JP2004256128A - Polyethylene terephthalate resin-made heat-resistant bottle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PET resin-made heat-resistant bottle keeping the self-standing property without causing deformation in a bottom part even when the bottle is heated for a long time by a hot warmer or the like after hot beverage is filled therein. <P>SOLUTION: The PET resin-made heat-resistant bottle has, on a bottom portion 5, a ground contact portion 6 with the outside diameter of 70-86% of the maximum diameter R<SB>1</SB>of a barrel portion 4, a conical riser portion 7 with the outside diameter of 70-80% of R<SB>1</SB>and forming an angle of 35-60° to a surface formed by the contact portion 6, a recessed portion 8 with the outside diameter of 60-75% of R<SB>1</SB>and swollen in a projecting shape inward of the bottle, a flat surface 9 at a center part of the recessed portion 8, hollow longitudinal ribs 10 which are formed radially from the flat surface 9 and protruded outward of the bottle, and valley portions 11 between the longitudinal ribs 10. Each longitudinal rib 10 comprises a curved ridge portion 12 projecting inward of the bottle, and an inclined surface 13 to be connected to a lower end part of the ridge portion 12 at the angle of 20-35° with respect to the surface formed by an upper edge. Bottom surfaces of the valley portions 11 are curved surfaces which are projecting inward of the bottle, and recessed inward of the bottle with respect to the flat surface 9 in a vicinity of the flat surface 9. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat-resistant bottle made of polyethylene terephthalate resin.
[0002]
[Prior art]
In recent years, small bottles made of polyethylene terephthalate resin (hereinafter sometimes abbreviated as “pet resin”) having an internal volume of 1,000 ml or less, for example, about 300 ml, filled with beverages such as tea, coffee, and milk coffee are sold after heating. That is being done. The PET resin bottle is filled with the beverage aseptically at room temperature, and then held in a state of being heated by a hot warmer or the like so that the content liquid is about 50 to 60 ° C.
[0003]
The PET resin bottle is generally formed by blow-molding a preform in a mold and biaxially stretching. Is given. However, since the bottom of the PET resin bottle is not sufficiently stretched in the blow molding, if the state of being heated as described above continues for a long time, the bottle cannot withstand heat and pressure of the contents and is deformed. Occurs.
[0004]
As a result, in the PET resin bottle, the appearance of the container may be deteriorated, or the size of the container may change, and the container may be difficult to come out when stored in a hot bender or the like. Further, the concave portion bulging inward in the bottle bulges outward in the bottle, and in extreme cases, the independence of the bottle may be impaired.
[0005]
Therefore, various techniques for imparting heat deformation resistance to the bottom of the PET resin bottle have been proposed. As an example of the technique, as shown in FIG. 7, an annular grounding portion 22, a concave portion 23 bulging convexly inside the bottle on the inner peripheral side of the grounding portion 22, and a central portion of the concave portion 23, as shown in FIG. There is known a PET resin bottle 26 having a plurality of hollow vertical ribs 25 radially formed from a flat surface 24 formed toward the ground portion 22 and protruding outward from the bottle. In the PET resin bottle 26, the vertical rib 25 includes a first slope 27 connected to the flat surface 24 at the center of the recess 23, and a second slope 28 connected to the ground from the end of the first slope, The angle θ formed by the first slope 27 with respect to the horizontal plane is set in a range of 40 to 90 ° (see Patent Document 1).
[0006]
In the PET resin bottle 26 shown in FIG. 7, the distance H between the inclined surfaces 27 and 28 and the bottom surface 29 of the vertical rib 25 can be increased by forming the vertical rib 25 into the above-described shape. Therefore, in the blow molding, the blow molding amount of the concave portion 23 can be made sufficiently large, and in order to prevent deformation of the concave portion 23 when a beverage such as tea, coffee, or milk coffee is filled. It is said that sufficient heat deformation resistance and strength can be imparted.
[0007]
However, according to the study of the present inventors, the PET resin bottle 26 shown in FIG. 7 is filled with a beverage such as tea, coffee, milk coffee or the like at an aseptic temperature at room temperature, and then the content liquid is reduced to about 50 to 60 ° C. If it is heated with a hot warmer or the like and stored for a long time, there is a disadvantage that the deformation of the concave portion 23 cannot be avoided.
[0008]
[Patent Document 1]
JP-A-2002-308245
[Problems to be solved by the invention]
The present invention solves such inconveniences, and after filling beverages such as tea, coffee and milk coffee at a high temperature, even if heated for a long time with a hot warmer or the like, the bottom does not deform and the independence is improved. An object of the present invention is to provide a polyethylene terephthalate resin heat-resistant bottle that can be held.
