Synthetic resin container

Abstract

A synthetic resin container has an outer layer body and an inner layer body and formed by biaxial stretching blow molding. The synthetic resin container has a cylindrical mouth portion, a shoulder portion located below the mouth portion and having a diameter gradually increasing downward, a body portion being continuous with a lower end of the shoulder portion, and a bottom portion configured to close a lower end of the body portion. The mouth portion has an outside air introduction port configured to introduce outside air between the outer layer body and the inner layer body, and the shoulder portion has at least one shoulder rib forming a concave or convex shape and extending from the mouth portion side to the body portion side.

Claims

1. A synthetic resin container including an outer layer body and an inner layer body disposed inside the outer layer body and formed by biaxial stretching blow molding, the synthetic resin container comprising: a cylindrical mouth portion formed by a cylindrical outer mouth portion and a stepped cylindrical inner mouth portion, the stepped cylindrical inner mouth portion including: a flange located at an upper end of the outer mouth portion, a cylindrical upper tube extending downward from an inner peripheral edge of the flange and contacting an inner surface of the outer mouth portion, a conical inclined tube extending downward from a lower end of the upper tube, the conical inclined tube having a decreasing diameter in a downward direction of the synthetic resin container, a cylindrical lower tube extending downward from a lower end of the conical inclined tube, a convex piece extending from an upper end of the conical inclined tube along an axial direction of the synthetic resin container, and an outside air introduction port configured to introduce outside air between the outer layer body and the inner layer body; a shoulder portion located below the mouth portion and having an increasing diameter along a downward direction of the synthetic resin container, the shoulder portion having at least one shoulder rib configured to form a concave shape or a convex shape and extend from a mouth portion side to a body portion side, a body portion extending continuous from a lower end of the shoulder portion; and a bottom portion configured to close a lower end of the body portion, wherein: the convex piece protrudes toward the outer layer body to maintain a space for ventilation between the outer layer body and the inner layer body, the convex piece being located below the outside air introduction port.

2. The synthetic resin container according to claim 1, wherein a synthetic resin material forming the outer layer body and the inner layer body is polyethylene terephthalate.

3. The synthetic resin container according to claim 2, wherein the shoulder portion forms a curved shape having an inflection point, the shoulder portion having, along a longitudinal section, an upper side relative to the inflection point that is concave and a lower side relative to the inflection point that is convex.

4. The synthetic resin container according to claim 2, wherein the at least one shoulder rib extends along a radial direction of the shoulder portion in a top plan view.

5. The synthetic resin container according to claim 4, wherein the shoulder portion forms a curved shape having an inflection point, the shoulder portion having, along a longitudinal section, an upper side relative to the inflection point that is concave and a lower side relative to the inflection point that is convex.

6. The synthetic resin container according to claim 1, wherein the at least one shoulder rib extends along a radial direction of the shoulder portion in a top plan view.

7. The synthetic resin container according to claim 6, wherein the shoulder portion forms a curved shape having an inflection point, the shoulder portion having, along a longitudinal section, an upper side relative to the inflection point that is concave and a lower side relative to the inflection point that is convex.

8. The synthetic resin container according to claim 1, wherein the shoulder portion forms a curved shape having an inflection point, the shoulder portion having, along a longitudinal section, an upper side relative to the inflection point that is concave and a lower side relative to the inflection point that is convex.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the accompanying drawings:

(2) FIG. 1 is a partial sectional side view of a synthetic resin container according to an embodiment of the present disclosure;

(3) FIG. 2 is a top view of the synthetic resin container illustrated in FIG. 1;

(4) FIG. 3 is a partial sectional side view of a preform before molded into the synthetic resin container illustrated in FIG. 1;

(5) FIG. 4 is a partial sectional side view of a variation of the synthetic resin container illustrated in FIG. 1; and

(6) FIG. 5 is a top view of the synthetic resin container illustrated in FIG. 4.

DETAILED DESCRIPTION

(7) A synthetic resin container according to an embodiment of the present disclosure will be described in more detail below with reference to the drawings.

(8) As illustrated in FIG. 1, a synthetic resin container 1 (hereinafter referred to also as a container 1) according to this embodiment has an outer layer body 2 and an inner layer body 3 disposed inside the outer layer body 2, and is formed by biaxial stretching blow molding. In this embodiment, the container 1 is configured as a delamination container having a double container structure including the outer layer body 2 and the inner layer body 3.

