JP6971652B2 - Flexible container - Google Patents

Description

The present invention relates to a flexible container.

Conventionally, there have been many requests from users who want to use up the contents filled in the container to the end.

Immediately after the start of use, the container filled with the contents is filled with the contents, and the contents can be easily taken out by pushing the body. However, if the content is reduced after continued use, the body will be crushed and the contents will remain at the tip of the container from the shoulder to the opening of the mouth and neck.

Then, the user tries to squeeze the contents further by crushing this tip part. However, the tip of the container is made of a material that is harder than the body, or even if it is the same type of material, it is often made thicker, and it is generally stiffer than the body and difficult to crush. It is a place.

Therefore, a user who wants to use up the contents remaining in the container, for example, "crushes the tip part with force to squeeze out the contents", "cuts the body part and scoops the contents", "body part". It may take measures such as "putting air in the container and pushing out the contents together with the air."

Squeezing the tip with force can be painful to the fingertips and can injure in some cases. If the body is cut, it cannot be resealed, and there is a concern that the contents may deteriorate. If air is introduced into the body, there is concern about oxidative deterioration of the contents.

Under these circumstances, a container whose tip is easily crushed is being developed.

For example, Patent Documents 1 and 2 relate to a flexible container whose shoulder portion is easily crushed, respectively.

Patent Document 1 has a torso, a mouth and neck thinner than the torso, and a shoulder between the torso and the mouth and neck, and the contents are provided from the tip opening of the mouth and neck. A flexible container to be extruded, the shoulder portion having an axial height in the range of 0.5 to 0.7 times the diameter of the trunk portion, and having a curvature from the trunk portion toward the mouth neck portion. Having a continuous curved surface having a radius of 0.9 to 1.2 times the diameter of the body, and having a dome-shaped portion having an upper end diameter of 0.5 to 0.7 times the diameter of the body. A featured flexible container is described.

Patent Document 2 is a flexible container having a torso and a mouth and neck thinner than the torso and extruding the contents from the opening at the tip of the torso, and the torso and the nose and neck. It has a shoulder portion between the portions, the shoulder portion has a dome-shaped portion, a ring-shaped shoulder groove is provided in the circumferential direction below the dome-shaped portion, and the dome-shaped portion is vertically formed. A flexible container is described characterized by a raised shoulder rib on the outside in the direction.

On the other hand, among flexible containers, especially in a blow tube container for filling spices such as kneaded wasabi and kneaded sardine, a groove or a defect is formed in the screw tube portion of the container mouth neck where the screw protrudes. A technique is known in which the screw cylinder portion is easily crushed by dividing the screw or making the screw into multiple rows. That is, in the case of a normal single-threaded screw, the screw protruding from the outer surface circulates around the neck of the container with more than one lap, and there is no part that becomes a "fold line" when crushing. The rigidity of the screw tube is high and it is extremely difficult to crush. On the other hand, for a split screw or a multi-threaded screw, the gap between the split portion or other adjacent screws can be a "folding line", and the screw cylinder portion can be easily crushed. It will be possible.

For example, in Patent Document 3, in a container having a male threaded portion on the outer peripheral surface of the neck portion of the container body and a female threaded portion on the inner peripheral surface of the peripheral wall of the lid, the container body intersects the circumferential direction of the neck portion. It is characterized in that concave grooves extending in the circumferential direction are formed at intervals in the circumferential direction, and an outward convex portion is provided at a position eccentric in the circumferential direction between adjacent concave grooves. The container is listed. In this container, the male screw formed on the outer peripheral surface of the screw cylinder portion is divided by the concave groove, and the screw cylinder portion can be easily crushed by using the concave groove portion as a folding line.

Patent Document 4 describes a flexible container that extrudes contents from an opening at the tip of the mouth and neck, and faces the male screw provided on the outer periphery of the mouth and neck (screw cylinder) in the circumferential direction. Two pairs, three pairs, or four pairs of male screw defects are provided so as to be evenly spaced in the circumferential direction, and the male screw is used as a male screw in which a short short male screw portion is intermittent. When the short male screw portions adjacent to each other across the male screw defect portion come into contact with each other by pushing the male screw defect portion facing each other to flatten the mouth and neck portion, the opposite male screw defect portion A flexible container is described in which the distance is 1/3 to 2/3 of the inner diameter of the mouth and neck. In this container, the screw cylinder portion can be easily crushed by using the gap between adjacent multi-threaded screws as a folding line.

