JP2001108110A - Water-swelling seal material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-swelling seal material easy to handle when working, allowing little elution of a water-swelling component from the seal material, and rapidly swelling overall by contact with water. SOLUTION: In this water-swelling seal material, a water-swelling material is filled in a hollow elongate base substance having rubber elasticity, while one or more communication holes or cutout parts penetrating from the outer surface to the inside of the elongate base substance are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-swellable sealing material which is mounted on a joint of a concrete or steel product in civil engineering, a construction, a joint of a concrete casting, or a joint of a civil engineering segment. Things.

[0002]

2. Description of the Related Art Conventional water-swellable sealing materials include natural rubber, chloroprene rubber or butyl rubber and a water-absorbing resin (polyvinyl alcohol, polyacrylate, etc.) or a water-swellable urethane resin. It has been known. These materials are molded and used in accordance with the shape of the place to be used (Japanese Patent Laid-Open No. 3-134390).
No.). In addition, for example, Japanese Unexamined Patent Application Publication No. 4-243
No. 97 and Japanese Patent Application Laid-Open No. 9-195692 disclose a water-swellable sealing material in which a water-swellable rubber layer and a non-swellable rubber layer are laminated. Further, Japanese Utility Model Publication No. 5-34379 discloses a water-swellable sealing material in which a water-soluble film is laminated on a water-swellable rubber layer.

[0003]

In the above-mentioned water-swellable sealing materials, natural rubber, chloroprene rubber or butyl rubber mixed with a water-absorbing resin has an expansive substance dispersed in a rubber component. Even when it comes into contact with water, expansion occurs only gradually from the rubber surface, and a sufficient water stopping effect cannot be obtained until the rubber completely expands. Further, when immersed in water for a long period of time, there is a problem that the swelling substance such as a water-absorbing resin is eluted with the swelling, and the swelling rate is reduced. Further, when the amount of the swelling substance added is increased, the swelling rate is increased, but the amount of the swelling substance eluted with the swelling is also increased. Therefore, there is a problem that the rate of swelling rapidly decreases when drying and water absorption are repeated. The sealing material using a water-swellable urethane resin can be a sealing material that has rubber elasticity itself, but even when kneaded with the urethane resin itself or rubber, it starts expanding from the surface that comes in contact with water first because it expands to the inside. It takes time to inflate, and it is difficult to realize the water stopping effect early.

Further, since at least a part of these water-swellable sealing materials is formed of a water-swellable layer, the surface of the water-swellable resin adheres depending on the kind of the water-swellable resin. Therefore, there is a problem that it is difficult to attach the seal materials when these seal materials are incorporated into the concave portion of the adherend, and that the seal materials are adhered to each other, which is troublesome. Therefore, the object of the present invention is to solve the above-mentioned problems, that is, less elution of the inflatable substance from the water-swellable sealing material, expand quickly and entirely by contact with water,
Another object of the present invention is to provide a water-swellable sealing material that is easy to handle during operation.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided an elongated substrate having rubber elasticity, the interior of the elongated substrate is filled with a water-swellable substance, and the interior of the elongated substrate is removed from the outer surface. The above-mentioned problem has been solved by a water-swellable sealing material provided with one or more communication holes or notches.

The elongated substrate having a hollow inside and rubber elasticity according to the present invention may have any shape such as a circle, a trapezoid or a square as long as the cross section is hollow. It is arbitrarily formed according to the shape of the sealed portion of the structure into which the material is to be incorporated. In addition, as a material for forming the elongated substrate, natural rubber, synthetic rubber, synthetic resin, and the like can be used. However, the material is suitable for following the expansion of the water-swellable substance filled in the elongated substrate. It is necessary to have high elasticity. Specific examples include isoprene rubber, styrene butadiene rubber, chloroprene rubber, butadiene rubber, nitrile butadiene rubber, ethylene propylene rubber, butyl rubber, acrylic rubber, and urethane rubber.