(9) As illustrated in FIGS. 1 and 2, the container 1 has a substantially cylindrical mouth portion 4, a shoulder portion 5 being continuous with a lower end of the mouth portion 4 and having a diameter gradually increasing downward, a body portion 6 being continuous with a lower end of the shoulder portion 5, and a bottom portion 7 configured to close a lower end of the body portion 6. Herein the up-down direction means a direction along a central axis line O of the mouth portion 4, the up direction means a direction from the bottom portion 7 to the mouth portion 4 (e.g. upside in FIG. 1) and the down direction means its opposite direction. Further, a longitudinal section means a section of a plane including the central axis line O, and a cross section means a section of a plane vertical to the central axis line O.

(10) The mouth portion 4 has a male thread 4a configured to screw a spout cap. However, the mouth portion 4 may have, instead of the male thread 4a, a convex portion of an annular shape and the like that can be engaged with a spout cap by plugging in an undercut manner. Under the mouth portion 4 is provided with an annular neck ring 8. It is to be noted that the shape of the neck ring 8 can be appropriately changed. The mouth portion 4 may not be provided with the neck ring 8. The mouth portion 4 has an outside air introduction port 13 configured to introduce outside air between the outer layer body 3 and the inner layer body 2. The detailed configuration of the outside air introduction port 13 will be described later.

(11) The shoulder portion 5 has a substantial conical shape that is concentric with the central axis line O of the mouth portion 4 and has a curved shape having an inflection point where the upper side is concave and the lower side is convex in the longitudinal section.

(12) The body portion 6 has a cylindrical shape that is concentric with the central axis line O of the mouth portion 4, in which a portion extending from an intermediate portion to an upper end portion in the up-down direction is narrowed. However, the shape of the body portion 6 can be appropriately changed. For example, the body portion 6 may have a cylindrical shape having no narrow portion. The body portion 6 may also have a groove-shaped annular rib extending in the circumferential direction.

(13) The bottom portion 7 has an annular grounding portion 7a concentric with the central axis line O of the mouth portion 4 and a bottom panel 7b located inside the grounding portion 7a. However, the shape of the bottom portion 7 can be appropriately changed.

(14) In this embodiment, the outer layer body 2 is formed of polyethylene terephthalate (PET). Further, the outer layer body 2 forms the outer shell of the container 1, and a portion thereof forming the body portion 6 has a flexibility so as to be deformable by squeezing (pressing) operation and a restorability so as to be restorable by elastic force after deformation. It is to be noted that, when a container with a pump is configured by the container 1, the outer layer body 2 may not have such flexibility and restorability. Synthetic resin materials forming the outer layer body 2 are not limited to PET, and may be olefin-based resins such as polypropylene (PP) and polyethylene (PE), for example. The outer layer body 2 is not limited to a single layer structure, and may have a multi-layer structure that can improve barrier properties and the like.

(15) In this embodiment, the inner layer body 3 is formed of PET. Further, the inner layer body 3 is formed in a bag shape with a thickness smaller than that of the outer layer body 2. A storage space S being continuous with an upper end opening 4b of the mouth portion 4 is formed inside the inner layer body 3. A storage space S can contain foods such as food seasonings like soy source or beverages, cosmetics such as lotion, toiletries such as shampoo, rinse or liquid soap and the like as contents. It is to be noted that the contents are not limited to foods, cosmetics or toiletries. The synthetic resin materials forming the inner layer body 3 are not limited to PET, and may be nylon or ethylene vinyl alcohol copolymer resin (EVOH) and the like. Further, the inner layer body 3 is not limited to those having a single layer structure, and may be those having a multi-layer structure that can improve barrier properties/or resistance to contents and the like.

(16) In this embodiment, synthetic resin materials forming the outer layer body 2 and the inner layer body 3 are biaxially stretchable PET. Examples of such biaxially stretchable PET include homo PET, and the like. However, other PET such as isophthalic acid (IPA) modified PET or CHDM modified PET may be used. Further, the PET forming the outer layer body 2 and the PET forming the inner layer body 3 may be different from each other.

