JPH0573880B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water stop construction method, particularly in the fields of civil engineering and construction, which has good workability and maintains a stable water stop effect for a long period of time.

Conventionally, rubber and thermoplastic resin products have been widely used as water-stopping materials for segment waterproofing work such as seal construction methods, hume pipe connections, and various water-stopping packing materials, but these products are not always sufficient in terms of water-stopping properties. In order to solve this problem, a method has been proposed in which a water-absorbing composition comprising a highly water-absorbing resin such as rubber is used as a base material.

In this method, when water enters the water stop material, the water stop material and the super absorbent resin absorb water and swell, and this swelling fills the voids and prevents further water from entering. This method is intended to achieve a water-stopping effect, and the method itself is very excellent.

However, in any case, when these methods are used for segment waterproofing work, for example,
For example, it is necessary to use an adhesive or the like to adhere a water-stop material (water-stop tape) formed into a tape shape to the segments in advance, which not only makes on-site construction very complicated, but also requires a lot of work. As the number of segments increases, the amount of work becomes extremely large, which poses a serious problem in terms of workability.

For this reason, the present inventors have studied and found a method for waterproofing construction that not only has excellent water-stopping properties but also has good workability without using adhesives or the like. successfully developed a completely new water-swellable composition containing a styrene elastomer, a superabsorbent resin, a tackifier, and an ethylene-vinyl acetate copolymer resin, and used the composition in a specific method. The present inventors have discovered that, by doing so, very excellent effects can be obtained to achieve the above object, leading to the present invention.

That is, in order to prevent water leakage between adjacent structures, the present invention provides a water-swellable material containing a styrene elastomer, a super absorbent resin, a tackifier, and an ethylene-vinyl acetate copolymer resin on the surfaces of opposing structures. The present invention provides a water-stop construction method characterized by forming a water-stop layer by heat-sealing a water-stopping composition into a band-like or planar shape.

Here, in the water-swellable composition used in the present invention, the styrenic etramer includes:
Block copolymers containing styrene as an essential component, such as styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and styrene-ethylene-butylene-styrene block copolymer (SEBS). Combination is exemplified, and SBS and SIS are particularly preferably used.

Such styrene-based elastomers easily exhibit fluidity when heated and turn into a rubbery state when cooled, which is a unique property of elastomers. It exhibits physical properties similar to those of vulcanized rubber, and has excellent mechanical strength and long-term stability.

In addition, the superabsorbent resin may be used without any particular restriction as long as it is insoluble in water and can absorb 10 to 1000 times its own weight of water, such as starch-sodium acrylate (or acrylamide). Examples include graft copolymers, three-dimensional crosslinked products of sodium polyacrylate, three-dimensional crosslinked products of polyvinyl alcohol, and saponified products of vinyl ester/ethylenically unsaturated carboxylic acid or derivative copolymers thereof. A saponified product of an ethylenically unsaturated carboxylic acid or its derivative copolymer is preferred, and in particular, a superabsorbent resin obtained by saponifying a copolymer of vinyl acetate and (meth)acrylic acid ester has excellent gel strength, perishability, and Preferable in terms of weather resistance.

The tackifier is selected from rosin, petroleum resin, polybutene, chlorinated paraffin, chlorinated polyethylene and wax, with rosin and petroleum resin being preferred. Further, the ethylene-vinyl acetate copolymer resin acts as a softener, but also has the effect of further increasing tackiness when coexisting with a tackifier.

In such a water-swellable composition, the content ratio of the above four components is not particularly limited, but from the viewpoint of swelling degree, water stopping property, price, etc., it is usually 5 to 100 parts by weight of super absorbent resin per 100 parts by weight of styrene elastomer. , 10 to 200 parts by weight of the tackifier, and 5 to 100 parts by weight of the ethylene-vinyl acetate copolymer resin as a softener.

The water-swellable composition used in the present invention is
It contains the following ingredients as essential ingredients, but if necessary, plasticizers, water-swellable urethane,
It may contain compounding agents such as carbon black, inorganic fillers, thickeners, anti-aging agents, vulcanizing agents, vulcanization accelerators, blowing agents, coloring agents, thermoplastic resins and the like.

The water-swellable composition specified by the present invention can be easily obtained by mixing the above-mentioned components in a conventional manner, for example, in a commonly used mixing device such as a Banbury mixer, mixing roll, or kneader. It is advantageous to increase the flow viscosity by preheating the styrenic elastomer or preheating the mixing device during mixing, since a more homogeneous composition can be obtained in a short time.

The water-swellable composition thus obtained has heat-sealing properties and also has properties that are not found in conventional water-stopping compositions, such as being able to swell significantly upon absorption of water.