The shape of the elongated substrate may be any shape such as a circle, a triangle or a square as long as it is hollow, and is formed in accordance with the shape of the sealed portion of the structure into which the water-expandable sealing material is fitted. Is done. The thickness of the elongate base varies depending not only on the material and cross-sectional shape but also on the material and amount of the water-swellable substance filled therein. However, when the cross-sectional area is 10 cm ² or less, the cross-sectional area increase magnification is 9%. If it is twice or less, it is preferably about 1 to 10 mm. In this case, if it is thinner than 1 mm, a crack may occur at the time of expansion, and if it is thicker than 10 mm, it is difficult to expand. In addition, even if the cross-sectional area is larger than 10 cm ² or the cross-sectional area is 10 cm ² or less, if the cross-sectional area increase magnification exceeds 9 times, it is necessary to increase the thickness.

Next, a description will be given of a communication hole or a cutout provided for allowing water to permeate from the outside. The shape, size, position and number can be set arbitrarily,
It is necessary to take care so that the water-swellable substance filled in the elongated substrate does not flow out. For example, when a string-shaped water-absorbing body is inserted into the communication hole, it is possible to prevent the water-swellable substance from flowing out from the inside and to easily guide water from the outside. Further, the surface of the communication hole may be covered with a water-permeable membrane or fiber to prevent the water-swellable substance from flowing out. The size of this communication hole depends on the size, thickness,
Depends on the material, etc.
In this case, 0.1 mm to 5 mm is appropriate. As for the relationship between the size and the number of the communication holes, it is needless to say that the smaller the size of the holes, the larger the number of the communication holes.

Further, in the case of the notch, the notch extends along the longitudinal direction of the elongated base or spirally from end to end.
It is conceivable to provide two notches or provide a number of short notches at regular intervals, but in consideration of the outflow of the water-swellable substance from the inside as described above, the A film or a layer may be attached to the outer surface or the inner surface of the elongated substrate, or a groove may be provided on each end surface of the cutout portion as shown in FIG. 4 and a water-permeable film may be fitted. . A sheet made of fibers such as polypropylene, polyethylene, polyester, nylon, vinylon, acrylic, rayon, cupra, cotton, wool, pulp, hemp, glass, etc., as a water-permeable membrane or layer used to prevent elution of the water-swellable resin Fiber is good. When a communication hole or a notch is provided in the water-swellable seal material, it is important to consider the shape of the adherend and the water entry path in the structure where the water-swellable seal material is installed. .

The water-swellable substance used in the present invention includes:
Various water-swellable resins such as acrylic acid type, polyvinyl alcohol type, maleic anhydride type and urethane type as described in JP-A-62-277457 are exemplified.
Even among these water-swellable resins, acrylic acid-based and polyvinyl alcohol-based resins are preferred from the viewpoint of easy control of the expansion coefficient and easy handling. In addition, the water-swellable resin is usually a powdery or granular solid in many cases. However, in order to fill and use the hollow portion of the long substrate, the water-swellable resin has a particle size or The choice must be made in consideration of the shape. The particle size must be increased to some extent in consideration of the contact with water in the state of being filled in the elongated substrate, but the particle size is preferably smaller in consideration of the swelling property in order to increase the filling rate.
Therefore, it is also preferable to use a combination of water-swellable resins having different particle diameters in order to balance the two.

The particle size of the water-swellable resin is preferably about 10 to 500 μm for the reasons described above. The water-swellable resin used in the present invention may be used singly, or may be used by mixing several kinds of water-swellable resins having different expansion ratios and expansion speeds in consideration of the expansion tendency.
Further, a filler such as calcium carbonate, talc, clay, silica sand and the like, and a non-expandable substance such as cellulose fiber and floc pulp can be mixed and used for controlling the expansion rate. In some cases, the water-swellable resin may be dispersed or dissolved in an organic solvent or a liquid plasticizer to form a liquid, and then filled into the long substrate. In order to rapidly expand the filled water-swellable resin, the water-absorbing body inserted into the communication hole or the notch may be a water-absorbing fiber such as cotton or a thread.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. FIG. 1 is a perspective view showing a water-swellable sealing material according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a hollow elongate base, 2 denotes a hollow portion filled with a water-expandable resin, and 3 denotes an outer surface. It is a communication hole for allowing water to permeate from the part to the hollow part, and 4 is a water absorbing body. FIG. 2 is a perspective view showing another embodiment of the water-swellable sealing material according to the present invention, and 5 is a water-permeable membrane (nonwoven fabric) covering the surface of the water-swellable resin so that the water-swellable resin does not flow out. ). FIG. 3 is a perspective view showing another embodiment of the water-swellable sealing material according to the present invention, and 6 is a sheet-like water-swellable substance.

