JPH09111899A - Shaped seal member, and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate stop of water at a gap of a complicated form by composing a bubble film having separate bubbles and continuous bubbles to have water- absorbing and swelling properties, and specifying the number of bubbles per unit length. SOLUTION: Natural rubber or synthetic rubber such as chloroprene rubber, ethylene propylene terpolymer, etc., vulcanizng agent, foam agent, and filler are kneaded with water-absorbing and swelling polymer of a polyacrylic acid or starch graft, and a kneaded substance is molded into a sheet. It is then vulcanized and foamed by heat, and it is then cooled to be a foam body mainly comprising separate bubbles. 30-60% of the bubbles are then broken by pressurization using a mixing roll or the like to provide a half-continuous and half-separate foam body including 8-10 bubbles/cm, which is then cut and worked in a specified size and form as necessary. Favorable water stopping effect can thus be achieved in getting in contact with water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a standard seal material composed of a water-swellable foamed molded article.

[0002]

2. Description of the Related Art Conventionally, it has been known that a water-swellable polymer foam is used as a sealing material for tunnel construction, water supply and sewerage construction, and a water-stopping material for civil engineering / construction construction. Many proposals have been made regarding the composition and manufacturing method of foams (for example, JP-A-6-65410, JP-A-6-25380, JP-A-7-109369, and JP-B-5-48775). , Tokuhei 7-683
96 publication). In the conventional water-swellable polymer foam seal material, the main purpose of foaming is to improve water handling and handling workability by weight reduction.

As is well known, the foamed structure includes continuous foaming and independent foaming, and it is usual that even the same substance becomes continuous cells or independent cells depending on the foaming method and the expansion ratio, and both are mixed. In many cases, the mixed foam of open cells and closed cells may be referred to as a semi-open / semi-independent foam hereinafter. In the above water-swellable foam seal material, in order for the seal effect due to the water-swellability to be fully exhibited, water must be spread over the seal material so that the entire water-swelling material absorbs and expands uniformly. Is necessary for this purpose, and it requires a certain amount of time after the water comes into contact with the seal material.

[0004]

However, according to the results of the study conducted by the present inventors, the conventional water-swellable foam sealing material completely exhibits the sealing effect due to the water-swellability after contact with water. The initial sealability before the application is insufficient. In order to satisfy this initial sealing property, if a foam mainly composed of independent foaming is used, not only the sealing effect due to water swelling property cannot be satisfactorily exhibited but also it becomes difficult to deform and becomes complicated. It becomes difficult to mount it in a large gap.

An object of the present invention is to provide a water-swellable foam seal material which can be easily mounted in a gap having a complicated shape, guarantees the initial sealability, and has a seal effect due to the water-swellability. It is an object of the present invention to provide a standard seal material capable of exhibiting excellent properties and a manufacturing method thereof.

[0006]

The fixed-size seal material according to the present invention is a foam structure having both closed and open cells, and has a water-absorbing and swelling foam film, and a bubble per 1 cm in length. The configuration is characterized in that the number is eight or more. The method for producing a standard seal material according to the present invention is a method in which a part of the bubbles of a foamed molded article mainly composed of independent foaming of a composition containing a water-swellable polymer is ruptured by pressurization to obtain closed cells. It is characterized in that the above-mentioned standard seal material is obtained by molding a foamed structure having both open cells and open cells.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A natural rubber or a synthetic rubber (chloroprene rubber, ethylene / propylene / terpolymer, etc.), a vulcanizing agent, a foaming agent, and a filling agent are used to produce the molded seal material according to the present invention. A water-swelling polymer (eg, polyacrylic acid type, starch graft type, etc.) is kneaded together with an agent and the like with a Banbury mixer, mixin sphere, etc., and this kneaded product is molded into a sheet and heated. By vulcanizing and foaming by, and cooling to obtain a foam mainly composed of closed cells,
A part of the bubbles are ruptured by pressurization to obtain a semi-reinforced / semi-independent foam, and if necessary, this semi-ream / semi-independent foam is cut into a predetermined size and a predetermined shape. In this case, mixin globules or the like can be used for breaking the bubbles by applying pressure. It should be noted that the foam mainly composed of closed cells refers to a foam having a closed cell ratio of approximately 50% or more.

The regular seal material according to the present invention is a semi-continuous / semi-foam foam, the number of bubbles per cm ³ is about 8 ^{3 or} more, and about 30% to 60% of the bubbles are broken. It is foamed. When the number of broken bubbles is 30% or less, it becomes difficult to deform and it becomes difficult to fill a complicated gap, and when it is 60% or more, the initial sealability becomes insufficient. In the shaped seal material according to the present invention, the preferable number of bubbles per 1 cm is in the range of 8 to 10 (when the number is 11 or more, the size of the bubbles becomes so small that it is difficult to break them. become).

The shaped seal material according to the present invention is particularly suitable as a water sealing material, for example, a joint material for a bath unit, a kitchen unit, etc., and a seal for a pipe joint of a water supply pipe or a drain pipe. It can be used as a roof material, a rear combination lamp seal for automobiles, a waterproof material for houses, etc.

The regular seal material according to the present invention is advantageous for filling a complex gap to stop water, and in order to facilitate the filling work, the seal space is more suitable than the gap space. It is preferable to make the cross-sectional area of the seal material slightly larger and to fill the seal material with a compression rate as low as possible.

