JP6842651B2 - Plastic container and container with contents - Google Patents

Description

The present invention relates to a plastic container having a bottom having a specific shape and a container containing the contents, which is filled with the contents and attached with a cap.

In recent years, in order to prevent oxidation of wine, tea, fruit juice beverages, sports drinks, etc. filled in plastic containers during storage, the plastic containers are filled with an inert gas such as nitrogen. The filling of the inert gas creates a positive pressure inside the plastic container.

Further, when the container is filled with a carbonated drink such as natural effervescent water (sparkling water), the inside of the container becomes slightly positive pressure. Alternatively, when a container is filled with a content liquid such as green tea or coffee and the container is heated, the inside of the container becomes positive pressure due to the thermal expansion of the content liquid and the air inside.

In this way, when the inside of the container becomes positive pressure, in the container 100 having the bottom 101 having a general shape as shown in FIGS. 7 and 8, the bottom 101 swells, the bottom 101 is deformed, and the unevenness is reversed. The problem is that the total height of the container 100 becomes high, or the container 100 does not stand upright and falls over.

In order to give pressure resistance to the plastic container and prevent this deformation and inversion, the amount of resin material used for the plastic container is increased.
However, as the amount of resin material used increases, new problems such as an increase in the weight of the plastic container itself and an increase in manufacturing cost have arisen.

In addition, it is generally practiced to have a petaloid shape at the bottom in order to prevent deformation and inversion.
Generally, plastic bottles with a petaloid-shaped bottom have excellent pressure resistance, and many of them are used for filling and selling carbonated drinks. For this reason, consumers have a strong image that plastic bottles with a petaloid-shaped bottom are filled with carbonated drinks. Therefore, it is practically difficult to use such a plastic bottle having a petaloid-shaped bottom as a container for green tea, coffee, or the like because consumers may misunderstand the contents.

The present invention has been made in consideration of the above-mentioned problems, and the shape is deformed or inverted even when the inside of the plastic container becomes positive pressure without causing an increase in weight and cost of the plastic container itself. It is an object of the present invention to provide a plastic container having a bottom that does not generate.
Furthermore, it is an object of the present invention to provide a plastic container having a bottom that does not mislead consumers into misunderstanding the contents from the appearance.

The plastic container of the present invention includes a mouth portion, a neck portion, a shoulder portion, a body portion, and a bottom portion, the bottom portion has an annular ground contact portion, and the diameter of the ground contact portion is the maximum diameter of the body portion. It is 65% or more and 80% or less, and the bottom portion has a plurality of concave ribs extending radially from the central side toward the peripheral side, and each concave rib has an inner end portion on the central side and an outer end on the peripheral edge side. It has a portion and an intermediate portion located between the inner end portion and the outer end portion, and the intermediate portion of each concave rib has a constant depth along the length direction.

In the above aspect, it is preferable that the outer end portion of each concave rib is located on the central side of the body portion having the maximum diameter.

In the above aspect, it is preferable that the grounding portion forms a grounding wire.

In the above aspect, the number of concave ribs is preferably 5 or more and 19 or less.

In the above aspect, it is preferable that a protrusion protruding downward is formed in the center of the bottom portion.

In the above aspect, it is preferable that an annular flat surface is formed around the protrusions in the bottom portion, and the inner end portion of each concave rib is terminated by the flat surface.

In the above aspect, in the vertical cross section, a curved line is formed from the ground contact portion toward the center side, and the curved line is a central curved line having a first radius of curvature and a second curved line different from the first radius of curvature. It has a peripheral curved line having a radius of curvature, and the central curved line and the peripheral curved line are connected to each other at the turning point, and there is a tangent line of the peripheral curved line at the turning point and a ground contact portion. The angle formed by the ground plane is preferably 45 ° or more and 70 ° or less.

In the above aspect, the thickness of the bottom portion of the ground contact portion is preferably 0.1 mm or more and 1.5 mm or less.