[0010]
[Means for Solving the Problems]
In order to achieve such an object, a polyethylene terephthalate resin heat-resistant bottle of the present invention includes a mouth, a shoulder connected to the mouth, a body connected to the shoulder, and a bottom connected to the body. In the polyethylene terephthalate resin heat-resistant bottle, the bottom portion has an annular ground portion having an outer diameter in a range of 70 to 86% of the maximum diameter of the body, and a bottom portion having an outer diameter in a range of 70 to 80% of the maximum diameter of the body. A rising portion having an outer diameter, rising up in a conical shape inside the bottle at an angle of 35 to 60 ° with respect to a plane formed by the grounding portion on the inner peripheral side of the grounding portion, and a maximum diameter of the body portion A concave portion having an outer diameter in the range of 60% to 75%, and connected to the upper end edge of the rising portion and bulging convexly inside the bottle; a flat surface formed at the center of the concave portion; Hollows formed radially toward the rising part and protruding outward from the bottle A vertical rib, and a valley formed between the vertical ribs and bulging toward the inside of the bottle, wherein the vertical rib has an upper end connected to a flat surface at the center of the concave portion, and has a curved line protruding inward of the bottle. And the ridge line portion is gradually enlarged from the lower end portion of the ridge line portion toward the rising portion, and forms an angle of 20 to 35 ° with respect to a plane formed by the upper edge of the rising portion. A slope forming a top at the lower end of the ridge, and a bottom surface of the valley extending from a flat surface at the center of the recess to an upper edge of the rising portion, and projecting inward in the bottle. In the vicinity of the outer periphery of the flat surface, the flat surface is a curved surface that is recessed inward of the bottle from the flat surface.
[0011]
In the heat-resistant bottle made of PET resin of the present invention, the bottom portion can be prevented from being deformed by heat by providing the ground portion with an outer diameter in the range of 70 to 86% of the maximum diameter of the body portion. If the outer diameter of the grounding portion is less than 70% of the maximum diameter of the body, the bottom outside the grounding portion is easily deformed by heat, and the upright stability of the bottle is deteriorated. When the outer diameter of the grounding portion exceeds 86% of the maximum diameter of the trunk portion, the inside of the grounding portion on the bottom portion is easily deformed by heat.
[0012]
Further, in the heat-resistant bottle made of PET resin of the present invention, the rising portion provided on the inner peripheral side of the grounding portion has an outer diameter in a range of 70 to 80% of a maximum diameter of the trunk portion. The part can be prevented from being deformed by heat. When the outer diameter of the rising portion is less than 70% of the maximum diameter of the body portion, the outer peripheral side of the contact portion is easily deformed by heat, and when it exceeds 80%, the inner peripheral side of the rising portion is easily deformed by heat. Become.
[0013]
Since the rising portion forms an angle of 35 to 60 ° with respect to a plane formed by the ground portion, the ground portion forms a central portion of a concave portion formed on an inner peripheral side of the rising portion. It can be located higher with respect to the plane. If the angle with respect to the plane formed by the grounding portion is less than 35 °, the central portion of the concave portion cannot be located sufficiently high. If the angle exceeds 60 °, the outer diameter of the concave portion becomes excessively large, and the concave portion becomes too hot. This makes it easy to deform and bulge.
[0014]
In the PET resin heat-resistant bottle of the present invention, the concave portion provided on the inner peripheral side of the rising portion has an outer diameter in a range of 60 to 75% of the maximum diameter of the body portion, so that the concave portion is heat-resistant. Thus, deformation can be prevented. When the outer diameter of the concave portion is less than 60% of the maximum diameter of the body portion, the outer peripheral portion of the outer diameter is easily deformed by heat and swells. When the outer diameter of the concave portion exceeds 75% of the maximum diameter of the body portion, the concave portion of the inner peripheral portion having the outer diameter is easily deformed by heat and easily swells outward.
[0015]
In the heat-resistant bottle made of PET resin of the present invention, the vertical ribs and the valleys formed between the vertical ribs form radial irregularities from the flat surface toward the ground portion, Thereby, the concave portion can be prevented from being deformed by heat. Here, in order to obtain the heat resistance, the vertical rib has a curved ridge portion that is convex in the inward direction of the bottle, and is gradually enlarged from a lower end portion of the ridge portion toward the rising portion to form the rising portion. A slope forming a top at the lower end of the ridge line, the slope being at an angle of 20 to 35 ° with respect to the plane formed by the upper edge of the rising portion. When the angle formed by the slope with respect to the plane formed by the upper edge of the rising portion is less than 20 °, the concave portion is easily deformed by heat and easily swells outward. It becomes difficult to form a curved shape that is convex inward, and the heat resistance deformation resistance and the pressure resistance are reduced.
