JP2023053796A - plastic bottles and beverage products - Google Patents

Abstract

The present invention provides a plastic bottle capable of suppressing deformation of the bottom portion due to an increase in pressure inside the bottle and having an excellent cosmetic appearance. A plastic bottle comprising a mouth portion, a shoulder portion continuing to the mouth portion, a body portion continuing to the shoulder portion, and a bottom portion continuing to the body portion, the cross section along the circumferential direction of the body portion. It has a substantially circular shape, and the bottom portion includes a substantially annular grounding portion continuous with the body portion, a bottom wall portion continuous with the inner peripheral edge portion of the grounding portion and extending toward the inside of the plastic bottle, and a bottom wall. and a recessed bottom that is continuous with the part and recessed toward the inside of the plastic bottle. The ratio of the length between the horizontal surface and the concave bottom to the diameter of the inner peripheral edge of the ground contact is 1:1.51-3.91. [Selection drawing] Fig. 1

Description

The present invention relates to plastic bottles and beverage products.

Plastic bottles are used as containers for containing contents such as beverages. The production volume of such plastic bottles has been increasing in recent years. On the other hand, for the purpose of reducing the amount of plastic used from the viewpoint of resource saving, etc., there is a demand for reducing the weight of plastic bottles. In order to reduce the weight of plastic bottles, the thickness of the plastic bottles has to be made thinner. However, as the thickness of the plastic bottles is reduced, the rigidity of the plastic bottles in particular decreases, resulting in poor appearance due to deformation of the plastic bottles. There is a risk of

In recent years, alcoholic beverages are sometimes provided in plastic bottles. Alcoholic beverages are sometimes filled after being heated to a high temperature for sterilization. When the hot alcoholic beverage filled in the plastic bottle is cooled, the inside of the plastic bottle is decompressed and the body of the plastic bottle may be deformed. When the body of the plastic bottle is deformed, the cosmetic appearance (beauty) of the plastic bottle deteriorates, which may lead to a decrease in consumers' willingness to purchase or make it difficult for the plastic bottle to stand on its own. In order to suppress the deformation of the plastic bottle due to such decompression, liquid nitrogen is injected when the plastic bottle is filled with hot alcoholic beverages to keep the inside of the plastic bottle in a positive pressure state. . However, when liquid nitrogen is injected to create a positive pressure inside the plastic bottle, the bottom of the plastic bottle may deform (buckling). Therefore, there is a demand for a plastic bottle having excellent pressure resistance that can suppress deformation (buckling) of the bottom portion even when the inside of the plastic bottle is in a positive pressure state.

In order to solve this problem, conventionally, the bottom has a plurality of legs extending from the center to the periphery and protruding downward, each including a ground contact surface, and between the legs extending from the center to the periphery. A flat surface extending downward is formed, and the ground contact surface of each leg is formed in a curved shape in a cross section from the central portion to the peripheral edge portion. A pressure-resistant bottle (Patent Document 1) in which a groove is formed toward the part side, or the shape of the bottom part is petaloid, and the crystallinity of the part in the range of 30 mm in diameter centered on the central axis position of the bottom surface of the bottom part is 20% or less. , a plastic bottle having a wall thickness of 1.5 mm or more (Patent Document 2), etc. have been proposed.

JP 2011-020687 A JP 2007-084654 A

As in Patent Documents 1 and 2, by using a plastic bottle having a petaloid bottom, it is possible to reduce the weight of the plastic bottle while increasing the rigidity of the plastic bottle, particularly the bottom. However, since alcoholic beverage products such as wine have been provided in glass bottles for many years, consumers are permeated with a brand image and a sense of high quality based on appearance. Therefore, if the bottom of the plastic bottle has a petaloid shape, the appearance of the plastic bottle may be degraded, and consumers may lose their willingness to buy.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a plastic bottle that can suppress deformation of the bottom portion due to an increase in pressure inside the bottle and has excellent appearance and cosmeticity.