In the above aspect, the length of the concave rib along the longitudinal direction is preferably 10 mm or more and 45 mm or less.

In the above aspect, it is preferable to further include at least a plastic member provided in close contact with the periphery of the body portion.

The container containing the contents of the present invention is characterized by including the plastic container, a carbonated drink filled in the plastic container, and a cap attached to the mouth portion of the plastic container.

The container containing the contents of the present invention is characterized by including the plastic container, wine filled in the plastic container, and a cap attached to the mouth portion of the plastic container.

In the above aspect, it is preferable that the plastic container is filled with the inert gas.

In the above aspect, the pressure in the plastic container filled with the inert gas is preferably 25 kPa or more and 300 kPa or less in terms of gauge pressure.

In a plastic container provided with a mouth, a neck, a shoulder, a body, and a bottom of the present invention, the relationship between the diameter of the bottom and the maximum diameter of the body is set to a specific range, and the circumference of the bottom is from the center side. By providing a plurality of concave ribs extending radially toward the veranda and having a specific structure, it is possible to prevent shape deformation and inversion of the bottom portion that may occur when the inside of the container is subjected to positive pressure.
Further, according to the present invention, since it is not necessary to increase the amount of the resin material used for manufacturing the plastic container, it is possible to suppress an increase in the weight of the plastic container itself and an increase in the manufacturing cost thereof.
Further, according to the present invention, it is possible to prevent consumers from misunderstanding the contents from the appearance of the bottom portion.

FIG. 1 is a partial vertical sectional view showing a plastic container 10 according to an embodiment of the present invention. FIG. 2 is a front view showing the bottom 30 of the plastic container 10 according to the embodiment. FIG. 3 is a vertical cross-sectional view showing the bottom 30 of the plastic container 10 according to the embodiment. FIG. 4 is a partial vertical sectional view showing a plastic container 10 according to an embodiment of the present invention. FIG. 5 is a partial vertical sectional view showing a plastic container 10 according to an embodiment of the present invention. FIG. 6 is a schematic view showing an embodiment of a method for manufacturing the plastic member 40a. FIG. 7 is a schematic view showing an embodiment of a method for manufacturing the plastic member 40a. FIG. 8 is a perspective view showing the bottom 101 of the conventional plastic container 100. FIG. 9 is a perspective view showing the bottom 101 of the conventional plastic container 100.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 are diagrams showing an embodiment of the present invention.

First, the outline of the plastic container according to the present embodiment will be described with reference to FIGS. 1 to 5.
In the present specification, the terms "upper" and "lower" mean the upper and lower parts of the plastic container in an upright state (FIG. 1), respectively.

(Plastic container 10)
As shown in FIG. 1, the plastic container 10 includes a mouth portion 11, a neck portion 12, a shoulder portion 13, a body portion 20, and a bottom portion 30.

The capacity of the plastic container 10 is not particularly limited, and may be an arbitrary capacity of 100 mL or more and 2 L or less, more specifically, 280 mL, 500 mL, 750 mL, or 1 L.
Further, the thickness of the plastic container 10 may be the same or different for the mouth portion 11, the neck portion 12, the shoulder portion 13, the body portion 20, and the bottom portion 30.

In one embodiment, the plastic container 10 is not limited to, but is limited to polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), and polylactic acid. (PLA), polyglycolic acid (PGA), ethylene vinyl alcohol copolymer (EVOH), ionomer resin (IO) and other resin materials are injection-molded, and the prepared preform is biaxially stretched and blow-molded. be able to.
Further, a blended resin material in which two or more kinds of the above resin materials are mixed may be used.
Among the above-mentioned resin materials, polyethylene terephthalate (PET) is preferable from the viewpoint of moldability of the bottom portion 30.

Further, the preform may have a multi-layer structure, and the preform may be biaxially stretch-blow molded to form a multi-layer plastic container 10. For example, it can be a multi-layered plastic container 10 including a layer containing a resin material having gas barrier properties and light-shielding properties such as PGA, EVOH or PEN.

