JP6351492B2 - Synthetic resin bottle - Google Patents

Description

  The present invention relates to a bottle used for a synthetic resin container and capable of being fitted with a cap by a stopper, and more particularly to a synthetic resin bottle having a mouth structure that is excellent in sealing performance with a cap.

Synthetic resin containers in which an openable / closable cap is attached to the mouth of a bottle by a stopper are widely used as various liquid pouring containers such as seasonings.
As a conventional technique of a synthetic resin container in which a cap is plugged into a bottle mouth portion, a mouth portion having an engagement protrusion projecting annularly on the outer periphery is fitted into a fitting groove of the cap, and the engagement protrusion of the mouth portion is inserted. A liquid dispensing container having a mouth structure in which a strip engages with a reduced diameter projection on the cap side and a fitting groove sandwiches the mouth and the cap is attached to the mouth is fixed (for example, , See Patent Document 1).

JP 2002-225836 A

As shown in FIG. 6 (a), the liquid dispensing container of Patent Document 1 includes a bottle Aa, an inner cap Ba of the cap, and an upper lid Ca that is screwed into the inner plug Ba. The cap is attached to the bottle Aa by fitting and fixing the inner stopper Ba.
In the bottle Aa, a shoulder portion 102 is formed on the upper portion of the body portion 101, and a substantially cylindrical mouth portion 103 is erected on the upper end of the shoulder portion 102.
As shown in FIG. 6 (b), an engaging ridge 104 protruding to the outer periphery is provided at the upper end of the mouth portion 103, and the engaging ridge 104 is formed in the same plane as the top surface 105. An upper surface, a curved surface 110 connected to the outer edge of the upper surface, an inclined surface 106 and a cylindrical surface 107 that form an outer peripheral surface following the curved surface 110, and a lower end surface of the engaging protrusion 104 following the cylindrical surface 107. And a lower end engaging portion 108 to be formed.
A rounded curved surface 110 is formed at the upper end corner portion a1 where the top surface 105 and the inclined surface 106 intersect, and a central corner portion b is annular at a portion where the inclined surface 106 and the cylindrical surface 107 intersect. Is formed.

On the other hand, the inner plug Ba is provided with a fitting cylinder part 120 for fitting the mouth part 103, and the fitting cylinder part 120 includes an outer peripheral surface of the inner cylinder 121 fitted on the inner peripheral side of the mouth part 103, and an outer surface. A fitting groove 123 formed by the inner peripheral surface of the cylinder 122 is provided.
Reference numeral 125 denotes a pouring cylinder for guiding the content liquid, which is continuously provided on the upper inner peripheral side of the inner cylinder 121.
A diameter-reducing ridge 124 that protrudes inward is provided at the lower end portion of the inner peripheral surface of the outer cylinder 122, and when the opening 103 is fitted in the fitting groove 123, the diameter-reduced ridge 124 is engaged. The cap 104 is engaged and fixed so that it does not fall off the bottle Aa by engaging with the lower end engaging portion 108 of the strip 104, and the outer peripheral surface of the inner cylinder 121 and the inner peripheral surface of the outer cylinder 122 sandwich the mouth portion 103. ing.

However, the bottle Aa of the liquid dispensing container described in Patent Document 1 can obtain a stable mouth shape that can withstand capping according to biaxial stretch blow molding such as PET, but in the case of direct blow molding In the thick portion at the tip of the mouth 103 where the engaging protrusions 104 are provided, as shown in FIG. 6B, the inner peripheral surface 112 may be sinked, and a slight recess 111 may be generated.
When the concave portion 111 is generated due to the sink of such material, the mouth portion 103 achieves sealing with the cap mainly by bringing the inner peripheral surface 112 into intimate contact with the outer peripheral surface of the inner cylinder 121. In some cases, the content liquid leaked and the content liquid leaked out.

According to direct blow molding, there is an advantage that a bottle laminated with a gas barrier material such as EVOH can be easily manufactured. However, due to molding problems in such a mouth structure, a bottle of a container whose internal pressure such as heat filling is increased. It was difficult to use as.
Therefore, when the mouth shape of the direct blow molded bottle is changed, a stopper cap used for a normal PET bottle by biaxial stretch blow molding or the like cannot be used in the direct blow molded bottle as it is.

  An object of the present invention is to solve the above-mentioned problems, to prevent the occurrence of sink marks at the mouth during direct blow molding, to improve the sealing performance, and to be used for conventional PET bottles by biaxial stretch blow molding or the like. An object of the present invention is to provide a synthetic resin bottle to which a cap cap can be attached.