Japanese Unexamined Patent Publication No. 2016-11126 Japanese Unexamined Patent Publication No. 2014-19460 Japanese Unexamined Patent Publication No. 2013-249493 Japanese Unexamined Patent Publication No. 2012-162300

In the flexible container described in Patent Document 1, the shoulder portion is easily crushed, and the crushed state is maintained. However, regarding the resealing of the container after crushing the shoulder, "By appropriately setting the dimensional relationship between the diameter of the lower end of the opening of the cap that closes the tip opening of the mouth and neck and the outer circumference of the shoulder, It is only possible to seal the tip opening with the shoulder crushed, "and there is no description of a specific embodiment for enabling reliable resealing.

It is explained that the flexible container described in Patent Document 2 can easily crush the shoulder portion, and when the crushing is stopped, the shoulder portion is restored to the original state. However, the shape restoration after crushing is not taken into consideration for the screw cylinder portion of the container.

In the container of Patent Document 3, restoration after crushing the screw cylinder portion of the container having the male screw divided by the concave groove is not considered.

It is explained that in the flexible container of Patent Document 4, the screw cylinder portion of the container can be crushed by using the gap between the adjacent multi-threaded screws as a fold line, and the cap can be re-capped. However, regarding restoration after crushing the screw cylinder, it is stated that the cross section of the screw cylinder will not remain flat "if it is restored", and when resealing, the crushed screw cylinder will be removed. The user is required to restore the original shape by himself.

As described above, in the field of flexible containers, a configuration is known that makes it easy to crush the region from the mouth neck to the shoulder of the container in order to use up the contents to the end. However, when the relevant part of the container is crushed, it is rare that the contents are used up to the end at one time, and in many cases, the contents are resealed in order to avoid drying, oxidative deterioration, etc. I need. Regarding this point, in the prior art, the shape restoration of the screw cylinder part, which is necessary for surely resealing after crushing the container once and taking out the contents, is not considered at all, or the user himself / herself. You are required to restore the original shape by yourself.

The present invention has been made in consideration of the above circumstances in the prior art. Therefore, an object of the present invention is that the screw cylinder portion is easily crushed and the contents can be easily used up to the end, but when the crushing is stopped, the crushed screw cylinder portion is naturally restored to the original shape. , To provide a flexible container that can be reliably resealed with a cap.

The present invention is as follows.

[1] A flexible container having a torso, a mouth and neck, and a shoulder connecting the mouth and neck and the torso, and extruding the contents from the tip opening of the mouth and neck.
The mouth and neck portion has a screw cylinder portion in which a male screw protrudes from the outer peripheral surface.
The male screw has a complete thread portion and an incomplete thread portion, and has a complete thread portion and an incomplete thread portion.
The completely threaded portion is a threaded portion in which the protrusion distance from the outer peripheral surface of the threaded cylinder portion is maintained substantially constant.
The incomplete thread portion is
A thread portion that exists at the end of the complete thread portion and has a portion in which the protrusion distance from the outer peripheral surface gradually decreases, and a portion in which the protrusion distance from the outer peripheral surface gradually decreases from the complete screw thread portion. The shape of the incomplete thread portion appearing as the outermost circumference is concave or linear in the radial direction of the screw cylinder portion.
The screw cylinder portion has at least a pair of easy-folding regions facing each other in the radial direction, and the easy-folding region does not have the complete screw thread portion when the screw cylinder portion is observed in the axial direction. Moreover, it is a region where the incomplete thread portion exists.
Flexible container.
[2] The incomplete thread portion exists at both ends of the complete thread portion, the protrusion distance from the outer peripheral surface gradually decreases, and the complete thread portion converges to the outer peripheral surface of the screw cylinder portion. The flexible container according to [1], which is a threaded portion.
[3] The flexible container according to [1] or [2], wherein the male screw is a double-threaded screw and the number of the easily bent regions is a pair.
[4] The flexible container according to [1] or [2], wherein the male screw is a four-thread screw and the number of the easily bent regions is two pairs.
[5] The incomplete thread portion is
A thread portion existing at both ends of the complete thread portion, the protrusion distance from the outer peripheral surface gradually decreases, and the thread portion converges from the complete thread portion to the outer peripheral surface of the screw cylinder portion, and the middle of the male screw. The flexible container according to [1], which comprises both of the threaded portions present in, and then gradually increasing and returning to the original protruding distance after the protruding distance from the outer peripheral surface is gradually reduced.
[6] The item according to any one of [1] to [5], wherein the mouth neck portion further has a mouth cylinder portion having a diameter smaller than that of the screw cylinder portion on the opening end side of the screw cylinder portion. Flexible container.
[7] The flexible container according to any one of [1] to [6], which is used as a tube container or a bottle container for food.

