JPS6234977A - Water stopping agent - Google Patents

Abstract

PURPOSE:A water stopping agent, containing a hydraulic cement, specific two kinds of (meth)acrylates and polymerization catalyst, having a high strength and improved elastic force and capable of stabilizing the ground and preventing the spring water and leakage of water in tunnels, leakage of water from under ground pipes, etc. CONSTITUTION:A water stopping agent containing (A) a hydraulic cement, (B) a compound expressed by formula I (R1 is H or methyl; m is an integer >=2), e.g. ethylene glycol monoacrylate, alone or a mixture thereof, (C) polyethylene glycol di(meth)acrylate expressed by formula II (R2 and R3 are H or methyl; n is an integer 2-50), e.g. ethylene glycol diacrylate, alone or a mixture thereof and (D) a polymerization catalyst, e.g. sodium persulfate.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is useful for stabilizing the ground, preventing spring water and leakage in tunnels, underground construction, etc., and preventing water leakage from joints of underground pipes, cracks, etc. Regarding water stop agents for the purpose of prevention.

[Conventional technology]

Conventionally, cement-based and water glass-based water-stopping agents have been used as inorganic water-stopping agents for the purpose of stabilizing the ground and preventing water springs and leaks, while urea-based and urethane-based waterstopping agents have been used as polymer-based waterstopping agents. Acrylamide, which is a water-soluble vinyl compound,
Water-stopping agents such as acrylates have been used.

However, each of these waterproofing agents has the following problems.

It is difficult to use urea-based, urethane-based, and acrylamide-based water-stopping agents, which are polymeric water-stopping agents, due to their safety. In addition, acrylate-based water sealants take a short time to start gelling (hereinafter referred to as gelling time), making it difficult to control the gelling time and making it difficult to form a uniform gel during curing. In addition to its tendency to partially gel, the hardened gel is highly elastic and sticky, making it difficult to use conventional tools when excavating hardened soil or cutting or smoothing hardened gel. The work is extremely difficult, and in some cases, parts other than those intended for excavation or cutting may be removed, causing problems such as water leakage.

Water glass-based inorganic water sealing agents have durability problems,
It is generally used only for the purpose of temporary water stoppage.

On the other hand, as cement-based water sealants, there are the LW method, in which water glass solution is solidified with cement suspension, and the method in which cement-based quick hardening agents are added to shorten the gelation time. .

In the case of the cement/water glass LW construction method, the strength and gelation time are determined by the amount of cement, and both cannot be determined arbitrarily. Therefore, as an improvement on this, a high-strength solidified product can be obtained without increasing the amount of cement and while maintaining an appropriate gelation time.Blast furnace slag cement/water glass type, micronized slag A water stop agent consisting of a colloidal cement/water glass system is used.

Further, as a cement/accelerate hardener-based water stop agent, a mixture of calcium aluminate, calcium sulfate, etc. (a molten mixture of limestone, bokekite, and gypsum) is used as an instant hardener. The above-mentioned blast furnace slag cement/water glass-based, fine particle slag-based colloidal cement/water glass-based, and cement/accelerant-based water stop agents all have too short a gelation time, so the amount of retarder can be adjusted to increase the gelation time. Adjust.

[Problem that the invention seeks to solve]

However, cement-based water stop agents have the following problems as water stop agents.

1) It is difficult to control the gelation time. That is, the gelation time is adjusted by adding a retarder such as an inorganic salt or an organic acid salt, but it is difficult to set an appropriate gelation time.

2) Since the gelation rate is slow, if the spring water is strong,
It may flow out without gelling.

3) Cutting hardened gel requires special tools. For example, when preventing water leakage from joints or cracks in underground pipes, it is necessary to remove unnecessary hardened material, but since hardened material is hard and brittle, it is difficult to cut it without using special tools. Removing parts other than the intended purpose may cause water to leak again.

4) In severe cases of dilution with groundwater, solidification may not occur. If the spring water is strong, the gelation rate is slow and at the same time it is diluted and the gelation time is delayed, so in some cases it may not gel at all.