In order to solve the above-mentioned problem, the present invention provides a synthetic resin bottle molded by a direct blow molding method having a cylindrical mouth portion that is fitted and fitted into a fitting groove of a cap by a stopper. In the outer periphery of the mouth, a plurality of projecting rings and one engagement ring are provided in an annular shape in parallel with the axial direction of the mouth, and the engagement rings disposed below the plurality of projecting rings are: An opening that is disposed at a position that engages with a reduced diameter protrusion protruding into the fitting groove of the cap, and that is provided with an annular groove between adjacent protruding rings and between the protruding ring and the engaging ring. A configuration characterized by having a partial structure is adopted.

As a specific embodiment of the synthetic resin bottle, each of the plurality of projecting rings and engagement rings has an inclined surface that expands downward on the outer peripheral surface and a cylindrical surface that continues to the large-diameter portion side of the inclined surface. The structure characterized by this, or a some protrusion ring consists of the 1st protrusion ring of the most front end side of a mouth part, and the 2nd protrusion ring below it, and it is the 2nd protrusion ring from the cylindrical surface of the 1st protrusion ring. The cylindrical surface of the second projecting ring is slightly smaller in diameter than the cylindrical surface of the engagement ring or the same diameter, and the upper surface is the mouth. In the first projecting ring that is flush with the top surface of the front end of the section, the upper corner of the outer edge of the upper surface connected to the inclined surface is a single engagement with the cap instead of the plurality of projecting rings and one engagement ring. It is formed as a coupling portion, the inclined surface through a curved surface from the upper surface forming the top surface flush with the cylindrical therebelow DOO is in the case of an engagement protrusion formed, as compared to the upper corner portion where the upper surface and the inclined surface intersecting the radial height is formed lower inclined surface of the first protrusion ring is the engagement A configuration characterized by being formed so as to have a minute gap and an inclined surface of the ridge is adopted.

In the synthetic resin bottle of the present invention, a plurality of projecting rings and one engagement ring are provided in an annular shape on the outer periphery of the mouth in parallel with the axial direction of the mouth, and the engagement ring is engaged with the reduced diameter protrusion of the cap. When the mouth part is fitted in the fitting groove of the cap, the plurality of projecting rings and the engagement ring are pressed into contact with the inner surface of the fitting groove at three or more points so that the cap is brought into the mouth part. While engaging reliably, a high sealing pressure can be ensured by firmly pressing the inner peripheral surface of the mouth portion against the inner surface of the fitting groove.
In addition, since an annular groove is provided between the plurality of protruding rings and one engaging ring, the thick portion is not continuous as in the conventional engaging protrusion, and the portion corresponding to the annular groove is thinned. Therefore, no sink marks are generated on the inner peripheral surface of the mouth, and the sealing performance is not lowered even by direct blow molding. Therefore, the normal PET bottle stopper cap used in the conventional example can be used as it is.

It is a principal part perspective view of the synthetic resin bottle which is an Example of this invention. It is side surface sectional drawing of the principal part which attached the cap to the Example synthetic resin bottle. (A) is a top view of an example synthetic resin bottle, (b) is a front half sectional view of an example synthetic resin bottle. It is an enlarged view of the principal part G of FIG.3 (b). It is side surface sectional drawing of the cap of the closed state before a stopper. It is a figure which shows the synthetic resin bottle of a prior art example, (a) is a side half sectional view of the principal part which attached the cap, (b) is a cross-sectional enlarged view of the principal part of the bottle which produced the sink.

  Next, the synthetic resin bottle of the present invention will be described with reference to the drawings showing examples.

1 to 5, A is a synthetic resin bottle, and C is a cap attached to the synthetic resin bottle A.
The cap C includes a cap body C1 and an upper lid C3 that is connected to the cap body C1 via a hinge C2.

As shown in FIGS. 1 to 3, the synthetic resin bottle A includes a body portion 1 having a bottom portion (not shown), a shoulder portion 2 continuously connected to the body portion 1 and having a diameter reduced upward, and an upper portion of the shoulder portion 2. It consists of a cylindrical mouth portion 3 standing upright.
A neck ring 5 projects from the lower part of the outer periphery of the mouth part 3, and a first projecting ring 7, a second projecting ring 8, and an engagement ring 9 are arranged on the upper part from the tip side in the axial direction of the mouth part 3. It protrudes in an annular shape in parallel to form an engaging portion with the cap C.
A flat top surface 10 is formed at the upper end of the mouth 3 and forms the same plane as the upper surface of the first projecting ring.
On the lower surface of the engagement ring 9, a lower end engagement portion 11 that engages with a reduced diameter protrusion 60 of the cap C described later is formed on a surface substantially perpendicular to the axial direction of the mouth portion 3.

