is sent to the inner bag container by the action of the check valve. It will not be introduced, but will be introduced into the space between the inner bag container and the outer cylinder container through a flow path different from the pouring path of the cap. As a result, the inner bag container shrinks by the amount that the content liquid is discharged, and each time the content liquid is discharged, the inner bag container shrinks. In an airless bottle in which the content liquid is discharged by such a method, the content liquid can be dispensed and the intrusion of air into the inner bag container filled with the content liquid is effectively prevented. There is an advantage that the freshness of the content liquid can be maintained for a long period of time.

Therefore, in the double-structured container, in order to secure the air flow as described above, an introduction port that penetrates the wall of the neck of the outer cylinder container is generally provided, and further, it is attached to the neck of the outer cylinder container. A valve body that swings up and down is provided on the inner surface of the tubular side wall (skirt portion) of the cap to be formed, and the valve body is configured to control the flow of air through the introduction port. (See, for example, Patent Document 1).
Therefore, in the double-structured container as described above, it is necessary to form an air inlet by post-processing, and there is a problem that the productivity is low.

Further, the cap attached to the double-structured container is generally attached by screw engagement (for example, Patent Document 2), but in such a method, the neck portion of the outer cylinder container (or the neck portion of the inner cylinder container). A screw thread for attaching the cap is required on the outer surface of the container, which increases the height of the outer cylinder container and the inner bag container, resulting in a large amount of resin and a heavy container weight. It ends up.

JP-A-2018-2198 JP-A-2017-222141

Therefore, an object of the present invention is that air can be taken in and out of the space between the outer cylinder container and the inner bag container in an extremely simple form without forming an air inlet at the neck of the outer cylinder container. The purpose is to provide a double-structured container.
Another object of the present invention is to provide a double-structured container in a form suitable for attaching a cap by plug fitting.

According to the present invention, in a double-structured container composed of an outer cylinder container and an inner bag container housed inside the outer cylinder container,
The outer cylinder container has an outer cylinder neck portion and a body portion connected to the outer cylinder neck portion and formed by stretching.
The inner bag container has an inner bag neck portion and a bag-shaped portion connected to the inner bag neck portion and formed by stretching.
The outer surface of the inner bag neck portion is provided with a ring-shaped protrusion for fitting and fixing to the inner surface of the outer cylinder neck portion at a lower portion, and the ring-shaped protrusion has a notch for forming an air passage. At the same time, a small flange having a diameter smaller than that of the ring-shaped protrusion extends outward in the horizontal direction at the upper end of the inner bag neck portion.
A double-structured container characterized in that, in a state where the inner bag container is housed in the outer cylinder container, the ring-shaped protrusion of the inner bag neck portion is fitted and fixed to the inner surface of the outer cylinder neck portion. Provided.

In the double-structured container of the present invention, the following aspects can be preferably adopted.
(1) The upper end of the inner surface of the outer cylinder neck portion is a contact surface with which an air valve formed on a cap mounted on the double-structured container comes into contact, and is an outer surface of the bag-shaped portion of the inner bag. The air passage for introducing air into the space between the outer cylinder container and the inner surface of the body of the outer cylinder is the inner surface of the outer cylinder neck portion, the contact surface of the upper end portion of the inner surface, and the air passage for discharging air from the space. It shall be formed along the upper end surface of the outer cylinder neck and the outer surface of the outer cylinder neck.
(2) The surface that the air valve comes into contact with is an inclined surface that inclines and descends inward from the upper end of the inner surface of the outer cylinder neck portion.
(3) An undercut for plugging and fitting the cap is provided on the upper part of the outer surface of the outer cylinder neck portion, and the undercut is formed with a notch forming the air passage. ..
(4) The outer surface of the inner bag neck portion is provided with a ring-shaped protrusion for fitting and fixing to the inner surface of the outer cylinder neck portion, and the ring-shaped protrusion is formed with a notch forming the air passage. is being done.
(5) The inner surface of the outer cylinder neck portion is provided with a step that regulates the axial position of the inner bag neck portion in the outer cylinder neck portion by engaging with the ring-shaped protrusion.

In the double-structured container of the present invention, a small flange extending outward in the horizontal direction is formed on the outer surface of the upper end of the inner bag neck portion, and this small flange is used to form a preform for forming the inner bag. It is pushed into the preform for the outer cylinder container (plugging), and the ring-shaped protrusion for fitting and fixing provided below the outer surface of the inner bag neck is fitted to the inner surface of the outer cylinder neck to fit the inner surface. The bag preform is stably held in the outer cylinder preform, and is manufactured by performing stretch blow molding in this state. In the double-structured container manufactured in this manner, the fitting and fixing ring is provided with a notch for forming an air passage, and at the same time, the small flange provided at the upper end of the outer surface of the inner bag neck is provided. , The diameter is set smaller than the above-mentioned ring-shaped protrusion for fitting and fixing. For this reason, the small flange of the inner bag neck that is housed in the outer cylinder neck does not have a structure that covers the upper end surface of the outer cylinder neck, and the upper end of the outer cylinder neck and the upper end of the inner bag neck A gap is formed between them. That is, a straight space is formed along the inner surface of the outer cylinder neck portion above the ring-shaped protrusion of the inner bag neck portion, and this space is formed in the ring-shaped protrusion for forming an air passage. Through the notch, it communicates with the space (working space) between the bag-shaped part of the inner bag container and the body part of the outer cylinder container. Therefore, the straight space formed along the inner surface of the outer cylinder neck portion can be used as an air passage for introducing air into the working space. In the present invention, since this straight space can be used as an air passage, it is not necessary to form an air inlet at the neck of the outer cylinder, which is the greatest advantage of the present invention.