In order to solve the above problems, the present invention provides a plastic bottle comprising a mouth portion, a shoulder portion continuing to the mouth portion, a body portion continuing to the shoulder portion, and a bottom portion continuing to the body portion, The body has a substantially circular cross-sectional shape along the circumferential direction, and the bottom includes a substantially ring-shaped ground contact portion that is continuous with the body portion and the plastic bottle that is continuous with the inner peripheral edge of the ground contact portion. and a recessed bottom portion continuous with the bottom wall portion and recessed toward the inside of the plastic bottle, and when the plastic bottle is erected on a horizontal surface, the center of the bottom portion the length along the bottle axis perpendicular to the horizontal plane passing through the bottom, the ratio of the length between the horizontal plane and the concave bottom to the diameter of the inner peripheral edge of the grounding portion being 1:1. 51 to 3.91.

The concave bottom portion may include a horizontal bottom portion substantially parallel to the horizontal surface and an inclined bottom portion continuous between the horizontal bottom portion and the bottom wall portion, and the plastic bottle is erected on the horizontal surface. A first angle formed by the horizontal plane and a first plane including the bottom wall portion, and a second plane including the horizontal plane and the inclined bottom portion when viewed in a cross section along the axis of the bottle in the folded state. The ratio of the second angle formed by may be 1:0.19-1.05, wherein the bottom wall portion and the concave bottom portion are convexly curved toward the interior of the plastic bottle. and the curved corner may be substantially quadrant-shaped in a cross-sectional view along the bottle axis of the plastic bottle, and the curved corner may have a radius of curvature of 1 mm or more and 5 mm or less, and a plurality of radial ribs extending over the bottom wall portion and the concave bottom portion may be provided, and in a plan view from the bottom side, the plurality of radial ribs are , may be provided at substantially equal intervals in the circumferential direction of the bottom portion.

The body portion is provided with a plurality of wavy ribs that surround the body portion, and the waveforms of at least two of the wavy ribs have the same wavelength, and the amplitude directions of the plurality of wavy ribs are the same. may be parallel to the bottle axis of the plastic bottle, and the tops of the two wavy ribs may be offset from each other in the circumferential direction of the body, and , texturing may be applied.

Also, the present invention provides a beverage product in which the plastic bottle is filled with a beverage.

The beverage may be an alcoholic beverage.

ADVANTAGE OF THE INVENTION According to this invention, while being able to suppress deformation|transformation of the bottom part accompanying the pressure rise inside a bottle, it can provide the plastic bottle excellent in external appearance cosmeticity.

FIG. 1 is a side view showing a schematic configuration of a plastic bottle according to one embodiment of the present invention. FIG. 2 is a plan view showing a schematic configuration of the plastic bottle shown in FIG. 1 as seen from the bottom side. FIG. 3 is a cross-sectional view of the plastic bottle shown in FIG. 2 along line AA. FIG. 4 is a cross-sectional view of the plastic bottle shown in FIG. 2 along line BB. 5 is a partially enlarged sectional view of the plastic bottle shown in FIG. 3. FIG. FIG. 6 is a partially enlarged view showing a schematic configuration of wavy ribs provided on the body of the plastic bottle according to one embodiment of the present invention. FIG. 7 is a partially enlarged view showing a schematic configuration of the body of the plastic bottle according to one embodiment of the present invention. 8 is a cross-sectional view showing a schematic configuration of the bottom of the plastic bottle of Example 3. FIG. 9 is a cross-sectional view showing a schematic configuration of the bottom of the plastic bottle of Comparative Example 1. FIG. 10 is a cross-sectional view showing a schematic configuration of the bottom of the plastic bottle of Comparative Example 2. FIG. 11 is a bar graph showing test results of Test Example 3. FIG.