As shown in FIG. 4, the first projecting ring 7, the second projecting ring 8, and the engagement ring 9 are conical surface-shaped first inclined surfaces 21 and second inclined surfaces that expand downward on the outer peripheral surface, respectively. 23, the engagement inclined surface 25 has a first cylindrical surface 22, a second cylindrical surface 24, and an engagement cylindrical surface 26, respectively, continuously from the large diameter portion side of each inclined surface.
A first annular groove 12 is formed between the first projecting ring 7 and the second projecting ring 8, and a second annular groove 13 is formed between the second projecting ring 8 and the engagement ring 9.
By providing the first inclined surface 21, the second inclined surface 23, and the engaging inclined surface 25, when the cap C is stoppered, the lower end portion of the cap body C1 expands along each inclined surface. Easy to plug.

In the present embodiment, the depth of the first annular groove 12 and the second annular groove 13 is such that the thickness of the mouth portion 3 at the bottom surface is greater than the thickness of the base portion 14 of the mouth portion 3 below the engagement ring 9. It is set to be smaller.
Further, the inner diameter of the mouth portion 3 of this embodiment is about 27 mm, but the height from the lower end engaging portion 11 to the top surface 10, that is, the first and second projecting rings 7 and 8 and the engaging ring 9 are provided. Further, the width (in the axial direction) of the first annular groove 12 and the second annular groove 13 is about 1 mm, respectively, with respect to the height of the entire engaging portion of about 4.5 mm.
The first and second projecting rings 7 and 8 have a width (in the axial direction) of about 0.5 mm to 1 mm, and the engagement ring 9 obtains an engagement strength with the reduced diameter protrusion 60. It is desirable to have a width (in the axial direction) of about 1 mm or more, and in particular, gradually increase the thickness in the axial direction in the order of the first projecting ring 7, the second projecting ring 8, and the engagement ring 9. If it makes it, it will be balanced and a fitting state with a cap will become favorable.

The imaginary line (two-dot chain line) in FIG. 4 shows the mouth structure of a normal PET bottle provided with a single engaging protrusion by biaxial stretch blow molding or the like shown in the conventional example, A conventional example will be described using the terms and symbols described with reference to FIG.
The lower end engaging portion 11 and the engaging cylindrical surface 26 of the engaging ring 9 have shapes substantially matching the lower end engaging portion 108 and the cylindrical surface 107 of the engaging protrusion 104 of the conventional example, respectively.
In the embodiment, the second inclined surface 23 and the second cylindrical surface 24 of the second protruding ring 8 are slightly smaller in diameter than the inclined surface 106 and the cylindrical surface 107 of the conventional example, respectively, but are the same as the conventional example. The diameter may be used.
A portion where the second inclined surface 23 and the second cylindrical surface 24 intersect with each other substantially coincides with the axial height of the central corner portion b of the conventional example.

The first projecting ring 7 shares the upper surface with the top surface 10, and the radial height of the upper end corner portion a where the upper surface and the first inclined surface 21 intersect and connect is the engagement protrusion of the conventional example. The first inclined surface 21 is formed to have a small radial height so as to have a minute gap s with respect to the inclined surface 106 of the conventional example. Has been.
In a normal PET bottle that is biaxially stretched and blow-molded with an engaging portion consisting of a single engaging protrusion 104, the curved surface 110 can be easily formed near the upper end corner portion a1 as in the conventional example. In the case of direct blow molding, if the minute gap s is not provided in the first projecting ring 7, the shape of the outer edge near the upper end corner portion a can be improved. It is desirable to provide a minute gap s because the outer edge of the cap is likely to be sharp and the sharp outer edge is caught on the lower end of the cap or the inner surface of the fitting groove 51, making it difficult to plug. .

In the embodiment, two protruding rings are provided. However, the number is not necessarily limited to two, and three or more may be provided as long as a predetermined strength is ensured.
Further, the depth and width of each annular groove are not limited to those in the embodiment, and can be appropriately set within a range in which thinning without causing sink marks, ensuring sealing performance, and engagement strength can be obtained.