[0013]

Embodiment 1 Next, a method for producing a water-swellable sealing material of the present invention will be described. First, the hollow elongated substrate was subjected to a tensile strength of 1
It was manufactured by usual extrusion molding using chloroprene rubber having an elongation of 0 to 15 MPa and an elongation of 500 to 700%. At this time, the dimensions of the elongated substrate were a circle having a diameter of 30 mm, a thickness of about 2.5 mm, and a length of about 5 m. Then, communication holes having a diameter of about 0.5 mm were opened in the hollow elongated substrate at intervals of 30 mm, and a cotton thread was inserted therein so as to protrude about 20 mm outside and about 30 mm outside. After the elongate substrate is suspended and one end is closed, a mixed powder (by weight) of an acrylic acid-based water-absorbing resin and a heavy calcium carbonate having a particle diameter of about 100 to 150 μm and a water absorption ratio of 100 times from the upper end. The former: the latter = 1: 1) was poured into the hollow base of the elongated substrate, and then the other end was closed to produce a water-swellable sealing material having the shape shown in FIG.

[0014]

Example 2 The mixed powder to be filled in the hollow part was about 10 in particle size.
A water-swelling resin having a shape as shown in FIG. 1 in the same manner as in Example 1 except that a water-swellable acrylic acid resin of 0 to 150 μm and heavy calcium carbonate (the former: the latter = 1: 2 by weight) were used. A sealing material was manufactured.

[0015]

Example 3 Tensile strength 10-15 MPa, elongation 500
% To 700% chloroprene rubber was used to produce a long substrate by ordinary extrusion molding. At this time, the dimensions of the elongated base were 100 mm in width, 2.5 mm in thickness, and 5 m in length. Then, holes having a diameter of about 5 mm are formed in the long base at intervals of 30 mm, and a non-woven fabric of 30 mm width and 0.2 μm thick polyolefin non-woven fabric is applied to the communicating holes so as to cover the holes. Adhered with care. Next, the long substrate is vulcanized and bonded at both ends in the longitudinal direction with the nonwoven fabric on the inner surface, and the diameter is 30 m.
m, a hollow elongated substrate having a length of about 5 m was formed. Then, after suspending the elongated substrate and closing one end, the particle size is approximately 100 to 150 μm from the upper end, and the water absorption ratio is 100.
The mixed powder of acrylic acid-based water-swellable resin and No. 7 silica sand (the former: the latter = 1: 1 by weight) is poured into the hollow portion of the elongated base, and then the other end is closed. Then, a water-swellable sealing material having a shape as shown in FIG. 2 was manufactured.

[0016]

Example 4 Tensile strength 10-15 MPa, elongation 500
% To 700% of a chloroprene rubber to produce a long-sized substrate by ordinary extrusion molding. At this time, the dimensions of the elongated base were 100 mm in width, 2.5 mm in thickness, and 5 m in length. Next, holes having a diameter of about 5 mm are formed in the long base at intervals of 30 mm, and a non-woven fabric of a polyolefin-based material having a width of 30 mm and a thickness of 0.2 μm is covered with an adhesive so as to cover the holes. Adhered with care. Next, a particle size of about 100 to 150 μm, a water absorption ratio of 1
A mixture of a water-expandable acrylic acid-based resin and cotton-like pulp having a ratio of 00 times (the former: the latter = 1: 2 by weight) is sandwiched between non-woven fabrics and molded into a sheet shape. A roll having a roll diameter of about 25 mm was formed. Next, the roll is placed on the elongated substrate, and formed into a cylindrical shape by abutting both ends in the longitudinal direction, and both ends are vulcanized and adhered, and both ends of the cylindrical shape are closed. A water-swellable sealing material having the following shape was produced.