A plastic bottle according to this embodiment will be described with reference to the drawings. FIG. 1 is a side view showing the schematic configuration of the plastic bottle according to the present embodiment, FIG. 2 is a plan view showing the schematic configuration when viewed from the bottom side of the plastic bottle shown in FIG. 1, and FIG. 3 is a cross-sectional view along line AA of the plastic bottle shown in FIG. 2; FIG. In the present embodiment, a plastic bottle used for filling a beverage will be described as an example, but the present invention is not limited to this aspect, and various contents (for example, seasonings such as soy sauce, cosmetics such as lotion, pharmaceuticals such as stomach medicine, etc.). Beverages that can be filled in the plastic bottle according to the present embodiment include, for example, brewed alcoholic beverages (e.g., Japanese sake, fruit liquors such as wine, liqueurs such as plum wine, etc.), distilled liquors (e.g., whiskey, shochu, brandy, etc.). ) alcoholic beverages; mineral water, tea beverages (e.g., green tea, black tea, oolong tea, blended tea, etc.), vegetable beverages (e.g., tomato juice, carrot juice, tomato mix juice, carrot mix juice, etc.), fruit drinks (e.g., apple juice, orange juice, fruit juice drinks, etc.), mixed fruit/vegetable juices, coffee drinks, grain milk (e.g. soy milk, rice milk, coconut milk, almond milk, etc.), vinegar drinks (e.g. fruit vinegar drinks, etc.), etc. soft drinks and the like. Since the plastic bottle according to the present embodiment has an excellent cosmetic appearance, the beverage to be filled in the plastic bottle is preferably fruit wine such as wine.

The plastic bottle 1 according to the present embodiment includes polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, and polytrimethylene naphthalate; polyolefin resins such as polyethylene and polypropylene; polycarbonate resins; and polyacrylate resins. It is composed of a resin material such as The capacity of such a plastic bottle 1 is, for example, 180-3000 mL.

A plastic bottle 1 according to this embodiment includes a mouth portion 2 , a shoulder portion 3 continuing to the mouth portion 2 , a body portion 4 continuing to the shoulder portion 3 , and a bottom portion 5 continuing to the body portion 4 .

The mouth portion 2 has a substantially cylindrical shape, and a screw thread 21 for attaching a cap (not shown) is formed on the side surface of the opening end side of the mouth portion 2 . As a result, the plastic bottle 1 can be hermetically sealed by attaching the cap to the mouth portion 2 after the plastic bottle 1 is filled with the beverage.

The body portion 4 that occupies most of the vertical direction of the plastic bottle 1 (the direction perpendicular to the horizontal surface when the plastic bottle 1 is placed on a horizontal surface with the mouth portion 2 positioned upward) is the circumferential direction of the body portion 4. The cross-sectional shape along the is substantially circular. The term "substantially circular shape" is meant to include not only a perfect circular shape, but also an elliptical shape, an oval shape, and the like. In this embodiment, the diameter of the trunk 4 may be slightly smaller than the maximum diameters of the shoulder 3 and the bottom 5 (for example, about 0.3 to 1.0 mm), or the maximum diameter of the shoulder 3 and the bottom 5. It may be the same as the diameter. As shown in FIG. 1, the body portion 4 has a substantially rectangular shape in side view, but is not limited to such a shape. It may have a shape (a shape with a constriction) that is slightly curved inward of the plastic bottle 1 at the substantially central position in the vertical direction of the body portion 4 .

As shown in FIGS. 2 and 3, the bottom portion 5 includes a substantially annular ground portion 51 that is continuous with the body portion 4 and an inner peripheral edge portion 511 of the ground portion 51 that extends toward the inside of the plastic bottle 1 . It includes a bottom wall portion 52 and a recessed bottom portion 53 that is continuous with the bottom wall portion 52 and recesses toward the inside of the plastic bottle 1 .

