JPH051274A - Water-swellable sealant - Google Patents

Abstract

PURPOSE:To provide a sealant which is excellent in water-swellability, mechanical strengths, and chemical stability and used for waterproofing, water-stopping, or effecting airtightness in the fields of civil engineering and construction. CONSTITUTION:The sealant is prepd. by compounding a blend of a natural rubber with a synthetic rubber, a urethane prepolymer prepd. by reacting a polyether polyol having hydrophilic groups with an isocyanate compd., and a curing agent consisting of water, an organometallic compd., and cellulose.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-swellable waterproof material used for waterproofing / waterproofing or airtightness in various civil engineering / construction fields.

[0002]

2. Description of the Related Art Conventionally, as a water blocking material used in a shield construction method or the like, there is a material obtained by adding a water absorbing material to natural rubber or butyl rubber as disclosed in JP-A-54-7463. This water-absorbing substance consists of water-absorbing resin such as polyvinyl alcohol (including partial hydrolysis product of polyvinyl acetate), polyacrylic acid ester, polyacrylic acid salt, etc., and water-swelling urethane resin. Additives such as tar, asphalt, animal and vegetable oils and fats,
Plasticizer such as DOP, DBP, calcium carbonate, clay,
It contains a filler such as talc and titanium dioxide, a coloring agent, and an antioxidant.

The water-blocking material disclosed in JP-A-54-7463 and the like has better moldability than that made of only a water-absorbing substance, and since it has high strength, it has a tape-like or linear shape. It is preferable to be used after molding and has better water-stopping property than that made of only rubber, and can compensate for some errors during construction.

[0004]

However, those using the above water-absorbent resin have a low swelling degree of the water blocking material itself, or have an extremely high swelling degree with respect to a solution containing an electrolyte component such as seawater. However, there was a drawback that water was easily leaked. Further, although the water swelling urethane resin is used, the deterioration of the swelling resistance in seawater is improved, but the one having satisfactory swelling property, heat resistance and chemical stability has not been developed yet.

It is an object of the present invention to provide a water-swellable water-stopping material which eliminates the above-mentioned disadvantages of the prior art and is excellent in swelling property, mechanical strength and chemical stability.

[0006]

The present inventor has conducted extensive studies in order to improve the above-mentioned drawbacks, and as a result, a composite rubber having an appropriate ratio of natural rubber and synthetic rubber, and a poly-rubber having a hydrophilic group have been obtained. A composition characterized by reacting and curing, as a curing agent, water and a metal organic compound and cellulose that also functions as a water-absorbent filler, to a urethane prepolymer consisting of an ether polyol and an isocyanate, is swelling, mechanical It has been found that it is useful as a water-swelling waterproofing material having excellent strength and chemical stability.

That is, the component of the composite rubber in the swelling waterproofing material composition of the present invention is composed of natural rubber and one or more synthetic rubbers, and their ratio is the weight ratio of the natural rubber and the synthetic rubber. In the range of 15:85 to 98: 2, preferably 18:82 to
It is in the range of 95: 5, and if it exceeds the above range or if it is used as a rubber alone, good mechanical strength in terms of heat resistance cannot be obtained. Natural rubber used in the present invention refers to those taken from the sap of a rubber plant, synthetic rubber is neoprene rubber, isoprene rubber, styrene butadiene rubber, butyl rubber, chloroprene rubber, butadiene rubber, acrylic nitrylyl butanediene rubber, It is composed of one or more of ethylene / propylene rubber and the like.

The urethane prepolymer in the swellable waterproof composition of the present invention comprises a polyether polyol having a hydrophilic group and an isocyanate, more specifically, a polyether polyol comprising an ethylene / propylene copolymer polyol and T.I. D. I (2.4-toluene diisocyanate and
2.6-toluene diisocyanate).

Examples of the metal organic compound which is one of the curing agents in the present invention include silicon organic compounds, titanium organic compounds, aluminum organic compounds and zirconium organic compounds. Specific silicon organic compounds include alkoxysilanes (methyltriethoxysilane,
In addition to methyltriisopropoxysilane, methyltributoxysilane, methyltriphenoxysilane, phenyltriethoxysilane, tetra (2-ethylhexyl) silicate, tetratridecylsilicate, etc., silane having an unsaturated group or epoxy group in the alkoxy group. Class (γ-
Methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, long-chain alkyltrialkoxysilane, etc.) and alkoxysilane isocyanates, and the like, or one or more of them.

As the titanium organic compound, alkoxy titaniums (tetra-i-propoxy titanium, tetra-n-
Butoxytitanium, etc., titanium acylates (Tri-n)
-Butoxytitanium monostearate, i-propoxytitanium dimethacrylate-i-stearate, etc.), titanium chelates (dihydroxybis (lactone) titanium,
Ethylene glycolato titanium bis dioctyl phosphate, etc.) or one or more kinds thereof.

Aluminum organic compounds include aluminum alcoholates (aluminum isopropylate, mono-sec-butoxyaluminum diisopropylate, etc.), aluminum chelates (ethyl acetate aluminum diisopropylate, aluminum tris (
(Ethyl acetoacetate, etc.) and the like.

Examples of the zirconium organic compound include one or more of alkoxyzirconiums such as zirconium-n-butoxide and alkoxychelates such as acetylacetone zirconium butoxide, and a plurality of different metal organic compounds. It does not prevent the combination. Further, the compounding amount of various organic metal compounds of silicon, titanium, aluminum and zirconium listed above is preferably 10% or less with respect to the total amount of urethane prepolymer and cellulose, and when 20% is exceeded, the elasticity of urethane itself is increased. And the water leaks.

