JP2023056965A - Synthetic resin container - Google Patents

Abstract

To provide a synthetic resin container that suppresses buckling distortion, which starts around the ground part of the bottom corner part of a square bottle.SOLUTION: The synthetic resin container includes: a trunk side face part 41; a bottom side face part 51 that forms a trunk part 4 so as to surround a trunk corner part 42 that is beveled and positioned between each trunk side face part 41 and that is positioned under each trunk side face part 41; a bottom corner part 52 that is positioned under each trunk corner part 42 and positioned between each bottom side face part 51 and is formed toward the bottom face side so as to be squeezed down to the inside of the container; and a recessed groove part 53 on the bottom corner part 52 that includes a ground part 55 formed on the bottom face and forms a bottom 5 so as to continue to each of the bottom side face part 51 and the bottom corner part 52 via a ground part neighboring area 54 that rises so as for the vertical cross section to be arc-shaped or oval-shaped as the outer periphery of the ground part 55 distances from the ground part 55 and protrudes to the inside of the ground part neighboring area 54 with its lower side going over upper end 54a of the ground part neighboring area 54.SELECTED DRAWING: Figure 1

Description

The present invention relates to synthetic resin containers.

Conventionally, thermoplastic resins such as polyethylene terephthalate are used to produce cylindrical preforms with bottoms by injection molding or compression molding, and these preforms are molded into bottles by biaxial stretch blow molding. Manufactured containers are used in a wide range of fields as containers containing various beverages, various seasonings, and the like.

In this type of synthetic resin container, after the contents are filled and sealed and shipped, they are often stacked in a boxed state during transportation and storage, and the load applied in the axial direction at that time. It is required not to impair the commercial value due to buckling deformation due to deformation.

Where the buckling deformation is likely to start depends on the balance between the overall shape of the container and the shape of the details. It is intended to suppress the buckling deformation starting from the annular groove formed for the purpose.

JP 2016-179847 A

The inventors of the present invention have completed the present invention as a result of extensive studies to suppress buckling deformation originating from the vicinity of the grounding portion of the bottom corner portion, particularly in a container called a square bottle. .

A synthetic resin container according to the present invention is a synthetic resin container comprising a mouth portion, a shoulder portion, a body portion, and a bottom portion, wherein the body portion is located between a side portion of the body portion and a side portion of the body portion. a bottom side located below the barrel side of the barrel and a barrel corner positioned below the barrel corner of the barrel; and a bottom corner portion located between the bottom side portions and formed so as to be narrowed inward of the container toward the bottom surface side of the bottom portion; and a grounding portion formed on the bottom surface of the bottom portion, The outer peripheral edge of the ground contact portion is continuous with the bottom side surface portion and the bottom corner portion via the ground contact portion adjoining region that rises so that the longitudinal cross-sectional shape becomes an arc or an elliptical arc as the distance from the ground contact portion increases. At least one recessed groove portion extending downward in the height direction is provided in the bottom corner portion, and the lower end side of the recessed groove portion extends beyond the upper end of the ground contact portion adjacent region, It is configured to protrude into the area adjacent to the grounding portion.

ADVANTAGE OF THE INVENTION According to this invention, the buckling deformation which starts near the contact|grounding part of the bottom corner part in a rectangular bottle can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the outline of the synthetic resin containers which concern on 1st embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the outline of the synthetic resin containers which concern on 1st embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows the outline of the synthetic resin containers based on 1st embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a bottom view which shows the outline of the synthetic resin containers which concern on 1st embodiment of this invention. FIG. 5 is an end view of the main part taken along line AA of FIG. 4; FIG. 5 is an end view of a main part taken along line BB of FIG. 4; 6. It is explanatory drawing which shows the part enclosed by the dashed-dotted line among the end faces shown in FIG. 5 by a solid line, and shows the part enclosed by the dashed-dotted line among the end faces shown in FIG. Fig. 2 is a perspective view showing an outline of a synthetic resin container according to a second embodiment of the present invention; Fig. 2 is a front view schematically showing a synthetic resin container according to a second embodiment of the present invention; Fig. 2 is a side view schematically showing a synthetic resin container according to a second embodiment of the present invention; Fig. 2 is a bottom view showing an outline of a synthetic resin container according to a second embodiment of the present invention; FIG. 12 is an end view of essential parts along CC of FIG. 11; FIG. 12 is an end view of a main part taken along line DD of FIG. 11; 13. It is explanatory drawing which shows the part enclosed by the dashed-dotted line among the end faces shown in FIG. 12 by a solid line, and shows the part enclosed by the dashed-dotted line among the end faces shown in FIG.