5) Conventionally, water stopping methods have been carried out using cement milk in combination with acrylamide and acrylates. However, in the case of acrylamide, its use is restricted due to safety concerns, and in the case of acrylates, Similar to the problems when used alone, there are workability problems in that it is difficult to adjust the gelation time and it is difficult to cut the gelled material.

The object of the present invention is to provide a water sealing agent that solves all of the problems of the conventional cement-based water sealants mentioned above, eliminates the problems associated with the combined use of acrylamide and acrylates, and has the following features.

1) The cured product has high strength and elasticity. In particular, in the case of water sealing agents intended to prevent water leakage from joints and cracks in underground pipes, it is necessary to have sufficient strength and elasticity, but conventional cement-based water sealants In the case of adhesives, they have the same strength, but they lack elasticity, and the cured product at the repaired area may crack, causing water to leak again.

2) It is preferable that the cured product does not shrink, but rather expands slightly, but in the case of conventional cement-based water sealants, it usually shrinks, or even if it expands, the expansion rate is very small at 0.1 inch. .

Particularly when the purpose is to prevent water leakage from joints, cracks, etc. of underground pipes, a small shrinkage or expansion rate after curing may cause water to leak again.

[Means for solving problems]

The present invention provides a, a hydraulic cement, b, a compound represented by the general formula (in the formula, R1 is a hydrogen atom or a methyl group, and m is an integer of 2 or more) singly or in a mixture C0 a compound represented by the general formula or in a mixture This is a water stop agent containing a d0 polymerization catalyst.

Polyethylene glycol monoacrylate or polyethylene glycol monomethacrylate is used as the PEG (meth)acrylic ester used in the present invention.

Examples of polyethylene glycol monoacrylate include diethylene glycol monoacrylate, triethylene glycol monoacrylate, tetraethylene glycol monoacrylate, and PEG+650 monoacrylate (an abbreviation for the average molecular weight of (CH2-CH2-0+m in general formula (a) of 350. ), PEG≠600 monoacrylate, PEG≠1000 monoacrylate,
PEG≠2000 monoacrylate, PK046000
Examples of polyethylene glycol monomethacrylate include diethylene glycol monomethacrylate, triethylene glycol monomethacrylate, tetraethylene glycol monomethacrylate, PEG4350 monomethacrylate, and PEG1 monomethacrylate.
Examples include #+600 monomethacrylate, pEa41ooO monomethacrylate, PFiG 2000 monomethacrylate, and PEG+6000 monomethacrylate.

The PEG (meth)acrylic acid esters used in the present invention are those in which the number of moles of ethylene oxide added is 2 or more, but ethylene oxide is added within a range that does not reduce water solubility and that odor does not adversely affect workability. There is no problem even if it is contaminated with one mole. At the same time, polypropylene glycol monoacrylate, methoxypolyethylene glycol monomethacrylate, ethyl diethylene glycol acrylate, methyl triethylene glycol acrylate, etc. may be added as long as they do not reduce water solubility.

In addition, as a crosslinking component, methylenebisacrylamide, 1,3-di(acrylamidomethyl)-2-imidazolitone, hexahydro-
It is also possible to use one or more of 1,3,5-triacryloyl-s-triazine, ethylene urea bisacrylamide, or glycerol diacrylate in combination.

Polyethylene glycol diacrylate or polyethylene glycol dimethacrylate is used as the PEG di(meth)acrylic ester used in the present invention.

Examples of polyethylene glycol diacrylate include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and PEG+350 diacrylate [general formula (
The average molecular weight of +CH2-CH2-0sn in b) is 35
Abbreviation of 0, same below. ], PEG+600 diacrylate, PEG+1000 diacrylate, PFiG≠20
00 diacrylate, etc., and polyethylene glycol dimethacrylate includes, for example, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, PEG≠350 dimethacrylate, PEG+600 dimethacrylate, PEG≠1000 dimethacrylate,
Examples include PEG+2000 dimethacrylate.