Regarding cellulose, natural pulp, natural crystalline cellulose, methyl cellulose, hydroxypropylmethyl cellulose, ethyl cellulose, carboxymethyl cellulose, ethyl hydroxyethyl cellulose,
One or more of nitrocellulose and cellulose acetate may be mentioned.

In addition, various fillers (eg, carbon black, calcium carbonate, etc.) used as additives to the rubber compound, vulcanizing agents (eg, sulfur, lead oxide, etc.), modifiers (thermoplastic resins), It goes without saying that generally known substances such as colorants, stabilizers and antiaging agents can be added.

[0015]

The composition of the present invention is one in which a rubber substance, a water-swelling urethane resin and water, a metal organic compound, cellulose, and an additive are added, and the mixture is kneaded and molded by a kneader, and then vulcanized and cured. In the conventional waterproof material, the rubber component and the water-absorbent resin or swelling urethane resin do not have a cross-linking structure, and mechanical strength (tensileness, elongation) and swelling performance may decrease in a long-term heat resistance environment test. Easy,
The structure of the composition of the present invention is considered to have a three-dimensional structure in which the swelling urethane resin undergoes a crosslinking reaction with cellulose and a metal organic compound at the same time as it is cured by water as a curing agent, and the metal organic compound is a rubber substance. Since they are crosslinked, not only mechanical and thermal stability can be obtained, but also elution resistance can be stabilized.

[0016]

EXAMPLE A method for preparing a sample will be described with reference to Example 1.
Natural rubber 95 parts, neoprene rubber 5 parts, urethane prepolymer (trade name TP-645P) consisting of ethylene propylene copolymer polyol and toluene diisocyanate 120 parts, sulfur 0.5 parts, calcium carbonate 10 parts, carbon black 10 parts and water 2 Parts, 1 part of methyltributoxysilane, 30 parts of crystalline cellulose (trade name Avicel), and 0.1 part of an antioxidant as an additive.

This is kneaded with a kneader at 100 ° C to form a desired shape, and then 140 ° C-6 in an oven.
The 0 minute vulcanized and cured product was evaluated by performing the swelling degree, the tensile strength, the elongation, and the water stopping performance test in the mounted state by the following test methods.

Hereinafter, Examples 2 to 10 and Conventional Examples 1 and 2,
In Comparative Example, a sample was prepared in the same manner as in Example 1 except that the type and amount of rubber component, metal organic compound, cellulose, and other additives were changed, and their composition and test results. Is shown in Table 1 below.

Test method 1) The tensile strength and tensile elongation, which are general physical properties, are measured according to JIS6301. 2) Regarding heat resistance, after heating the sample at an ambient temperature of 70 ° C. for 50 days, the measurement of the method 1) was performed to calculate the tensile strength and the residual tensile elongation ratio with respect to the initial values. 3) The water swelling performance was calculated by the volume change rate before and after the test in which a sample having a length of 50 mm, a width of 20 mm, and a thickness of 5 mm was immersed in pure water and 3% concentration saline for 7 days. 4) The change in mass was calculated from the weight difference before and after the test after immersing the dimension sample of 3) in hot water of 70 ° C for 3 days, taking it out and drying it at 50 ° C for 10 days.

[0020]

[Table 1]

[0021]

As described above, in the water-swellable water-stopping material of the present invention, the composition of the rubber substance, the swelling urethane resin, and the filler reacts with each other through the curing agent and crosslinks.
It has a dimensional matrix structure, which provides mechanical stability as a waterproofing material and thermal stability in terms of swelling performance, and also becomes chemically stable because the functional groups in each molecule are bonded to each other. The elution is suppressed.

By using such a composition as a water blocking material, the water blocking performance is excellent, water leakage does not occur, and the mechanical strength of the water blocking material does not deteriorate even in a long-term environment, and it is highly reliable and airtight. That is what gives retention.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area E04B 1/684

Claims (6)

[Claims] 1. A composite rubber of natural rubber and synthetic rubber, a urethane polyol having a hydrophilic group and an urethane prepolymer made of isocyanate, and a curing agent made of water and a metal organic compound and cellulose contained therein. A water-swellable water blocking material composition characterized by the above. 2. The synthetic rubber is one or more of neoprene rubber, isoprene rubber, butyl rubber, chloroprene rubber, acrylic-nitrile butadiene rubber, ethylene / propylene rubber, butadiene rubber, styrene / butadiene rubber, and acrylic rubber. The water-swellable water blocking material according to claim 1. 3. The ratio of natural rubber to synthetic rubber constituting the composite rubber is in the range of 15:85 to 98: 2 (parts by weight).
The water-swellable waterproof material described. 4. The water-swellable waterproof material according to claim 1, wherein the urethane prepolymer comprises an alkylene oxide copolymerized polyether polyol and an isocyanate. 5. The metal organic compound is a silicon organic compound,
The water-swellable water-stop material according to claim 1, comprising one or more of a titanium organic compound, an aluminum organic compound, and a zirconium organic compound. 6. The water-swellable waterproof material according to claim 1, wherein the cellulose comprises one or more of natural pulp, natural crystalline cellulose and cellulose ether, cellulose ester, and nitrocellulose.