The ground portion 51 is a portion that comes into contact with a horizontal surface when the plastic bottle 1 is placed on a horizontal surface with the mouth portion 2 positioned upward. Further, as shown in FIG. 2, the ground portion 51 has a substantially annular shape in a plan view from the bottom portion 5 side of the plastic bottle 1 . The term "substantially circular ring shape" is intended to include not only a true circular ring shape but also an elliptical ring shape, an oval ring shape, and the like. The width W of the ground portion 51 is not particularly limited as long as the plastic bottle 1 can stably stand on its own.

The concave bottom portion 53 is continuous with the bottom wall portion 52 and is recessed toward the inside of the plastic bottle. As shown in FIG. 3 , the concave bottom portion 53 may include a horizontal bottom portion 531 substantially parallel to the horizontal plane and an inclined bottom portion 532 continuous between the horizontal bottom portion 531 and the bottom wall portion 52 . The fact that the horizontal bottom 531 is substantially parallel to the horizontal plane is meant to include manufacturing errors and the like during manufacturing. It may be inclined at an angle of less than °.

The bottom wall portion 52 continues to the inner peripheral edge portion 511 of the ground portion 51 and extends toward the inside of the plastic bottle 1 . In a state in which the plastic bottle 1 is erected on a horizontal plane, the bottle axis BA (a direction perpendicular to the horizontal plane passing through the center of the bottom 5 when the plastic bottle 1 is placed on a horizontal plane with the mouth 2 positioned upward). 5), the first angle θ1 formed by the horizontal plane and the first plane P1 including the bottom wall portion 52 and the second plane P2 including the horizontal plane and the inclined bottom portion 532 The ratio (θ1:θ2) to the formed second angle θ2 may be 1:0.19 to 1.05, preferably 1:0.24 to 0.94, more preferably 1:0.24 to 0.94. 1:0.25 to 0.63 is sufficient. Since the relationship between θ1 and θ2 is such a relationship, deformation of the plastic bottle 1 can be suppressed even if the pressure inside the plastic bottle 1 filled with beverage increases.

The first angle θ1 may be in the range of 50 to 89°, preferably in the range of 60 to 85°, more preferably in the range of 80 to 85°. The second angle θ2 may be in the range of 15° or more and less than 90°, preferably in the range of 20 to 80°, more preferably in the range of 20 to 50°.

The length L along the bottle axis BA perpendicular to the horizontal plane passing through the center of the bottom 5 when the plastic bottle is erected on the horizontal plane, and the length L between the horizontal plane and the concave bottom 53, and the grounding portion 51 to the diameter D of the inner peripheral edge 511 is 1:1.51-3.91, preferably 1:2.00-3.13, more preferably 1:2.32-2. is 40. Since the ratio of the length L between the horizontal surface and the concave bottom portion 53 to the diameter D of the inner peripheral edge portion 511 of the ground portion 51 satisfies the above relationship, even if the internal pressure of the plastic bottle 1 increases, the plastic Deformation of the bottle 1 can be suppressed.

As shown in FIG. 3 , the bottom wall portion 52 and the concave bottom portion 53 may be continuous via a curved corner portion 54 that curves convexly toward the inside of the plastic bottle 1 . By having the curved corner portion 54 , it is possible to suppress the occurrence of reversal (buckling) of the bottom portion 5 of the plastic bottle 1 due to an increase in the internal pressure of the plastic bottle 1 . Moreover, in a cross-sectional view of the plastic bottle 1 along the bottle axis BA, the curved corner portion 54 may be substantially in the shape of a quadrant. The term "substantially quadrant" means that the central angle of the circular arc forming the curved corner portion 54 is allowed to be in the range of 90±20°. The curvature radius of the curved corner portion 54 is not particularly limited, but may be, for example, 1 mm or more and 5 mm or less, preferably 3 mm or more and 5 mm or less, more preferably 5 mm. In this embodiment, the bottom wall portion 52 and the concave bottom portion 53 are connected to each other through a curved corner portion 54 that curves convexly toward the inside of the plastic bottle 1. However, it is not limited to such a mode, and the bottom wall portion 52 and the concave bottom portion 53 may be directly connected without the curved corner portion 54 interposed therebetween.