Further, by depositing an inorganic oxide such as silica or alumina or amorphous carbon on the inner wall of the plastic container 10, the gas barrier property can be improved while maintaining the transparency. When a coating means is used, the gas barrier property is improved by coating a thermosetting crosslinked coating film of an aromatic polyvalent epoxy compound obtained by reacting metaxylylenediamine and epichlorohydrin with the polyvalent amine, EVOH, or the like. be able to. When EVOH is coated, the gas barrier property is lowered due to moisture absorption, so it is preferable to coat it with a moisture-proof resin such as a polyolefin resin. Any one of such means for improving the gas barrier property may be used, but the gas barrier property can be further improved by using two or more kinds of means in combination.

Further, by mixing an inert gas (nitrogen gas, argon gas) with the melt of the resin material, a foamed preform having a foamed cell diameter of 0.5 to 100 μm is formed, and this foamed preform is blow-molded. The plastic container 10 may be manufactured according to the above. Since the plastic container 10 thus obtained has a foam cell built-in, the light-shielding property is improved.

As shown in FIGS. 2 and 3, it is preferable that the bottom portion 30 has an annular grounding portion 31, and the grounding portion 31 forms a grounding wire.
In the present embodiment, the diameter φ1 of the ground contact portion 31 is 65% or more and 80% or less of the maximum diameter φ2 of the body portion 12. More preferably, it is 70% or more and 78% or less. As a result, it is possible to prevent the bottom portion 30 from being deformed and inverted when the inside becomes positive pressure without impairing the moldability, and it is possible to prevent the plastic container 10 from tipping over.
The diameter φ1 of the ground contact portion 31 is preferably changed as appropriate according to the capacity of the container, but is preferably 28 mm or more and 65 mm or less, and more preferably 35 mm or more and 58 mm or less.

As shown in FIG. 2, the bottom portion 30 has a plurality of concave ribs 32 extending radially from the central side toward the peripheral side. Since the bottom portion 30 has the concave rib 32, deformation and inversion of the bottom portion 30 can be further prevented.

The number of concave ribs 32 on the bottom portion 30 is preferably 5 or more and 19 or less, and more preferably 5 or more and 12 or less. Further, in order to further prevent deformation and inversion of the bottom shape, it is preferable that the number of concave ribs 32 is an odd number.

As shown in FIG. 3, each concave rib 32 includes an inner end portion 32a on the central side, an outer end portion 32b on the peripheral side, and an intermediate portion 32c located between the inner end portion 32a and the outer end portion 32b. The intermediate portion 32c of each concave rib 32 has a constant depth along the length direction. As a result, the pressure is not locally concentrated, and the deformation and inversion of the bottom portion 30 can be further prevented.
The intermediate portion 32c preferably has a depth of 0.5 mm or more and 4.5 mm or less, more preferably 1 mm or more and 3.5 mm or less.

The length of the concave rib 32 along the longitudinal direction (the length from the apex of the inner end portion 32a to the outer end portion 32b) is preferably changed as appropriate according to the capacity of the container, and is, for example, 10 mm or more and 45 mm or less. It is preferably 20 mm or more, and more preferably 40 mm or less.
The length of the intermediate portion 32c along the longitudinal direction is preferably 6 mm or more and 42 mm or less, and more preferably 8 mm or more and 36 mm or less.

Further, as shown in FIG. 3, the outer end portion 32c of each concave rib 32 is preferably located on the central side of the body portion 20 with respect to the region having the maximum diameter φ2.

The bottom portion 30 is formed with a (convex) protrusion 33 that projects downward in the center thereof. The molding stability can be improved by forming the protrusion 33 on the bottom portion 30.
The height h of the protrusion 33 from the ground contact portion 31 is preferably 3 mm or more and 30 mm or less, and more preferably 5 mm or more and 20 mm or less.