As shown in FIG. 5, the cap body C <b> 1 has an annular fitting groove 51 into which the mouth portion 3 is fitted, and has a fitting cylinder portion 50 provided continuously with the dispensing cylinder 52.
The fitting groove 51 of the cap body C <b> 1 includes an outer peripheral surface of the inner cylinder 54 that is continuous with the extraction cylinder 52 on the inner peripheral side, a lower surface of the upper wall 55 that is continuous with the upper part of the inner cylinder 54, It is formed by the inner peripheral surface of the outer cylinder 56 suspended from the outer peripheral side.
The lower surface of the upper wall 55 that forms the upper surface of the fitting groove 51 is formed with a flat top surface 58 on the inner peripheral side and a corner inclined surface 59 on the outer peripheral side, and at the lower end portion of the inner peripheral surface of the outer cylinder 56 The diameter-reducing ridge 60 projecting inward is provided.

Next, usage modes and operational effects of this embodiment will be described.
The cap C is pressed from the upper part in the plugging process, and the reduced diameter protrusion 60 gets over the first projecting ring 7, the second projecting ring 8 and the engaging ring 9 and engages with the lower end engaging part 11 of the engaging ring 9. Then, the opening 3 is fitted into the fitting groove 51 and attached to the synthetic resin bottle A (see FIG. 2).
At this time, the inclined surfaces of the first inclined surface 21, the second inclined surface 23, and the engaging inclined surface 25 guide the reduced diameter ridge 60 and facilitate the fitting to the mouth portion 3.
Further, the radial height of the upper end corner portion a where the upper surface of the first projecting ring 7 and the first inclined surface 21 intersect is slightly higher than the radial height of the upper end corner portion a1 of the engaging protrusion 104 of the conventional example. Since the first inclined surface 21 is formed so as to be lower than the conventional inclined surface 106 with a small gap s so that the first inclined surface 21 has a small gap s, the plugging process can be easily performed. .

The first inclined surface 21 and the second inclined surface 23 are in pressure contact with the corner inclined surface 59 of the fitting groove 51, and the first cylindrical surface 22, the second cylindrical surface 24, and the engaging cylindrical surface 26 are respectively cylindrical surfaces. The cap 56 is securely engaged with the mouth portion 3 together with the lower end engaging portion 11 that engages with the reduced diameter protrusion 60 of the cap C by slightly expanding the outer cylinder 56 outward.
In this embodiment, the first and second projecting rings 7 and 8 and the engagement ring 9 are brought into pressure contact with the inner peripheral surface of the outer cylinder 56 at three points, and the engagement protrusion comprising a single thick portion of the conventional example. The contact pressure is distributed to the three points in a well-balanced manner with more flexibility than 104, the cap C is securely engaged with the mouth portion 3, and the inner peripheral surface 15 of the mouth portion is firmly pressed against the outer peripheral surface of the inner cylinder 54 to provide the necessary seal. Pressure can be secured.

And the engaging part which consists of the 1st protrusion ring 7, the 2nd protrusion ring 8, and the engagement ring 9 of a present Example does not have a continuous thick part like the engagement protrusion 104 of a prior art example, and is 1st. Since the thickness of the annular groove 12 and the second annular groove 13 is reduced, there is no sink on the inner peripheral surface 15.
Therefore, even if the inner peripheral surface 15 of the mouth 3 is in pressure contact with the outer peripheral surface of the inner cylinder 54 and is a synthetic resin bottle molded by the direct blow molding method, the sealing performance is not lowered.
Therefore, the synthetic resin bottle of the present embodiment can use a cap that fits into a PET bottle or the like made of the single engaging protrusion 104 of the conventional example, and there is no need to use properly depending on the bottle. Therefore, parts management becomes easy, and a synthetic resin container can be manufactured efficiently and at low cost.

  The following Table 1 shows the case where the same stopper cap is fitted to a synthetic resin bottle having an engaging portion made up of two protruding rings and an engaging ring of this embodiment, and is engaged with one protruding ring. The performance in comparison with the case of being fitted to a synthetic resin bottle having an engagement portion that is composed of a ring and has only one annular groove is experimentally compared.

Cap rotation torque refers to the torque at which the cap starts rotating when a rotational force is applied to the cap, and indicates the adhesion between the bottle mouth and the cap. You can predict.
The striking force indicates a pressing force required at the time of striking, and the detachment force indicates a force required to peel the fitted cap from the mouth.
In particular, the reference value of the cap rotation torque required for the container to be hot-filled is 150 N · cm or more, and in a direct blow molded synthetic resin bottle with one protruding ring, it is lower than the reference value of 128 N · cm.