According to the present invention, the screw cylinder portion is easily crushed and the contents are easily used up to the end, but when the crushing is stopped, the crushed screw cylinder portion is naturally restored to the original shape. A flexible container that can be securely resealed with a cap is provided.

FIG. 1 is a schematic perspective view showing the shape of the flexible container of the present invention. FIG. 2 is a schematic top view showing the shape of the flexible container of the present invention. FIG. 3 is a schematic diagram for explaining the shape of the incomplete thread portion. FIG. 4 is a schematic diagram for explaining the shape of the second incomplete thread portion in the second embodiment of the present invention. FIG. 5 is a drawing of the container sample prepared in Example 1. FIG. 6 is a schematic perspective view (a) and a schematic top view (b) showing the shape of the incomplete thread portion of the male screw in the container sample produced in Example 1. FIG. 7 is a schematic view for explaining the compression direction at the time of the compression load evaluation in the embodiment. FIG. 8 is a schematic perspective view showing the shape of the incomplete thread portion of the male screw in the container sample produced in Comparative Example 1. FIG. 9 is a schematic perspective view (a) and a schematic top view (b) showing the shape of the incomplete thread portion of the male screw in the container sample produced in Comparative Example 2.

The flexible container of the present invention
A flexible container having a mouth and neck, and a shoulder connecting the mouth and neck and the body, and extruding the contents from the opening at the tip of the mouth and neck.
The mouth and neck portion has a screw cylinder portion in which a male screw protrudes from the outer peripheral surface.
The male screw has a complete thread portion and an incomplete thread portion, and has a complete thread portion and an incomplete thread portion.
The complete screw thread portion is a complete screw thread portion in which the protrusion distance from the outer peripheral surface of the screw cylinder portion is maintained substantially constant.
The incomplete thread portion is
It is a thread portion that exists at the end of the complete thread portion and has a portion in which the protrusion distance from the outer peripheral surface gradually decreases, and is a thread portion.
The shape of the incomplete thread portion that appears as the outermost circumference of the portion where the protrusion distance from the outer peripheral surface gradually decreases from the complete thread portion is concave or linear in the radial direction of the screw cylinder portion. ,
The screw cylinder portion has at least a pair of easy-folding regions facing each other in the radial direction, and the easy-folding region is completely formed when the outer peripheral surface of the screw cylinder portion is observed in the axial direction of the screw cylinder portion. This is a region where the thread portion does not exist and the incomplete thread portion exists.
It is a flexible container.

The flexible container of the present invention has a screw cylinder portion in the mouth and neck where a male screw protrudes from the outer peripheral surface. The screw cylinder portion has at least a pair of easily bendable regions facing each other in the radial direction. When observed in the axial direction of the screw tube portion, there is no complete thread portion but an incomplete thread portion in this easily bent region. The fully threaded portion is a portion where the protrusion distance from the outer peripheral surface is maintained to be substantially constant and a relatively large bending resistance is exhibited in order to define a trajectory for the cap to slide. On the other hand, the incomplete thread portion has a portion where the protrusion distance from the outer peripheral surface gradually decreases when observed along the trajectory direction defined by the screw thread, and the shape of the portion where the protrusion distance gradually decreases is a screw. It is a portion where the bending resistance is relatively small because the tubular portion is recessed or linear in the radial direction and the protrusion distance from the outer peripheral surface is relatively small.