In the shaped seal material according to the present invention, a part of the air bubbles of the fine closed cells having a size of 8 cells or more per 1 cm is broken by pressurization. Since the capillaries are stretched around finely, when they come into contact with water, the water permeates into every corner due to the capillarity, and the film of the entire seal material absorbs water evenly and expands.
The contact pressure at the interface between the sealing material and the surface to be sealed is increased, and an excellent water blocking effect is exhibited. Further, since it has closed cells, it is possible to sufficiently prevent water from passing through the seal material before the water stop is exhibited, and it is possible to ensure sufficient water stop even in the initial stage of contact with water. .

Since it is a foamed structure, the stress relaxation effect is remarkable, and under anhydrous conditions, the contact pressure at the interface between the seal material and the surface to be sealed decreases with time. As described above, when it comes into contact with water, excellent water stopping performance is exhibited in a sufficiently short time, so that water stopping can be satisfactorily achieved despite its stress relaxation effect.

[0013]

【Example】

[Example] A composition having the following composition (parts by weight) was kneaded with mixin-gall, and this kneaded product was heated in an oven at 150 ° C for 30 ° C.
It is vulcanized and foamed by heating under the conditions of minutes, taken out from the oven, and cooled to obtain a foam mainly composed of independent cells having 8 to 10 cells per cm. A part of was broken to obtain a semi-german semi-ream form. The specific gravity of this foam was 0.13 g / ml.

Blending Ethylene propylene terpolymer 100 parts Zinc white 5 parts Stearic acid 3 parts Carbon black 5 parts Cray 70 parts Process oil 40 parts Sulfur 1.5 parts Butylthiourea 2.0 parts Blowing agent ( Azodicarbonamide) 20 parts Water absorption expansion polymer 30 parts (Sanyo Kasei Co., Ltd., trade name Sunfresh ST-500MPS) Foaming aid (Eiwa Kasei Co., Ltd., trade name Cellpaste K-5) 14 parts

Example 2 Example 1 is different from Example 1 except that the amount of foaming material is changed to 15 parts and the amount of foaming auxiliary agent is changed to 5 parts.
And the same. The number of bubbles per 1 cm in this Example 2 was 12 to 15.

Comparative Example 1 The same as Example 1 except that the bubbles were not broken by pressurization. [Comparative Example 2] The same as Example 2 except that the bubbles were not broken by pressurization. [Comparative Example 3] The same as Example 1 except that the amount of the foaming agent was 25 parts and the amount of the defoaming agent was 5 parts (comparative example 3). went). The number of bubbles per cm in Comparative Example 3 was 4 to 5.

Each of the products of Examples and Comparative Examples described above was processed into a string having a square cross section with a thickness of 10 mm and a width of 10 mm, and each of the samples A was processed as shown in FIGS. 1 (a) and 1 (b). As shown in [a cross-sectional view taken along the line (a) of FIG. 1], a U-shaped sample was sandwiched between glass plates 1 and 1, and a sample A thereof was prepared.
The glass plates 1 and 1 were fastened with bolts and nuts 3 ... While maintaining the space between the spacers 2 and 2 so that the compression ratio in the thickness direction of the glass plate was 30%. After this bolting, when water 4 was put into the U-shape of sample A at a water head h = 100 mm, no water leakage was observed in Examples 1 and 2, but any of Comparative Examples 1, 2, and 3. Water leakage was also observed in the sample. Further, when the same test was performed with the compression ratios of 50% and 70%, the results are as shown in Table 1.

[0018]

The example products 1 and 2 are different from the comparative example products 1 and 2.
The reason for exhibiting excellent water leakage resistance is that the capillaries are formed by the foam breakage in the Example product, and the sealing action due to the expansion of the water-swelling polymer due to the water permeating and diffusing due to the capillary phenomenon is well achieved. On the other hand, it is presumed that this is because it is difficult for the water absorbing and swelling polymer to expand due to the expansion of the water absorbing and swelling polymer due to the production of the comparative example which is not subjected to foam breaking. Further, in Comparative Example 3, even if the bubbles were broken, the diameter of the capillaries formed by the bubbles was large due to the relatively large bubble size, and the permeation and diffusion of water due to the capillary phenomenon was not sufficiently performed. It is presumed that this is because (the penetration depth of water due to the capillary phenomenon is inversely proportional to the diameter of the capillary).

[0020]

According to the standard seal material of the present invention,
Due to the capillarity, water can be sufficiently swirled into every corner, and the initial seal until the sealing effect due to water swelling is fully exhibited can be sufficiently guaranteed due to the closed cells. Since it can be easily mounted even in a complicated space having a corner portion due to the ruptured bubbles, it is extremely useful for stopping water in a complicated gap.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a test method for testing the water-stopping property of a regular seal material according to the present invention, and FIG.
The sample set state is shown, and (b) in FIG. 1 is (a) in FIG.
3 is a cross-sectional view taken along the line.

[Explanation of symbols]

 A sample 1 glass plate 2 spacer 3 bolts and nuts 4 water

Claims (2)

[Claims] 1. A foamed structure having a closed cell and an open cell, wherein the foam film has water-swelling property and has a length of 1 c.
A standard seal material having 8 or more bubbles per m. 2. A foamed molded article mainly composed of independent foaming of a composition containing a water-swelling polymer, which has a structure in which a part of the cells is broken by pressurization to have both closed and continuous cells. The standard sheet according to claim 1, which is formed by molding a foam structure.
A method for producing a standard seal material, which comprises obtaining a seal material.