As shown in FIGS. 2 and 4 , the bottom portion 5 may be provided with a plurality of radial ribs 55 extending over at least the bottom wall portion 52 and the concave bottom portion 53 . Although five radial ribs 55 are provided in the embodiment shown in FIG. 2, the number of radial ribs 55 is not particularly limited. Since the radial ribs 55 are provided, deformation of the plastic bottle 1 (bottom portion 5) can be suppressed even if the internal pressure of the plastic bottle 1 increases. In plan view from the bottom portion 5 side, the plurality of radial ribs 55 may be provided at substantially the same intervals. Since the plurality of radial ribs 55 are provided at substantially the same intervals, the internal pressure of the plastic bottle 1 is dispersed in the bottom portion 5, thereby effectively suppressing deformation of the plastic bottle 1 (bottom portion 5). be able to. The term "substantially the same interval" means that, in plan view from the bottom portion 5 side, the center of gravity of the plan view shape formed by the outlines of N (N is an integer equal to or greater than 2) radial ribs 55 is the bottle. It means that they are arranged at angular intervals of (360/N)±10° around the axis BA. The length, width, depth, groove angle, and the like of the radial ribs 55 are not particularly limited, and can be appropriately set in consideration of the strength required for the plastic bottle 1 and the like.

The trunk portion 4 may be provided with a plurality of wavy ribs 41 that encircle the trunk portion 4 (see FIG. 6). In this embodiment, two wavy ribs 41 are provided, but the number of wavy ribs 41 is not limited to this. The amplitude direction of each of the plurality of wavy ribs 41 is parallel to the bottle axis BA of the plastic bottle 1, and the wavy edges of at least two wavy ribs 41 have the same wavelength. It is sufficient that the top portions 41T of the respective top portions 41T are shifted from each other in the circumferential direction of the trunk portion 4 . By providing a plurality of wavy ribs 41 in such a manner on the body portion 4, deformation when pouring a beverage from the plastic bottle 1 is suppressed, and the beverage can be poured stably. The wavy rib 41 has a shape that repeats and continues with a predetermined waveform as one unit. The number of predetermined waveforms per unit may be about 2 to 4, for example. As shown in FIG. 6, the amount of displacement S of the tops 41T of the two wavy ribs 41 may be about 0.2 to 0.5 wavelengths in the circumferential direction of the body 4. As shown in FIG. Since the apexes 41T of the two wavy ribs 41 are offset from each other in the circumferential direction of the body 4, the contact area between the gripping fingers and the wavy ribs 41 increases, improving the grip. The number of wavy ribs 41 is not particularly limited, and may be at least two, may be three, may be four, or may be n (n is an integer of 2 or more). However, it is preferable that the plurality of wavy ribs 41 be provided within the range of the label attaching portion 42 described later and hidden by the attached label in consideration of the aesthetic appearance.

As shown in FIG. 7, at least a part of the surface of the body portion 4 may be textured (the hatched portion in FIG. 7) around the body portion 4 (FIG. 7). reference). Since the labeling part 42 is textured, the label attached to the plastic bottle 1 and the labeling part 42 of the plastic bottle 1 can be easily peeled off via an adhesive, and the bottles can be separated. It becomes possible. Note that the size and location of the label attaching portion 42 are not particularly limited, and can be appropriately adjusted according to the size of the label to be attached to the plastic bottle 1 and the like.

The plastic bottle 1 according to this embodiment can be made into a beverage product by filling it with a beverage. In particular, the plastic bottle 1 according to the present embodiment can exhibit excellent pressure resistance and has the same appearance and cosmeticity as a glass bottle, so it is suitable for beverage products filled with alcoholic beverages such as wine. ing.