On the other hand, in this embodiment having two protruding rings, it can be seen that the cap rotational torque is 193 N · cm, which is much higher than the reference value, and has a high sealing performance capable of heat filling.
Therefore, in this embodiment, since the cap does not easily rotate with respect to the synthetic resin bottle A, it is possible to maintain the sealing performance between the mouth 3 and the outer peripheral surface of the inner cylinder 54 fitted in a liquid-tight manner, It has a structure that can sufficiently handle high temperature filling of 65 degrees or more.
Further, the cap detachment force is 20N for one projecting ring, whereas this example having two projecting rings exceeds 33N, and the cap is difficult to fall off.
Thus, even if an annular groove is formed so as not to cause sink marks in direct blow molding, the required sealing pressure cannot be obtained with only one projecting ring. It can be seen that a high fitting force with the cap can be obtained, and at the same time, a high adhesion force and a high sealing pressure can be secured.
From this experimental result, it can be seen that at least two protruding rings of the mouth engaging portion are necessary.

  The synthetic resin bottle of this example can be fitted with a stopper cap used for a normal PET bottle even by direct blow molding, and has a high sealing property and can be easily laminated with a gas barrier material such as EVOH. It can be widely used as various beverages and food containers, and can be suitably used as a container for seasonings and the like that particularly require hot filling.

A, Aa Bottle Ba Inner plug Ca Top lid C Cap C1 Cap body C2 Hinge C3 Top lid a, a1 Top corner b Central corner h Minute height s Minute gap 1,101 Body 2,102 Shoulder 3,103 Mouth 5,109 Neck ring 7 First projecting ring 8 Second projecting ring 9 Engaging ring 10, 105 Top surface 11, 108 Lower end engaging part 12 First annular groove 13 Second annular groove 14 Portion base parts 15, 112 Inner circumference Surface 21 First inclined surface 22 First cylindrical surface 23 Second inclined surface 24 Second cylindrical surface 25 Engaging inclined surface 26 Engaging cylindrical surface 50, 120 Fitting cylinder portion 51, 123 Fitting groove 52, 125 54, 121 Inner cylinder 55 Upper wall 56, 122 Outer cylinder 58 Top surface 59 Corner part inclined surface 60, 124 Reduced diameter protrusion 104 Engagement protrusion 106 Inclined surface 107 Cylindrical surface 110 Curved surface 111 Recess

Claims (4)

A synthetic resin bottle formed by a direct blow molding method having a cylindrical mouth portion that is fitted into the fitting groove of the cap by a stopper,
On the outer periphery of the mouth portion, a plurality of projecting rings and one engagement ring project in an annular shape parallel to the axial direction of the mouth portion, and the engagement ring disposed below the plurality of projecting rings is fitted with a cap. It is arranged at a position that engages with the reduced diameter protrusion protruding into the groove,
A synthetic resin bottle having a mouth structure in which an annular groove is provided between adjacent projecting rings and between a projecting ring and an engagement ring.   The plurality of projecting rings and engaging rings each have an inclined surface that expands downward on the outer peripheral surface and a cylindrical surface that continues to the large-diameter portion side of the inclined surface. Synthetic resin bottle.   The plurality of projecting rings are composed of a first projecting ring on the most distal end side of the mouth and a second projecting ring below the first projecting ring, and the diameter of the cylindrical surface of the second projecting ring is larger than the cylindrical surface of the first projecting ring. The synthetic resin bottle according to claim 2, wherein the cylindrical surface of the second projecting ring has a diameter slightly smaller than or equal to the cylindrical surface of the engagement ring. In the first protruding ring whose upper surface is flush with the top surface of the front end of the mouth, the upper corner of the outer edge of the upper surface connected to the inclined surface is replaced with a plurality of protruding rings and a single engaging ring. An upper surface and an inclined surface are formed as an engaging ridge formed as one engaging portion, and an inclined surface and a cylindrical surface below the inclined surface are formed from the upper surface forming the same plane as the top surface through a curved surface. The radial height is formed lower than the intersecting upper end corners, and the inclined surface of the first projecting ring is formed to have a minute gap with the inclined surface of the engaging protrusion. The synthetic resin bottle according to claim 2 or 3.

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