JP7720680B2 - container - Google Patents

Description

The present invention relates to a container made of synthetic resin.

Synthetic resin containers are known that allow the contents to be dispensed (squeezed) by deforming the container body. These containers are used for viscous foods such as various seasonings, cosmetics, and pharmaceuticals, and have been designed to satisfy many technical requirements, such as ease of filling, long shelf life of the contents, ease of dispenser, and ease of disposal.

For example, Patent Documents 1 and 2 disclose a flat-shaped container made of synthetic resin for use with contents having a relatively high viscosity. It is disclosed that this flat container prevents abnormal deformation when filled with high-temperature contents. It is also disclosed that this flat container is easy to crush, reducing the amount of contents remaining inside.

There are various possible container designs based on different design concepts to prevent abnormal deformation when filling with high-temperature contents and reduce the amount of residual liquid inside.

Japanese Patent Application Laid-Open No. 2019-081559 Japanese Patent Application Laid-Open No. 2019-081560

The present invention aims to provide a container that properly absorbs the reduced pressure inside the container that occurs when filling it with high-temperature contents, preventing abnormal deformation.

According to one aspect of the present invention, the container is made of synthetic resin and has a flexible body portion, and the body portion has a cross-sectional shape perpendicular to the main axis of the body, which includes, when imagining a first imaginary circle and two second imaginary circles located on either side of the first imaginary circle and having a smaller diameter than the first imaginary circle, a central portion that passes through part of the upper and lower contours of the first imaginary circle, side portions that pass through part of the outer left and right contours of the second imaginary circle, and side portions that pass outside the first and second imaginary circles, connecting the central portion and the side portions and forming sides that are convexly curved inward.

The present invention provides a plastic container that does not undergo abnormal deformation due to reduced pressure after being filled with high-temperature contents.

FIG. 1 is a perspective view showing an outline of an example of the configuration of a capped container according to one embodiment. FIG. 2A is a front view showing an outline of an example of the configuration of a container according to one embodiment. FIG. 2B is a plan view showing an outline of a configuration example of a container according to one embodiment, taken from the mouth portion toward the sealing portion. FIG. 2C is a right side view illustrating an outline of an exemplary configuration of a container according to one embodiment. FIG. 2D is a plan view showing an outline of an example configuration of a container according to one embodiment, taken from the sealing portion toward the mouth portion. FIG. 2E is a rear view illustrating an outline of an exemplary configuration of a container according to an embodiment. FIG. 3A is an end view taken along line AA in FIG. 2A, illustrating a schematic configuration example of a container according to one embodiment. FIG. 3B is an end view taken along line BB in FIG. 2A, illustrating a schematic configuration example of a container according to one embodiment. FIG. 3C is an end view taken along line CC shown in FIG. 2A, illustrating a schematic configuration example of a container according to one embodiment. FIG. 3D is an end view taken along line DD in FIG. 2A, illustrating a schematic configuration example of a container according to one embodiment. FIG. 3E is an end view taken along line EE shown in FIG. 2A, illustrating a schematic configuration example of a container according to one embodiment. FIG. 4 is a diagram for explaining the general shape of a cross section of a container according to one embodiment taken along line CC shown in FIG. 2A. FIG. 5 is a plan view showing an outline of a configuration example of a container according to another embodiment, taken from the opening portion toward the sealing portion. FIG. 6 is an enlarged cross-sectional view showing an example of a layer structure of a wall portion of a container according to one embodiment. FIG. 7A is a diagram for explaining the state after the content of the container of one embodiment has been pushed out, and is an end view corresponding to the line CC shown in FIG. 2A. FIG. 7B is a diagram for explaining the state after the content of the container of one embodiment has been pushed out, and is an end view corresponding to the line EE shown in FIG. 2A. FIG. 8A is a lateral end view for illustrating the outline of the shape of a container according to a comparative example. FIG. 8B is a vertical end view for explaining the outline of the shape of a container according to a comparative example. FIG. 9A is a lateral end view for explaining the outline of the shape of a container according to a comparative example after the content has been pushed out. FIG. 9B is a vertical end view for explaining the outline of the shape of the container according to the comparative example after the content is pushed out. FIG. 10A is a front view illustrating an example of dimensions of a container according to one embodiment. FIG. 10B is a plan view illustrating an example of dimensions of a container according to one embodiment. FIG. 10C is a right side view illustrating an example of dimensions of the container according to one embodiment. FIG. 11 is a diagram showing an outline of an example of the configuration of the mouth of a container according to one modified example.

One embodiment will be described with reference to the drawings. This embodiment relates to a container made of synthetic resin. The container of this embodiment can be used, for example, as a container for spreads, semi-solid seasonings, etc., but is not limited to this. The container of this embodiment may also be used for other purposes, such as cosmetics or medicines.

The container of this embodiment is configured so that when a relatively viscous content is placed inside, it can be squeezed out with almost no viscous content remaining inside the container. While not intended to be limiting, this container is particularly effective when the content is a semi-solid substance, such as tartar sauce, with solid material, for example, in the form of granules or flakes, dispersed within it. Generally, when a viscous content is highly viscous, the process of removing the content from the container is time-consuming. Even when using a squeeze container, if the container is highly rigid, a high amount of pressure is required when squeezing. When the pressure is released, the container is prone to elastic recovery, i.e., it is prone to suck-back, causing the content to flow back into the container. The squeeze container of this embodiment is effective in reducing the amount of content remaining inside the container.