Further, on the bottom portion 30, an annular flat surface 34 is formed around the protrusion 33. Since the flat surface 34 is formed on the bottom portion 3, the shapeability can be improved. Further, as shown in FIGS. 2 and 3, the inner end portion 32a of the concave rib 32 is terminated by the flat surface 34.

In the vertical cross section of the plastic container 10 shown in FIG. 3, a curved line is formed from the ground contact portion 31 toward the center side. This curved line has a central curved line α1 having a first radius of curvature and a peripheral curved line α2 having a second radius of curvature different from the first radius of curvature, and has a circumference with the central curved line α1. The edge-side curved line α2 is connected to each other at the inflection point X.
The angle θ between the tangent Y of the peripheral curved line α2 at the inflection point X and the grounding surface Z on which the grounding portion 31 exists, that is, the grounding surface Z in contact with the grounding portion 31 when the plastic container 10 is established, is , 45 ° or more and 70 ° or less, and more preferably 50 ° or more and 65 ° or less. This makes it possible to prevent deformation and inversion of the bottom portion 30 that may occur due to the positive pressure inside the plastic container 10.

The thickness of the bottom 30 may be the same over the entire bottom 30 or may vary from site to site.
Further, in order to more effectively prevent deformation of the bottom portion 30 of the plastic container 10, the thickness of the ground contact portion 31 of the bottom portion 30 is preferably 0.1 mm or more and 1.5 mm or less, and 0.2 mm or more and 1 mm or more. The following is more preferable.

In one embodiment, the body 20 of the plastic container 10 may have a constant diameter as shown in FIG. In this case, the diameter φ (= maximum diameter) is preferably 40 mm or more and 90 mm or less, and more preferably 50 mm or more and 75 mm or less.
Further, in one embodiment, the body portion 20 of the plastic container 10 may be composed of a plurality of portions having different diameters, as shown in FIG. In this case, the maximum diameter is measured at the thickest point of diameter.
In this case, the maximum diameter of the body portion 20 is preferably 40 mm or more and 90 mm or less, and more preferably 50 mm or more and 75 mm or less.

In one embodiment, the mouth portion 11 has a screw portion 14 screwed to a cap (not shown) and a flange portion 15 provided below the screw portion 14. The shape of the mouth portion 11 may be a conventionally known shape.

In one embodiment, the neck portion 12 is provided between the flange portion 15 and the shoulder portion 13 and has a substantially cylindrical shape having a substantially uniform diameter.
Further, the shoulder portion 13 is located between the neck portion 12 and the body portion 20, and has a shape in which the diameter gradually increases from the neck portion 12 side to the body portion 20 side. In the cross-sectional view, the shoulder portion 13 is curved in a substantially S shape (see FIG. 1), but the cross section of the neck portion 13 may be linear.

In one embodiment, as shown in FIG. 5, the plastic container 10 of the present embodiment may include at least a plastic member 40 provided in close contact with the body portion 20 thereof. As a result, various functions and characteristics such as gas barrier property and light-shielding property can be imparted to the plastic container 10.
The plastic member 40 may be provided at least on the body portion 20, and may be provided so as to cover the entire area except the mouth portion 11, that is, the neck portion 12, the shoulder portion 13, and the bottom portion 30.

The plastic member 40 includes PE, PP, PET, PEN, PGA, EVOH, poly-4-methylpentene-1, polystyrene, AS resin, ABS tree, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol. , Polyvinyl acetal, Polyvinyl butyral, Dialyl phthalate resin, Fluorine resin, Polymethyl methacrylate, Polyacrylic acid, Methyl polyacrylate, Polyacrylonitrile, Polyacrylamide, Polybutadiene, Polybutene-1, Polyisoprene, Polychloroprene, Ethylenepropylene Rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluororubber, nylon 6, nylon 6,6, MXD-6, aromatic polyamide, polycarbonate, ethylene polyterephthalate, butylene polyterephthalate, ethylene polynaphthalate, U Polymer, liquid crystal polymer, modified polyphenylene ether, polyether ketone, polyether ether ketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene sulfide, polyether sulfone, silicone resin, polyurethane, phenol resin, urea resin, polyethylene oxide, It can contain resin materials such as polypropylene oxide, polyacetal, epoxy resin, and ionomer resin. Further, it may contain a blended resin in which two or more kinds of the above resin materials are mixed.