Therefore, the easily bent region where the incomplete thread portion is present and the complete screw thread portion is not present is a region where the bending resistance is small and the bending is easy. A screw cylinder portion having at least a pair of such easily bent regions at positions facing each other in the radial direction is easily crushed in a direction in which the pair of easily bent regions have a major axis of an ellipse with these easily bent regions as fold lines.

However, since the incomplete thread portion has a screw protruding from the outer peripheral surface although it is incomplete, it exhibits a significant repulsive force when bent. Due to this repulsive force, when the crushing is stopped, the shape of the screw cylinder portion is naturally restored to the original shape.

With the above mechanism of action, the flexible container of the present invention can easily crush the screw cylinder portion, and when the crushing is stopped, the flexible container can easily and quickly return to a state where it can be reliably resealed by the cap. You can.

The flexible container of the present invention is a flexible container having a mouth and neck, a body, and a shoulder connecting the mouth and neck, and extruding the contents from the tip opening of the mouth and neck. Hereinafter, the configuration of the flexible container of the present invention will be described in detail by taking a preferred embodiment thereof as an example.

<First Embodiment>
In the first embodiment of the present invention, incomplete threaded portions are present at both ends of the complete threaded portion, the protrusion distance from the outer peripheral surface is gradually reduced, and the complete threaded portion is transferred to the outer peripheral surface of the threaded cylinder portion. With respect to a flexible container, which is a threaded portion that converges with.

1 and 2 show schematic views for explaining the shape of the soluble container of the present embodiment.

FIG. 1A is a schematic perspective view showing the shape of the flexible container of the present embodiment, and FIG. 1B is a partially enlarged view thereof.

The flexible container shown in FIG. 1 (a) is a flexible container having a mouth and neck portion 1 and a body portion 2 and pushing out the contents from the tip opening of the mouth and neck portion 1. The diameter of the mouth and neck 1 may be smaller than that of the torso 2, and there is a shoulder 3 between the mouth and neck 1 and the body 2 that gradually decreases in diameter from the body 2 to the mouth and neck 1. doing. The mouth neck portion 1 may have a screw cylinder portion 1a, and may further have a mouth cylinder portion 1b on the opening end side of the screw cylinder portion 1a. The diameter of the mouth cylinder portion 1b may be the same as the diameter of the screw cylinder portion 1a, or may be smaller than the diameter of the screw cylinder portion 1a.

FIG. 1B is a partially enlarged view of the screw cylinder portion 1a of the flexible container shown in FIG. 1A. In the screw cylinder portion 1a, the male screw 11 protrudes from the outer peripheral surface 10. The male screw 11 exists at both ends of the complete thread portion 11a in which the protrusion distance from the outer peripheral surface 10 is maintained substantially constant, and the protrusion distance from the outer peripheral surface 10 is gradually reduced to complete the male screw 11. It has an incomplete thread portion 11b that converges from the thread portion 11a to the outer peripheral surface 10.

2 (a) is a schematic top view of the flexible container of FIG. 1 (a) as viewed from the direction of the arrow, and FIG. 2 (b) is a partially enlarged view thereof.

The screw cylinder portion 1a of the flexible container of the present embodiment has a pair of easily bendable regions 4 at positions facing each other in the radial direction thereof (FIG. 2A). The easily bent region 4 is a region in which the completely threaded portion 11a does not exist and the incomplete threaded portion 11b exists when the screw cylinder portion 1a is observed in the axial direction of the screw cylinder portion.

Since the screw cylinder portion 1a of the flexible container has at least a pair of such easily bendable regions 4, the mouth neck portion 1 including the screw cylinder portion 1a can be easily bent with the easily bendable region 4 as a fold line when crushed. Moreover, it has the advantage that it can be easily restored when it is stopped to be crushed.

