JP2002029554A - Plastic two-part cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic two-part cap in which a barrier thin film layer is formed to prevent effect of contents and effect exerted during attachment to a container main body. SOLUTION: In the two-part cap 10 composed of a cap main body 100 and an inner stopper 200, which is fitted below a top plate 110 of the cap main body, the thin film layer 300 of ceramic is formed on at least the underside of the top plate of the cap main body or the upper side of the inner stopper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic two-part cap with good barrier properties, which is mounted on the mouth and neck of a container.

[0002]

2. Description of the Related Art Recently, plastic containers have been widely used in various fields such as foods and pharmaceuticals because of their various characteristics such as ease of molding, light weight, and low cost. Has been widely used as. In this plastic container, a cap is screwed or engaged with the mouth and neck of the container body.

[0003]

However, plastic containers have the property of transmitting low molecular gases such as oxygen, carbon dioxide, and water vapor, and various methods have been considered for the container body to solve this problem. Have been. For example, there is a method in which a plurality of plastic materials are laminated, and a material having low gas permeability and at least another material are combined. In addition, it is molded with a material obtained by blending a material having gas barrier properties. However, since the container is composed of the container main body and the cap, even if the gas barrier property of the container main body is improved by the above-described method, if the gas barrier property of the cap is low, when the entire container is viewed. Many cases have been found to be containers with low gas barrier properties. Therefore, in order to improve the barrier properties of the cap, insert molding of a film having a high barrier property has been performed, but in these cases, the manufacturing process becomes complicated or the cost becomes high. Had such problems. In recent years, it has been observed that a thin film layer is provided on the cap surface to impart a barrier property. However, no measures have been taken in terms of the effects of contents and protection of the thin film layer when the thin film layer is attached to the container body.

SUMMARY OF THE INVENTION An object of the present invention is to provide a barrier thin film layer so as not to be affected by the contents and the effect of mounting on a container body, and to reduce the cost. An object of the present invention is to provide a plastic two-part cap having good barrier properties.

[0005]

That is, the first aspect of the present invention is as follows.
In a two-part cap comprising a cap body and an inner plug inserted under the top plate of the cap body, a ceramic thin film is formed on at least one of the lower surface of the top plate of the cap body and the upper surface of the inner plug. It is a plastic two-part cap characterized in that a layer is formed.

Next, a second invention of the present invention relates to a two-part cap comprising a cap body and an inner plug inserted under the top plate of the cap body, wherein the lower surface of the top plate of the cap body and the inner cap are provided. A plastic two-part cap, wherein a ceramic thin film layer is formed on an upper surface of a stopper.

Next, according to a third aspect of the present invention, a plastic material according to the first or second aspect, wherein the material of the cap body and the material of the inner plug are made of different resins. It is a two-part cap.

Next, according to a fourth aspect of the present invention, the unevenness on the lower surface of the top plate of the cap body and the upper surface of the inner plug is 0.2 mm.
A plastic two-part cap according to any one of the first to third inventions, characterized in that:

Next, a fifth invention of the present invention is the plastic two-part according to the first to fourth inventions, wherein the ceramic thin film layer is a thin film layer containing silicon oxide as a main component. Cap.

Next, according to a sixth aspect of the present invention, the ceramic thin film layer is formed by a CVD deposition method (chemical deposition method, Chemi
The plastic two-part cap according to any one of the first to fifth inventions, wherein the two-part cap is formed by a cal vapor deposition (cal vapor deposition).

In a seventh aspect of the present invention, the ceramic thin film layer is formed by a PVD vapor deposition method (physical vapor deposition method, Phys
The plastic two-part cap according to any one of the first to fifth inventions, wherein the two-part cap is formed by an electrical vapor deposition.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the plastic 2 of the present invention will be described.
An embodiment of a parts cap will be described in detail with reference to the drawings. FIG. 1 is a partial cross-sectional view showing a main part when the cap according to the present embodiment is screwed onto the mouth and neck of the container body, and FIG. 2 is a front view.

As shown in FIG. 2, the cap (10) of this embodiment is screwed onto the mouth and neck (21) of the container body (20) filled with the contents to seal the container body. As shown in FIG. 1, the cap body (100) and the top plate (11) of the cap body are protected.
0) 2 consisting of a disc-shaped inner plug (200) inserted below
Part cap, the peripheral wall of the cap body (120)
A screwing portion (121) screwed with a screwing portion (22) (male screw) of the mouth and neck portion (21) of the container body (20) is provided on the inner peripheral surface of the container body (20).
(Internal thread) provided on the lower surface of the inner plug, an inner sealing ring (210) for sealing the mouth of the mouth and neck of the container body.
(The container is sealed with the outer peripheral surface being in close contact with the inner peripheral surface of the mouth of the container body). The ceramic thin film layer (300) is formed on at least one of the lower surface of the top plate of the cap body and the upper surface of the inner plug. this is,
It depends on the purpose of use of the container and the suitability for film formation of parts.
When a higher barrier property is required, a ceramic thin film layer may be formed on both the lower surface of the top plate of the cap body and the upper surface of the inner plug. When the cap is unscrewed from the container body, the lower surface of the cap body and the upper surface of the inner plug can be separated.