Further, the plastic member 40 may have a single-layer structure or may have a multi-layer structure.
When the plastic member 40 is composed of multiple layers, the layer structure of the innermost surface and the outermost surface may be the same or different. For example, from the innermost surface, low density PE / adhesive layer / EVOH / Examples thereof include those having an adhesive layer / low density PE layer structure and those having a PP / adhesive layer / EVOH / adhesive layer / PP layer structure.
Examples of the adhesive constituting the adhesive layer in this case include a polyvinyl acetate adhesive, a polyacrylic acid ester adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, a cellulose adhesive, and a polyester adhesive. Examples thereof include adhesives, polyamide-based adhesives, polyimide-based adhesives, amino-resin-based adhesives, phenol-resin-based adhesives, epoxy-based adhesives, polyurethane-based adhesives, rubber-based adhesives, and silicone-based adhesives.

Further, the plastic member 40 may or may not have heat shrinkage, but from the viewpoint of adhesion to the plastic container 10, it may have heat shrinkage. preferable.

Further, the plastic member 40 may be designed or printed. In this case, it is possible to display images and characters without separately attaching a label or the like to the plastic container 10.
Printing can be performed by, for example, a printing method such as an inkjet method, a gravure printing method, an offset printing method, or a flexographic printing method.

The plastic member 40 can be manufactured by fitting a preform into a bottomed or bottomless cylindrical plastic member 40a manufactured by the method illustrated below, and then integrally stretching and blowing the preform. it can.

In one embodiment, the plastic member 40a can be manufactured by molding a resin sheet containing the above-mentioned resin material and the like.
Examples of the molding method include deep drawing molding, or a method of molding a resin sheet into a tube shape and fusing or adhering its ends.

In one embodiment, the plastic member 40a is a plastic member 40a, as shown in FIG. 6A.
(1) First, the resin material 51 is heated and melted and extruded from the die 52 into a tube shape to form a tubular parison 53.
(2) Next, as shown in FIG. 6B, for example, the tubular parison 53 is sandwiched between the two-divided molds 54.
(3) Next, as shown in FIG. 6 (c), air is blown into the tubular parison 53 from the blowing nozzle 55, the tubular parison 53 is molded according to the mold 54, cooled, opened, and taken out. By sequentially performing this, a bottomed cylindrical plastic member 40a as shown in FIG. 6D can be obtained (direct blow molding).
According to this method, the design of the obtained plastic member 40a can be changed by changing the design of the mold, and the plastic member 40a having high adhesion to the preform 10a can be produced. ..

In one embodiment, the heat-shrinkable plastic member 40a can be produced by the following method.
First, the above-mentioned resin material or the like is heated and melted in an extruder, and the melted resin material or the like is continuously extruded from a ring die and cooled to form an unstretched extrusion tube 1 (FIG. 7 (a)). )reference). The multi-layered plastic member 40a can be manufactured by co-extruding two or more resin materials.
One end of the extruded tube is then closed by welding or adhering one end of the unstretched extruded tube.
Further, the extruded tube 61 having one end closed is arranged in a mold 62 having an inner diameter larger than the outer diameter of the extruded tube 61 (see FIG. 7B).
Next, the blow device 63 is arranged (mounted) on the other end of the extrusion tube 1 (see FIG. 7C). At this time, it is preferable that the blow device 63 is in close contact with the extrusion tube 61 so that air does not leak between them.
Subsequently, the extrusion tube 61, the mold 62, and the blow device 63 are sent into the heating furnace 64 in this arrangement and heated to 70 to 150 ° C. inside the heating furnace 64 (see FIG. 7D). As the heating furnace 64, a hot air circulation type heating furnace may be used in order to keep the inside thereof at a uniform temperature. Alternatively, the extrusion tube 61, the mold 62, and the blow device 63 may be heated by passing through the heated liquid.
Next, the extrusion tube 61, the mold 62, and the blow device 63 are taken out from the heating furnace 64, and air is blown into the extrusion tube 61 from the blow device 63 to pressure-stretch the inner surface of the extrusion tube 61. As a result, the extrusion tube 61 expands and the diameter is expanded along the inner surface shape of the mold 62 (see FIG. 7E).
Then, the extrusion tube 61 is cooled in cold water while the air is ejected from the blow device 63, and the extrusion tube is taken out from the mold 62 (see FIG. 7 (f)). By cutting this into a desired size, a heat-shrinkable plastic member 40a can be obtained (see FIG. 7 (g)).