In the first embodiment, the incomplete threaded portion in the threaded cylinder portion exists at both ends of the complete threaded portion, the protrusion distance from the outer peripheral surface gradually decreases, and the incomplete threaded portion converges from the complete threaded portion to the outer peripheral surface. It is an area. When observing from the axial direction of the screw tube, is the shape of the incomplete thread that appears as the outermost circumference of the thread from the complete thread to the outer peripheral surface recessed inward in the radial direction of the screw tube? , Or linear. Specifically, as shown in FIG. 3A, the shape of the incomplete thread portion is a “dogleg” shape whose outermost circumference is composed of a straight line having a large inclination and a straight line having a small inclination. Well; as shown in FIG. 3B, the outermost circumference may be an arc shape recessed inward in the radial direction of the screw cylinder portion; as shown in FIG. 3C, the outermost circumference may be substantially linear. May be. However, as shown in FIG. 3D, the shape in which the outermost circumference bulges outward in the radial direction of the screw cylinder portion has many parts where the protrusion distance from the outer peripheral surface is maintained relatively large, and bending resistance. Since the degree of reduction is small, it is not preferable and is excluded from the scope of the present invention.

The shape of the incompletely threaded portion is preferably recessed inward in the radial direction of the threaded cylinder portion from the viewpoint of lowering the bending resistance in the easily bent region, and is composed of a straight line having a large inclination and a straight line having a small inclination. It is more preferable to have a dogleg shape. If the shape of the outermost circumference of the incomplete thread portion is a "<" shape, the bending point of this "<" shape becomes a folding line, and the bending resistance in the easy bending region can be extremely lowered. From the viewpoint of, it is more preferable.

The male screw included in the screw cylinder portion may be a multi-thread screw having an even number of threads. In the first embodiment, since the incomplete thread portions constituting the easy-folding region exist at both ends of the complete screw thread portion of the male screw, the multi-threaded screw having an even number of threads has the easy-folding region as a screw cylinder. It is easy to arrange the portions at two points facing each other in the radial direction and to make these into a pair of easily bent regions. The male screw may be, for example, a two-thread screw, a four-thread screw, or a six-thread screw. In a flexible container having a relatively large diameter of the mouth and neck, the number of male threads may be further increased, and for example, 8-threaded screws, 10-threaded screws, 12-threaded screws and the like may be used.

When the male screw is a double-threaded screw composed of a first male screw and a second male screw, the easy-folding region is a pair composed of a first easy-folding region and a second easy-folding region. It may be there. Here, when the end of each male screw on the opening end side of the mouth neck is the start point and the end on the opposite side is the end point, in the case of a double-threaded screw, the first easy-bending region has a complete screw thread. There may be no portion and an incomplete thread portion on the end point side of the first male screw and an incomplete thread portion on the start point side of the second male screw; the second easy In the bent region, there is no complete thread portion, and there is an incomplete thread portion on the end point side of the second male screw and an incomplete thread portion on the start point side of the first male screw. You may be.

When the male screw is a four-threaded screw in which the first to fourth male screws are present in this order on the circumference of the screw cylinder portion, the easy bending region is the first easy bending region and the third easy bending region. It may be a pair composed of a pair composed of a pair composed of a second easy-folding region and a pair composed of a fourth easy-folding region. In this case, the complete screw thread portion does not exist in the first easy bending region, and the incomplete thread portion on the end point side of the first male screw and the incomplete thread portion on the start point side of the second male screw are incomplete. A thread portion may be present; a complete thread portion is not present in the second easily bent region, and an incomplete thread portion on the end point side of the second male screw and a third thread portion are present. There may be an incomplete thread on the start point side of the male thread; there is no complete thread in the third easy bend region and there is an incomplete thread on the end point side of the third male thread. There may be a threaded portion and an incomplete threaded portion on the starting point side of the fourth male thread; the fourth easily bent region does not have a complete threaded portion and the fourth There may be an incomplete thread portion on the end point side of the male screw and an incomplete thread portion on the start point side of the first male screw.