In addition, the container of this embodiment generates a moderate reaction force when squeezed, making it a comfortable and easy-to-squeeze container.

The container of this embodiment is also designed to be suitable for high-temperature filling, in which the contents are filled with high-temperature material and sealed while still hot. As a result, the container of this embodiment is able to appropriately absorb the reduced pressure inside the container that occurs as the container cools after filling, preventing abnormal deformation.

[Container structure]
FIG. 1 is a perspective view showing the appearance of a capped container 1 according to this embodiment. The capped container 1 includes a container 2 and a cap 3. The container 2 has a hollow, elongated, flat shape. The container 2 is flexible and has a generally conical shape resembling the mantle of a squid. The cap 3 is provided at the front end (mouth) of the longitudinal axis of the elongated container 2. The cap 3 preferably has a flat surface 39 on the side opposite the container 2. Because the cap 3 has the flat surface 39, the capped container 1 can be placed upright with this flat surface 39 facing downwards, i.e., with the mouth side of the container 2 facing downwards.

The shape of the container 2 will be further explained with reference to Figures 2A to 2E and Figures 3A to 3E. Figure 2A shows a front view of the container 2. Figure 2B shows a plan view of the container 2. Figure 2C shows a right side view of the container 2. Figure 2D shows a bottom view of the container 2. Figure 2E shows a rear view of the container 2. Figures 3A to 3E show schematic end surface shapes taken along lines A-A to E-E shown in Figure 2A, respectively. That is, Figures 3A to 3D show the end surface shape of the container 2 in a plane perpendicular to the major axis of the container 2, and Figure 3E shows the end surface shape of the container 2 in a vertical plane passing through the major axis of the container 2. Note that in Figures 3A to 3E, the thickness of the container 2 is shown thicker than it actually is for ease of viewing.

The container 2 has a body 10 and a mouth 60. The container 2 is configured so that the contents stored in the body 10 are ejected from the mouth 60. The contents are pushed from the side of the body 10 opposite the mouth 60 (rear side) toward the mouth 60 (front side).

The body 10 is molded from synthetic resin and has a hollow shape. As shown in FIG. 2A, the body 10, viewed from the front, has a shape that is elongated in the front-to-rear direction. That is, assuming a main shaft extending in the front-to-rear direction, the mouth 60 is provided at the front end of the main shaft of the body 10, and the sealing portion (pinch portion) 31 is formed at the rear end of the main shaft opposite the front end. When viewed from the front, the body 10 has a central region 12 that is wider than the front side 11 (the mouth 60 side) and the rear side 13 (the sealing portion (pinch portion) 31 side). Therefore, both sides of the body 10, viewed from the front, have an outwardly convex curved shape. In this embodiment, when viewed from the front, both sides of the body 10 have an outwardly convex curved shape of the container 2. That is, the body 10 is sealed in a roughly arc shape at the end of the rear side 13, and gradually widens from the rear side 13 towards the central region 12, reaching its widest point at the widest part of the central region 12, and then gradually narrowing from there towards the front side 11.

The mouth portion 60 is roughly cylindrical and has a circular opening 61. A screw 62 is formed on the side of the mouth portion 60 so that the cap 3 can be attached.

The outer surface of the front side of the body 10 as seen in Figure 2A will be referred to as the first surface 21, and the outer surface of the back side of the body 10 as seen in Figure 2E will be referred to as the second surface 22. If the length perpendicular to the main axis of the container as shown in Figure 2A is taken as the width of the container 2, and the maximum value of the distance between the first surface 21 and the second surface 22 as shown in Figure 2C is taken as the thickness of the container 2, then, as can be seen from Figures 3B to 3D, the body 10 has a flat shape that is wider than it is thick.

As can be seen from Figures 2C and 3E, the body 10 gradually thickens from the rear side 13 toward the central region 12, is thickest at the bulge in the central region 12, and then gradually thins from there toward the front side 11. In the cross section of the container 2 of this embodiment shown in Figure 3E, the first surface 21 and the second surface 22 have a curved shape that convexly curves outward from the container 2.

As shown in Figures 3B to 3D, the cross-sectional shape perpendicular to the main axis of the body 10 is roughly as follows: On each of the first surface 21 and the second surface 22, the central portion 41 has a shape that generally convex outward from the container 2. The side portions 42 on both sides of the central portion 41 have a shape that convex inward from the container 2, and the side portions 42 on the first surface 21 and the second surface 22 are connected by side portions 43. The central portion 41, side portions 42, and side portions 43 extend in a band-like manner around the body 10 along the main axis.