The PEG di(meth)acrylic acid ester of the present invention used has an average number of added moles of ethylene oxide in the range of 2 to 50. When this value is less than 2, the strength of the gel decreases and it becomes unfavorable from the standpoint of safety as a water sealing agent.On the other hand, when this value exceeds 50, the viscosity of the mixture decreases and the polymer is crosslinked. It becomes difficult to obtain a good elastic gel due to the decrease in density.

The PEG di(meth)acrylic ester used in the present invention is 0.1 to 500 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the PEG (meth)acrylic ester.
It is preferable to use 00 parts by weight as a water stop agent.

In addition, the mixture of P'EG (meth)acrylic esters and PEG di(meth)acrylic esters usually has a concentration of 3 to 90% of the aqueous solution of the present invention excluding the hydraulic cement. Used in concentration.

On the other hand, in cases where the cured product of the water stopper of the present invention is required to adhere to concrete IJ, steel sheet piles, etc., the characteristics of the present invention may not be lost, that is, excavability and cutting properties may be deteriorated. It is also possible to add acrylates to the extent that they do not cause any damage. For example, PEG (meth)acrylic acid esters and P
Magnesium acrylate, sodium acrylate, potassium acrylate, ammonium acrylate, calcium acrylate, zinc acrylate, barium acrylate, aluminum acrylate, and acrylic are added to the mixture of FiG di(meth)acrylates as necessary. It is also possible to use a polymerizable compound to which acrylates such as nickel acrylate, chromium acrylate, and strontium acrylate or methacrylates thereof are added as the curing component.

The polymerization catalyst used in the present invention is usually a redox catalyst, and the oxidizing agent is sodium persulfate, hydrogen peroxide, ammonium chlorate, perchloric acid, and the reducing agent is hydrogen sulfite. strium, sodium sulfite,
Potassium sulfite, sodium thiosulfate, ferrous sulfate, formaldehyde sodium sulfoxylate, dimethylaminopropionitrile, triethylamine, triethanolamine, N-methylmorpholine, nitrilo-lispropionamide or sodium or potassium sulfate. Metabisulfites, etc.

Examples of suitable redox catalyst combinations include sodium persulfate and triethanolamine, sodium persulfate and sodium thiosulfate, potassium persulfate and sodium sulfite, potassium persulfate and triethanolamine, and the like.

The amount of the catalyst used is in the range of 0.1 to 150%, preferably 1 to 150%, based on the total weight of PEG (meth)acrylic esters and PEG (meth) diacrylic esters.
The range is 100 inches.

In the polymerization according to the present invention, reducing metal ions such as 5n(II), Fe(■), etc. are added to the redox catalyst.
, Mn (■), Ca (II), Z n' (■), N1 (
1) When using a combination of pb(I), Ag(1), and Co(IT) ions or a tertiary amine as a redox catalyst, the mixture of the tertiary amine and the above reducing metal ion is further added. Chelating agents that form stable complexes in the presence of reducing metal ions and tertiary amines, such as oxyacids such as tartaric acid, citric acid, malic acid, lactic acid, succinic acid, ethylenediaminetetraacetic acid or its water-soluble salts, oxalic acid , ammonium oxalate, nitrilotriacetic acid or a water-soluble salt thereof, ammonium acetone, and the like may be added and used as appropriate.

Hydraulic cements used in the present invention include ordinary bolt lachod cement, alumina cement, mixed cement, (blast furnace cement, silica cement, fly ash cement), and particulate blast furnace slag cement.

The amount of hydraulic cement used in the present invention can be varied depending on the required properties as a water sealing agent, but generally PEG (meth)acrylates, PEG di(meth)acrylates and 10 to 200 g per 100 ml of an aqueous solution consisting of a polymerization catalyst, preferably 40 to
It is preferable to use it at a rate of 150 g as a water stop agent.

When sodium persulfate, potassium persulfate, or the like is used as an oxidizing agent for the polymerization catalyst, the amount of hydraulic cement used is 2,500 parts by weight or more based on ioo parts by weight of these persulfate compounds.

Further, if necessary, a water reducing agent, bentonite, or water-soluble polymer may be added to increase the dispersion stability of the cement.