<Second embodiment>
In the second embodiment of the present invention, the incomplete thread portion is
A thread portion (first incomplete screw) that exists at both ends of the complete thread portion and whose protrusion distance from the outer peripheral surface gradually decreases and converges from the complete thread portion to the outer peripheral surface of the screw cylinder portion. Threaded portion) and a threaded portion (second incomplete threaded portion) that exists in the middle of the male screw and gradually increases and returns to the original protruding distance after the protruding distance from the outer peripheral surface gradually decreases.
With respect to a flexible container consisting of both.

The threaded cylinder portion of the flexible container of the present embodiment has at least a pair of easily bendable regions at positions facing each other in the radial direction thereof. This easily bent region has no complete threaded portion when the threaded cylinder portion is observed in the axial direction, and at least one of the first incomplete threaded portion and the second incomplete threaded portion. Is the area where

The male screw in the screw cylinder portion of the flexible container of the present embodiment is, for example, a single-thread screw having a sliding stroke angle of about one circumference (about 360 °) around the outer circumference of the screw cylinder portion, and a sliding stroke angle of about 1.5. It may be a single-threaded screw having a circumference (about 540 °), a double-threaded screw having a sliding stroke angle of about one circumference (360 °), or the like. When the end on the opening end side of the mouth neck is the start point and the end on the opposite side is the end point, the male screw may have a first incomplete thread portion on the start point side and the end point side, respectively. It may be interrupted at one or more places in the middle by the second incomplete thread portion.

When the screw cylinder portion of the flexible container of the present embodiment is observed from the axial direction, it appears as the outermost circumference of the screw thread of the portion where the protrusion distance from the outer peripheral surface gradually decreases and then gradually increases and returns to the original protrusion distance. The shape of the incomplete thread portion of 2 is arbitrary. For example, as shown in FIG. 4A, the protrusion distance from the outer peripheral surface gradually decreases in an arc shape recessed inward in the radial direction of the screw cylinder portion, and then gradually increases in an arc shape recessed inward in the radial direction. The original protrusion distance may be returned; as shown in FIG. 4 (b), the protrusion distance from the outer peripheral surface may be gradually decreased linearly and then gradually increased linearly to return to the original protrusion distance. In the second incomplete thread portion of FIGS. 4A and 4B, the point where the protrusion distance from the outer peripheral surface is the smallest does not reach the outer peripheral surface.

The screw cylinder portion in the flexible container of the second embodiment is a pair of easy-folding regions composed of a first easy-folding region and a second easy-folding region at positions facing the diameter direction of the screw cylinder portion. May have. When the male screw is a single-threaded screw having a sliding stroke angle of approximately one round, for example, the complete screw thread portion does not exist in the first easy bending region, and the first incompleteness on the starting point side of the male screw. There may be a threaded portion and a first incomplete threaded portion on the end point side. The second easily bent region may not have a complete threaded portion and may have a second incomplete threaded portion in the middle of the male thread.

<Manufacturing of flexible containers>
The flexible container of the present embodiment is, for example, injection molded using an appropriate material selected from, for example, polyolefins such as polyethylene and polypropylene; polyamides such as nylon; polyesters such as polyethylene terephthalate and polyethylene naphthalate; and the like. , May be manufactured by an appropriate method such as blow molding.

<Flexible container cap>
The flexible container of the present embodiment may be used as, for example, a food tube container, a bottle container, or the like in combination with a cap that is screwed with a male screw of a screw cylinder portion to seal the container.

<Application of flexible container>
The flexible container of the present embodiment is suitable as, for example, a blow tube container, particularly a blow tube container for filling spices such as wasabi and mustard.

In the following examples, a sample was prototyped and evaluated by a stereolithography method using a laser beam irradiation using a 3D printer. The stereolithography method is excellent in dimensional accuracy and the smoothness of the surface of the modeled object, and is considered to be suitable for trial production of a sample of a flexible container.

The examples and comparative samples have a basic shape as a tube having a body and a mouth and neck, and the mouth and neck have a tip opening and a screw cylinder in which a male screw protrudes from an outer peripheral surface. The prototype was made by changing only the shape of the incomplete thread portion of the male screw and the presence or absence of the concave groove in the screw cylinder portion.