For example, in the double-structured container of the present invention, since the upper end surface of the outer cylinder neck portion is not covered by the small flange of the inner bag neck portion, the inner surface of the upper end portion of the outer cylinder neck portion has a cap attached to this container. It can be a surface that comes into contact with the air valve, and with such a structure, the inner surface of the outer cylinder neck portion, the contact surface of the inner surface upper end portion, the upper end surface of the outer cylinder neck portion, and the outer cylinder neck portion. An air passage is formed along the outer surface of the outer cylinder, and the space (working space) between the outer surface of the bag-shaped part of the inner bag and the inner surface of the body of the outer cylinder container is formed without forming an air inlet at the neck of the outer cylinder. It is possible to introduce air and expel air from the space.

Further, the contact surface may be a so-called straight straight body surface, but by making this portion an inclined surface, the structure of this double-structured container can be attached to this container (outer cylinder container). It is suitable for attaching the cap by tapping (that is, fitting by pushing). That is, the air valve that controls the inflow and outflow of air through the air passage may be brought into contact with the inclined surface formed at the upper end of the inner surface of the outer cylinder neck portion, which effectively damages the air valve due to the plugging. This is because it can be avoided. Therefore, this aspect can reduce the height and weight of the double-structured container as much as possible, which is extremely advantageous in terms of manufacturing cost.

Further, instead of providing the contact surface as described above, by providing a valve on the top plate portion of the cap mounted so as to cover the outer cylinder neck portion and the inner bag neck portion, the outer cylinder neck portion and the inner bag neck portion can be connected. The straight space formed between them can also be used as an air passage.

The figure which shows the schematic structure of the double structure container of this invention. A side sectional view showing an enlarged main part of a suitable form together with a part of a cap in the double-structured container of the present invention. FIG. 2 is a schematic perspective view of an outer cylinder neck portion in the double-structured container of FIG. The schematic perspective view of the inner bag neck part in the double-structured container of FIG. The perspective view which shows the part of the neck part in the state which the inner bag container is fitted and fixed in the outer cylinder container. The figure which shows the preform used for molding of the double structure container of this invention. The figure which shows the neck part in the state which the cap is attached to the double structure container of this invention.

First, the schematic structure of the double-structured container of the present invention will be briefly described.
With reference to FIG. 1 showing the schematic structure of the double-structured container, the double-structured container shown by 1 as a whole is a bottle-shaped outer cylinder container 3 and an inner bag container 5 in which a content liquid such as soy sauce is stored. As can be understood from FIG. 1, the inner bag container 5 is inserted and held inside the outer cylinder container 3.

The outer cylinder container 3 has a neck portion (outer cylinder neck portion) 11, a shoulder portion 13 connected to the outer cylinder neck portion 11 and expanding in diameter downward, and a body portion 15 connected to the shoulder portion 13. The lower end of the body portion 15 is closed by the bottom portion 17. A support ring 19 is formed on the outer surface of such an outer cylinder neck portion 11, and a cap is fitted and fixed to a portion above the support ring 19.
Further, the inner bag container 5 is composed of a neck portion (inner bag neck portion) 21 and a bag-shaped portion 23 in a bulging form connected to the inner bag neck portion 21.

The outer cylinder container 3 and the inner bag container 5 as described above are not limited to this, but are blow-moldable thermoplastics typified by, for example, polyester such as polyethylene terephthalate and polyolefin such as polyethylene and polypropylene. It is molded using resin.

In the double-structured container 1 as described above, the body portion 15 of the outer cylinder container 3 usually has a slightly recessed shape, and by pressing (squeezing) the recessed portion (squeeze region), the body portion 15 is normally formed. The body portion 15 is greatly dented, and the bag-shaped portion 23 of the inner bag container 5 is pressed accordingly, whereby the content liquid contained in the bag-shaped portion 23 is discharged. When the content liquid is discharged, the bag-shaped portion 23 contracts according to the weight loss of the content liquid, but the body portion 15 of the outer cylinder container 3 returns to its original shape due to its elasticity, and a gap (action space) between the two is restored. Z) will be formed.

By the way, when the discharge operation as described above is repeated, the bag-shaped portion 23 contracts more greatly according to the amount of the content liquid discharged. Therefore, when the air in the working space Z described above is discharged when the body portion 15 is squeezed, the body portion 15 of the outer cylinder container 3 is used in order to discharge the content liquid in the contracted bag-shaped portion 23. It must be pressed harder to deform it significantly, and eventually the contents cannot be discharged. Therefore, when the body portion 15 is pressed to discharge the content liquid, the air in the working space Z is not discharged, the air is allowed to exist in the working space Z, and the bag-shaped portion 23 is pressed through the air layer. It is necessary to
Further, when the content liquid is discharged, the volume of the bag-shaped portion 23 is reduced by the amount of the content liquid discharged, while the body portion 15 of the outer cylinder container 3 recovers from the recessed state, so that the inside of the working space Z Is in a negative pressure state. Therefore, after the content liquid is discharged, it is necessary to introduce air into the working space Z and return the pressure in the working space Z to normal pressure. If the negative pressure remains, not only will the body 15 not return to its original shape smoothly, but if the body 15 is pressed and the content liquid is discharged, the body 15 must be greatly recessed. This is because it becomes difficult to effectively discharge the content liquid.