The shape of the water-swellable sealing material according to the present invention is as follows:
In FIGS. 1 to 3 and the like, the communication holes are provided linearly along the longitudinal direction, but there is no problem if they are provided at various positions. Also,
A communication hole may be provided so as to face the long base at an equal interval, and the water absorbing body may penetrate the long base and the water-swellable resin. Further, the rubber of the portion to be the communication hole and the cutout portion may be thickened in advance, or if necessary, reinforcement such as attaching rubber around the communication hole and the cutout portion may be added.

The water-swellable sealing materials produced in Examples 1 to 4 were immersed in purified water, and the results of measurement of the swelling of the diameter were shown in Table 1. In addition, in the comparative example, since the expansion coefficients of the entire inflatable sealing material are almost the same and compared, as a comparative example 1, a vulcanized rubber-based water-expandable sealing material having a diameter of 30 mm and an expansion ratio of 3 times (corresponding to Examples 2 and 4). ), Comparative Example 2 having a diameter of 30
Tables 1 and 2 show the results obtained by immersing a vulcanized rubber-based water-swelling sealing material (corresponding to Examples 1 and 3) having a swelling ratio of 8 mm (equivalent to Examples 1 and 3) in purified water and measuring the rate of increase in the diameter dimension. Table 2 is a graph of the values in Table 1 for easy understanding.

[0019]

[Table 1]

[0020]

[Table 2]

In this test, Example 1, Example 3,
When the results of Comparative Example 2 were compared with the results of Example 2, Example 4, and Comparative Example 1, it was confirmed that the expansion started faster than the Comparative Example. In addition, it was confirmed that, in the comparative example, when the immersion was performed for a long period of time, the expansion was significantly reduced. Further, in Comparative Examples 1 and 2, it was confirmed that the water-swellable sealing material having a large expansion ratio had a remarkable decrease in the expansion coefficient.

[0022]

As described above, the water-swellable sealing material according to the present invention has one or more communication holes or cutouts extending from the outer surface to the inside of the long base. Water immediately penetrates and expands into the filled water-swellable substance. In addition, since a water-permeable membrane or layer is provided around the communication hole or the notch, there is almost no elution of the water-swellable substance, and it has a stable swelling property over a long period of time. Can be held. Furthermore, since there is no surface tackiness unlike a water-swellable sealing material in which a water-swellable substance is kneaded, attachment to a structure becomes easy and workability is remarkably improved.

[Brief description of the drawings]

FIG. 1 is a perspective view and a sectional view showing a water-swellable sealing material of the present invention.

FIG. 2 is a perspective view and a sectional view showing a water-swellable sealing material of the present invention.

FIG. 3 is a perspective view and a sectional view showing a water-swellable sealing material of the present invention.

FIG. 4 is a perspective view and a sectional view showing a water-swellable sealing material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Long base 2 Water-swellable resin layer 3 Communication hole 4 Fiber 5 Non-woven fabric 6 Sheet-like water-swellable substance 7 Water-permeable fiber layer 8 Notch

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Satoshi Yasushige 1456, Hazama-cho, Hachioji-shi, Tokyo Three Bond Co., Ltd. (72) Inventor Naoki Maeda 6-7 Uehonmachi, Sakata-shi, Yamagata F term (reference) 3J040 EA16 FA06 FA20 HA03 HA15 4H017 AA03 AA04 AA14 AA25 AA39 AB01 AB07 AC06 AD05 AE03

Claims (4)

[Claims] Claims: 1. An interior of a long substrate having rubber elasticity is made hollow, and the interior is filled with a water-swellable substance.
A water-swellable sealing material provided with one or more communication holes or notches from the outer surface to the inside of the elongated base. 2. The water-swellable sealing material according to claim 1, wherein a string-shaped or sheet-shaped water-absorbing body made of a water-absorbing fiber is inserted into said communication hole or notch. 3. The water-swellable sealing material according to claim 1, wherein the communication hole or the notch is closed with a water-permeable membrane or layer. 4. The water-swellable sealing material according to claim 3, wherein the water-permeable membrane or layer is formed from a nonwoven fabric.