The general cross-sectional shape of the torso portion 10 will be further explained with reference to Figure 4. Figure 4 shows the general outline of the outline of the torso portion 10 in the portion shown in Figure 3C in solid lines. As shown in this figure, the cross-sectional shape of the torso portion 10 is determined by setting a first imaginary circle 71, shown by a dashed line, which defines the cross-sectional shape of the central portion 41, and two second imaginary circles 72, shown by dashed lines, located on both sides of the first imaginary circle 71 and having a smaller diameter than the first imaginary circle 71, which define the cross-sectional shape of the side portions 43. The general shape of the central portion 41 is determined by portions of the upper and lower contours of the first imaginary circle 71. The general shape of the side portions 43 is determined by portions of the outer left and right contours of the second imaginary circle 72. The general shape of the side portions 42 is determined by a curve 73 that curves inwardly and passes outside the first and second imaginary circles 71 and 72, connecting the central portion 41 and the side portions 43. The diameters of the first imaginary circle 71 and the second imaginary circle 72 and the distance between the centers of these imaginary circles vary depending on the axial position of the body 10, so the cross-sectional shape varies depending on the axial position of the body 10. Having such a cross-sectional shape provides the effects described below.

In the illustrated embodiment, two first ribs 33 extending in the front-to-rear direction of the body 10 are provided symmetrically about the center line in the central portion 41 of the first surface 21. The first ribs 33 have a convex shape that protrudes inwardly toward the container 2. Furthermore, two second ribs 34 extending in the front-to-rear direction of the body 10 are provided symmetrically about the center line in the central portion 41 of the second surface 22. The second ribs 34 have a convex shape that protrudes outwardly from the container 2. The first ribs 33 and second ribs 34 are positioned symmetrically about the plane that passes between the first surface 21 and the second surface 22. The first ribs 33 and second ribs 34 serve to reinforce the central portions 41 of the first surface 21 and the second surface 22.

In another embodiment, as shown in FIG. 5, both the first rib 33 and the second rib 34 have a convex shape that protrudes outward from the container 2. In yet another embodiment, both the first rib 33 and the second rib 34 have a convex shape that protrudes inward from the container 2. Both rib shapes serve to reinforce the central portions 41 of the first surface 21 and the second surface 22.

The container 2 is manufactured, for example, by direct blow molding. Specifically, the container 2 is formed by extruding a heat-plasticized synthetic resin into a long, hollow, cylindrical parison, clamping the long, hollow, cylindrical parison between molds, and blowing air into the parison from the mouth 60 side to form a mold-shaped container. The sealed portion (pinch portion) 31 at the rear end of the body 10 is formed by clamping the parison between the molds. As shown in Figure 3E, the sealed portion (pinch portion) 31 is formed by bonding the first synthetic resin layer 23, which forms the first surface 21, and the second synthetic resin layer 24, which forms the second surface 22, together at their inner surfaces. In the case of direct blow molding, the sealed portion (pinch portion) 31 is bonded together while the synthetic resin is heat-softened, ensuring sufficient seal strength even when the container is relatively thick. From this sealing portion (pinch portion) 31, the first synthetic resin layer 23 and the second synthetic resin layer 24 gradually separate toward the front, forming an internal space 19.

In direct blow molding, for example, a container is produced by closing the mold while pressurizing the inside of the parison with low-pressure air of about 0.1 kg/ ^cm2 to seal the sealing portion (pinch portion) 31, and then blowing air of about 5 kg/ ^cm2 into the parison to expand it, thereby producing a container in the shape of the mold.

In this case, if the hollow cylindrical parison before blow molding is concentric, during the expansion process of the parison, the parison first comes into contact with the mold surface in the minor diameter direction corresponding to the central portion 41 and is cooled. In contrast, the side portions 43 (the connection between the first surface 21 and the second surface 22) and the side portions 42 of the first surface 21 and the second surface 22 are stretched further before coming into contact with the corresponding mold surfaces and being cooled. As a result, the central portion 41 becomes relatively thick-walled, while the side portions 42 and side portions 43 become relatively thin-walled.

As shown in Figure 4, in the container 2 of this embodiment, the side portion 43 is shaped along the second imaginary circle 72. If blow molding were performed using a mold in which the cross-sectional shape of the side portion was sharp and acute, the synthetic resin might not extend to the narrow corners, making it difficult to obtain a shape that corresponds to the mold. However, by making the cross-sectional shape of the side portion 43 circular, as in the container 2 of this embodiment, it is possible to accurately obtain the shape of the side portion 43 that corresponds to the mold, i.e., the design, during blow molding.

The synthetic resin layer in the center section 41 is thicker than that in the side sections 42, and ribs are also provided, making the center section 41 more rigid than the side sections 42. Furthermore, the synthetic resin layer in the side sections 43 is relatively thin, but has a curved shape with a small radius of curvature, which forms a pillar structure, making the side sections 43 more rigid than the side sections 42.

The central portion 41, side portions 42, and side portions 43, which extend in a strip-like shape along the main axis of the body portion 10, smoothly connect to the sealing portion (pinch portion) 31 at the rear end of the body portion 10. That is, the central portion 41 of the first surface 21 and the second surface 22 smoothly extends to the sealing portion (pinch portion) 31 and is bonded together at the sealing portion (pinch portion) 31. The side portions 43 are connected to the edges on both sides of the sealing portion (pinch portion) 31. That is, the space surrounded by the sealing portion (pinch portion) 31 and the first and second surfaces 21 and 22 smoothly connects to the space surrounded by the side portions 43 and the first and second surfaces 21 and 22. More specifically, the inner edge of the sealing portion (pinch portion) 31, which is several millimeters wide, is inclined at its front side toward the inner surface of the side portion 43. The connection between the inner edge of this inclined portion and the inner surface of the side portion 43 forms an obtuse angle, and the inner edge of the sealing portion (pinch portion) 31 smoothly connects to the inner surface of the side portion 43. The smooth connection from the inner edge of the sealing portion (pinch portion) 31 to the inner surface of the side portion 43 prevents defects such as pinholes from forming in this area, resulting in high moldability.

