JPH0487954A - Inner plug for container - Google Patents

Abstract

PURPOSE:To make vitamin E hard to be adsorbed to a mouth part of a container without spoiling elastic fitting property and sealability between the mouth part of the container and a cap by forming an inner plug which is fitted in the mouth part, of a flexible ethylene-vinyl acetate copolymer resin. CONSTITUTION:A cap 2 with a thread part 2a, protruding plug 2b and step part 2c is formed of a chemical resistant hard synthetic resin which does not adsorb vitamin E (e.g. polyethylene terephthalate, polybutylene terephthalate, etc.). For a single structural inner plug 5 which is made of a flexible ethylene- vinyl acetate copolymer resin, a fitting part 5a which is fitted in the inner peripheral wall of a mouth part (1a) of a container main body 1, an annular flange 5b which continues from the fitting part 5a and joins to the upper end surface of the mouth part (1a), and a nozzle part 5d which continues from the annular flange 5b and has a pour-out hole 5c are integrally formed respectively. A vinyl acetate content for the inner plug shall be 28-33wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inner stopper of a container from which a small amount of liquid contained in the container body is applied and poured after removing the cap.

[Conventional technology]

FIG. 3 shows a conventional example of an inner stopper for a container containing a solution containing a component that is easily adsorbed to the inner wall of the container.

The inner stopper A includes an outer cylinder 3 made of a soft synthetic resin (e.g., polyethylene resin, polypropylene resin, etc.) that takes into account elastic fitting and sealing properties with the opening 1a of the container body 1 and the cap 2, and an outer cylinder 3 made of a soft synthetic resin (e.g., polyethylene resin, polypropylene resin, etc.). It has a double structure with an inner cylinder 4 made of hard synthetic resin with little deterioration (eg, polyethylene terephthalate, polybutylene terephthalate, etc.) (see, eg, Jikkoi Publication No. 18529).

Incidentally, the container body 1 and the cap 2 are made of hard synthetic resin like the inner tube 4.

The outer cylinder 3 has an opening 3a on its upper wall, an annular groove 3b in the middle of the inner peripheral wall, and an annular flange 3c on the outer peripheral wall opposite to the annular groove 3b. The inner cylinder 4 has a spout hole 4a in the upper wall portion having a fitting part to the opening 3a, and an annular protrusion 4b in the middle of the outer circumferential wall which fits into the annular groove 3b and acts to prevent removal. , an annular collar portion 4c that is joined to the lower end surface 3d of the outer cylinder 3 is formed below.

The cap 2 is formed with a threaded part 2a that is threaded into the threaded part 1b formed on the outer peripheral wall of the mouth part 1a of the container body 1, and is fitted into the spout hole 4a of the inner cylinder 4 on the inner wall of the upper surface. A protruding plug 2b is formed to press the annular flange 3c of the outer cylinder 3, and a step 2C is formed in the middle of the inner circumferential wall.

Therefore, the inner cylinder 4 is fitted into the outer cylinder 3, and the inner stopper A, in which the annular protrusion 4b is fitted and locked in the annular groove 3b, is inserted into the opening 1 of the container body 1.
a, the annular flange 4c of the hard synthetic resin inner cylinder 4 acts as a seal with the inner circumferential wall of the opening 1a, and the lower surface of the annular flange 3c of the soft synthetic resin outer cylinder 3 Mouth part 1
The lower end surface 3d of the outer cylinder 3 is joined to the upper surface of the annular flange 4C of the inner cylinder 4.

Further, when the cap 2 is screwed onto the mouth portion 1a, the protrusion plug 2b closes the spout hole 4a of the inner plug A, and the cap 2
The inner wall of the upper end presses against the upper surface of the inner plug A, and the stepped portion 2c of the cap 2 presses the annular flange 3c of the outer cylinder 3, causing the mouth portion 1
The annular flange 3c is pressed between it and the upper end surface of a.

Therefore, regardless of whether the lid is closed or when liquid is poured, the stored liquid does not come into contact with the soft synthetic resin outer cylinder 3, so the quality of the stored liquid does not change, and the opening of the container body 1] Since the seals between A and the inner stopper A and between the inner stopper A and the cap 2 are ensured, there is no leakage of the stored liquid.

[Problem to be solved by the invention]

The inner plug A having a double structure has an outer cylinder 3 and an inner cylinder 4 formed separately in advance, and the inner cylinder 4 is fitted into the outer cylinder 3, and the annular protrusion 4b is fitted into the annular groove 3b. Since the assembly is made by assembling, the manufacturing is troublesome, and if the annular grooves 3b and protrusions 4b are made small to facilitate fitting, there is a risk that the inner cylinder 4 will fall off from the outer cylinder 3.

Further, minute gaps are likely to be formed at the joint between the lower end surface 3d of the outer cylinder 3 and the annular flange 4c of the inner cylinder 4 (there is a risk that the liquid contained therein may enter the gap and cause deterioration of the quality of the liquid contained therein).

