JP3466992B2 - cap - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ESCR (envi) which is mounted on a container body containing a liquid containing a surfactant.
ronmental stress cracking resistance: A cap with excellent effects on environmental stress fracture.

[0002]

2. Description of the Related Art A liquid containing a surfactant such as a bleaching agent is contained in a resin bottle container, and a cap attached to the mouth and neck of the container body is removed and removed. Use the inner solution while appropriately measuring with a cap. After using the inner solution, attach the cap again to close the bottle container. In such a bottle container, while the cap is repeatedly removed and attached, and by measuring the internal solution with the cap, the liquid adheres to the cap and is affected by the surfactant, and at the time of attachment and detachment. It was apt to cause the damage of the cap due to the environmental stress destruction under the repeated stress of. Further, when the inner solution was a liquid containing a surfactant and sodium hypochlorite, environmental stress fracture was more likely to occur due to their synergistic effect.

The damage of the cap due to environmental stress destruction is a place where stress is concentrated and applied, that is, a place where the upper end of the male screw formed on the mouth and neck of the bottle container fits, that is, a female screw. It is likely to occur when a crack occurs at the end portion on the top surface of the cap. According to the conventional technique, the cap of such a portion is thickened to reinforce the cap to prevent damage to the cap due to environmental stress damage, but the amount of resin as the material of the cap increases. At the same time, in the manufacturing process such as injection molding, it takes a plasticizing time and a cooling time, which lowers the productivity.

An object of the present invention is to provide a cap capable of effectively preventing damage to the cap due to environmental stress damage without increasing the thickness of the cap.

[0005]

The present invention relates to a surfactant and a surfactant.
A cap having a female screw formed on the inner peripheral surface thereof, which is screwed into the mouth and neck of a container main body in which a liquid containing sodium hypochlorite is contained, wherein the female screw has 2 to 4 threads. Ah is, and the 2-4-threaded screw made of a spiral of the thread engagement convex
When attached and fixed to the mouth and neck,
Insert the inner plug between the tip and the tip of the mouth and neck.
Thus , the above object is achieved by providing a cap that comes into close contact with the inner plug .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cap 10 according to a preferred embodiment of the present invention shown in FIGS. 1 to 3 is a mouth neck of a container body 12 in a bottle container 11 made of polyethylene containing a chlorine bleach as an internal solution. The part 13 is detachably screwed and used. That is, a female screw 14 is formed on the inner peripheral surface of the cap 10, and the female screw 14 is screwed into the male screw 15 formed on the outer peripheral surface of the mouth / neck portion 13 of the container body 12 so that the cap 10 is closed. It is attached and fixed to the mouth / neck portion 13 of the main body 12.

According to the cap 10 of the present embodiment, the female screw 14 formed on the inner peripheral surface is a two-thread screw consisting of two helically threaded projecting threads 14a and 14b. In addition, the threaded projections 14a and 14b forming the female screw 14
Has a screw angle θ of 80 to 120 ° and a screw height (height from the root of the screw to the tip of the screw) H of the female screw 1.
1 to 15% of the root radius of 4 (radius at the root of the screw) R
(See FIG. 3).

The cap 10 is made of polyethylene,
Manufactured by injection molding. The cap 10 is composed of a circular top surface portion 16 and a peripheral wall portion 17 extending in a skirt shape from the peripheral edge portion of the top surface portion 16. The top surface portion 16 is a circular flat plate-shaped portion having a diameter of about 33 mm, and an annular outer inner ring portion 19 and an inner inner ring portion 20 are concentrically arranged with the top surface portion 16 on the inner surface thereof. It is provided heavily. When the cap 10 is attached and fixed to the mouth / neck portion 13 of the container body 12, the outer inner ring portion 19
Insert the inside plug 21 between the tip of the
And writing so closely abutting on the in stopper 21, the inner inner ring portion 20 is in close contact inserted into the fitting ring portion 22 so as to expand pushing the fitting ring 22 provided on the inside plug 21. With these, the container body 12 is hermetically closed to effectively prevent leakage of the chlorine bleach inside.