Examples of water reducing agents include polyalkylaryl sulfonate salts (naphthalene sulfonate, etc.), melamine formalin resin sulfonate salts, lignin sulfonate salts, and the like.

Examples of water-soluble polymers include dispersants such as water-soluble cellulose ether, polyacrylamide, sodium polyacrylate, and polyvinyl alcohol.

[Effect]

The applicant has developed a water-stopping agent that solves the above-mentioned problem.
In 1972, a water stop agent was first developed for use in an aqueous solution system by adding a polymerization catalyst to a mixture of G(meth)acrylic acid esters and PEG di(meth)acrylic esters.
Patent Application No. 093121 (Special Publication No. 57-15631)
and Patent Application No. 087838 of 1987 (Unexamined Japanese Patent Publication No. 58-
206680), but in a water stop method that uses cement-based chemicals, PEG (meth) is added to hydraulic cement.
By adding a mixture of acrylic acid esters and PEG di(meth)acrylic esters and a polymerization catalyst, the resulting gel has no syneresis, is water-impermeable, durable, and is drug-resistant. Extremely safe, compared to conventional PEG
It has higher strength than a water stop agent used in an aqueous solution system by adding a polymerization catalyst to a mixture of (meth)acrylic acid esters and PEG di(meth)acrylic acid esters.
Also, since it has appropriate permeability, it is also excellent as a cavity photonic agent.

Furthermore, compared to cement-based water sealants, the water sealant of the present invention has P
EG(meth)acrylic acid esters and PEG di(meth)
It is gelled by the radical polymerization reaction of acrylic acid esters, and then the water-use reaction of cement gradually occurs and hardens, so the gelling time can be easily adjusted and the gelling speed (startup of gelling) is rapid. be.

Furthermore, the water stopper of the present invention has excellent caking properties even when diluted with groundwater etc. due to the hydrophilicity of the polyethylene glycol chains contained in PEG (meth)acrylic esters and PEG di(meth)acrylic esters. Since the cured product that is formed does not have a rubber-like appearance and has a suitable hardness, it is easy to excavate, cut, etc. after the water has stopped, and there is no need to use special tools, greatly improving workability.

Furthermore, the combination of a 7-ment type water stopper, PEG (meth)acrylic acid esters, and PEG di(meth)acrylic acid esters has new characteristics as a water stopper that cannot be imagined. In particular, when used to prevent water leakage from the joints of underground pipes, cracks, etc., it is necessary to have both high strength and elasticity. has.

Therefore, there will be no re-leakage due to cracks from the repaired area.

(2) Also, the cured product does not shrink, but expands in the initial stage of curing,
After that, the expansion rate remains constant and does not change, making it an excellent water stopper.

〔Example〕

The present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

For the examples, the amount of cement added is PEG (meth)
Aqueous solution IQ consisting of acrylic esters (A), PEG di(meth)acrylic esters (B) and polymerization catalyst
It was expressed as the amount (y number) added to Qrnl.

The compressive strength and elasticity were measured using an inner diameter of 35 m/m.

A mold with a height of 70 m/m was filled with a chemical solution prepared according to the formulations of Examples and Comparative Examples, solidified, and after 1 hour, the resulting gelled product was removed from the mold. and compressive strain (elasticity) were measured.

Regarding dimensional stability, the volume change after 7 days of curing in water after curing was measured.

The gelation time was determined by measuring the time until gelation for each formulation at a temperature of 20°C.

Table 1 shows examples, and Table 2 shows comparative examples of cement-based water sealants.

As is clear from Tables 1 and 2, the cured product of the present invention has a high compressive strength, excellent elasticity, dimensional stability, no shrinkage, and an expansion rate similar to that of cement. Among the agents, it is significantly larger than when using expandable cement, making it an excellent water treatment agent.

=19- -6Il11n-

Claims (1)

[Claims] a. Hydraulic cement b. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 is a hydrogen atom or a methyl group, and m is an integer of 2 or more). Or mixture c, general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_2 and R_3 are each a hydrogen atom or a methyl group, and n is an integer of 2 or more and 50 or less) Individual or mixture d , a water stop agent containing a polymerization catalyst.