(17) The container 1 is formed by biaxial stretching blow molding the preform 9 illustrated in FIG. 3. The preform 9 has an outer body 10 forming the outer layer body 2 and an inner body 11 forming the inner layer body 3. In this embodiment, the preform 9 has a double preform structure including the outer body 10 and the inner body 11. Further, since the preform 9 is not substantially stretched during the biaxial stretching blow molding, it has a mouth portion 4 configured substantially in the same manner as the mouth portion 4 of the container 1. A preform body portion 12 of a bottomed cylindrical shape (test tube shape) is connected below the mouth portion 4.

(18) The outer body 10 has a cylindrical outer mouth portion 10a forming the mouth portion 4. The outer periphery of the outer mouth portion 10a is provided with a male thread 4a and a neck ring 8. Further, the outer mouth portion 10a is provided with an outside air introduction port 13 forming a horizontal through hole at a portion between the male thread 4a and the neck ring 8. In this embodiment, at the outer mouth portion 10a, the outside air introduction port 13 is provided to each of two portions across the central axis line O. However, the number, the arrangement and the shape of the outside air introduction port 13 may be appropriately changed. The male thread 4a has a notch 14 immediately above the outside air introduction port 13, and through the notch 14, the outside air inlet provided at the spout cap is communicated with the outside air introduction port 13. However, the male thread 4a may not have such notch 14.

(19) Under the outer mouth portion 10a is continuous with the outer body portion 10b that forms the preform body portion 12. The outer body portion 10b has an upper portion having an outer diameter gradually decreasing downward and a thickness gradually increasing, a cylindrical intermediate portion having a thickness being substantially constant in the up-down direction and a hemispherical bottom portion configured to close the lower end of the intermediate portion. However, the shape of the outer body portion 10b may be appropriately changed.

(20) The inner body 11 has a stepped cylindrical inner mouth portion 11a forming the mouth portion 4. The inner mouth portion 11a has an annular flange 15 placed on the upper end of the outer mouth portion 10a, a cylindrical upper tube 16 drooping from an inner peripheral edge of the flange 15 and being in contact with an inner surface of the outer mouth portion 10a, a conical inclined tube 17 having a diameter decreasing downward from the lower end of the upper tube 16, and a portion (excluding a lower portion) of a cylindrical lower tube 18 drooping from a lower end of the inclined tube 17. The upper end of the inclined tube 17 is located above the upper end of a pair of outside air introduction ports 13.

(21) An inner body portion 11b forming the preform body portion 12 is continuous with under the inner mouth portion 11a. The inner body portion 11b has an upper portion including a lower portion of a lower tube 18 and an inclined portion 19 having an outer diameter gradually decreasing downward from the lower portion and a gradually increasing thickness, a cylindrical intermediate portion having a thickness being substantially constant in the up-down direction, and a hemispherical bottom portion configured to close the lower end of the intermediate portion. However, the shape of the inner body portion 11b can be appropriately changed depending on the shape of the outer body portion 10b.

(22) The inner body 11 has a convex piece 20 extending from the upper end of the inclined tube 17 to the upper portion of the inclined portion 19 along the up-down direction. Three convex pieces 20 are provided on both sides of the axis line passing through both of a pair of outside air introduction ports 13, and are configured to maintain an excellent space for ventilation between the outer layer body 2 and the inner layer body 3 around or below the outside air introduction port 13 even after the biaxial stretching blow molding. However, the number, the arrangement and the shape of the convex piece 20 may be appropriately changed. The convex piece 20 may not be provided to the inner body 11.

(23) Such preform 9 can be molded into the container 1 by biaxial stretching blow molding in which an axial stretching by a stretching rod and a circumferential stretching by pressurized air (or liquid as contents) are performed. The container 1 formed in the above described manner has, on the shoulder portion 5 thereof, at least one shoulder rib 21 formed by conforming to a shape of a cavity of a mold for blow molding.

(24) As illustrated in FIGS. 1 and 2, in this embodiment, the container 1 has 18 shoulder ribs 21 arranged at equal intervals in the circumferential direction of the central axis line O. However, the number and the arrangement of the shoulder rib 21 can be appropriately changed. Each shoulder rib 21 has a concave shape and extends from the mouth portion 4 side to the body portion 6 side. Further, each shoulder rib 21 extends in the radial direction in a top plan view. Moreover, each shoulder rib 21 has a U-shaped cross-sectional shape whose width gradually narrows inward in the radial direction of the central axis line O in the cross section over substantially the entire length. Therefore, in each shoulder rib 21, the inner layer body 3 can be easily separated from the outer layer body 2. Further, since the shoulder rib 21 is provided, after the inner layer body 3 is separated from the outer layer body 2, the inner layer body 3 is difficult to adhere to the outer layer body 2. In this manner, an air duct can be stably secured between the inner layer body 3 and the outer layer body 2.