[0016]
In order to obtain the heat resistance, the valley portion has a bottom surface extending from the flat surface of the central portion of the concave portion to the upper edge of the rising portion, and forms a curved surface that is convex in the bottle inward direction. The portion is recessed in the bottle inward near the outer periphery of the flat surface than the flat surface. If the valley does not have a portion near the outer periphery of the flat surface that is recessed inward of the bottle from the flat surface, the recess is easily deformed by heat.
[0017]
According to the heat-resistant bottle made of PET resin of the present invention, it is possible to impart excellent heat resistance to the bottom by providing all of the above shapes, and after filling beverages such as tea, coffee and milk coffee at a high temperature, Even if it is heated for a long time by a hot warmer or the like, it is possible to prevent deformation of the bottom portion and to maintain independence.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. 1 is a front view schematically showing a polyethylene terephthalate resin heat-resistant bottle of the present embodiment, FIG. 2 is a plan view showing the bottom of the heat-resistant bottle shown in FIG. 1, and FIG. 3 is a sectional view taken along the line III-III in FIG. 4 is a sectional view taken along line IV-IV. 5 and 6 are graphs showing the amount of deformation of the bottom of the heat-resistant bottle shown in FIG. 1 over time.
[0019]
The polyethylene terephthalate resin heat-resistant bottle 1 of the present embodiment is a small bottle having an inner volume of 280 ml formed by blow molding a preform in a mold and biaxially stretching the same. It is used for containers of beverages sold after heating. As shown in FIG. 1, a PET resin heat-resistant bottle 1 of the present embodiment has a mouth portion 2 having a screw portion on an outer peripheral surface, a shoulder portion 3 connected to the mouth portion 2, and a substantially cylindrical shape connected to the shoulder portion 3. And a bottom 5 connected to the body 4. Barrel 4 is in the range of maximum diameter R ₁ is 50 to 70 mm, an annular groove (not shown) on the surface, the panel portion and the like may be formed.
[0020]
The bottom part 5 includes an annular grounding part 6, a rising part 7 rising conically inside the PET resin heat-resistant bottle 1 on the inner peripheral side of the grounding part 6, and a PET resin heat-resistant bottle on the inner peripheral side of the rising part 7. 1 has a concave portion 8 which protrudes in a convex shape. As shown in FIG. 2, the recess 8 has a flat surface 9 formed at the center. The concave portion 8 includes eight hollow vertical ribs 10 formed radially from the flat surface 9 toward the rising portion 7 and protruding outward from the PET resin heat-resistant bottle 1. Are formed with the same number of valleys 11 as the vertical ribs 10. The vertical rib 10 includes a ridge portion 12 and a slope 13 that is gradually enlarged from an end of the ridge portion 12 toward the rising portion 7 and continues to an upper edge of the rising portion 7.
[0021]
As shown in FIG. 3, the grounding portion 6 is connected to the body 4 via a curved surface 14 that is convex toward the outside of the PET resin heat-resistant bottle 1 on the outer peripheral side, and the rising portion 7 on the inner peripheral side. Is connected to the concave portion 8 through the opening. Outer diameter _{R 2} of the ground portion 6 is set to be in the range of 70 to 86% of the maximum diameter _{R 1} of the body portion 4, the width w of the ground portion 6 to be in the range of 0~3mm Is set.
[0022]
The outer diameter R ₃ of the rising portion 7 is set to be 70 to 80% of the maximum diameter R ₂ of the body portion 4, the rising portion 7, the angle θ with respect to the plane formed by the ground part 6 ₁ is set in the range of 35 to 60 °. The outer diameter R ₄ of the recess 8 is set to be in a range of 60 to 75% of the maximum diameter R ₂ of the body 4.
[0023]
The ridge portion 12 of the vertical rib 10 is continuous with the flat surface 9 and has a curved shape protruding inward of the PET resin heat-resistant bottle 1. The slope 13 has an angle θ ₂ with respect to a plane formed by the upper edge of the rising portion 7. The angle is set in the range of 20 to 35 °, and the top 15 is formed at the lower end of the ridge 12. In addition, the flat surface 8 is set so that the diameter R5 of the portion connected to the ridgeline portion 12 is in the range of ₇ to 10 mm.
[0024]
On the other hand, the valley portion 11 continues from the flat surface 9 to the grounding portion 6 as shown in FIG. 4 and forms a curved surface that is convex in the bottle inward direction. The valley 10 has a recess 16 near the outer periphery of the flat surface 9 and recessed inward of the PET resin heat-resistant bottle 1 more than the flat surface 9. The valley portion 11 is connected to the flat surface 9 on the outer peripheral side from the position where the ridge portion 12 of the vertical rib 10 connects to the flat surface 9, and the flat surface 9 has a diameter R of a portion connected to the valley portion 11. ₄ is set in the range of 11 to 14 mm.