When the plastic bottle 1 according to the present embodiment is filled with an alcoholic beverage such as wine to produce a beverage product, the liquid temperature of the alcoholic beverage is raised to a high temperature and the plastic bottle 1 is filled with the alcoholic beverage. Thereafter, when cooling down to room temperature, if liquid nitrogen is not dropped, the inside of the plastic bottle 1 is decompressed due to the temperature drop, and the body portion 4 of the plastic bottle 1 is deformed. In order to suppress this decompression deformation, after the plastic bottle 1 is filled with a hot alcoholic beverage, liquid nitrogen is dripped into the plastic bottle 1 and a cap is attached to the mouth portion 2 . By dropping the liquid nitrogen, the inside of the plastic bottle 1 becomes a positive pressure state, but since the plastic bottle 1 according to the present embodiment has excellent pressure resistance, deformation of the plastic bottle 1 due to the positive pressure state is prevented. can be suppressed. When manufacturing a beverage product in which the plastic bottle 1 is filled with an alcoholic beverage, heat sterilization of the alcoholic beverage is required. As a heat sterilization method for alcoholic beverages, in addition to the method of filling the plastic bottle 1 with the alcoholic beverage heated to a high temperature as described above, the plastic bottle 1 is filled with the alcoholic beverage at room temperature and heat sterilized using a pasteurizer or the like. there is a way to do it. In the latter method, since a pasteurizer is essential for the production line of beverage products, there are disadvantages such as the need to secure installation space for the pasteurizer and the need for a large amount of water when using a pasteurizer. mentioned. In this regard, by using the plastic bottle 1 according to the present embodiment, the plastic bottle 1 can be deformed under a positive pressure state, so that the plastic bottle 1 can be filled with a hot alcoholic beverage that has been sterilized by heating. . As a result, it is possible to omit the space for installing the pasteurizer in the production line of beverage products (saving the production line space), and it is possible to eliminate the need to use a large amount of water.

The above-described embodiments are for facilitating understanding of the present invention, and are not for limiting the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples and the like.

[Example 1]
A plastic bottle 1 made of polyethylene terephthalate (PET) having the configuration shown in FIGS. 1 to 6, having a height of 280 mm, a full capacity of 748 mL (for 720 mL of product), and a body portion 4 having an outer diameter of 69.5 mm was prepared.

The length L between the horizontal surface and the concave bottom portion 53, which is the length along the bottle axis perpendicular to the horizontal surface passing through the center of the bottom portion 5 when the plastic bottle 1 of the sample 1 is set up on the horizontal surface, and , and the diameter D of the inner peripheral edge portion 511 of the grounding portion 51 is 1:2.35, and the radius of curvature of the curved corner portion 54 between the bottom wall portion 52 and the concave bottom portion 53 is 5 mm. In addition, the body portion 4 is provided with two wavy ribs 41 that surround the body portion 4, and the amplitude directions of the two wavy ribs 41 are parallel to the bottle axis BA of the plastic bottle 1, and the two wavy ribs 41 A positional deviation amount S between the top portions 41T of the ribs 41 is set to 0.2 wavelength.

[Example 2]
A plastic bottle 1 having the same configuration as that of Example 1 was prepared, except that the radius of curvature of the curved corner portion 54 between the bottom wall portion 52 and the concave bottom portion 53 was set to 1 mm.

[Example 3]
A plastic bottle 1 having the same structure as in Example 1 was prepared, except that the bottom wall portion 52 and the concave bottom portion 53 were directly connected to each other without the curved corner portion 54 interposed therebetween, as shown in FIG.

[Comparative Example 1]
As shown in FIG. 9, the length L along the bottle axis BA' perpendicular to the horizontal plane passing through the center of the bottom 5' and between the horizontal plane and the concave bottom 53' and the grounding portion 51' A plastic bottle 1' made of polyethylene terephthalate (PET) having the same configuration as in Example 2 was prepared, except that the ratio of the inner peripheral edge 511' to the diameter D was 1:3.92. .