The peripheral wall portion 17 is a cylindrical portion integrally joined to the peripheral portion of the top surface portion 16, and has a vertical portion 23 having a length of about 26 mm and a thickness of about 3 mm, and a continuous portion below the vertical portion 23. And a taper portion 24 having an enlarged diameter. Vertical part 2
A female screw 14 is formed on the inner side surface of 3 while leaving about 10 mm below the top surface portion 16. The outer surface of the vertical portion 23 is knurled so that the fingers do not slip when the cap 10 is rotated (see FIG. 2).

According to the present embodiment, the pair of threaded projections 14a and 14b constituting the female screw 14 are respectively started at the positions of the lower end portion of the vertical portion 23 which are opposed to each other in the radial direction of the inner peripheral surface. After starting, they are spirally extended toward the top surface portion 16 side so as to be alternately overlapped with each other, and thereafter, the positions facing each other in the radial direction are finished as the end portions.

Each of the threaded projections 14a and 14b has a substantially isosceles trapezoidal cross-section which is oriented laterally, and as shown in FIGS. 3 (a) and 3 (b), the screw angle θ at the tip thereof. Is 80-1
It is 20 °. When the screw angle is 80 to 120 °, it is possible to efficiently disperse the stress when the cap 10 is fastened to the mouth / neck portion 13 of the container body 12, which is also preferable in terms of molding. Further, the screw height H of each threaded projection 14a, 14b is 1 to 15% of the root radius R of the female screw 14. The screw height H is 1 to 15 of the root radius R of the female screw 14.
%, It is possible to maintain a good degree of engagement of the male screw 15 of the mouth / neck portion 13 when the cap 10 is fastened to the mouth / neck portion 13 of the container body 12.

According to the present embodiment, as shown in FIG. 1, the cap 10 is detachably screwed to the mouth / neck portion 13 of the container body 12 having the male screw 15 formed by the double thread. Here, the male screw 15 is a pair of threaded projections 15a, 1
5b, and these threaded protrusions 15a, 15
b starts from the position on the radially opposite side of the outer peripheral surface of the mouth / neck portion 13 as a starting point, and after extending spirally toward the distal end portion so as to alternately overlap, the position on the radially opposite side is set. Each ends as a terminal part. Further, the cap 10 has an inner plug 21 fitted into the tip opening of the mouth / neck portion 13,
It is screwed and attached to the mouth / neck portion 13 with the intervening. The inner plug 21 is a member made of synthetic resin and prevents a large amount of chlorine-based bleaching agent from flowing out from the mouth / neck portion 13 at one time when the chlorine-based bleaching agent stored in the container body 12 is used. However, it is attached in order to control the outflow amount from the spout 30 to be an appropriate amount.

The cap 10 of this embodiment is also used as a measuring instrument, and since the chlorine-based bleaching agent is once transferred to the cap 10 and measured, it is used.
Chlorine bleach adheres to the inner surface of the. Also cap 1
0 is repeatedly subjected to stress by being repeatedly attached to and detached from the mouth / neck portion 13 of the container body 12. Therefore, the cap 10 is in a situation where environmental stress fracture is likely to occur due to the influence of the chlorine-based bleaching agent and the repeated stress.
Particularly, the tip of the outer inner ring portion 19 is the tip of the mouth / neck portion 13.
Inner plug 21 interposed so as to be sandwiched between the end face
After contact abut on, when to be further Shimetsukeyo cap 10, a stress is intensively loaded at the end portion of the top panel 16 side of the female screw 14, easily broken in this portion occurs.

According to the cap 10 of the present embodiment, since the female screw 14 is composed of the two-thread screw consisting of the pair of threaded projections 14a and 14b, the stress of the female screw 14 is concentrated. It is possible to effectively suppress the occurrence of cracks at the end portion on the top surface portion 16 side. That is, the threaded projections 14 a, 14 b are the threaded projections 15 a, 15 of the male screw 15.
It becomes a cantilever beam against the stress from the contact point with b, and cracks are likely to occur at its base end, but this stress is dispersed by being supported at two points by a pair of threaded projections 14a, 14b. Therefore, it becomes possible to effectively alleviate the stress.

Therefore, according to the cap 10 of the present embodiment, it is possible to effectively prevent damage to the cap due to environmental stress damage without increasing the thickness of the cap 10.