Therefore, it is required that the discharge of air from the above-mentioned working space Z is prevented, and that air is appropriately introduced into this space Z. The double-structured container 1 of the present invention can easily form a valve function that satisfies such a requirement.

The double-structured container 1 having the above structure is manufactured by stretch blow molding using a stack preform in which the preform for the inner bag container is inserted and held inside the preform for the outer cylinder container. In the outer cylinder container 3, the shoulder portion 13, the body portion 15, and the bottom portion 17 are thinned parts by blow stretching, and in the inner bag container 5, the bag-shaped portion 23 is thinned by blow stretching. is there. That is, in the state immediately after molding, the bag-shaped portion 23 of the inner bag container 5 is in close contact with the shoulder portion 13, the body portion 15 and the bottom portion 17 of the outer cylinder container 3, and the above-mentioned working space Z is closed. Is in a state of being.

An undercut 31 is formed on the outer surface of the upper end portion of the neck portion (outer cylinder neck portion) 11 of the outer cylinder container 3 with reference to FIGS. 2 to 5 described above, and the relationship with the undercut 31 is formed. The cap 100 is attached by utilizing the combination, and is held stably. Further, the undercut 31 is partially cut out so that an air passage X (see FIG. 2) from the working space Z to the outside is formed along the inner surface to the upper end surface and the outer surface of the outer cylinder neck portion 11. An air passage forming slit 31a is formed. As can be seen from FIG. 3, the slit 31a has a bifurcated inverted V shape so that air can easily flow. The number and shape of such slits 31a are not particularly limited, but if they are provided at a plurality of locations within a range that does not impair the engaging force with the cap 100, air can be smoothly taken in and out of the working space Z. Is suitable.

An inclined surface 33 inclined inward is formed at the upper end of the inner surface of the outer cylinder neck portion 11. The inclined surface 33 is a contact surface with the air valve A of the cap 100 described below, and air is introduced into the working space Z by utilizing the contact and detachment of the air valve A. Further, it is possible to secure a valve function for blocking the discharge of air from the working space Z.

Further, a step 35 protruding inward is formed on the inner surface of the outer cylinder neck portion 11 (a portion below the inclined surface 33). The step 35 is formed to stabilize the position of the inner bag neck portion 21 in the outer cylinder neck portion 11.

Further, on the inner surface of the outer cylinder neck portion 11, preferably, a shallow groove (plug guide groove) 37 extending linearly from the lower end of the inclined surface 33 to the vicinity of the step 35 is formed. , Many are formed at regular intervals. By providing such a groove 37, it is possible to effectively prevent inconvenience (so-called diagonal fitting) such that the inner bag neck portion 21 is inserted in an oblique state when the inner bag neck portion 21 is pushed into the outer cylinder neck portion 11. ..

On the other hand, a small flange 41 protruding outward is formed at the upper end of the outer surface of the neck portion (inner bag neck portion 21) of the inner bag container 5 located inside the outer cylinder neck portion 11. The small flange 41 is formed to be gripped by a predetermined jig when the preform for the inner bag is inserted into the preform for the outer cylinder at the stage before blow molding. .. Further, the small flange 41 is formed with recesses 41a at a plurality of locations. That is, by forming such a recess 41a, the holder for assembling the stack preform by fitting and fixing the inner bag preform to the outer cylinder preform can be easily attached and detached. Because it can be done. For example, if a notch corresponding to the recess 41a is provided, the neck portion of the inner bag preform is inserted into the holder, and the holder is rotated 90 degrees, the inner bag preform is placed in the holder. It is held stably, and the stack preform can be held stably by transporting it, fitting and fixing it in the outer cylinder preform by tapping, etc. Furthermore, blow molding can also be performed, and after the operation is completed, By rotating the holder 90 degrees, the holder can be quickly removed.

Further, on the outer surface of the inner bag neck portion 21, a ring-shaped protrusion 43 for fitting and fixing is provided below the small flange 41, and the small flange 41 has a smaller diameter than the ring-shaped protrusion 43. It is formed. That is, the outer diameter of the ring-shaped protrusion 43 has a size comparable to the inner diameter of the outer cylinder neck portion 11, and when the inner bag neck portion 21 is inserted into the outer cylinder neck portion 11, the ring-shaped protrusion 43 The outer surface is in close contact with the inner surface of the outer cylinder neck portion 11, and the fitting and holding are stably performed without rattling. Further, at this time, the ring-shaped protrusion 43 engages with the step 35 formed on the outer cylinder neck portion 11 so that the inner bag neck portion 21 is positioned so as not to be deeply inserted.
Further, since the small flange 41 is formed to have a smaller diameter than the ring-shaped protrusion 43, the small flange at the upper end of the inner bag neck portion 11 is in a state where the inner bag neck portion 21 is fitted and fixed in the outer cylinder neck portion 11. Reference numeral 41 denotes not covering the upper end surface of the outer cylinder neck portion 11, and a straight space Y along the inner surface of the outer cylinder neck portion 11 directly communicates with the upper space above the ring-shaped protrusion 43 (FIG. 2). reference). Moreover, a notch 43a is formed in the ring-shaped protrusion 43 so that the above-mentioned working space Z and the space between the above-mentioned straight space Y outer cylinder neck 11 and inner bag neck 21 communicate with each other. Has been done. Therefore, it is possible to form an air passage X from the working space Z to the outside through this straight space Y.