The body 10 is flattened at the sealing portion (pinch portion) 31, and therefore the value W/D, which represents the flatness of the body 10, calculated by dividing the width W of the body 10 by the thickness D, is large at the rear side 13. On the other hand, at the front side 11, the value W/D, which represents the flatness, decreases toward the circular opening 60. Accordingly, the value W/D, which represents the flatness, gradually decreases from the rear side 13 to the front side 11.

For example, in the rear side 13, the value W/D representing the flatness is, for example, approximately 1.42 to 1.60; in the central region 12, which includes the widest part, the value W/D is, for example, approximately 1.29 to 1.35; and in the front side 11, which is closer to the mouth 60, the value W/D is, for example, approximately 1.19 to 1.28.

As shown in Figures 2A and 3A, a recess 36 is provided in the central portion 41 of the first surface 21 adjacent to the mouth portion 60. The recess 36 is a portion used during capping. Specifically, during the process of capping the mouth portion 60 after filling the container 2 with high-temperature contents, torsional stress is generated in the container 2 due to rotation. In the case of a container whose elastic modulus has decreased due to filling with high-temperature contents, the torsional stress caused by rotation may cause the container itself to twist or collapse, resulting in significant deformation. One method for preventing this is to form a recess 36 near the mouth portion 60 of the container 2 and use a jig that engages and holds this portion during capping to prevent the container 2 from rotating. In other words, by forming an effective container rotation prevention portion near the thick-walled mouth portion 60, the container 2 can be reliably capped after filling with high-temperature contents. In particular, when performing high-temperature filling as described above, the container 2 becomes soft, so the recess 36 is used as an effective means of preventing the container 2 from rotating.

In this example, the cap 3 is attached to the container 2 using a screw 62. However, the method of sealing the container is not limited to this, and in the case of a push-on cap, the cap 3 may be screwed onto the container 2.

The synthetic resin constituting the container 2 is a multilayer structure containing at least an olefin resin constituting the inner and outer layers, a gas barrier resin layer, an adhesive resin layer, and a regrind resin layer. The regrind resin layer preferably contains at least an olefin resin. To prevent drawdown during molding, the polyolefin resin constituting the inner and outer layers is preferably an olefin resin having a melt flow rate (190°C, 2.16 kg load) of 0.1 to 2.0 g/10 min and a density of 0.900 g/ ^cm3 or more but less than 0.990 g/ ^cm3 . In particular, polypropylene, high-density polyethylene, medium-density polyethylene, high-pressure low-density polyethylene, and linear low-density polyethylene are suitable.

In addition, in the multilayer container of the present invention, the polyethylene resin that constitutes the inner and outer layers is preferably petroleum-derived polyethylene resin from the perspective of product cost, but from the perspective of environmental compatibility, plant-derived polyethylene resin or a blend of plant-derived polyethylene resin and petroleum-derived polyethylene resin may of course be used. When using plant-derived polyethylene, its content can be adjusted based on the biomass content determined by C14 radiocarbon dating.

Furthermore, in the multilayer container of the present invention, a gas barrier resin layer is formed as an intermediate layer between the inner and outer olefin resin layers, thereby effectively suppressing oxidative degradation of the contents due to oxygen permeation. Examples of such gas barrier resins include ethylene-vinyl alcohol copolymers (saponified ethylene-vinyl acetate copolymers) and aromatic polyamides. Ethylene-vinyl alcohol copolymers are particularly preferred due to their high oxygen barrier properties. Preferred ethylene-vinyl alcohol copolymers are generally saponified copolymers obtained by saponifying an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, particularly 25 to 50 mol%, to a degree of saponification of 96 mol% or higher, particularly 99 mol% or higher. The gas barrier resin layer preferably accounts for, but is not limited to, 1 to 10% by mass of the entire container. Furthermore, the thickness of the container body wall (thinnest portion) is generally preferably in the range of 1 to 20 μm. When multiple gas barrier resin layers are formed, the total thickness should be within the above range.

An example of the composition of the synthetic resin that forms the container 2 is shown in Figure 6. As shown in this figure, the container 2 has a multi-layer structure. For example, from the inside out, the container 2 comprises a first layer 81 made of low-density polyethylene (LDPE), a second layer 82 containing an adhesive, a third layer 83 made of ethylene-vinyl alcohol copolymer (EVOH), a fourth layer 84 containing an adhesive, and a fifth layer 85 made of LDPE. In this way, the container 2 has a structure in which the LDPE and EVOH are bonded together with an adhesive.

The thickness of the container 2 is determined by taking into consideration factors such as the strength of the container 2, gas barrier properties, amount of material used, and the magnitude of the repulsive force generated when pushing the container 2 to expel the contents. The thickness is, for example, 0.3 to 0.7 mm.

