JPH0848321A - Plastic bottle - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a resin bottle in which the sealing property of the bottle mouth portion and the sealing material of the cap is good and there is no risk of the contents leaking outside. [Structure] An inclined surface 2 having an angle θ of more than 45 ° to 80 ° with respect to the opening end face at the inner peripheral edge of the opening end of a mouth part 1 of a resin bottle that is sealed by screwing or capping a cap Are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin bottle having a mouth shape having a good cap sealing property.

[0002]

2. Description of the Related Art A resin bottle (so-called PET bottle) made of a polyester resin such as polyethylene terephthalate is filled with a content such as juice and then a cap is screwed or capped. As a result, the mouth is sealed. This state is shown in detail in FIG. Inclined surfaces are provided at the inner peripheral edge and the outer peripheral edge of the opening end of the bottle mouth portion 1 and are sealed by being pressed by the sealing material on the inner surface of the cap. The cap 4 comprises a cap body 4a having a thread formed therein and a sealing material 4b, and is screwed to the bottle by the screw and the screw 3 at the mouth. However, in the conventional bottle, as shown in FIG.
As shown in, the angle of the inclined surface provided on the inner peripheral edge portion or the outer peripheral edge portion of the opening end of the bottle is 30
It was found that since the temperature was not more than 0 °, the sealing property between the upper end of the mouth part 1 and the sealing material 4b was not sufficient, and there was a possibility that liquid leakage might occur during storage or transportation.

In addition, since the inside of such a resin bottle may be contaminated with fungi or the like between the sterilization process after the manufacturing and the filling of the contents, the inside is sealed with an inner stopper to keep the inside in a sterile state. It has to be kept, and various methods have been proposed so far. However, in the conventional bottle, there is a problem that the upper end portion of the mouth portion 1 and the inner plug (not shown) are not sufficiently sealed for the same reason as described above, and the inside may be contaminated. I found out.

Therefore, an object of the present invention is to provide a good sealing property between the bottle mouth portion and the sealing material and inner stopper of the cap so that the contents are not exposed to the outside and there is no risk of contamination of the inside. Is to provide.

[0005]

As a result of intensive research to solve the above problems, the present inventors have found that the inner peripheral edge of the opening end of the mouth of the bottle exceeds 45 ° with respect to the opening end face and exceeds 80 °. Or an inclined surface having an angle of 35 ° to 80 ° with respect to the opening end surface at the outer peripheral edge portion, or with respect to the opening end surface at the inner peripheral edge portion and the outer peripheral edge portion. 35 ° ~ 80
If an inclined surface having an angle of ° is formed so that the opening end does not have a substantially flat portion, the opening end of the mouth part deeply digs into the sealing material of the inner plug and the cap to improve the sealing performance. Was discovered and the present invention was completed.

That is, the resin bottle of the first invention is
It is characterized in that an inclined surface having an angle of more than 45 ° and up to 80 ° with respect to the opening end surface is formed at the inner peripheral edge portion of the opening end of the mouth of the bottle into which the cap is screwed or capped.

The resin bottle of the second aspect of the present invention has an angle of 35 ° to 80 ° with respect to the opening end face at the outer peripheral edge of the opening end of the mouth of the bottle into which the cap is screwed or capped. It is characterized in that an inclined surface is formed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. The mouth part of the present invention shown in FIG.
It shows the mouth of a resin bottle as shown in FIG.
FIG. 1 is a sectional view of a main part of an opening end of a mouth portion of a resin bottle according to a first embodiment of the present invention. On the inner peripheral edge of the opening end of the mouth portion 1, an inclined surface 2 having an angle θ with respect to the opening end surface is formed. If θ is 45 ° or less, the pressing force is too small, and if it exceeds 80 °, the tip may be deformed by pressing.Therefore, the angle θ is more than 45 ° and up to 80 °, preferably 46 ° ~ 60 °

FIG. 2 is a sectional view showing the principal part of the opening end of the mouth of a resin bottle according to the second embodiment of the present invention. An inclined surface is formed on the outer peripheral edge portion of the opening end of the mouth portion 1, and the inclined surface has an angle φ of 35 ° to 80 ° with respect to the opening end surface.

As described above, in the resin bottle of the present invention, the inclined surface having an angle of 35 ° to 80 ° with respect to the opening end face is formed on the outer peripheral edge of the opening end of the mouth of the bottle. As with the first embodiment, when the cap is put on, the opening end of the mouth of the bottle is further bited by the sealing material, so that the hermeticity is increased.

FIG. 3 is a sectional view showing the principal part of the opening end of the mouth of a resin bottle according to the third embodiment of the present invention. Inclined surfaces are formed on the inner peripheral edge and the outer peripheral edge of the opening end of the mouth 1, respectively, and the inclined surfaces are respectively 35 ° to 80 ° with respect to the opening end face.
Have angles θ and φ of.

As described above, in the resin bottle of this embodiment, inclined surfaces having an angle of 35 ° to 80 ° with respect to the opening end face are formed at the inner peripheral edge and the outer peripheral edge of the opening end of the bottle mouth. Therefore, as in the first embodiment, when the cap is put on, the opening end of the mouth of the bottle is further invaded by the sealing material, so that the sealing property is improved.