As shown in FIG. 2, the double-structured container 1 of the present invention having the above-mentioned structure is put into use with the cap shown by 100 as a whole.
Although the schematic structure of the cap 100 is shown in FIG. 2, the reverse is that the contents contained in the inner bag container 5 are allowed to be discharged, but the inflow of air into the inner bag container 5 is blocked. The check valve is omitted, and the upper lid provided on the cap 100 is omitted. The cap 100 is attached to the neck portion 11 of the outer cylinder container 3, and an air valve A is provided separately from the omitted check valve, and the cap 100 is provided on the outer surface of the tubular side wall of the cap 100. Is formed with a circumferential protrusion B that engages with the undercut 31 formed on the outer cylinder neck portion 11 described above, and the top plate portion that is connected to the tubular side wall 121 and extends in the horizontal direction has a tubular shape. An inner ring C extending downward at a distance from the side wall is provided. As can be understood from FIG. 2, the air valve A is an annular flap piece extending downward in the cap axial direction, which can swing in and out, and includes the tubular side wall and the inner ring C. At a position between them, it extends downward from the top plate portion, and its lower end abuts on an inclined surface 33 formed at the upper end of the inner surface of the outer cylinder neck portion 11.

In such a cap 100, the outer surface of the inner ring C is in close contact with the inner surface of the neck portion 21 of the inner bag container 5, whereby the sealing property of the inner bag container 5 is ensured. Further, although not shown, the peripheral projection B formed on the inner surface of the tubular side wall is partially formed with a notch, and the air passage X formed from the working space Z to the outside is blocked. It is configured not to be done.

In the present invention, when the cap 100 is attached to the double-structured container 1 (the neck portion 11 of the outer cylinder container 3), the space between the air valve A (flap piece) and the tubular side wall of the cap 100 is outside. The upper end portion of the neck portion 11 of the tubular container 3 is in a state of being inserted. That is, as described above, the small flange 41 does not cover the upper end surface of the cylinder neck portion 11, and a straight space Y is formed above the ring-shaped protrusion 43 along the inner surface of the outer cylinder neck portion 11. Therefore, it is possible to put such an air valve A in a state of being inserted.

That is, the neck portion 21 of the inner bag container 5 is located on the inner surface side of the air valve A, and when the air valve A swings and tilts outward, the lower end of the air valve A is the outer cylinder. It comes into contact with the inner surface (inclined surface 33) of the neck portion 11 of the container 3.

In the double-structured container 1 to which the cap 100 as described above is attached, under normal conditions, the air passage X communicating the working space Z and the outside is blocked by the contact between the air valve A and the inclined surface 33. Has been done. In this state, when the upper lid of the cap 100 is opened, the double-structured container 1 is tilted, and the body portion 15 (squeeze region in FIG. 1) of the outer cylinder container 3 is squeezed and recessed, the bag-shaped portion of the inner bag container 5 is recessed. 23 is also recessed, whereby the content liquid in the inner bag container 5 is discharged to the outside through a check valve (omitted in FIG. 2) formed in the cap 100. At this time, the pressure in the working space Z rises due to the dent of the body portion 15, but the air valve A bends outward due to this pressure rise and is strongly pressed against the inclined surface 33, so that the air passage X is opened. Therefore, the air in the working space Z does not flow to the outside. Even if the air valve A and the inclined surface 33 are separated from each other in the normal state, the internal pressure in the working space Z rises sharply when squeezed, so that the air valve A bends outward. Since it comes into contact with the inclined surface 33, the air in the working space Z does not flow to the outside during the squeeze.

On the other hand, when the squeeze of the body portion 15 is stopped, the check valve provided on the cap 100 is closed, and air does not flow into the inner bag container 5 from the outside, but the outer cylinder container 3 recessed by the squeeze. The body portion 15 returns to its original shape. Therefore, the bag-shaped portion 23 of the inner bag container 5 shrinks by the amount of the discharged content liquid, but the working space Z becomes a negative pressure due to the restoration of the body portion 15 of the outer cylinder container 3 to its original shape. As a result, the air valve A that was in contact with the inclined surface 33 bends inward, and a gap is formed between the air valve A and the inclined surface 33. As a result, the air passage X is opened and the working space is opened from the outside. Air will flow into Z. Therefore, when the body portion 15 of the outer cylinder container 3 is squeezed next time, air exists in the working space Z, and air is present between the bag-shaped portion 23 of the inner bag container 5 and the body portion 15 of the outer cylinder container 3. The layer is present, and the bag-shaped portion 23 that has shrunk due to the previous discharge of the content liquid is quickly pressed, and the content liquid is quickly discharged as in the previous squeeze.
For example, when air does not flow into the working space Z after the squeeze is stopped, the bag-shaped portion 23 is contracted, so that it is necessary to strongly press the body portion 15 to make a large dent in order to discharge the content liquid. Eventually, the content liquid cannot be discharged. In the double-structured container 1 of the present invention, such an inconvenience is effectively solved by forming an inclined surface 33 in contact with the air valve A.