(25) Further, in this embodiment, the shoulder portion 5 is continuous with the lower end of the mouth portion 4. Thus, as compared with the case where the shoulder portion 5 is continuous with the lower end of an annular step portion whose diameter increases in a stepwise manner from the lower end of the mouth portion 4, for example, it is easier to secure an air duct between the outside air introduction port 13 and the body portion 6. However, it is sufficient that the shoulder portion 5 is located below the mouth portion 4, and is not limited to be configured such that it is continuous with the lower end of the mouth portion 4.

(26) Further, in this embodiment, the shoulder portion 5 has a curved shape having an inflection point where the upper side is concave and the lower side is convex in the longitudinal section. Thus, as compared with the case where the shoulder portion 5 has a curved shape in which the whole is convex in the longitudinal section, for example, it is easier to secure an air duct between the outside air introduction port 13 and the body portion 6. However, it is sufficient that a diameter of the shoulder portion 5 gradually increases downward, and the shape thereof can be appropriately changed.

(27) Further, in this embodiment, at least one shoulder rib 21 extends along the radial direction of the shoulder portion 5 in a top plan view. Thus an air duct extending from the outside air introduction port 13 to the body portion 6 can be shortened to allow the outside air to be smoothly introduced. However, the shape of at least one shoulder rib 21 is not limited to the above described shape, and the at least one shoulder rib 21 may extend in a direction inclined with respect to the radial direction of the shoulder portion 5 in a top plan view, or may have a curved or bent shape in a top plan view. For example, as a variation of this embodiment, a synthetic resin container 1′ may have 18 shoulder ribs 21′ each extending in a direction inclined with respect to the radial direction of the shoulder portion 5 and having a curved shape in a top plan view as illustrated in FIGS. 4 and 5.

(28) The above explanation merely describes an embodiment of the present disclosure, and is not intended to limit the scope of the claims. The above described embodiment can be modified in various manners as described below, for example, on the basis of the basic matters of the present disclosure.

(29) In the above described embodiment, the mouth portion 4, the shoulder portion 5 and the body portion 6 of the container 1 form a circular tubular shape in the cross section. However, it is not limited thereto, and it may have a polygonal or elliptical tubular shape, for example, in the cross section.

(30) Further, in the above described embodiment, although the outside air introduction port 13 is a through hole that passes through a portion that forms the mouth portion 4 of the outer layer body 2 (outer mouth portion 10a), it is not limited thereto, and it may be formed between a portion forming the mouth portion 4 of the outer layer body 2 (outer mouth portion 10a) and a portion forming the mouth portion 4 of the inner layer body 3 (inner mouth portion 11a). For example, the outside air introduction port 13 may be configured by a concave groove provided on the lower surface of the flange 15 of the inner mouth portion 11a and the outer peripheral surface of the upper tube 16 so as to be continuous from the outer peripheral edge of the flange 15 to the lower end of the upper tube 16 and/or by a concave groove provided on the upper end surface of the outer mouth portion 10a and the inner peripheral surface of the outer mouth portion 10a so as to be continuous from the outer peripheral edge on the upper end surface of the outer mouth portion 10a to a position beyond the lower end of the upper tube 16.

(31) In the above described embodiment, at least one shoulder rib 21 forms a concave shape, but is not limited thereto, and may form a convex shape.

REFERENCE SIGNS LIST

(32) 1, 1′ Synthetic resin container 2 Outer layer body 3 Inner layer body 4 Mouth portion 4a Male thread 5 Shoulder portion 6 Body portion 7 Bottom portion 7a Grounding portion 7b Bottom panel 8 Neck ring 9 Preform 10 Outer body 10a Outer mouth portion 10b Outer body portion 11 Inner body 11a Inner mouth portion 11b Inner body portion 12 Preform body portion 13 Outside air introduction port 14 Notch 15 Flange 16 Upper tube 17 Inclined tube 18 Lower tube 19 Inclined portion 20 Convex piece 21, 21′ Shoulder rib O Central axis line S Storage space