[Decompression absorption during high-temperature filling]
As an example, the container 2 of this embodiment is filled with high-temperature contents. That is, the container 2 is filled with heated contents through the opening 61 of the mouth 60, and then the opening 61 is sealed. At this time, the contents are heated to, for example, about 75 to 80°C. After sealing, the container 2 filled with the contents is cooled, and as the temperature of the contents drops, the volumes of the contents and headspace gas contract, causing a pressure reduction inside the container 2. As a result, the container 2 absorbs the reduced pressure and deforms.

In the container 2, the central portion 41 has an outwardly convex shape and is reinforced by the first rib 33 and the second rib 34, while the side portions 42 have an inwardly convex shape and are thin and easily deform inward. While the side portions 43 are also thin, they are the joints between the side portions 42 on the first surface 21 and the side portions 42 on the second surface 22, and have a curved surface with a small radius of curvature that is outwardly convex, as shown by the second imaginary circle 72 in Figure 4, forming a strong columnar structure. This suppresses decompression deformation that would cause the side portions 43 to collapse. Furthermore, the more the side portions 42 deform inward due to reduced pressure inside the container 2, the stronger the columnar structure of the side portions 43 becomes, making the side portions 42 even more susceptible to selective deformation.

As a result of the above, only the side sections 42 are selectively more likely to absorb and deform due to reduced pressure during cooling after high-temperature filling, thereby avoiding major deformation of the container that would destroy its commercial value. In other words, in the container 2 of this embodiment, the side sections 42, which are curved inward at the areas that have been stretched and thinned during blow molding, are identified as areas that are more likely to deform during reduced pressure, thereby effectively and neatly absorbing the reduced pressure deformation that occurs during cooling after high-temperature filling.

The thickness of the four side sections 42 sandwiched between the two upper and lower central sections 41 and the two left and right side sections 43 may vary slightly during the manufacturing process, and the thicknesses of the four side sections 42 may not be completely consistent. However, compared to the central section 41, which has ribs, and the side sections 43, which form a pillar structure and tend to become stronger with pressure reduction deformation, the four side sections 42 are relatively and selectively susceptible to deformation. As a result, only the four side sections 42 in the body 10 absorb pressure reduction and deform, and the shape deformation of the container 2 is stable.

In this way, the container 2 of this embodiment combines differences in the thickness of the synthetic resin layer depending on the location and differences in rigidity (hardness) depending on the shape, achieving stable pressure reduction absorption deformation and stable discharge of viscous contents.

[Container deformation when squeezed]
The dischargeability of the contents will now be described. A consumer presses the first surface 21 and the second surface 22 of the container 2 to discharge the contents from the opening 61. In this case, the container 2 of this embodiment is characterized by a flat cross section. Furthermore, the first rib 33 and the second rib 34 provide the central portions 41 of the first surface 21 and the second surface 22 with appropriate rigidity (hardness), while the side portions 42 are thin-walled, making them prone to selective deformation. Therefore, when the container 2 is pressed to squeeze out the contents, the side portions 42 are selectively deformed, which generates an appropriate repulsive force when crushed.

The rear side 13, which has a relatively small blow ratio, is thick and has high rigidity (hard), and is formed without ribs, whereas the central region 12, which has a relatively large blow ratio, is relatively thin and has low rigidity (soft), and ribs are provided, thereby obtaining a uniform reaction force throughout the entire front-to-rear direction of the container 2, and providing a uniform pushing feeling.
From the above, the container 2 is a container that is easy to use and squeeze out.

Looking at the container shape shown in Figure 2A, the rear end is semicircular, gradually widening from the rear side 13 toward the central region 12. This allows the consumer to push the contents radially forward from the rear end. This shape of the rear end also contributes to ensuring that the contents are not left behind in the container. In particular, when the contents contain a solid substance dispersed in a semisolid substance, the shape of the solid contents can easily become caught, but with a smoothly curved shape like this embodiment, there are fewer areas where the solid contents can become caught, resulting in less solid contents remaining.

Furthermore, looking from the rear side 13 to the central region 12 of the container 2, the width formed by the first surface 21 and the second surface 22 increases monotonically from the rear end toward the front, all the way to the widest part of the body 10 where the width is at its widest. This shape in which the width increases monotonically is effective in achieving the effect of smooth squeezing from the rear side 13 toward the central region 12. Furthermore, by monotonically narrowing the width at the front side 11 toward the narrowing mouth 60, the curved surface up to the mouth 60 is smoothed, resulting in the effect of smooth squeezing of the contents.

The area around the sealing portion (pinch portion) 31 at the rear end is an area that is not stretched much during blow molding, and is a region where the synthetic resin layer is relatively thick and hard. Considering the cross-sectional shape perpendicular to the parting surface, as shown in Figure 3E, the container 2 of this embodiment has a thin, flat structure around the sealing portion (pinch portion) 31 that is easily crushed, making it easy to squeeze out the contents.

As described above, the container 2 has a shape in which the value W/D, which represents the degree of flatness obtained by dividing the width W of the body 10 by the thickness D, gradually decreases from the flat rear side 13 to the front side 11, where the mouth 60, which has a circular cross-sectional shape, is located. This shape reduces the degree of flattening in the relatively easily crushed region from the central region 12, which has a high blow ratio and is prone to deformation, to the front side 11, thereby ensuring the capacity of the container 2. Furthermore, by making the cross-sectional shape closer to a circle at the front side 11, the curved surface up to the mouth 60 is smoothed, resulting in the effect of allowing the contents to be squeezed out smoothly.