FIG. 4 is a sectional view showing the principal part of the opening end of the mouth of a resin bottle according to the fourth embodiment of the present invention. An inclined surface 2 having an angle θ with respect to the opening end face is formed on the inner peripheral edge portion of the opening end of the mouth portion 1, and a substantially flat surface is not formed at the tip of the opening end portion of the mouth portion of the bottle. . It is preferable to form the inclined surface 2 at the inner peripheral edge portion. The angle of slope 2 is 45
It is more than ° and up to 80 °, preferably 46 ° to 60 °, and particularly preferably 50 °. FIG. 5 shows a state in which the inner plug 5 is fixed to the open end.

FIG. 6 shows an example of the inner stopper used for the resin bottle. The inner plug 5 is made of a relatively flexible resin such as polyethylene, polypropylene, vinyl chloride, or vinylidene chloride, and it is preferable that the opening end bites when pressed by the inclined opening end of the resin bottle. . For this reason, the slanted open end of the bottle mouth portion 1 deeply digs into the inner plug 5 due to the stopper, and exhibits a good sealing property due to the wedge effect.

A ring-shaped projection 6 is formed on the side surface of the inner plug 5.
If a plurality of ring-shaped projections 6 are provided and the outer circumference of the ring-shaped protrusion 6 is slightly larger than the inner diameter of the bottle mouth portion 1, the inner plug 5 is plastically deformed when press-fitted into the mouth portion 1 and exhibits a good sealing effect.

Examples 1 to 5 and Comparative Examples 1 to 5 PET bottles (θ = 50 °) were filled with juice, and a capped bottle was used to perform a liquid leakage test. The types of caps and capping conditions are shown in Table 1 below. The leak test is performed using a bottle filled with juice.
After storing at 1 ° C. for 1 day, dropping from the height of 2 m to the side was repeated 5 times, and then the presence or absence of liquid leakage was confirmed.

Further, as a comparative example, a PET bottle having an inclined surface with an angle θ = 30 ° at the inner peripheral edge of the opening end of the mouth,
What was capped under the same conditions as in Example 1 was used. Table 2 below shows the comparison results of the leak test of the product of the present invention and the conventional product.

Table 1 Cap type: Aluminum screw type cap with inner sealing material Cap diameter: 38mmφ Capper: Alcoa # 301 Top load: 180kgf

Table 2 Examples (θ = 50 °) Comparative examples (θ = 30 °) NO. Result NO. Result 1 ○ 1 ○ 2 ○ 2 × 3 ○ 3 × 4 ○ 4 ○ 5 ○ 5 × (○: No liquid leakage, ×: liquid leakage)

As can be seen from the table, in the PET bottle of the present invention, the cross-sectional shape of the opening end of the mouth part becomes narrower upward and the area of the upper end part becomes smaller. Even with the cap, the pressure at which the opening end of the bottle mouth portion presses the sealing material increases, and the opening end of the mouth portion bites deeper into the sealing material, so that liquid leakage can be prevented.

Although the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to screw caps and can be used for tapping and the like. The present invention is not limited to these, and various modifications can be made without departing from the idea of the present invention.

[0022]

As described above in detail, in the resin bottle of the present invention, does the inner peripheral edge portion of the opening end of the mouth form an inclined surface having an angle of more than 45 ° and up to 80 ° with respect to the opening end face? , An inclined surface having an angle of 35 ° to 80 ° with respect to the opening end face is formed at the outer peripheral edge, or an inclined surface having an angle of 35 ° to 80 ° with respect to the opening end face at the inner peripheral edge portion and the outer peripheral edge portion Since the opening is formed, the opening end bites deeper into the sealing material inside the cap, so that the hermeticity is improved and liquid leakage and internal contamination can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an open end of a mouth portion of a resin bottle according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing an open end of a mouth portion of a resin bottle according to a second embodiment of the present invention.

FIG. 3 is a sectional view of an essential part showing an open end of a mouth portion of a resin bottle according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view of essential parts showing a resin bottle according to a fourth embodiment of the present invention.

5 is a cross-sectional view of essential parts showing a state when the resin bottle of FIG. 4 has an inner stopper.

FIG. 6 is a front view showing an example of an inner stopper for stoppering a resin bottle of the present invention.

FIG. 7 is a front view showing an example of a resin bottle of the present invention.

[Fig. 8] When a conventional resin bottle is capped,
It is a principal part sectional view which shows the opening end of a bottle mouth part.

[Explanation of symbols]

 1 Bottle mouth 2 Inclined surface 3 Screw 4 Cap 4a Cap body 4b Seal material θ, φ Inclined angle

Claims (5)

[Claims] 1. A resin bottle which is sealed by screwing or stoppering a cap, wherein an inner peripheral edge portion of the opening end of the mouth of the bottle in which the cap is screwed or stoppered has a diameter of 45 relative to the opening end face. A resin bottle characterized in that an inclined surface having an angle of over 80 ° is formed. 2. A resin bottle which is hermetically sealed by screwing or stoppering a cap, wherein the outer peripheral edge portion of the opening end of the mouth of the bottle to which the cap is screwed or stoppered is closed with respect to the opening end face. A resin bottle characterized in that an inclined surface having an angle of ° to 80 ° is formed. 3. The resin bottle according to claim 2, wherein an inclined surface having an angle of 35 ° to 80 ° with respect to the opening end face is formed on the inner peripheral edge portion of the opening end of the mouth of the bottle. A resin bottle characterized by that. 4. The resin bottle according to claim 2 or 3, wherein an angle of the inclined surface with respect to the opening end surface is 45 °.
Resin bottle characterized by -60 °. 5. The resin bottle according to any one of claims 1 to 4, wherein a substantially flat surface is not formed at the tip of the opening end of the mouth of the bottle.