[0025]
As a result of the concave portion 8 having the above-mentioned shape, the height h of the flat surface 9 from the plane formed by the grounding portion 6 is set in a range of 10 to 15 mm.
[0026]
Next, the inner volume is 280 ml, the maximum diameter R ₁ of the trunk 4 is 66 mm, the outer diameter R _{2 of} the grounding section 6 is 51 mm, the inner diameter R ₃ of the grounding section 6 is 50 mm, and the grounding section 6 of the rising section 7 is The angle θ ₁ = 45 ° with respect to the plane to be formed, the outer diameter R ₄ = 42 mm of the concave portion 8, the angle θ ₂ = 25 ° with respect to the plane formed by the upper edge of the rising portion 7 of the slope 13, and the ground portion 6 forms A heat-resistant bottle 1 made of PET resin having a height h = 12 mm of the flat surface 9 with respect to the flat surface was prepared. After filling the contents (tea drink) into the heat-resisting bottle 1 made of PET resin, it is placed on a hot plate whose plate temperature is set to 90 ° C. and heated, and a flat surface with respect to the plane formed by the grounding portion 6 The change with time of the height h of No. 9 was measured. The results are shown in FIGS.
[0027]
From FIG. 5, although the height h of the flat surface 9 was 12 mm at the start of heating and the height h of the flat surface 9 was reduced to slightly more than 8 mm after 12 hours, the height of slightly more than 8 mm was maintained thereafter. It is clear that you are. Further, from FIG. 6, in the PET resin heat-resistant bottle 1 of the present embodiment, the height h of the flat surface 9 maintains the height of slightly more than 8 mm even after a further 7 days, and the bottom portion 5 It is clear that it has excellent heat resistance.
[0028]
In the present embodiment, the heat-resistant bottle 1 made of PET resin having a substantially cylindrical body 4 is described, but the body 4 may have a rectangular column shape. Further, in the present embodiment, the internal volume of the heat-resistant bottle 1 made of PET resin is 280 ml, but the internal volume is not particularly limited.
[Brief description of the drawings]
FIG. 1 is a front view schematically showing a polyethylene terephthalate resin heat-resistant bottle according to the present invention.
FIG. 2 is a plan view showing the bottom of the PET resin heat-resistant bottle shown in FIG.
FIG. 3 is a sectional view taken along line III-III of FIG. 2;
FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;
5 is a graph showing the amount of deformation of the bottom of the heat-resistant bottle shown in FIG. 1 over time.
6 is a graph showing the amount of deformation of the bottom of the heat-resistant bottle shown in FIG. 1 over time.
FIG. 7 is an explanatory cross-sectional view showing one configuration example of the bottom of a conventional PET resin bottle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Heat resistant bottle made of polyethylene terephthalate resin, 5 ... Bottom part, 6 ... Ground part, 7 ... Rise part, 8 ... Depression, 9 ... Flat surface, 10 ... Hollow vertical rib, 11 ... Valley part, 12 ... Ridge part, 13 ... slope.

Claims (1)

In a heat-resistant bottle made of a polyethylene terephthalate resin including a mouth, a shoulder connected to the mouth, a body connected to the shoulder, and a bottom connected to the body,
The bottom portion has an annular ground portion having an outer diameter in a range of 70 to 86% of a maximum diameter of the body portion, and an outer diameter in a range of 70 to 80% of a maximum diameter of the body portion, and A rising portion conically rising inside the bottle at an angle of 35 to 60 ° with respect to a plane formed by the grounding portion on the inner peripheral side of the bottle, and a range of 60 to 75% of the maximum diameter of the body portion; A concave portion having an outer diameter and connected to the upper edge of the rising portion and bulging convexly inside the bottle; a flat surface formed at the center of the concave portion; and a plurality of radially extending from the flat surface toward the rising portion. A hollow vertical rib formed and protruding outward from the bottle, comprising a valley formed between the vertical ribs and bulging toward the inside of the bottle,
The vertical rib has a ridge line portion whose upper end portion is continuous with the flat surface of the center portion of the concave portion and has a curved shape protruding inwardly of the bottle, and is gradually enlarged from the lower end portion of the ridge line portion to the rising portion, and A slope that forms an apex at a lower end of the ridge line, and connects to an upper edge of the rising portion at an angle of 20 to 35 ° with respect to a plane formed by an upper edge of the portion.
The bottom surface of the valley portion extends from the flat surface at the center of the concave portion to the upper edge of the rising portion, and is convex in the inward direction of the bottle. A heat-resistant bottle made of polyethylene terephthalate resin, which has a curved surface into which it enters.

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