In addition, the area near the mouth 60 on the front side 11 of the body 10 is relatively hard and difficult to crush due to the cylindrical shape of the mouth 60. However, the first surface 21 tends to bend easily starting from the valley fold shape of the depression 36 provided in this area, making it easier to crush compared to a case where the depression 36 is not present. When capping, a jig is inserted into the depression 36, and the force applied is a torsional stress, not a force that crushes the first surface 21 and second surface 22 between them. Therefore, the presence of the depression 36 does not make this area more susceptible to deformation.

The cross-sectional shape of the container after the contents have been dispensed is shown in Figures 7A and 7B. Figure 7A shows the state of the cross section shown in Figure 3C after the contents have been dispensed, and Figure 7B shows the state of the cross section shown in Figure 3E after the contents have been dispensed. As shown in these figures, the first synthetic resin layer 23 forming the first surface 21 of the container 2 is turned over so that the first surface 21 matches the shape of the second surface 22, and the container is folded without creating any internal space. Therefore, after the consumer pushes out the contents, almost no contents remain inside the container 2.

Here, the pillar structure of the side portion 43 is less likely to bend in the direction of the central axis and has a stable shape. The surface that makes up the soft side portion 42 rotates, for example, from the first surface 21 side to the second surface 22 side, around the pillar structure of the side portion 43, which is arranged elongated in the front-to-rear direction, reducing the internal volume of the container 2, and ultimately causing the first surface 21 to be completely crushed toward the second surface 22 side.

As shown in Figure 3C, even when the contents are filled, the shape of the side portion 43 in cross section generally has an acute interior angle, and because it is thin, after the contents are dispensed, the side portion 43 collapses without creating any internal space, as shown in Figure 7A.

In the front view shown in Figure 2A, the central region 12 has a wide, curved shape, and in the side view shown in Figure 2C, the central region 12 also has a thick, curved shape. Due to these curved shapes, the crushed container 2 takes on a boat-like shape, as shown in Figures 7A and 7B. This shape is stable, leaving few gaps and resulting in almost no contents remaining inside the container 2.

The first rib 33 and second rib 34 serve as a reinforcing structure for the first surface 21 and the second surface 22, and these ribs also have the effect of stabilizing the folded shape.

In this embodiment, the first rib 33 has an inwardly convex shape, and the second rib 34 has an outwardly convex shape. Therefore, the first rib 33 and the second rib 34 overlap when folded, and almost no contents remain in that area.

Let's consider the process from when container 2 is full to when the contents are gradually expelled until container 2 is finally empty. At first, the consumer may press any position on container 2 to push out the contents. However, once the amount of contents has decreased to a certain extent, it is likely that the consumer will crush container 2 from the rear side 13 to the front side 11 so as to leave no contents inside container 2.

As shown in Figure 3E, when the contents are filled, the content storage space near the sealing portion (pinch portion) 31 on the rear side 13 is a space formed by the first surface 21 and the second surface 22 being close to each other and spaced apart closely. As shown in Figure 7B, after the contents are dispensed, the rear side 13 is crushed without creating any extra space inside, and is then gradually crushed from the rear end toward the front.

The rear side 13, where the synthetic resin layer is relatively hard, has an original flat shape and is therefore easy to maintain its crushed shape. The ribs also improve the strength of the central region 12, where the synthetic resin layer is relatively soft, making it easier to maintain its crushed shape. In other words, when the body 10 is crushed starting from the rear side 13, the crushed shape is easily maintained. For these reasons, there is no need to re-crush the container 2 when using it repeatedly, and crushability is improved not only in the cross-sectional direction of the container, but also in the axial direction of the container.

In this case, the first rib 33 and second rib 34 are arranged linearly in the front-to-rear direction, which also functions to guide the contents from the back to the front. In particular, when the contents are a semi-solid substance with solid substances dispersed in it, the ribs also function to guide the solids from the back to the front.

The presence of the first rib 33 and the second rib 34 gives the body 10 an appropriate degree of hardness, and the presence of the first rib 33 and the second rib 34 also has the effect of maintaining the shape of the body 10 after the contents are pushed out (the container 2 is crushed). In other words, when the rear side 13 of the container 2 is crushed and the contents of the rear side 13 are pushed out toward the front side 11, this crushed shape tends to propagate toward the front side 11 along which the contents move, tending to promote the squeezing effect.

When the container 2 is crushed, it deforms into a boat shape, ensuring a consistent flow line for the contents as they are pushed out from the rear end of the rear side 13 toward the opening 60 of the front side 11. The contents move along this flow line, and the distance they travel is short, providing the advantage of ensuring a stable amount of squeezed-out content with an appropriate amount of pressure.

Further explanation will be given with reference to comparative examples. Fig. 8A shows an end view of a container 100 filled with the contents of a comparative example, corresponding to Fig. 3C, and Fig. 8B shows an end view of a container 100 filled with the contents of a comparative example, corresponding to Fig. 3E. Fig. 9A shows an end view of a container 100 from which the contents of a comparative example have been expelled, corresponding to Fig. 7A, and Fig. 9B shows an end view of a container 100 from which the contents of a comparative example have been expelled, corresponding to Fig. 7B.