Further, in one embodiment, the plastic member 40a can also be obtained by an injection molding method. Specifically, first, the mixture containing the above-mentioned resin material and the like is heated and melted. Then, the heated and melted mixture is injected into the mold. The plastic member 40a can also be obtained by cooling this and taking it out of the mold.

The contents that can be filled in the plastic container 10 of the present embodiment are not particularly limited, but the plastic container 10 of the present embodiment is unlikely to cause deformation of the bottom 30 even if the inside thereof becomes positive pressure. Therefore, it is preferable that the content needs to be filled with a carbonated drink such as natural effervescent water (sparkling water) or an inert gas such as wine that can be oxidized during storage.

The present embodiment also provides a container containing contents including a plastic container 10, a carbonated drink or wine filled in the plastic container 10, and a cap (not shown) attached to the mouth 11 of the plastic container 10.

Further, in one embodiment, the container containing the contents is filled with an inert gas such as liquid nitrogen in addition to the carbonated beverage or wine. The filling of the inert gas may be before or after filling the contents, but it is preferably after filling because the gas escapes if the time until capping is long.
The pressure in the plastic container after filling with the inert gas is preferably 25 kPa or more and 300 kPa or less, and more preferably 50 kPa or more and 200 kPa or less in terms of gauge pressure. By setting the pressure inside the plastic container within the above numerical range, it is possible to further prevent oxidation of the contents during storage without applying extra force to the container.

Next, a specific embodiment in the present embodiment will be described.

(Example 1)
First, the plastic container 10 (Example) shown in FIG. 1 having the bottom portion 30 shown in FIG. 2 was produced. The plastic container 10 was made by biaxially stretching blow molding 23.8 g of a PET preform.
The diameter φ1 of the annular grounding portion 31 is 53 mm, the maximum diameter φ2 of the body portion 20 is 70 mm, and the diameter φ1 of the grounding portion 31 is 75.8% (φ1 / φ2 ×) of the maximum diameter φ2 of the body portion 20. It was 100).
Further, the bottom portion 30 has concave ribs 32, the number of which is 9, and the depth of the intermediate portion 32c is constant at 2 mm.
Further, the bottom portion had a protrusion 33, and the height h from the protrusion 33 to the ground contact portion 31 was 10 mm.
Further, the bottom portion 30 is formed with a curved line from the ground contact portion 31 toward the center side, and this curved line connects the central curved line α1 and the peripheral curved line α2 connected at the inflection point X. Had had. Further, the angle formed by the tangent Y of the peripheral curved line at the inflection point X and the ground contact surface Z where the ground contact portion 31 exists was 62 °.

Next, the inside of the plastic container 10 is set to a positive pressure, the internal pressure is gradually increased, and the degree of deformation of the bottom 30 of the plastic container 10 when the internal pressures are set to 50 kPa, 75 kPa, and 100 kPa is visually determined to invert the bottom. It was evaluated by. The measurement results are shown in Table 1.
Here, the bottom reversal determination means a determination as to whether or not a portion other than the initially grounded portion is grounded by visually observing the bottom portion in a pressurized state.