The present invention is a water stop construction method that effectively takes advantage of the properties of such a water-swellable composition, and in order to prevent water leakage between adjacent structures, the composition is applied to the surfaces of opposing structures in a band-like or planar shape. In this method, a water stop layer is formed by heat-sealing the material to form a water stop layer.

In the present invention, it is necessary to heat-seal the composition to the adherend in the form of a band or a sheet in order to form a water-stopping layer at the location where water is to be stopped. are selected as appropriate depending on the conditions, but usually they are heat-sealed in a band shape within an effective range to prevent water from entering.

In the present invention, the method of heat-sealing the water-swellable composition is not particularly limited. For example, the composition may be formed into a string or tape shape in advance, and the surface of the formed object may be heated, or Any method may be employed, such as heating the body surface in advance and then compressing the molded product, applying the nearly completely melted composition in a strip using a flat tube, or using a hot melt gun. The heat fusion method using a hot melt gun is the most advantageous in terms of workability.

In particular, when using a hot melt gun, it is extremely advantageous in practice in large-scale water stop construction in the civil engineering and architectural fields, such as segment waterproofing work. A water-stopping layer can be formed arbitrarily and easily depending on the structure, and by filling the gap between existing structures with the water-swellable composition, a band-like or planar layer can be formed along both walls of the structure. Various uses are possible, such as being able to form a water-stopping layer.

In the case of using a hot melt gun, the composition is preformed into a string, tape, or pellet shape, depending on the type of hot melt gun used, so that it can be easily supplied to the hot melt gun.

Thus, according to the method of the present invention, a water-stopping layer can be easily provided without using adhesives, etc., and workability is significantly improved, which is a very important practical benefit. Therefore, it is extremely advantageous as a water stop construction method.

The present invention will be explained below with reference to Examples.

Example 1 100 parts by weight of Solprene T-414 (manufactured by Asahi Kasei Co., Ltd.), a styrene-butadiene-styrene block polymer, and 50 parts by weight of Evatate R5011 (manufactured by Sumitomo Chemical Co., Ltd.), an ethylene/vinyl acetate copolymer resin, were placed in a kneader. After heating to 150℃ and melting, 50 parts by weight of Sumikagel SP-520 (Sumitomo Chemical Co., Ltd.), a super absorbent resin based on vinyl ester/ethylenically unsaturated carboxylic acid ester copolymer, and petroleum resin adhesive. Picolite, an imparting agent
100 parts by weight of A115 (manufactured by Etsuo Chemical Co., Ltd.) and 5 parts by weight of Sumilizer TNP (manufactured by Sumitomo Chemical Co., Ltd.) as a stabilizer were added and mixed thoroughly to obtain a water-swellable composition with a water absorption rate of 7 g/g.

This water-swellable composition was extruded into a width of 30mmφ using an extruder.
A tape of 20 mm and 3 mm thickness was made.

While supplying the obtained tape to a hot melt gun, caulking was applied to the segment joints to a width of about 6 cm using a hot melt gun at a nozzle temperature of 200°C.

When a segment waterproofing test was conducted on this product, no water leakage was observed.

Example 2 100 parts by weight of Solprene T-414, Evatate
50 parts by weight of R5011, 70 parts by weight of Sumikagel SP-520
Water swelling with a water absorption rate of 9 g/g in the same manner as in Example 1 using 100 parts by weight of Ester Gum H (product of Arakawa Chemical Co., Ltd.), a rosin-based tackifier, and 5 parts by weight of Sumilizer TNP. A composition was obtained.

When a segment was caulked using this water-swellable composition in the same manner as in Example 1 and a segment waterproofing test was conducted in the same manner, water leakage was observed at the beginning, but the water stopped completely after 1 hour. .

Reference example 1 Evatate R5011 and Sumikagel SP-
An elastomer composition was obtained in exactly the same manner as in Example 1 except that 520 was not used, and after caulking the segments using this composition in the same manner as in Example 1, a segment waterproofing test was conducted.
Water leakage was observed, and the water did not stop even after a day had passed.

Claims (1)

[Claims] 1. In order to prevent water leakage between adjacent structures, the surfaces of the opposing structures are coated with (a) styrene elastomer, (b) super absorbent resin, (c) rosin, petroleum resin, polybutene, A water-swellable composition containing a tackifier selected from chlorinated paraffin, chlorinated polyethylene, and wax, and (d) an ethylene-vinyl acetate copolymer resin is heat-sealed in a band or planar shape to stop water. A water stop construction method characterized by forming a layer. 2. The water stop construction method according to claim 1, which is carried out using a hot melt gun.