Preferred embodiments of the present invention are described below with reference to the drawings.

[First embodiment]
First, a first embodiment of the present invention will be described.
1 is a perspective view showing an outline of a synthetic resin container according to this embodiment, FIG. 2 is a front view of the same, FIG. 3 is a side view of the same, and FIG. 4 is a bottom view of the same.

The container 1 shown in these figures comprises a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5. The body portion 4 is generally called a rectangular bottle. It has a container shape.

Such a container 1 is produced by using a thermoplastic resin to prepare a preform molded into a cylindrical shape with a bottom by injection molding, compression molding, or the like, and biaxially stretch blow molding the preform to form a predetermined container. It can be manufactured by molding into shape.

Any resin that can be blow-molded can be used as the thermoplastic resin to be used. Specifically, thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, amorphous polyarylate, polylactic acid, polyethylene furanoate, or copolymers thereof can be used, particularly ethylene terephthalate such as polyethylene terephthalate. A thermoplastic polyester can be preferably used. Two or more of these resins may be mixed, or other resins may be blended. Polycarbonate, acrylonitrile resin, polypropylene, propylene-ethylene copolymer, polyethylene and the like can also be used.
In addition, the preform is not limited to being molded into a single layer, but can be molded into multiple layers including a gas barrier layer and the like depending on the properties required for the container 1 .

The mouth portion 2 is a cylindrical part that serves as an outlet for pouring contents, and a side surface of the mouth portion 2 on the open end side is provided with a screw thread 2a for attaching a lid (not shown).
Further, the mouth portion 2 is provided with an annular neck ring 2b protruding outward along the circumferential direction. The mouth portion 2 includes the neck portion 2c that hangs down in a cylindrical shape with approximately the same diameter from directly below the neck ring 2b. It is connected to the connecting shoulder portion 3 .

The trunk portion 4 occupies most of the height direction of the container 1 , and has an upper end connected to the shoulder portion 3 and a lower end connected to the bottom portion 5 .
Here, the height direction refers to the direction perpendicular to the horizontal surface when the container 1 is erected on a horizontal surface with the mouth portion 2 facing up. up, down, left, right, and vertical and horizontal directions.

In the present embodiment, the trunk portion 4, which is formed in a generally square tubular shape, has a rectangular shape (square or rectangular shape; in the illustrated example, a rectangular shape) whose corners are chamfered in an R-chamfered shape or a C-chamfered shape. It has a cross-sectional shape (the shape of a cross section cut along a plane orthogonal to the central axis C), and has two pairs of opposing body side portions 41 and chamfered portions located between the body side portions 41. It is formed so as to include a trunk corner portion 42 .

In the illustrated example, the body side portion 41 located on the longer side of the body portion 4 is denoted by reference numeral 41a, and the body portion side portion 41 located on the shorter side of the body portion 4 is denoted by reference numeral 41b. Although they are separate, they are collectively referred to as the trunk side portion 41 .

A circumferential groove 40 extending along the circumferential direction is provided in a portion of the trunk portion 4 nearer to the bottom portion 5 side from the center in the height direction for the purpose of increasing the rigidity of the portion. Such a circumferential groove 40 may be omitted as appropriate, but in the illustrated example, the upper and lower trunk portions 4a and 4b divided into upper and lower portions by the circumferential groove 40 have pressure-reduced pressure on the respective trunk side portions 41. Absorbent panels 45a, 45b are provided. The decompression absorption panels 45a and 45b also serve to sterilize the container 1, and when filling the heat-sterilized content liquid at a high temperature (hot filling), the pressure inside the container 1 decreases after the inside of the container is sealed. This is to prevent uneven shape change, and various panel shapes can be adopted according to the required vacuum absorption performance.

Further, in the illustrated example, longitudinal grooves 48 are provided along both side edges of the body corner portion 42 . Such an aspect is preferable in that the strength of the body portion 4 can be ensured while the body portion 4 is formed thinner.

The cross-sectional shape of the shoulder portion 3 that connects the trunk portion 4 and the mouth portion 2 formed in a cylindrical shape varies from the trunk portion 4 side toward the mouth portion 2 side. The cross-sectional shape (rectangular cross-sectional shape with chamfered corners) is formed so as to continuously change to the cross-sectional shape of the mouth portion 2 (circular cross-sectional shape). In the illustrated example, in order to change the cross-sectional shape of the shoulder portion 3 in this way, the shoulder portion 4 is positioned above each side surface portion 41 of the body portion 4, and the width is gradually narrowed symmetrically. A shoulder side surface portion 31 connected to the lower end of the portion 2 and a shoulder corner portion 32 located above each body corner portion 42 of the body portion 4 and between each shoulder side surface portion 31. A shoulder 3 formed to provide a connection between the body 4 and the mouth 2 .

On the other hand, the bottom portion 5 connected to the lower end of the trunk portion 4 is located below the bottom side surface portion 51 positioned below each trunk portion side surface portion 41 of the trunk portion 4 and below each trunk portion corner portion 42 of the trunk portion 4 . and a bottom corner portion 52 positioned between each bottom side surface portion 51 , and the bottom corner portion 52 is formed to be narrowed inward toward the bottom surface side of the bottom portion 5 . In the illustrated example, a dome-shaped raised bottom portion 50 is formed at the center of the bottom surface of the bottom portion 5, and the ground contact portion is defined in a polygonal shape (hexagonal shape in the illustrated example) with a step portion on the inner peripheral edge. 55 is formed on the bottom surface of the bottom portion 5 so as to surround the raised bottom portion 50 . By doing so, it is possible to effectively prevent the center of the bottom surface of the bottom portion 5 from protruding beyond the grounding portion 55 due to filling pressure or the like when filling the contents, and impairing the self-standing stability. there is

In addition, the ground contact portion 55 formed on the bottom surface of the bottom portion 5 has a vertical cross-sectional shape (shape of a cross section cut along a plane including the central axis C) of a circular arc or an elliptical arc as the outer peripheral edge of the ground contact portion 55 is separated from the ground contact portion 55. It is formed so as to be continuous with each of the bottom side surface portion 51 and the bottom corner portion 52 via the ground portion adjoining region 54 which rises in a shape of a shape.
It should be noted that the grounding portion adjoining region 54 is included in the bottom side portion 51 and the bottom corner portion 52 as part of their lower end sides.

In the container 1 thus formed, when a load is applied in the axial direction, the shoulder corner portion 32 of the shoulder portion 3, the body corner portion 42 of the body portion 4, and the bottom corner portion 52 of the bottom portion 5 are They function like pillars, and the load received by them propagates toward the grounding portion 55 . At this time, if the load is concentrated on the bottom corner portion 52 of the bottom portion 5, buckling deformation tends to occur starting from the vicinity of the contact portion 55 of the bottom corner portion 52.

In the present embodiment, in order to suppress the buckling deformation of the bottom corner portion 52 starting from the vicinity of the ground contact portion 55, the bottom corner portion 52 is provided with a groove extending downward in the height direction. At least one (three in the illustrated example) recessed grooves 53 are provided, and the lower end side of the recessed grooves 53 extends beyond the upper end 54 a of the grounding portion adjacent region 54 and into the grounding portion adjacent region 54 . I try to stand out.

Here, the ground contact portion adjoining region 54 can be formed so that its longitudinal cross-sectional shape is an arc shape with a constant radius of curvature or an elliptical arc shape with a curvature radius that monotonically decreases as the distance from the ground contact portion 55 increases. When the vertical cross-sectional shape of the ground contact portion adjacent region 54 is formed in an arc shape with a constant curvature radius, the vertical cross-sectional shape of the bottom side surface portion 51 or the bottom corner portion 52 is a boundary where the curvature radius changes. The upper end 54a of the ground contact portion adjacent region 54 (see FIG. 7) is formed in the vertical cross-sectional shape of the ground contact portion adjacent region 54 in the shape of an elliptical arc in which the radius of curvature monotonously decreases as the distance from the ground contact portion 55 increases. In this case, in the vertical cross-sectional shape of the bottom side surface portion 51 or the bottom corner portion 52, the upper end 54a of the ground contact portion adjacent region 54 is defined as the boundary where the radius of curvature starts to increase (see FIG. 14). .

In providing the concave groove portion 53 in the bottom corner portion 52 in this manner, the arrangement of the concave groove portion 53 is not particularly limited. For example, when one recessed groove 53 is provided in the bottom corner portion 52, it is preferably provided in the circumferential center of the bottom corner portion 52, and when a plurality of recessed grooves 53 are provided, the arrangement should be as highly symmetrical as possible. is preferable. In the illustrated example, a total of three recessed grooves 53 are provided in a highly symmetrical arrangement on and between the extension lines of the vertical grooves 48 provided along both side edges of the body corners 42 of the body 4. However, the arrangement of the concave groove portion 53 can be appropriately designed according to the portion that tends to become the starting point of buckling deformation, considering the balance between the shape of the entire container and the shape of the details.

The shape of the recessed groove portion 53 provided in the bottom corner portion 52 is also not particularly limited. For example, the groove may have a V-shaped cross section in which the groove side surfaces meet at the straight groove bottom, or may have a U-shaped cross section. In order to improve load-bearing strength (longitudinal compressive strength) against a load, the recessed groove portion 53 has a groove bottom portion with a predetermined width as shown in the figure, and groove side surfaces rise from the width direction side edges of the groove bottom portion. It is preferable that the groove has a trapezoidal cross section. Although not shown in particular, both or one of the upper end side and the lower end side of the recessed groove portion 53 provided in the bottom corner portion 52 may be tapered, and the upper end side of the recessed groove portion 53 may be tapered to the bottom portion 5 . It may be provided so as to reach the side of the trunk portion corner portion 42 across the connecting portion between the and trunk portion 4 .

Also, in order to suppress buckling deformation originating near the contact portion 55 of the bottom corner portion 52 , the lower end of the groove portion 53 provided in the bottom corner portion 52 is preferably closer to the contact portion 55 . However, if the lower end of the concave groove portion 53 is too close to the grounding portion 55, the shapeability of the grounding portion 55 is affected when the container 1 is blow-molded, resulting in poor shaping of the grounding portion 55. It is feared that If the ground portion 55 is not shaped well, for example, the following problems may occur. That is, in many cases, the container 1 in which the contents are filled and sealed is sold with a band-shaped label made of a heat-shrinkable shrink film attached, and when attaching the label to the container 1, It is known to attach a label after centering the container 1 by sucking the bottom surface side of the bottom portion 5 under negative pressure. There is a possibility that pressure suction may be hindered.

In order to effectively avoid such a problem, it is preferable that the lower end of the concave groove portion 53 provided in the bottom corner portion 52 is separated from the grounding portion 55 with a certain distance. More specifically, the height h from the grounding portion 55 to the lower end of the groove portion 53 along the height direction is preferably 0.5 to 3 mm.

Also, when the blow-molded container 1 is removed from the mold, the container 1 is usually not sufficiently cooled. Therefore, if there is a portion where a smooth flat surface or a curved surface exists in a relatively wide range, such a portion is likely to stick to the molding surface of the mold, and the portion stuck to the molding surface has a release agent. In this case, a load is applied to pull the part from the molding surface while deforming the part so as to bend. If such a load is applied to the portion stuck to the molding surface before it is sufficiently cooled, traces generally called sink marks may occur, and the shape of the surroundings may be distorted.

In the illustrated example, by forming the concave portion 56 in the bottom side surface portion 51, such a problem is effectively avoided, and the distortion that hinders negative pressure suction is prevented from occurring at the ground portion 55. It suppresses the occurrence of

In the illustrated example, when a load applied in the axial direction is received by the corner portions 32, 42, and 52, buckling deformation originating near the boundary between the shoulder portion 3 and the trunk portion 4 is prevented. For the purpose of restraint, the shoulder side extends across the articulation of the shoulder 3 and the trunk 4 so as to have a starting end on the side of the shoulder corner 32 and an end on the side of the trunk corner 42. A concave groove portion 36 is provided.

The shape of the shoulder-side concave groove portion 36 is not particularly limited. A groove shape with a V-shaped cross section, a groove shape with a U-shaped cross section, a groove shape with a trapezoidal cross-section, etc. can be used in the same manner as the recessed groove portion 53 provided in the bottom corner portion 52, but as shown in the figure. , is preferably provided in a tapered shape toward the starting end located on the shoulder corner portion 32 side.

Moreover, the position of the starting end of the shoulder-side groove 36 is not particularly limited as long as the shoulder-side groove 36 extends along the surface of the shoulder 3 . The starting end of the shoulder-side recessed groove 36 is preferably positioned closer to the mouth part 2 side, and particularly preferably positioned at the joint between the mouth part 2 and the shoulder part 3 . If the shoulder-side recessed groove portion 36 straddles the connecting portion between the shoulder portion 3 and the trunk portion 4 and extends to reach the trunk portion corner portion 42 side, the end position of the shoulder-side recessed groove portion 36 is also determined. Although not particularly limited, it is preferably positioned on the upper end side of the body corner portion 42 . Furthermore, it is preferable that the shoulder-side concave groove portion 36 is provided so as to extend along the widthwise central portion of the shoulder corner portion 32 and reach the widthwise central portion of the body corner portion 42 . These aspects can be appropriately selected so that buckling deformation originating from the vicinity of the boundary between the shoulder portion 3 and the body portion 4 of the corner portions 32 and 42 can be suppressed more effectively.

Further, the shoulder 3 can be provided with side edge grooves 37 along both side edges of the shoulder corner 32 . As a result, the strength of the shoulder portion 3 can be ensured while the shoulder portion 3 is formed to be thinner, and such an aspect is effective for the boundary between the shoulder portion 3 and the trunk portion 4 of the corner portions 32 and 42 . It is also advantageous in suppressing buckling deformation originating from the vicinity.

The side edge grooves 37 provided in the shoulder portion 3 are preferably arranged on extension lines of vertical grooves 48 provided along both side edges of the body corner portion 42 . By adopting such a mode, when a load is applied to the container 1 in the axial direction, the load received by the corner portions 32 and 42 is transferred to the side edge groove portion 37 provided in the shoulder portion 3 and the body portion 4. It propagates along the vertical groove portion 48 provided in the vertical groove portion 48 to the lower end side of the vertical groove portion 48 (near the circumferential groove 40 in the illustrated example) without causing buckling deformation on the way. can be As a result, the portion that can become the starting point of buckling deformation moves from the vicinity of the boundary between the shoulder portion 3 and the body portion 4 to the portion on the lower end side of the longitudinal groove portion 48. By appropriately adjusting the molding conditions and selectively forming the relevant portion to be thick to prevent buckling deformation from occurring at the relevant portion, the container 1 is formed thinner as a whole while maintaining the longitudinal compressive strength. can be further improved.

In this embodiment, a polyethylene terephthalate-based resin is used to injection-mold a preform weighing about 34 g, and the preform is biaxially stretched and blow-molded to obtain the container shape shown in FIG. 1 and the like. A container 1 with a capacity of 720 mL was molded, and a load was applied in the axial direction in a state where the contents were filled and sealed. No buckling deformation originating from the vicinity of the ground contact portion 55 of the bottom corner portion 52 occurred until the time of the test. On the other hand, a similar load-bearing test was carried out on a container that was formed in the same manner except that the recessed groove portion 53 was provided so as not to exceed the upper end 54a of the ground contact portion adjacent region 54. Buckling deformation originating near the contact portion 55 of the corner portion 52 occurred.

[Second embodiment]
Next, a second embodiment of the invention will be described.
8 is a perspective view showing an outline of a synthetic resin container according to this embodiment, FIG. 9 is a front view of the same, FIG. 10 is a side view of the same, and FIG. 11 is a bottom view of the same.

The container 1 shown in these figures is an example of use for sterilizing the container 1 with a chemical solution and filling the content liquid at room temperature (aseptic filling) in an environment controlled to be aseptic. For this reason, the body portion 4 is not provided with a vacuum absorption panel. Furthermore, the trunk portion 4 is formed in a generally square tubular shape, although it differs from the above-described first embodiment in that the portion of the trunk portion 4 that is closer to the bottom portion 5 side from the center in the height direction is constricted. The basic structure of the container 1 is such that it is formed to include two pairs of opposing body side portions 41 and chamfered body corner portions 42 located between the body side portions 41 . This typical form is common to the first embodiment described above.