The above-mentioned ceramic thin film layer has a property of preventing the permeation of gases such as oxygen, carbon dioxide and water vapor, and imparts a barrier property to the cap. Further, since the ceramic thin film layer has a structure sandwiched between the lower surface of the top plate of the cap body and the upper surface of the inner plug, the influence of the contents and the cap are screwed or screwed to the mouth and neck of the bottle body. It is protected from the influence of friction when coming off. As a method of forming a ceramic thin film layer, CVD is used.
Examples include vapor deposition and PVD vapor deposition, but are not limited thereto, and a method capable of forming a uniform barrier film is desirable. In addition, the lower surface of the top plate of the cap body and the upper surface of the inner plug, which form the thin film layer, are preferably flat surfaces having no unevenness of 0.2 mm or less. A layer is formed and a stable barrier property is obtained. On a surface having irregularities of 0.2 mm or more, it is difficult to form a uniform thin film layer. The material of the thin film layer is preferably a material containing silicon oxide as a main component, but is not limited to this.

The material of the cap body and the inner plug is not particularly limited, but may be selected according to the purpose of use of the container.
Including polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polystyrene, polycarbonate, vinyl chloride resin, polyvinyl acetate, nylon, thermoplastic resins such as ethylene-vinyl alcohol copolymer, and resins blended with them, , Manufactured by an injection molding method.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. <Example 1> First, the cap body was injection molded using high-density polyethylene, and the inner plug was produced by injection molding using low-density polyethylene. Next, a thin film layer of a silicon oxide compound was formed on the upper surface of the inner plug by a CVD deposition method. In addition,
The outer diameter of the cap body is φ30 mm and the weight is 2.6
g, the weight of the inner plug was 0.7 g, and the surface on which the inner plug was deposited was a flat surface having irregularities of 0.2 mm.

Under the top plate of the above-mentioned cap body, an inner plug having a thin film layer of a silicon oxide compound formed thereon is set,
A two-part cap of this example was manufactured. Then, this cap was screwed onto the mouth and neck of the glass container body, the container body was sealed, and the oxygen permeation amount of the whole container was measured. Assuming that the oxygen permeation amount of the container body is 0, the oxygen permeation amount of the cap of this embodiment is 0.005 fmol / (pkg · s ·
Pa).

Example 2 Alkali contents (pH = 1)
A cap having the same configuration and specifications as in Example 1 was screwed onto the mouth and neck of the glass container body filled with 0), the container body was sealed, and the cap was placed on the lower side at 40 ° C. and 90%. After storing for 24 hours under the conditions, the cap was removed, this cap was screwed onto the mouth and neck of another empty glass container body, the container body was sealed, and the cap was sealed in the same manner as in Example 1. Was measured. Oxygen transmission rate is 0.00
It was 5 fmol / (pkg · s · Pa), and the barrier properties of the cap did not decrease.

<Comparative Example 1> A two-part cap according to the present comparative example, which has the same structure as that of Example 1 but does not form a thin film layer of a silicon oxide compound on the upper surface of the inner plug, was manufactured. The oxygen permeation amount of the cap was measured in the same manner as in Example 1. The oxygen permeation amount of the cap of this comparative example was 0.030 fmol /
(Pkg · s · Pa), and the barrier property was remarkably inferior to the cap of Example 1.

[0020]

The plastic two-part cap of the present invention has a barrier property by forming a barrier thin film layer between the top plate of the cap body and the upper surface of the inner plug. The cap has a good barrier property without being affected by the contents and the effect of being attached to the container body.

Also, unlike a conventional cap having a barrier property by insert molding a film having a high barrier property, the cost is relatively low.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view when a plastic two-part cap according to an embodiment of the present invention is screwed to a mouth and neck of a container body.

FIG. 2 is a partial front view of the container of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Cap 20 ... Container main body 21 ... Neck and neck 22, 121 ... Screw part 100 ... Cap main body 110 ... Top plate 120 ... Peripheral wall 200 ... Inner plug 210 ... Inner sealing ring 300 ...... Thin film layer

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3E084 AA12 AA24 BA03 BA05 CA01 CC03 CC08 DA01 DB12 DC03 EA04 EC03 FA09 FB01 GA04 GA08 GB04 GB12 HA03 HB02 HC03 HC10 HD01 HD04 KB01 LA17 LB02 LB07 LD01 4F006 AA12 AA15 AA17 AA35 AA35 CA07 DA01

Claims (7)

[Claims] 1. A two-part cap comprising a cap body and an inner plug inserted under a top plate of the cap body, wherein at least one of a lower surface of the top plate of the cap body and an upper surface of the inner plug is provided with ceramic. A two-part plastic cap formed with a thin film layer. 2. A two-part cap comprising a cap body and an inner plug inserted under the top plate of the cap body, wherein a ceramic thin film layer is formed on the lower surface of the top plate of the cap body and the upper surface of the inner plug. A plastic two-part cap, characterized in that: 3. The plastic two-part cap according to claim 1, wherein a material of the cap body and a material of the inner plug are made of different resins. 4. The plastic two-part cap according to claim 1, wherein the unevenness of the lower surface of the top plate of the cap body and the upper surface of the inner plug are not more than 0.2 mm. 5. The plastic two-part cap according to claim 1, wherein said ceramic thin film layer is a thin film layer containing silicon oxide as a main component. 6. A two-part plastic cap according to claim 1, wherein said ceramic thin film layer is formed by a CVD deposition method. 7. The two-part plastic cap according to claim 1, wherein said ceramic thin film layer is formed by a PVD deposition method.