JPH0315533Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a water-expandable water-stopping material that is useful in civil engineering work, construction work, water supply and sewerage work, etc.

(Prior art) In the past, in construction work such as civil engineering work, construction work, water supply and sewage work, etc., where there are many opportunities to come into contact with water, bolts, nuts, etc. Locking members, etc. are widely used, and various gaskets, gaskets, and many other sealing materials are used to prevent water leakage that occurs through the periphery of these locking members. For this reason, rubber sealants are often used. These rubber sealing materials utilize their elasticity to stop water, but if used for a long time or after construction, the sealing material may become loose due to loosening of bolts or vibration from the outside. Water often leaks due to gaps at the stop. For this reason, it has been proposed to use water-expandable rubber as the sealant rubber.

(Problems to be solved by the invention) The above-mentioned conventional water-expandable water-stopping materials solve various drawbacks of non-water-expandable waterstopping materials, but they still do not work well when in contact with water for a long period of time. If the outer edge expands too much and the strength decreases or is significant,
Since it dissolves in water, there is a problem that it gradually loses its water-stopping effect. In particular, when the shape of such water-expandable waterproof material is coin-shaped with a hole in the center that communicates with the left and right sides so that it can be used by passing it through a bolt, etc., in addition to the above problems, , when the whole expands with water, the diameter of its central pore also expands,
A problem has arisen in that the diameter of the bolt is larger than that of the bolt, making it impossible to prevent water leakage.

As a result of intensive research in order to solve the problems of the prior art as described above, the inventor of the present invention has developed a coin-shaped water-expandable water-stopping material that does not consist entirely of water-expandable rubber. The present invention was completed based on the finding that the above-mentioned problem can be satisfactorily solved by forming only the wall surface of the communicating hole and/or the outer edge of the water-stopping material from non-water-expandable rubber.

(Means for Solving the Problems) That is, the present invention provides a plate-shaped water-stopping material having a hole in the center that communicates with the left and right sides, in which the wall surface of the hole and/or the outer edge of the water-stopping material is non-waterproof. The water stop material described above is made of an expandable rubber material, and the other parts are made of a water-expandable rubber material.

(Example) Next, the present invention will be described in more detail with reference to the accompanying drawings illustrating an example of the present invention.
The figure shows a front view of the water-expandable waterproof material 10 according to a typical embodiment of the present invention, FIG. 2 shows a side view of one side thereof, and FIG. 3 shows a cross-sectional view along its center line. FIGS. 4 to 6 show cross-sectional views of other embodiments.

As illustrated in the accompanying drawings, the water-expandable water-stop material 10 of the present invention has an external feature of being a plate-shaped body having a hole 1 in its center that communicates with the left and right sides, and as shown in FIGS. 3 to 6. Communication hole 1 in the center
Either the wall surface 2 of the plate is made of a non-water-expandable elastic rubber material (Fig. 3), or the outer edge 3 of the plate-shaped waterproof material is made of a non-water-expandable elastic rubber material (Fig. 3). (Fig. 4), or the main feature is that both the wall surface 2 of the communicating hole 1 and the outer edge 3 of the plate-shaped water stop material are made of a non-water-expandable rubber-like material (Fig. 5). There is. In the above, the parts other than the non-water-expandable rubber materials 2 and 3 are made of the water-expandable rubber material 4.

Further, the thickness of the wall surface 2 or the outer edge 4 of the communicating hole made of a non-water-expandable rubber material in the water-stopping material of the present invention is generally about 0.1 to 10 mm, and most preferably, The thickness ratio of the non-water-swellable portion to the water-swellable portion is in the range of 1:1 to 1:10. By setting it as such a range, the object of this invention is preferably achieved.

The water-expandable water stop material 10 of the present invention as described above may have a disc shape as shown in FIGS. 1 to 3, or any other shape such as a polygonal shape or an elliptical shape. Naturally, the external shape may be any shape. However, generally, the outer diameter is about 0.5 to 20 cm, the thickness is about 1 to 50 mm, and the diameter of the communicating hole in the center is most commonly about 1 to 50 mm.