As shown in Figure 3C, the container 2 according to this embodiment has side portions 42 that convex inward, and the thicknesses of the side portions 42 and side portions 43 are relatively thin. As a result, as shown in Figure 7A, the side portions 43 become the starting point of the hinge portion and are easily crushed. In contrast, as shown in Figure 8A, the side portions 143 of the container 100 according to the comparative example are round and thick. As shown in Figure 9A, the side portions 143 of the container 100 according to the comparative example are less likely to be crushed, and when crushed, a space remains inside, leaving behind residue.

As shown in FIG. 3E, in the container 2 of this embodiment, a plate-shaped seal portion is formed by bonding a synthetic resin layer at the sealing portion (pinch portion) 31, and the synthetic resin layer extends directly toward the mouth portion 60. As a result, as shown in FIG. 7B, the rear side 13 portion of the container 2 of this embodiment is easily crushed, whereas the container 100 of the comparative example shown in FIG. 8B has a bottom 113, and the sealing portion (pinch portion) 131 formed by bonding the parison is formed in the center of the bottom with its wall surface facing the bottom. Therefore, the bottom 113 of the container 100 of the comparative example shown in FIG. 9B is less likely to be crushed, and even if crushed, it leaves internal space in the bottom corners and is crushed into a shape that is likely to leave residue. Thus, the container 2 of this embodiment is characterized in that both the first surface 21 and the second surface 22 face outward relative to the main axis of the container 2.

In the above explanation, we have illustrated a state in which the first surface 21 collapses toward the second surface 22 when the contents are dispensed, but this collapse pattern is not limited to this. In other words, the second surface 22 may collapse toward the first surface 21.

Container 2 of this embodiment is filled with high-temperature contents. Containers used for high-temperature filling generally have a relatively thick synthetic resin layer to withstand high temperatures. This tends to make the container relatively hard, making it difficult to squeeze out the contents without leaving any residue. In contrast, container 2 of this embodiment is designed with an innovative shape that allows the contents to be squeezed out without leaving any residue, even from a container made of a relatively hard synthetic resin layer.

[Container dimensions]
Next, an example of the dimensions of the container 2 will be described with reference to Figures 10A to 10C. The dimensions shown here are just an example, and the present embodiment is not limited to these dimensions.

The overall length L1 of the container 2 in the longitudinal direction is, for example, 178 mm, and may be between 150 mm and 200 mm.
The length L2 of the mouth portion 60 in the longitudinal direction is, for example, 17 mm, and may be 12 mm to 20 mm.
The length L3 of the body 10 in the longitudinal direction is, for example, 161 mm, and may be 110 mm to 180 mm.
The width L4 of the widest part of the body 10 is, for example, 56 mm, and may be between 40 mm and 65 mm.
The thickness L5 of the thickest part of the body 10 is, for example, 42 mm, and may be 30 mm to 50 mm.
Therefore, the width L4 is, for example, 1.3 times the thickness L5, and may be 1.2 to 1.4 times.

The maximum width L9 of the central portion 41 is, for example, 34 mm, and may be 24 mm to 38 mm.
The maximum width L10 of the side portion 42 is, for example, 8 mm, and may be 6 mm to 12 mm.
The radius of curvature R1 of the outwardly convex central portion 41 of the body 10 varies depending on the location, but is, for example, 21 mm at the widest portion, and may be, for example, 14 mm to 24 mm.
The radius of curvature R2 of the inwardly convex sides 42 of the body 10 varies depending on the location, but is, for example, 23 mm at the widest part, and may be, for example, 18 mm to 25 mm.
The radius of curvature R3 of the outwardly convex side portion 43 of the body portion 10 varies depending on the location, but is, for example, 5 mm at the widest portion, and may be, for example, 3 mm to 6 mm.

The distance L6 from the end of the container 2 on the mouth 60 side to the front ends of the first rib 33 and the second rib 34 is, for example, 38 mm, and may be 35 mm to 40 mm.
The length L7 of the first rib 33 and the second rib 34 in the longitudinal direction is, for example, 127 mm, and may be, for example, 87 mm to 142 mm.
The radius of curvature R4 of the inwardly protruding first rib 33 is, for example, 3 mm, and may be 2 mm to 4 mm.
The radius of curvature R5 of the outwardly convex second rib 34 is, for example, 3 mm, and may be 2 mm to 4 mm.

The width L8 of the sealing portion (pinch portion) 31 is, for example, 3 mm, and may be 2 mm to 5 mm.
At the sealing portion (pinch portion) 31, the angle θ1 formed between the main axis of the container 2 and the first surface 21 is, for example, 26°, and may be in the range of 15° to 30°.

The volume of container 2 is, for example, 150 ml, but may also be between 50 ml and 200 ml.

[Modification]
A modification of the above-described embodiment will be described below. Only the differences will be described here, and the same parts will be denoted by the same reference numerals and the description thereof will be omitted.

Figure 11 shows a schematic front view of the mouth 60 of a container 2 according to one modified example. As shown in this figure, the threads 66 of the mouth 60 according to this embodiment end at a central portion 69 that is an extension of the central portion 41 of the first surface 21 or the second surface 22, and no threads 66 are formed in this portion. According to this modified example, the mouth 60 is easily crushed and deformed in the central portion 69 where no threads 66 are formed due to the thrust when the contents are dispensed. As a result, consumers can easily crush the entire mouth 60, reducing the amount of contents remaining in the mouth 60 after extrusion.

The thread 66 may be interrupted in portions on both the first surface 21 side and the second surface 22 side. Considering the stability of the attachment of the cap 3, it is preferable that the thread 66 be interrupted in one location. In this case, the thread 66 may be interrupted on the center line of either the first surface 21 side or the second surface 22 side.

In another variation, the recess 36 provided near the mouth 60 of the body 10 need not be provided if it is not used to prevent rotation of the container 2 during capping. The recess 36 may also be provided on both the first surface 21 and the second surface 22.

In another variation, a through-hole may be provided in the sealing portion (pinch portion) 31 at the rear end of the body 10. A hook-shaped exterior may also be added to the rear end of the body 10. These holes or hooks can be used, for example, when hanging a product on a rod for display at the time of sale. Since the rear end of the container 2 in this embodiment is not shaped to be self-supporting, it is suitable for having a hole or hook formed therein.

In the above-described embodiment, an example was shown in which the sealing portion (pinch portion) 31 was arc-shaped, but this is not limited to this. The sealing portion (pinch portion) 31 may also be linear. If the cross-sectional shape shown in Figure 3E gradually widens from the rear end, it may be possible to achieve ease of pushing out the rear end. However, as described above, by providing the sealing portion (pinch portion) 31 in an arc shape, the contents can be pushed out radially, further improving the ease of pushing out the contents for consumers.

In the above embodiment, an example was shown in which the container 2 was formed by direct blow molding, but the container molding method is not limited to this. Various methods, such as extrusion tube molding, can also be used. Therefore, for example, the rear end of the container 2 is not limited to molding a sealing portion (pinch portion) 31 sandwiched between molds.

Regardless of the shape of the rear side 13 of the container 2, as long as the body 10 has a cross-sectional shape as shown in Figures 3B to 3D, the side portions 42 provide a vacuum absorption effect and reduce residue when the contents are extruded. While the first rib 33 and second rib 34 are preferably provided, the first rib 33 and second rib 34 are not required. The cross-sectional shape of the body 10 is wider than it is thick, with the central portion 41 in the width direction convex outward and the side portions 42 inwardly convex, providing a vacuum absorption effect through the side portions 42 and reducing residue when the contents are extruded. Regardless of the shape or thickness of the side portions 43, the central portion 41 in the width direction convex outward and the side portions 42 inwardly convex, providing a vacuum absorption effect. In the cross-section shown in Figure 3E, the first surface 21 and second surface 22 of the container 2 of this embodiment have a curved shape that convex outward from the container 2, but the curved shape is not limited to this.

Furthermore, regardless of the cross-sectional shape of the body 10, if the shape of the rear side 13 of the container 2 is as described above, the rear side 13 will have the effect of reducing residue when the contents are extruded.

The above-mentioned variations can be applied in combination with each other.

The present invention has been described above by showing preferred embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention.

REFERENCE SIGNS LIST 1 Container with cap 2 Container 3 Cap 10 Body 11 Front side 12 Central region 13 Rear side 19 Internal space 21 First surface 22 Second surface 23 First synthetic resin layer 24 Second synthetic resin layer 31 Sealing portion (pinch portion)
33 First rib 34 Second rib 36 Depression 39 Flat surface 41 Central portion 42 Side portion 43 Side portion 60 Mouth portion 61 Opening 62 Screw 71 First imaginary circle defining the general shape of the central portion 72 Second imaginary circle defining the general shape of the side portion 73 Curve defining the general shape of the side portion

Claims (5)

A synthetic resin container having a flexible body,
The body portion has a cross-sectional shape perpendicular to the main axis of the body portion,
When a first imaginary circle and two second imaginary circles, each having a diameter smaller than that of the first imaginary circle and provided on both the left and right sides of the first imaginary circle, are assumed,
a central portion passing through a part of the upper and lower contour lines of the first imaginary circle;
a side portion passing through a part of the left and right outer contour lines of the second imaginary circle;
a portion having a shape that passes outside the first imaginary circle and the second imaginary circle, connects the central portion and the side portion, and forms a side portion that has an inwardly convex curve ,
the central portion, the side portions, and the lateral portions extend along the main axis of the body;
the central portion is thicker than the side portions and the lateral portions,
At the widest part of the body,
The radius of curvature R1 of the outwardly convex central portion is 14 mm to 24 mm,
The radius of curvature R2 of the inwardly convex side portion is 18 mm to 25 mm,
The radius of curvature R3 of the outwardly convex side portion is 3 mm to 6 mm.
container. The container described in claim 1, wherein the central portion has an area that is more rigid than the side portions. A container as described in claim 1 or 2, wherein the central portion is provided with a rib that reinforces the central portion. 4. The container according to claim 1, wherein the width of the body in the left-right direction increases monotonically from a sealing portion provided at one end of the main shaft of the body to a wide portion of the body that is the widest portion, and then decreases monotonically from the wide portion to a mouth portion provided at the other end of the main shaft of the body. 5. A container according to claim 1, wherein the thickness of the body in the vertical direction increases monotonically from a sealing portion provided at one end of the main axis of the body to a bulging portion where the body is thickest, and decreases monotonically from the bulging portion to a mouth portion provided at the other end of the main axis of the body.