Therefore, an inner plug made of soft synthetic resin is desired to have a single structure rather than a double structure, and from the viewpoint of elastic fitting and sealing performance with the opening 1a of the container body 1 and the cap 2. Depending on the type of liquid contained, synthetic resin has the property of adsorbing its components.

In the case of eye drops containing vitamin E, which is effective for symptoms such as blurred vision and tired eyes, when the eye drops come into contact with the soft synthetic resin inner stopper, the vitamin E is absorbed into the eyes. There was an inconvenience in that the eye drops were adsorbed by the stopper and the vitamin E content significantly decreased over time, causing the eye drops to lose their original function.

The present invention has been made in view of the above circumstances, and has an inner stopper with a single structure that allows vitamin E to be adsorbed without impairing elastic fitting and sealing properties with the mouth of the container body and the cap. The purpose is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a container body made of hard synthetic resin, a cap made of soft synthetic resin that is detachable from the mouth of the container body, and an inner plug attached to the mouth. In the container, the inner stopper is molded from a soft ethylene-vinyl acetate copolymer resin.

The vinyl acetate content of the inner plug made of a soft ethylene vinyl acetate copolymer resin is set to 28 to 33 wt%.

[For production]

Soft synthetic resin (for example, soft polyethylene resin) for the inner plug
The amount of vitamin E loss is significantly improved (the residual amount of vitamin E is improved), and the residual amount of vitamin E can be controlled by controlling the vinyl acetate content. .

By setting the vinyl acetate content to 28 to 33 wt%, the residual amount of vitamin E can be reduced to 95 to 95.9%.
%.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

Note that the same parts as in the conventional example are given the same reference numerals.

In FIG. 1, reference numeral 1 indicates a mouth portion 1a, a threaded portion 1. Container body having l-+, 2 spring portions 2a, protrusion plugs 2b, step portions 2C
All caps are chemical resistant and contain vitamin E.
It is molded (for example, injection molded) from a hard synthetic resin (for example, polyethylene terephthalate, polyethylene terephthalate, etc.) that does not adsorb.

Reference numeral 5 denotes a single-structure inner stopper made of a soft ethylene-vinyl acetate copolymer resin, and includes a fitting part 5a that fits into the inner circumferential wall of the mouth part 1a of the container body, and a mouth part continuous with the fitting part 5a. an annular flange 5b joined to the upper end surface of 1a;
A nozzle portion 5d having a pouring hole 5C is integrally molded (for example, by injection molding).

Since the inner stopper 5 is soft, it has good elastic fitting and sealing properties with the mouth portion 1a and the cap 2.

Therefore, the vinyl acetate content is 9, ]0, ]2.14.1
9.25.28.33.40 (wt%) nine types of soft ethylene vinyl acetate copolymer resin plates and soft polyethylene resin plates were immersed and stored in a vitamin E-containing chemical solution at 50°C for 24 hours. Table 1 and FIG. 2 show the measurement results of the residual amount of vitamin E in the drug solution.

Table 1 Table 1 (Continued) As shown in Table 1 and Figure 2, vinyl acetate was
It has been recognized that even if the inner plug is made of soft polyethylene resin (containing Owt% of vinyl acetate), the residual amount (%) of vitamin E in the drug solution will be dramatically improved compared to the inner stopper made of simple soft polyethylene resin (containing Owt% of vinyl acetate). be done.

By controlling the vinyl acetate content, the residual amount of vitamin E in the drug solution can be controlled, and when the vinyl acetate content is around 30%, the residual amount of vitamin E in the drug solution is 95% or more. I understand that.

〔effect〕

In the present invention, since the inner stopper is constructed with a single structure made of a soft ethylene vinyl acetate copolymer resin, (a) even if the stored liquid is a vitamin E-containing solution, the amount of vitamin E adsorbed to the inner stopper can be significantly reduced; can be significantly reduced.

(b) Resilient fitting and sealing properties between the opening of the container body and the cap are established.

(C) It is easy to manufacture and can be provided at low cost.

1... Container body, 1a... Mouth part, 2... Cap,
2b...Protrusion plug, 2C...Step part, 5...Inner plug, 5a...
... Fitting part, 5b... Annular flange, 5C... Spout hole, 5d... Nozzle part.

Claims (2)

[Claims] (1) A container consisting of a container body made of hard synthetic resin, a cap made of hard synthetic resin that can be attached and detached to the mouth of the container body, and an inner stopper that is attached to the mouth, in which the inner stopper is made of a soft plastic. An inner stopper for a container, characterized in that it is molded from an ethylene vinyl acetate copolymer resin. (2) The inner stopper of a container according to claim 1, wherein the inner stopper is made of a soft ethylene vinyl acetate copolymer resin and has a vinyl acetate content of 28 to 33 wt%.