In the above description, an example is shown in which the air valve contact surface with which the air valve A contacts is an inclined surface 33, but instead of such an inclined surface, a normal straight straight body surface is used as the air valve. It can also be used as a contact surface. That is, the air valve A made of the annular flap piece bends outward during squeeze play and comes into contact with the inner surface of the outer cylinder neck portion 11, so that air discharge can be effectively prevented.
However, when the air valve contact surface is a straight body surface, the air valve A is likely to be deformed when the cap 100 is attached by the stopper. Therefore, from the viewpoint of attaching the cap 100 by the stopper. The air valve contact surface is preferably an inclined surface 33 as described above.
Further, the air valve contact surface can be effectively degassed when the pressure in the working space Z rises due to the change in the environmental temperature (temperature rise), as shown in FIG. In addition, it is preferable to use an inclined surface 33. That is, if the air valve contact surface is a straight upright surface, when the internal pressure rises due to such a temperature rise, the air valve A contacts the upright surface, so that gas is not vented from the working space Z. .. Therefore, when the upper lid of the cap 100 is opened, the content liquid may be discharged. However, if the air valve contact surface is set as the inclined surface 33, for example, a linear groove extending in the height direction is provided on the outer surface (the surface on the side that comes into contact with the inclined surface 33) of the air valve A (annular flap piece). By forming at least one of the above, the degassing can be effectively performed, and the discharge of the content liquid when the upper lid is opened can be effectively prevented. This is because when the internal pressure rises to the extent of a change in the environmental temperature, the outward deflection of the air valve A is small, so that gas is released through the groove formed in the air valve A. Of course, at the time of squeeze, the internal pressure of the working space Z rises significantly, and the air valve A bends outward significantly, so that air is not discharged through such a groove.

The double-structured container 1 of the present invention having the above-mentioned structure is manufactured by the so-called stack preform method, as described briefly above.
An example of such a preform form is shown in FIG.

With reference to FIG. 6, the preform (outer cylinder preform) 51 for forming the outer cylinder container 3 has a test tube shape as a whole, and the upper portion is the outer cylinder neck portion 11 of the above-described form. The tubular portion 53 connected to the outer cylinder neck portion 11 is a stretch-molded portion (see FIG. 6A).

That is, as described above, the outer cylinder neck portion 11 of the outer cylinder preform 51 is formed with a support ring 19 and an undercut 31 on the outer surface thereof, and the undercut 31 is used to secure an air passage X. A notch 31a is formed. Further, on the inner surface of the outer cylinder neck portion 11, an inclined surface 33 is formed at the upper end, and a step 35 is formed below the inclined surface 33. Further, if necessary, a groove 37 is formed in the region between the inclined surface 33 and the step 35. The notch 31a and the groove 37 are omitted in the drawing.
Further, the tubular portion 53 is a portion to be stretch-molded, and by blow-molding, the portion to be the shoulder portion 13, the body portion 15 and the bottom portion 17 of the outer cylinder container 3 described above is shaped.

Further, the inner bag preform 61 for forming the inner bag container 5 also has a test tube shape as a whole, and the upper portion is the inner bag neck portion 21 of the above-mentioned form, and the inner bag neck portion 21 is formed. The tubular portion 63 connected to is a stretch-molded portion (see FIG. 6B).

That is, as described above, the inner bag neck portion 21 of the inner bag preform 61 is provided with a small flange 41 at the upper end and a ring-shaped protrusion 43 below the small flange 41 on the outer surface thereof, and the tubular portion 63 is stretched. It is a portion to be molded, and by blow molding, the portion to be the bag-shaped portion 23 described above is shaped.
In the drawing, the notch 41a formed in the small flange 41 and the notch 43a formed in the ring-shaped protrusion 43 are both omitted in the drawing.

The inner bag preform 61 and the outer cylinder preform 51 as described above are both molded by injection molding using the above-mentioned thermoplastic resin suitable for blow molding (for example, a polyester resin such as polyethylene terephthalate). The inner bag preform 61 is inserted into the outer cylinder preform 51 to assemble the stack preform 71 (see FIG. 6C). In the stack preform 71, the portion where the inner bag neck portion 21 is inserted into the outer cylinder neck portion 11 is the non-stretched region α, and the portion below this region α is the stretched region β. That is, in this stack preform 71, the form of the non-stretched region α is the form shown in FIGS. 2 and 5 described above.

The stack preform 71 having the above-described form is heated to a predetermined draw molding temperature and placed in a blow molding mold, and a blow fluid such as compressed air is blown into the stack preform 71 (inner bag preform 61). As a result, blow molding is performed. That is, the tubular portion 63 of the inner bag preform 61 is stretched while expanding the tubular portion 53 of the outer cylinder preform 51 by expansion, and as a result, the tubular portion 53 of the outer cylinder preform 51 is formed into a molded mold. Correspondingly, it is shaped into the form of the shoulder portion 13, the body portion 15, and the bottom portion 17. On the other hand, the tubular portion 63 of the inner bag preform 61 is shaped into the form of a bag-shaped portion 23 in close contact with the inner surfaces of the shoulder portion 13, the body portion 15 and the bottom portion 17 of the outer cylinder container 3, and thus the second invention of the present invention. The heavy-duty container 1 is manufactured.