(Comparison example)
On the other hand, as comparative examples, the plastic container 101 (Comparative Example 1) shown in FIG. 8 and the plastic container 102 (Comparative Example 2) shown in FIG. 9 were produced, respectively. In this case, as in the case of the plastic container 10 (Example) described above, 23.8 g of each preform was produced by biaxial stretching blow molding. The only difference between these three types of bottles was the shape of the bottom, and the shapes of the other parts (mouth, body, etc.) were the same.
Next, the insides of the plastic containers 101 and 102 were set to positive pressure, the internal pressure was gradually increased, and the total height change of the plastic containers 101 and 102 was measured when the internal pressures were set to 50 kPa, 75 kPa and 100 kPa. The measurement results are shown in Table 1.

10: Plastic container, 11: Mouth, 12: Neck, 13: Shoulder, 14: Thread, 15: Flange, 20: Body, 30: Bottom, 31: Ground, 32: Concave rib, 32a : Inner end, 32b: Outer end, 32c: Intermediate, 33: Protrusion, 40: Plastic member, 40a: Plastic member before blow molding, 51: Resin material, 52: Die, 53: Parison, 54 : Mold, 55: Blow nozzle, 61: Extrusion tube, 62: Mold, 63: Blow device, 64: Heating furnace, 100: Conventional plastic member, 101: Bottom of conventional plastic member, α1: Center Side curved line, α2: Peripheral curved line, X: Curved point, Y: tangent line, Z: Ground plane

Claims (12)

A plastic container with a mouth, neck, shoulders, body, and bottom.
The bottom portion has an annular ground contact portion, and the diameter of the ground contact portion is 65% or more and 80% or less of the maximum diameter of the body portion.
The bottom portion has a plurality of concave ribs extending radially from the central side to the peripheral edge side, and each concave rib has an inner end portion on the central side, an outer end portion on the peripheral edge side, the inner end portion, and the said portion. It has an intermediate part located between the outer end part and
Said intermediate portion of each concave ribs, Chi also a constant depth along its length,
A protrusion protruding downward is formed in the center of the bottom portion.
An annular flat surface is formed around the protrusion in the bottom portion, and the inner end portion of each concave rib reaches the outer periphery of the flat surface and ends at the flat surface . Plastic container. The plastic container according to claim 1, wherein the outer end portion of each concave rib is located on the central side of the region having the maximum diameter in the body portion. The plastic container according to claim 1 or 2, wherein the grounding portion forms a grounding wire. The plastic container according to any one of claims 1 to 3, wherein the number of the concave ribs is 5 or more and 19 or less. In the vertical cross section, a curved line is formed from the ground contact portion toward the center side, and the curved line has a central curved line having a first radius of curvature and a second radius of curvature different from the first radius of curvature. The central curved line and the peripheral curved line are connected to each other at an inflection point.
Any of claims 1 to 4 , wherein the angle formed by the tangent line of the peripheral curved line at the inflection point and the ground contact surface on which the ground contact portion exists is 45 ° or more and 70 ° or less. Or the plastic container described in item 1. The plastic container according to any one of claims 1 to 5 , wherein the thickness of the bottom portion of the ground contact portion is 0.1 mm or more and 1.5 mm or less. The plastic container according to any one of claims 1 to 6 , wherein the length of the concave rib along the longitudinal direction is 10 mm or more and 45 mm or less. The plastic container according to any one of claims 1 to 7 , further comprising at least a plastic member provided in close contact with the periphery of the body portion. The plastic container according to any one of claims 1 to 8.
The carbonated drink filled in the plastic container and
A container containing contents, which comprises a cap attached to the mouth portion of the plastic container. The plastic container according to any one of claims 1 to 8.
The wine filled in the plastic container and
A container containing contents, which comprises a cap attached to the mouth portion of the plastic container. The container containing the contents according to claim 9 or 10 , wherein the plastic container is filled with an inert gas. The container containing the contents according to claim 11 , wherein the pressure in the plastic container filled with the inert gas is 25 kPa or more and 300 kPa or less in gauge pressure.