The cap of the present invention can be variously modified without being limited to the above embodiment. For example, a female screw does not necessarily have to be a two-thread screw, but a three-thread screw
Alternatively, a 4-thread screw may be used.

[0017]

EXAMPLES The cap of the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Example 1 and Comparative Example 1] Ten caps having female threads consisting of double thread screws having the same shape as the cap 10 of the above embodiment were prepared as samples of Example 1. The root radius of the female screw is 15 mm, the screw angle θ at the tip of each thread to be screwed is 80 °, and the screw height H is 0.8 mm.
And On the other hand, as the sample of Comparative Example 1, ten caps having a female screw formed of a single thread having the same shape as the cap 10 of the above-described embodiment were prepared. As in Example 1, the root radius of the female screw was 15 mm, the screw angle θ at the tip of each thread to be screwed was 80 °, and the screw height H was 0.8 mm. It should be noted that the two-thread screw of Example 1 and the one-thread screw of Comparative Example 1 are developed as a development view along the inner peripheral surface of the cap.
Shown in (a) and (b). 1 of each of Example 1 and Comparative Example 1
ESC for 0 samples by the following opening and closing method
The R (environmental stress resistance fracture) effect was evaluated. The test results are shown in Table 1.

[0019]

[Table 1]

[Cap ESCR Test Method by Opening and Closing Method] For each of 10 samples, a kitchen hyter (trade name: manufactured by Kao Corporation) was weighed as a liquid containing a surfactant and sodium hypochlorite (female screw part). The amount of liquid soaked) is removed, the measured liquid is removed, and a drop of water is gently taken to attach the liquid to the inside of the cap. These samples were applied to the mouth and neck of the container body similar to that of the above-described embodiment, in which a male screw with a double thread or a single thread was formed.
The container is screwed in with a torque of kgf · cm and mounted, and these containers are stored at 50 ° C for 24 hours (one day and night). Each container is taken out once a day to check the presence or absence of cracks in the screw part of each sample, and the same method is repeated to store the container again at 50 ° C. for 24 hours. The ESCR time was evaluated by setting F50 to the time until a crack occurs in 5 samples, which is half of 10 samples, as F50.

According to the test results shown in Table 1, as compared with the cap of Comparative Example 1 which is a conventional cap having a single thread, the cap of Example 1 having a double thread according to the present invention is ESCR. Time has risen about three times, and ESCR
It turns out that the effect is significantly improved.

[0022]

According to the cap of the present invention, a surfactant is used.
And containing a liquid containing sodium hypochlorite
It is used by being screwed into the mouth and neck of the container body, and can effectively prevent damage to the cap due to environmental stress damage without increasing the thickness of the cap.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating a state in which a cap according to an embodiment of the present invention is screwed and attached to a mouth / neck portion of a container body.

FIG. 2 is a partially cutaway front view showing the cap according to the embodiment of the present invention.

3A is a partially enlarged cross-sectional view of a cap according to an embodiment of the present invention, and FIG. 3B is an enlarged view of a portion A of FIG.

4A is a development view along the inner peripheral surface of the cap for explaining the single thread screw of Comparative Example 1, and FIG.
It is a development view along an inner peripheral surface of a cap for explaining a thread.

[Explanation of symbols]

10 cap 11 bottle containers 12 container body 13 Mouth and neck 14 female screw 14a, 14b Threaded ridges to be screwed 15 Male screw 15a, 15b threaded ridge 16 Top surface 17 Peripheral wall 21 Inside plug 23 Vertical part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-81895 (JP, A) JP-A-11-70949 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65D 41/04

Claims (2)

(57) [Claims] 1. A cap having a female screw formed on an inner peripheral surface thereof, the cap being screwed to a mouth-neck portion of a container body in which a liquid containing a surfactant and sodium hypochlorite is housed. when the female screw, the Ri Oh 2-4-threaded screw made of spiral of the screwed convex 2-4 Article and mounted fixed to the mouth and neck, outer In'nari
Insert the inside plug between the tip of the ring and the tip of the mouth and neck.
A cap that comes into close contact with the inner plug as it is inserted . 2. The screw angle of the thread to be screwed is 80 to 12
0 ° and the screw height is 1 to 15 of the root radius of the female screw.
The cap of claim 1 which is% .