In the stack preform 71 shown in FIG. 6C, the inner bag preform 61 is completely inserted into the outer cylinder preform 51, and the upper end of the outer cylinder preform 51 and the inner bag preform 61 are inserted. Although it is assembled so as to be located on the same surface as the upper end of the inner bag, the present invention is not limited to this form, and for example, the upper end of the inner bag preform 61 (that is, the small flange at the upper end of the inner bag neck 21). 41) may be formed so as to exist in a state of protruding from the upper end of the outer cylinder preform 51 (that is, the upper end of the outer bag neck portion 11).
In this case, blow molding is performed with the jig inserted in the space between the small flange 41 at the upper end of the inner bag preform 61 and the upper end of the outer cylinder neck portion 11, and after blow molding, the jig is pulled out. By pushing the upper end of the protruding inner bag neck portion 21 into the outer cylinder neck portion 11 (plugging), the form shown in FIGS. 2 and 5 can be obtained. When the stack preform 71 is formed in such a form, a gap can be formed between the bag-shaped portion 23 of the inner bag container 5 and the shoulder portion 13 of the outer cylinder container 3 after molding. When discharging the content liquid, there is an advantage that air can be quickly introduced into the working space Z.

The double-structured container 1 produced as described above is put into use by filling the inner bag container 5 with the content liquid and then attaching a cap.
As the cap attached to the double-structured container 1, in principle, a so-called screw cap attached to the outer cylinder neck portion 11 by screw engagement can also be used. In this case, a cap engaging screw is provided on the outer surface of the outer cylinder neck portion 11, and a slit for securing the air passage X is formed in the screw.

However, in the double-structured container 1 of the present invention, it is necessary to bring the air valve A (specifically, the annular flap piece) formed on the cap into contact with the inclined surface 33 formed on the outer cylinder neck portion 11. In such an air valve A, as understood from FIG. 2, the inner bag neck portion 21 is located inside the air valve A. Therefore, in order to ensure the sealing of the inner bag container 5, it is necessary to use a member such as an inner ring C. From the viewpoint of ensuring such a structure, the cap applied to the double-structured container 1 of the present invention is preferably a plug-type cap. By applying such a plug-type cap, the height of the outer cylinder neck portion 11 and the inner bag neck portion 21 can be lowered, which is advantageous in terms of manufacturing cost.

Although the schematic structure of the stopper type cap 100 is shown in FIG. 2 described above, FIG. 7 shows a typical structure of the stopper type cap 100 mounted on the double-structured container 1 of the present invention. ..

In FIG. 7, the cap attached to the outer cylinder neck portion 21 of the double-structured container 1 by tapping is shown by 100 as in FIG. 2, and is formed on the outer surface of the air valve A and the outer cylinder neck portion 11. It includes an engaging protrusion B that engages with the undercut 31 and an inner ring C that is in close contact with the inner surface of the inner bag neck portion 21.

The cap 100 is composed of a cap body represented by 110 as a whole, an inner plug 111 held in the cap body 110, and a check valve 113.

The cap body 110 has a tubular side wall 121 attached to the neck portion 11 of the outer cylinder container 3 described above, and an upper lid 123 hinged to the tubular side wall 121.

At the upper end of the tubular side wall 121, a top plate portion 125 extending so as to close the internal space thereof is integrally formed.
Further, although not particularly limited, the tubular side wall 121 is formed with slits 127 extending from above to below, thereby forming a double wall structure. With such a double wall structure, the used cap 100 can be easily peeled off from the double structure container 1 without using a special instrument, and the separate disposal property is improved. ..

Further, an engaging projection B that engages with the undercut 31 of the outer cylinder neck portion 11 is formed on the inner surface of the tubular side wall 121. As described above, the engaging projection B is formed with a notch for securing the air passage X.

An inner ring C extending downward is formed on the lower surface of the top plate portion 125 extending inward from the upper end of the tubular side wall 121 at a distance from the tubular side wall 121. When C is in close contact with the inner surface of the inner bag neck portion 21, the sealing property of the inner bag container 5 is ensured.

Further, an auxiliary protrusion 133 is formed from the outer peripheral edge of the lower surface of the top plate portion 125 to the upper end portion of the inner surface of the tubular side wall 121, and the auxiliary protrusion 133 is in close contact with the outer surface from the upper end surface of the outer cylinder neck portion 11. As a result, the cap body 110 (cylindrical side wall 121) is firmly fixed to the outer cylinder neck portion 11 without rattling. Needless to say, the auxiliary projection 133 is also formed with a notch in order to secure the air passage X.

Further, on the lower surface of the top plate portion 125, an annular hanging flap piece that functions as an air valve A is provided on the outer side of the inner ring C. The air valve A engages with the inclined surface 33 formed on the inner surface of the upper end of the outer cylinder neck portion 11 described above, thereby forming a straight space Y formed along the inner surface of the outer cylinder neck portion 11 as an action space. It can be used as an air passage leading to Z, and air is taken in and out of the working space Z through such an air passage X.
Therefore, instead of providing the air valve A as described above, an opening may be formed in the top plate portion 125, and an air valve having a form capable of opening and closing the opening may be provided. This is because the opening formed in the top plate portion 125 communicates with the straight space Y described above.