[Comparative Example 2]
As shown in FIG. 10, the bottom wall portion 52 is not provided, and the grounding portion 51' and the concave bottom portion 53' are continuous. The ratio of the length L between the horizontal plane and the concave bottom 53' to the diameter D of the inner peripheral edge 511 of the grounding portion 51 is 1:2. A plastic bottle 1' made of polyethylene terephthalate (PET) having the same structure as in Example 1 was prepared, except that it was made to be 0.33.

[Test Example 1] Internal pressure deformation test Each bottle of Examples 1 to 3 and Comparative Examples 1 and 2 is filled with a beverage, and the internal pressure of each bottle is set to 80 kPa and stored at room temperature 50 ° C. for 7 days. The amount of displacement of the horizontal bottom portion 531 in the vertical direction and the elongation of the entire length of the bottle were measured, and the dimensional change amount of the length L was calculated from the difference between them. Table 1 shows the results. In addition, the amount of displacement of the horizontal bottom 531 in the vertical direction of the bottle in the test and the elongation of the total length of the bottle were determined by visual observation of the point where the amount of change before and after the test was maximum. Elongation was measured.

As shown in Table 1, when comparing Examples 1-3 with Comparative Examples 1-2, the amount of dimensional change was large in Comparative Examples 1-2, and the amount of dimensional change was extremely small in Examples 1-3. From these results, in Examples 1 to 3, the bottom of the bottle has a bottom wall portion, and the ratio of the length L between the horizontal surface and the concave bottom portion to the diameter D of the inner peripheral edge of the ground portion is 1:1.51 to 3.91, it was confirmed that the dimensional change of the length L can be suppressed. In Comparative Example 1, the ratio of the length L between the horizontal surface and the concave bottom portion to the diameter D of the inner peripheral edge portion of the contact portion is out of the range of 1:1.51 to 3.91. It is presumed that the amount of dimensional change in the length L increased. In Comparative Example 2, since the bottom wall portion 52 is not provided, it is presumed that the amount of dimensional change in the length L is increased.

Further, the bottles of Examples 1 and 2 and Comparative Example 1 were filled with beverages, and positive pressure was continuously applied to the inside of the bottles to simulate the occurrence of deformation of the bottom of the bottles from the relationship between the internal pressure of the bottles and the coefficient of volumetric expansion. As a result, as the internal pressure of the bottle increased, inversion (buckling) of the bottom was confirmed in Comparative Example 1, Example 2, and Example 1 in that order. In Example 1, buckling occurred at an internal pressure 1.16 times the internal pressure at which buckling occurred in Comparative Example 1, and in Example 2, buckling occurred at an internal pressure 1.04 times that at which buckling occurred.

From Test Example 1 and simulation results, it can be inferred that the bottom of the bottle does not reverse (buckling) because the bottle of Comparative Example 2 does not have a bottom wall, but the dimensional change increases. On the other hand, in Examples 1 to 3, since they have a bottom wall portion, dimensional change can be suppressed, but there is a possibility that inversion (buckling) of the bottom portion may occur. Therefore, by having a curved corner between the bottom wall and the concave bottom, the internal pressure that causes deformation of the bottom increases, and if the radius of curvature of the curved corner is increased, the bottom is reversed (buckling). It is presumed that the internal pressure also increases and that the occurrence of reversal of the bottom (buckling) can be suppressed.

[Reference Example 1]
A polyethylene terephthalate (PET) plastic bottle having the same configuration as in Example 1 was prepared, except that it had three annular ribs provided along the circumferential direction of the body.

[Reference example 2]
A plastic bottle made of polyethylene terephthalate (PET) having the same structure as in Example 1 was prepared, except that the body did not have ribs.

[Reference Example 3]
A plastic bottle made of polyethylene terephthalate (PET) having the same configuration as that of Example 1 except that the amount of displacement S between the tops of the two wavy ribs 41 in the vertical direction of the bottle was set to 1/2 wavelength. Got ready.