The sample was industrially designed to be the same size as the actual size of the container for wasabi paste manufactured by blow molding, but the wall thickness of the container was about twice the actual size. This modification of the wall thickness is to make the crushing resistance of the container closer to that of the actual material in consideration of the difference in hardness between the blow molding material and the stereolithography material.

The conditions for producing a sample using a 3D printer are as follows.
3D printer device: Italy, DSW Inc. Resin material for stereolithography manufactured by: Italy, DSW Inc. Made by the company, product name "GM08", thickness of one layer of acrylic resin photo-curing layer (thickness of stereolithography unit): 0.05 mm
Sample preparation method: A 3D model was designed using 3D CAD and used as an STL format file. This STL file is imported into software that sets the placement direction of the stereolithographic object with respect to the base of the 3D printer, and the stereolithographic object is manufactured by stacking the stereolithographic layers in the manufacturing direction of the stereolithographic object, that is, in which direction. I decided. Then, using the control software of the 3D printer device, the sample preparation conditions were set, and then the sample was prototyped.
Sample preparation time: Approximately 4 hours

The prepared sample was washed with methanol and then stored under shading. When the sample is exposed to light rays including ultraviolet rays such as sunlight for a long time, the curing reaction progresses and becomes hard, which hinders the evaluation. To avoid this, the sample is stored under light shielding.

The sample was allowed to stand for 12 hours or more in an environment of a temperature of 23 ° C. and a humidity of 50% RH to adjust the state, and then subjected to evaluation.

<Example 1>
A container sample (length: 49.8 mm) having the shape and size (unit: mm) shown in the drawing of FIG. 5 was prepared by the above stereolithography method, and the pair of easily bent regions became the major axis of the ellipse. The compressive load when crushed and the restoration time after crushing the mouth and neck of the container were evaluated.

The male screw in the container sample of Example 1 is a double-threaded screw, and the shape of the incomplete thread portion is such that the outermost circumference of the portion from the complete thread portion to the outer peripheral surface is a straight line having a large inclination and a straight line having a small inclination. It has a "<" shape consisting of (see FIG. 6 (a)).

[Evaluation method]
(1) Compression load evaluation Using a tensile tester (manufactured by Toyo Seiki Seisakusho Co., Ltd., model name "VGS-05E"), the container sample is sandwiched between two metal plates, and the pair of easy-folding regions is elliptical. The maximum stress when crushed in the direction of the major axis was measured (see FIG. 7).

(2) Restoration time evaluation The screw cylinder portion of the container sample was crushed with a finger in the direction in which the pair of easily bent regions had the major axis of the ellipse until the opposing inner walls touched each other, and the state was held for 5 seconds. After 5 seconds, the finger was released and the container was laid on its side and allowed to stand. The time when the finger was released was set to 0 seconds, and the outer diameter of the mouth and neck in the crushed direction was measured every 30 seconds. If the value of the difference (outer diameter difference) obtained by subtracting the outer diameter of the mouth and neck before crushing from this value is within -0.1 mm, it is possible to easily and surely reseal with the cap. You may judge that. On the other hand, when the value of this outer diameter difference is smaller than -0.1 mm (that is, when the difference from the outer diameter of the mouth and neck before crushing is large), for example, the cap is screwed into the mouth and neck. Inconveniences such as the cap being screwed in diagonally, the male screw on the mouth and neck and the female screw on the cap coming into contact with each other and being scraped off, or the cap once being sealed and then loosening may occur. There is a concern that resealing with the cap will be uncertain.

<Comparative Example 1>
A container sample similar to that of Example 1 was prepared and evaluated except that the shape of the incomplete thread portion was an arc shape with the outermost circumference bulging outward (see FIG. 8).