On the lower surface of the top plate portion 125 described above, an inner plug holding ring 137 (hereinafter, may be simply referred to as a ring) for holding the inner plug 111 is provided in a region surrounded by the inner ring C. The inner plug 111 is housed in the ring 137, but the ring 137 has a shape with a slightly reduced diameter downward so that the housed inner plug 111 is firmly held without falling off. A protrusion 139 is formed at the lower end of the inner surface of the ring 137. Further, a peripheral small protrusion 141 is formed on the lower surface of the top plate portion 125 on the inner side of the ring 137 in order to stably hold the inner plug 111.

On the other hand, on the upper surface of the top plate portion 125, a short upper lid engaging protrusion 143 is formed on the peripheral edge portion, whereby the upper lid 123 is firmly held when the upper lid 123 is closed.

Further, a guide cylinder 145 for pouring out the content liquid is erected at the center of the upper surface of the top plate portion 125.
The guide cylinder 145 communicates with the hollow space in the tubular side wall 121, and serves as a pouring path for the content liquid discharged from the inner bag container 5.

The upper lid 123 is rotatably connected to the upper end portion of the tubular side wall 121 or the outer peripheral edge of the top plate portion 125 by a hinge band 147.
The upper lid 123 is composed of a top plate portion 151 and a skirt portion 153 connected to the outer peripheral edge of the top plate portion 151.

In the upper lid 123, an engaging recess 155 is formed on the inner surface of the skirt portion 153, and when the upper lid 123 is swiveled and closed, the recess 155 engages with the above-mentioned upper lid engaging protrusion 143. As a result, the closed state of the upper lid 123 is stably maintained. Further, on the outer surface of the skirt portion 153, an opening tab 157 is provided at a position opposite to the hinge band 147. As a result, the tab 157 can be easily opened by holding the tab 157.

A tall cushioning protrusion 159 is formed in a circumferential shape on the inner surface (upper surface in FIG. 7) of the top plate portion 151. When the upper lid 123 is closed, the tip of the cushioning protrusion 159 is formed so as to abut on the upper surface of the top plate portion 125. That is, when a large vertical load is accidentally applied while the upper lid 123 is closed, the stress is relaxed by the cushioning protrusion 159, and the upper lid 123 and the like are prevented from being damaged.

Further, a pole 161 for energizing the check valve 113 is erected in the central portion of the top plate portion 151.
The pole 161 is a member for pressing and energizing the check valve 113 held by the inner plug 111 housed in the inner plug holding ring 137 when the upper lid 123 is closed. Therefore, when the upper lid 123 is closed, the pole 161 enters the content liquid injection guide cylinder 145 and comes into contact with the check valve 113. Therefore, the upper end of the guide cylinder 145 is formed to be short on the hinge band 147 side. Further, the pole 161 has a form in which the base portion side is formed with a relatively large diameter and the tip portion side is formed with a small diameter, and accordingly, the upper portion of the inner surface of the guide cylinder 145 is inwardly formed. A protruding inward protrusion 145a is provided. That is, when the upper lid 123 is closed, the pole 161 that has entered the guide cylinder 145 is firmly fixed at the base side of the large diameter by fitting with the inward protrusion 145a, and the tip side of the small diameter of the pole 161 is positioned. , It is configured to abut on the check valve 113 at a fixed position to urge the check valve 113.

Further, a small protective ring 163 is provided on the inner surface of the top plate portion 151 at a position surrounding the pole 161 and the guide cylinder 145 when the upper lid 123 is closed. As a result, when the content liquid adheres to the pole 161 and its peripheral portion, when the upper lid 123 is opened, the content liquid can be prevented from getting wet and spreading over the entire inner surface of the top plate portion 151. Further, for the same purpose, a small groove 165 is provided in the peripheral portion of the pole 161.

Further, the inner plug 111 is housed in the inner plug holding ring 137 provided on the cap main body 110, and the inner plug 111 communicates between the inside of the guide cylinder 145 and the inside of the inner bag container 5. An opening 170 is formed in the central portion. That is, the content liquid in the inner bag container 5 flows into the guide cylinder 145 through the opening 170 and is discharged from the guide cylinder 145.

The inner plug 111 as described above extends downward from the tip of the tubular base 171 and the circumferential inclined flange 173 extending upward from the lower end of the inner surface of the tubular base 171 and the peripheral inclined flange 173. It is formed of a descending wall 175 and a horizontal flange 177 protruding inward from the lower end of the descending wall 175, and the space surrounded by the horizontal flange 177 is the above-mentioned opening 170. Such a form of the inner plug 111 is formed in order to stably hold the check valve 113 described below.

That is, in order to discharge the content liquid contained in the inner bag container 5, the opening 170 must be opened, but in the state where the opening 170 is not discharged, air is discharged into the inner bag container 5. The opening 170 needs to be closed to prevent inflow. This is because when air flows in, the contracted bag-shaped portion 23 swells due to the discharge of the content liquid, which hinders the subsequent discharge of the content liquid. Further, when the content liquid is discharged, the content liquid adhering to the inner surface of the guide cylinder 145 is prevented from returning to the inside of the inner bag container 5, and the content liquid is discharged in order to maintain the quality of the content liquid in the inner bag container 5. After that, it is desired that the opening 170 is closed promptly. A check valve 113 is used to ensure such a function.