[Test Example 2] Grippability sensory evaluation test Each bottle of Example 1 and Reference Examples 1 to 3 was filled with a beverage, and five evaluation items related to grippability (ease of holding, stability when opening the cap, beverage The evaluation was made on the basis of spillage when pouring into a glass, anxiety while pouring into a glass, and stress when closing the cap. The results are shown in FIG. In addition, in the evaluation method in this test example, Reference Example 1 was given 3 points out of 5 points as a standard, and Example 1 and Reference Examples 2 and 3 were scored relative to Reference Example 1.

As shown in FIG. 11, when Example 1 was compared with Reference Examples 1 to 3, it was confirmed that gripping of the bottle was improved in all five evaluation items. In particular, in terms of stability when opening the cap and uneasiness when pouring into a glass, it was confirmed that Example 1 was greatly improved even when compared with Reference Examples 2 and 3.

DESCRIPTION OF SYMBOLS 1... Plastic bottle 2... Mouth part 3... Shoulder part 4... Body part 5... Bottom part 51... Grounding part 511... Inner peripheral edge part 52... Bottom wall part 53... Concave bottom part

Claims (12)

A plastic bottle comprising a mouth, a shoulder continuous with the mouth, a body continuous with the shoulder, and a bottom continuous with the body,
A cross-sectional shape along the circumferential direction of the trunk is substantially circular,
The bottom portion includes a substantially annular ground portion continuous with the body portion, a bottom wall portion continuous with an inner peripheral edge portion of the ground portion and extending toward the inside of the plastic bottle, and a bottom wall portion continuous with the bottom wall portion. a concave bottom recessed toward the interior of the plastic bottle;
A length along a bottle axis perpendicular to the horizontal plane passing through the center of the bottom when the plastic bottle is erected on a horizontal plane, the length between the horizontal plane and the concave bottom, and the ground A plastic bottle, wherein the ratio of the diameter of the portion to the diameter of the inner peripheral edge is 1:1.51 to 3.91. 2. The plastic bottle of claim 1, wherein the concave bottom includes a horizontal bottom substantially parallel to the horizontal plane and an inclined bottom continuous between the horizontal bottom and the bottom wall. a first angle formed by the horizontal plane and a first plane including the bottom wall when the plastic bottle is erected on the horizontal plane and viewed in cross section along the axis of the bottle; and the horizontal plane. 3. The plastic bottle according to claim 2, wherein the ratio of the second angle formed by the second plane containing the sloped bottom to the second angle is 1:0.19-1.05. 4. The bottom wall portion and the concave bottom portion are connected to each other through a curved corner portion that curves convexly toward the inside of the plastic bottle. plastic bottle. 5. The plastic bottle of claim 4, wherein the curved corners are substantially quadrant-shaped when viewed in cross-section along the bottle axis of the plastic bottle. 6. The plastic bottle according to claim 4, wherein the radius of curvature of the curved corner portion is 1 mm or more and 5 mm or less in a cross-sectional view along the bottle axis of the plastic bottle. 7. The plastic bottle according to any one of claims 1 to 6, wherein a plurality of radial ribs are provided across said bottom wall portion and said concave bottom portion. 8. The plastic bottle according to claim 7, wherein the plurality of radial ribs are provided at substantially equal intervals in the circumferential direction of the bottom when viewed from the bottom side. The body is provided with a plurality of wavy ribs that surround the body,
corrugations of at least two of said wavy ribs have the same wavelength as each other;
an amplitude direction of each of the plurality of wavy ribs is parallel to the bottle axis of the plastic bottle;
9. The plastic bottle according to any one of claims 1 to 8, wherein the tops of the two wavy ribs are offset from each other in the circumferential direction of the body. 10. The plastic bottle according to any one of claims 1 to 9, wherein at least part of said body portion is textured. A beverage product, wherein the plastic bottle according to any one of claims 1 to 10 is filled with a beverage. 12. The beverage product of claim 11, wherein said beverage is an alcoholic beverage.

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