In addition, in the first embodiment described above, an example in which the bottom corner portion 52 is provided with the three groove portions 53 is illustrated and described, but in the present embodiment, the bottom corner portion 52 is provided with the two groove portions 53. ing.

In addition, in the first embodiment described above, an example in which the vertical cross-sectional shape of the ground contact portion adjacent region 54 is formed in an arc shape with a constant radius of curvature is illustrated (see FIG. 7). In terms of form, the longitudinal cross-sectional shape of the ground contact portion adjacent region 54 is formed to be an elliptical arc whose radius of curvature monotonically decreases with increasing distance from the ground contact portion 55 (see FIG. 14).

In this embodiment, a polyethylene terephthalate-based resin is used to injection-mold a preform weighing about 28 g, and the preform is biaxially stretched and blow-molded to obtain the container shape shown in FIG. 8 and the like. A container 1 with a capacity of 720 mL was molded, a load was applied in the axial direction in a state where the contents were filled and sealed, and the load was gradually increased. No buckling deformation originating from the vicinity of the portion 55 occurred. On the other hand, a similar load-bearing test was carried out on a container molded in the same manner except that the concave groove 53 was not provided in the bottom corner portion 52. When a load of about 277 N was applied, the bottom corner portion 52 near the ground contact portion 55 was crushed. A buckling deformation was generated as a starting point.

This embodiment has been described with a focus on points that differ from the above-described first embodiment, but the same reference numerals as those of the first embodiment are attached to the drawings for configurations that are common to the first embodiment, and redundant description will be given. are omitted.

Although the present invention has been described above with reference to preferred embodiments, it goes without saying that the present invention is not limited to the above-described embodiments, and that various modifications can be made within the scope of the present invention. Nor.

1 Container 2 Mouth 3 Shoulder 31 Shoulder Side 32 Shoulder Corner 36 Shoulder Side Groove 37 Side Edge Groove 4 Body 41 Body Side 42 Body Corner 48 Vertical Groove 5 Bottom 51 Bottom Side 52 Bottom corner portion 53 Groove portion 54 Grounding portion adjacent region 54a Upper end of grounding portion adjacent region 55 Grounding portion

Claims (5)

A synthetic resin container comprising a mouth, a shoulder, a body, and a bottom,
the barrel includes a barrel side portion and a barrel corner portion located between the barrel side portions;
The bottom portion is positioned between a bottom side portion positioned below the barrel side portion of the barrel portion and the bottom portion side portion positioned below the barrel corner portion of the barrel portion. , a bottom corner portion formed so as to be narrowed inward of the container toward the bottom surface side of the bottom portion, and a grounding portion formed on the bottom surface of the bottom portion,
The outer peripheral edge of the ground contact portion extends to each of the bottom side surface portion and the bottom corner portion via the ground contact portion adjoining region rising so that the longitudinal cross-sectional shape becomes an arc or an elliptical arc as the distance from the ground contact portion increases. in succession,
At least one recessed groove portion extending downward in the height direction is provided in the bottom corner portion, and the lower end side of the recessed groove portion extends beyond the upper end of the ground contact portion adjacent region to the ground contact portion. A synthetic resin container, characterized in that it protrudes into an adjacent region. 2. The synthetic resin container according to claim 1, wherein the height from the grounding portion to the lower end of the concave groove along the height direction is 0.5 to 3 mm. The shoulder portion is located above the trunk side portion of the trunk portion, the shoulder portion side portion is symmetrically narrowed in width gradually and is connected to the lower end of the mouth portion, and the trunk portion of the trunk portion. a shoulder corner located above the shoulder corner and located between the shoulder side surfaces,
3. The synthetic resin container according to claim 1, further comprising a shoulder-side recessed groove having a starting end on the shoulder corner side and a terminal end on the body corner side. 4. The synthetic resin container according to claim 3, wherein side edge grooves are provided along both side edges of said shoulder corner portion. 5. The synthetic resin container according to claim 4, wherein vertical grooves are provided along both side edges of said body corner, and said vertical grooves are arranged on extension lines of said side edge grooves.

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