The check valve 113 has a dome-shaped valve body 181 that is circular and bulges slightly upward, and the valve body 181 can move up and down by a plurality of straps 185 extending from the annular support member 183. It is held in. The annular support member 183 is fitted and fixed inside the inner plug holding ring 137, and the valve body 181 is inserted inside the descent wall 175 so as to close the opening 170. When the valve body 181 rises, the opening 170 is opened and the content liquid is discharged through the opening 170. In this case, since the valve body 181 is held by the plurality of straps 185, the content liquid that has passed through the opening 170 flows into the guide cylinder 145 through the gap between the straps 185. Further, when the upper lid 123 is closed, the pole 161 described above firmly presses the valve body 181 so that the valve body 181 is fitted in the descending wall 175, and the opening 170 is firmly closed by the valve body 181. It will be in the state of being.

That is, by tilting the double-structured container 1 with the upper lid 123 open and pressing the body portion 15 (squeeze region) of the outer cylinder container 3, the bag-shaped portion 23 of the inner bag container 5 is pressed, at this time. The valve body 181 is lifted by the increase in the internal pressure of the valve body, and the content liquid is discharged through the opening 170 as described above. Further, when the squeeze of the body portion 15 is stopped, the valve body 181 returns to the position where the opening 170 is closed due to the elasticity of the strap 185, and further, by closing the upper lid 123, the valve body 181 is placed inside the descent wall 175. It will be held firmly.

The above-mentioned inner plug 111 and check valve 113 may be incorporated into the cap body 110. For example, after the check valve 113 is incorporated into the inner plug 111, the assembly is held in the inner plug of the cap body 110. This is done by pushing it into the use ring 137. As a result, the cylindrical base 171 of the inner plug 111 accommodating and holding the check valve 113 is firmly sandwiched between the protrusion 139 at the lower end of the ring 137 and the peripheral small protrusion 141 above. In this state, with the upper lid 123 closed, the cap 100 is attached by covering the double-structured container 1 filled with the contents and tapping the cap 100.

By the way, when the upper lid 123 is opened and the body portion 15 of the outer cylinder container 3 is pressed to push up the valve body 181 of the check valve 113 and discharge the content liquid, the inner surface of the outer cylinder container 3 and the inner bag container are discharged. It is necessary to prevent air from being discharged from the working space Z between the working space Z and to introduce air into the working space Z after discharging the content liquid to return the working space Z to normal pressure. In the present invention, in order to ensure such a function, the above-mentioned air valve A (annular hanging flap piece) is provided so as to abut on the inclined surface 33 formed at the upper end on the inner surface of the outer cylinder neck portion 11. That's why.

The cap body 110, the inner plug 111, and the check valve 113 described above are all injection-molded using an olefin resin such as low-, medium- or high-density polyethylene, linear low-density polyethylene, or polypropylene. Manufactured by compression molding or the like.

The double-structured container 1 to which such a cap 100 is attached can dispense the content liquid, prevent oxidative deterioration due to contact with air, and maintain the quality of the content liquid for a long period of time. , Soy sauce and other seasonings are preferably used as containers.

1: Double-structured container 3: Outer cylinder container 5: Inner bag container 11: Outer cylinder neck 13: Shoulder 15: Body 21: Inner bag neck 23: Bag-shaped 31: Undercut 33: Inclined surface 35: Step 43: Ring-shaped protrusion for fitting and fixing 100: Cap X: Air passage Y: Straight space Z: Working space A: Air valve of cap

Claims (5)

In a double-structured container consisting of an outer cylinder container and an inner bag container housed inside the outer cylinder container,
The outer cylinder container has an outer cylinder neck portion and a body portion connected to the outer cylinder neck portion and formed by stretching.
The inner bag container has an inner bag neck portion and a bag-shaped portion connected to the inner bag neck portion and formed by stretching.
The outer surface of the inner bag neck portion is provided with a ring-shaped protrusion for fitting and fixing to the inner surface of the outer cylinder neck portion at a lower portion, and the ring-shaped protrusion has a notch for forming an air passage. At the same time, a small flange having a diameter smaller than that of the ring-shaped protrusion extends outward in the horizontal direction at the upper end of the inner bag neck portion.
A double-structured container characterized in that, in a state where the inner bag container is housed in the outer cylinder container, the ring-shaped protrusion of the inner bag neck portion is fitted and fixed to the inner surface of the outer cylinder neck portion. The upper end of the inner surface of the outer cylinder neck portion is a contact surface with which an air valve formed on a cap mounted on the double-structured container comes into contact.
The air passage for introducing air into the space between the outer surface of the bag-shaped portion of the inner bag and the inner surface of the body portion of the outer cylinder container and discharging the air from the space is the inner surface of the outer cylinder neck portion. The double-structured container according to claim 1, which is formed along the contact surface of the upper end portion of the inner surface, the upper end surface of the outer cylinder neck portion, and the outer surface of the outer cylinder neck portion. The double-structured container according to claim 2, wherein the surface that the air valve contacts is an inclined surface that inclines and descends inward from the upper end of the inner surface of the outer cylinder neck portion. An undercut for plugging and fitting a cap is provided on the upper part of the outer surface of the outer cylinder neck portion, and the undercut is formed with a notch forming the air passage. The double-structured container according to any one of 3. Any of claims 1 to 4, wherein the inner surface of the outer cylinder neck portion is provided with a step that regulates the axial position of the inner bag neck portion in the outer cylinder neck portion by engaging with the ring-shaped protrusion. The double-structured container described in.