<Comparative Example 2>
A portion of the outer peripheral surface of the screw cylinder portion where no male screw exists in the axial direction of the screw cylinder portion (gap between two male screws) is formed, and a depth of 0.7 mm and an opening width of 1.5 mm are formed in this portion. A container sample similar to that of Comparative Example 1 was prepared and evaluated except that the concave groove in the axial direction was formed. The shape of the male screw in the vicinity of the incomplete thread portion in this container sample is shown as a schematic perspective view in FIG. 9 (a) and a schematic top view in FIG. 9 (b).

<Evaluation result>
The above results are summarized in Table 1. The result of the compression load evaluation is shown as a relative value with the value of Comparative Example 1 as 100.

According to the results in Table 1, the container of Comparative Example 1 having an arc-shaped incomplete thread portion bulging outward has a high compressive load, and after stopping the crushing of the screw tube portion, the container is securely resealed by the cap. It took 120 seconds to restore to the possible state. The container of Comparative Example 2 in which the groove in the axial direction was formed in the screw cylinder portion had a low compressive load, but after stopping crushing, it took 90 seconds to restore the container to a state where it can be reliably resealed by the cap. It took.

On the other hand, the container of Example 1 having the incomplete thread portion in the shape of a dogleg has a lower compression load than the container of Comparative Example 1, and after stopping the crushing of the screw cylinder portion, After 30 seconds, it was restored to a state where it could be securely resealed with a cap.

When the male screw was a 4-thread screw, a tendency similar to that of the above-mentioned 2-thread screw was observed.

1 Mouth neck 1a Screw tube 1b Mouth tube 2 Body 3 Shoulder 4 Easy bending area 10 Outer circumference 11 Male thread 11a Complete thread 11b Incomplete thread

Claims (7)

A flexible container having a mouth and neck, and a shoulder connecting the mouth and neck and the body, and extruding the contents from the opening at the tip of the mouth and neck.
The mouth and neck portion has a screw cylinder portion in which a male screw protrudes from the outer peripheral surface.
The male screw has a complete thread portion and an incomplete thread portion, and has a complete thread portion and an incomplete thread portion.
The completely threaded portion is a threaded portion in which the protrusion distance from the outer peripheral surface of the threaded cylinder portion is maintained substantially constant.
The incomplete thread portion is
It is a thread portion that exists at the end of the complete thread portion and has a portion in which the protrusion distance from the outer peripheral surface gradually decreases, and is a thread portion.
The shape of the incomplete thread portion that appears as the outermost circumference of the portion where the protrusion distance from the outer peripheral surface gradually decreases from the complete screw thread portion is recessed inward in the radial direction of the screw cylinder portion , and the outermost circumference is It is a "dogleg" shape consisting of a straight line with a large slope and a straight line with a small slope.
The screw cylinder portion has at least a pair of easy-folding regions facing each other in the radial direction, and the easy-folding region does not have the complete screw thread portion when the screw cylinder portion is observed in the axial direction. Moreover, it is a region where the incomplete thread portion exists.
Flexible container. The incomplete thread portion exists at both ends of the complete thread portion, and the protrusion distance from the outer peripheral surface gradually decreases, and the thread converges from the complete thread portion to the outer peripheral surface of the screw cylinder portion. The flexible container according to claim 1, which is a part. The flexible container according to claim 1 or 2, wherein the male screw is a double-threaded screw and the number of the easily bendable regions is a pair. The flexible container according to claim 1 or 2, wherein the male screw is a 4-thread screw and the number of the easily bendable regions is two pairs. The incomplete thread portion is
A thread portion existing at both ends of the complete thread portion, the protrusion distance from the outer peripheral surface gradually decreases, and the thread portion converges from the complete thread portion to the outer peripheral surface of the screw cylinder portion, and the middle of the male screw. The flexible container according to claim 1, wherein the flexible container is composed of both screw threads existing in the above and gradually increasing and returning to the original protruding distance after the protruding distance from the outer peripheral surface is gradually reduced. The flexible container according to any one of claims 1 to 5, wherein the mouth neck portion further has a mouth cylinder portion having a diameter smaller than that of the screw cylinder portion on the opening end side of the screw cylinder portion. .. The flexible container according to any one of claims 1 to 6, which is used as a tube container or a bottle container for food.

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