To explain the rubber material constituting the water-expandable water-stop material 10 of the present invention, the water-expandable rubber material 4 used in the present invention includes natural rubber, synthetic rubber, which has been widely used in water-stop materials in the past, A water-swellable polymer material is mixed into a thermoplastic elastomer or the like in an amount of about 1 to 100 parts by weight per 100 parts by weight of these rubber materials. These water-swellable polymeric materials themselves are already known and can be easily obtained from the market, and those particularly suitable for the purpose of the present invention include sodium polyacrylate, polyethylene glycol, polyacrylamide, and others. Examples include water-soluble polymer materials and crosslinked products thereof, soda salts of hydrolysates of starch acrylonitrile graft polymers, sulfonated products of crosslinked polystyrene, and hydrophilic modified products of block polymers consisting of polystyrene and diene polymers. These water-expandable polymeric materials are commercially available with expansion degrees ranging from several times to hundreds of times, and various expansions can be achieved by adjusting the expansion degree or the amount added to the rubber material. A degree of water-swellable rubber material is obtained. In the present invention, a water-swellable rubber material having a water-swelling degree particularly suitable is one having a water-swelling degree of about 1.5 to 30 times. This is the value obtained by dividing the weight of the expanded rubber when fully expanded by the weight before absorbing water.)

The non-water-swellable rubber materials 2 and 3 used in the present invention are the aforementioned general rubber materials to which no water-swellable polymeric material is added.

The method for forming the water-expandable water stop material 10 of the present invention from the rubber material described above can use conventional rubber molding techniques as is. For example, in order to mold a water-stopping material with the structure shown in Figure 6, a non-water-expandable rubber compound is charged over the entire inner surface of a mold provided with a cavity of a predetermined shape, and a water-expandable rubber compound is poured into the mold. It can be easily obtained by compression-molding and cross-linking the mixture in one piece. In this case, all surface portions 5 of the water-sealing material of the present invention are covered with a non-water-expandable rubber material, but such a water-swellable water-sealing material is naturally included within the scope of the present invention. It is something that will be done. Further, by forming a pipe-shaped molded product in a similar manner and cutting it to a predetermined thickness, the water-expandable water-stopping material of the present invention as illustrated in FIGS. 1 to 3 can be obtained. Furthermore, an annular body made of a non-water-expandable rubber material corresponding to the wall surface of the central communicating hole and/or an annular body made of a non-water-expandable rubber material corresponding to the outer edge of the water-stopping material are formed. The water-expandable water stop material of the present invention (FIGS. 4 and 5) can be easily obtained by setting the annular body in the entire mold, then charging the water-expandable rubber compound, and molding in the same manner.

(Function/Effect) The water-expandable water stop material of the present invention has the above-described structure, so that when it comes into contact with water, it expands as a whole, eliminating gaps where water may leak. In addition, even if it is in contact with water for a long time, its outer edge is surrounded by a highly elastic non-water-swellable rubber material, so the water-swellable rubber material expands excessively and loses its strength. never lose.
Another important feature is that when conventional water-expandable waterproof materials have a communicating hole in the center, the diameter of the communicating hole increases as the whole expands, causing water to leak from that area. On the other hand, in the water-expandable water stop material of the present invention, the wall surface of the communication hole is made of an elastic non-water-expandable rubber material, so its elasticity allows the inner diameter to expand before expansion. It is particularly effective in that it never becomes larger than the size of the rod and always comes into close contact with the rod-shaped body inserted through the communication hole, preventing water leakage.

[Brief explanation of the drawing]

FIG. 1 shows a front view of a water-expandable waterproof material according to a typical embodiment of the present invention, FIG. 2 shows a side view of one side thereof, and FIG. 3 shows a cross-section along its center line. 4 to 6 show cross-sectional views of other embodiments. 1...Communication hole, 2...Wall surface, 3...Outer edge, 4
...Water-expandable rubber, 5...Surface, 10...Water stop material.

Claims (1)

[Scope of utility model registration request] In a plate-shaped water-stop material having a hole in the center that communicates with the left and right sides, the wall surface of the hole and/or the outer edge of the water-stop material is made of a non-water-expandable rubber material, and the other parts are made of a water-expandable rubber material. The above-mentioned waterproof material is characterized by: