JPS63314293A - Waterproofing agent composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. which does not make ground water strongly acidic, and which comprises a water-soluble polymerizable monomer, a redox catalyst, a water-soluble alkaline substance, and water. CONSTITUTION:A water-soluble polymerizable monomer (a) comprising a water- soluble monovinyl or divinyl compd. (e.g., acrylamide) and a reducing agent component (b1) of a redox catalyst (e.g., NaHSO3) are dissolved in water (c) to prepare a solution (A). Separately, an oxidizing agent component (b2) of the redox catalyst (e.g., ammonium persulfate) and a water-soluble alkaline substance (d) (e.g., NaOH) is dissolved in component (c) to prepare a solution (B). Component A is mixed with component B to polymerize component (a), thereby preparing the title compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water stopper composition. Specifically, the present invention relates to a water stop agent composition comprising a combination of a water-soluble polymerizable monomer (hereinafter referred to as monomer) and a redox catalyst in the presence of an aqueous medium.

The water stop agent composition of the present invention forms a water-insoluble elastic gel body, and is used for general civil engineering and construction work such as stabilizing the ground and preventing water springs and leaks in the ground, as well as in sewer pipe facilities. Suitable for use in preventing water intrusion or leakage.

(Prior art) As chemical solutions for ground stabilization using water-soluble monomers, acrylamide-based, methylol acrylamide-based, (meth)acrylate-based, etc. have been known, and recently polyethylene glycol (di)( Various compositions have been proposed, including those based on meth)acrylic acid esters.

(Special Publication No. 57-15631, Japanese Patent Publication No. 61-23108
No. 1.

JP-A-62-22882, JP-A-62-34977.

(US Pat. No. 4,295,762, etc.) A redox catalyst containing a combination of a reducing agent and an oxidizing agent is used as a catalyst for polymerizing and gelling these water-soluble monomers.

Note that Japanese Patent Publication No. 57-15631 describes that primary to tertiary sodium phosphate, sodium tripolyphosphate, etc. may be added in order to prevent metal corrosion caused by persulfates.

[Problem that the invention seeks to solve]

The technical contents that have been proposed so far are related to improving the permeability of drug solutions, adjusting the curing time, reducing syneresis water, and improving the strength, swelling, shrinkage, and adhesion of gel bodies. There are various problems.

Usually, the water-soluble monomer is polymerized by mixing an aqueous solution containing a water-soluble monomer and a reducing agent for a redox catalyst (hereinafter referred to as liquid A) and an aqueous solution containing an oxidizing agent (hereinafter referred to as liquid B), A gel body is obtained.

In general, the pH of Solution A becomes strongly acidic when ferrous sulfate alone or ferrous sulfate and a chelating agent are used together as a reducing agent, and when commonly used reducing agents other than ferrous sulfate are used. If it is, it is weakly acidic or alkaline.

On the other hand, pl (of liquid B is usually in the range of 6 to 8).

The pN of the chemical solution obtained by mixing these A and B solutions at the initial stage of mixing is strongly acidic if the A solution is ferrous sulfate-based, and weakly acidic or alkaline in other cases. exhibits. However, when the gel body obtained by gelling this chemical solution is immersed in water, acidic substances generated by the redox catalyst contained in the gel body are eluted,
The pH of the immersion liquid becomes strongly acidic within a short time.

The acidic substance produced by the redox reaction contained in the gel body formed by the gelation of the chemical solution used for practical use is eluted into water, penetrates underground, acidifies groundwater, and is buried in the ground. It corrodes and deteriorates underground underground structures and concrete structures such as water pipes, sewage pipes, gas pipes, cables, concrete pipes, etc.

Furthermore, metal corrosion caused by persulfates cannot be prevented by the method proposed in Japanese Patent Publication No. 57-15631, in which mono- to tertiary sodium phosphate, sodium tripolyphosphate, etc. are added to an aqueous persulfate solution. However, if the amount of addition is such that it is not possible to prevent underground water from becoming strongly acidified by acidic substances eluted from the formed gel body, the purpose of the present invention cannot be achieved. Since an aqueous solution of soda is acidic, even if it is added to prevent metal corrosion caused by persulfates, it will not be effective in preventing corrosion or deterioration of underground objects or concrete structures.

The present inventors did not aim to prevent corrosion of metal by a persulfate aqueous solution, but rather, when a gel body formed using a redox catalyst is immersed in water, the purpose of the present invention is to prevent corrosion of metal by a persulfate aqueous solution. Various studies have been conducted on methods to prevent the pH of water from decreasing due to acidic substances.

An object of the present invention is to provide a water stop agent composition that does not cause groundwater to become strongly acidic.

[Means for Solving the Problem] The present inventors have solved the above problem by incorporating a water-soluble alkaline substance into a water-stop agent composition formed by combining a water-soluble polymerizable monomer and a redox catalyst. The present invention has been completed based on the discovery that the object can be achieved.

That is, the present invention provides a water stopper composition comprising a combination of a water-soluble polymerizable monomer and a redox catalyst in the presence of an aqueous medium, which is characterized by containing a water-soluble alkaline substance. Waterstop agent composition".

The present invention will be explained below.

Examples of the water-soluble polymer used in the present invention include water-soluble monovinyl or divinyl compounds. One or more of these may be used as a base for forming a water-insoluble gel body.

Water-soluble monovinyl compounds include (meth)acrylamide, methylol (meth)acrylamide, (meth)acrylate, hydroxyethyl (meth)acrylate,
Dimethylaminoethyl (meth)acrylate, furthermore, the following general formula (1)XCHx-C(R')-Co-0-(
-CHx-CHx-0-), -H.

(In formula (1), ill represents a hydrogen atom or a methyl group, and m represents an integer of 2 or more.) Polyethylene glycol (meth)acrylic acid esters and the like can be mentioned. .

In addition, water-soluble divinyl compounds include methylenebisacrylamide, 1,3-di(acrylamidomethyl)-
2-imidazolitone, hexahydro-1,3,5-triacryloyl-5-triazine, ethylene urea bisacrylamide, glycerol diacrylate, and the following general formula (2): CII*=C(R”)- CO-0-(-CHz-CHg
-0-)--CO-C(R'')=CHx.

(In formula (2), R1 and R3 represent a hydrogen atom or a methyl group, and n represents an integer of 2 to 50.) Polyethylene glycol di(meth)acrylic acid esters and the like can be mentioned.

In the present invention, the water-soluble monomer is preferably used in the form of an aqueous solution of 3 to 60% deafness.

The reducing agent components of the redox catalyst used in the present invention include ferrous sulfate, potassium hydrogen sulfite, sodium hydrogen sulfite, ammonium hydrogen sulfite, lithium sulfite, potassium sulfite, sodium sulfite, ammonium sulfite, sodium thiosulfate, Rongalite, A chelating agent that forms a stable complex in the presence of ferrous sulfate and a tertiary amine or the alkaline substance used in the present invention - for example, an oxyacid such as tartaric acid, citric acid, malic acid, or lactic acid or an alkali metal salt thereof , combinations of succinic acid, nitrilotriacetic acid, etc., and various amines, such as
Tertiary amines such as dimethylaminopropionitrile, dimethylaminoethanol, dimethylamitubrobanol, triethanolamine, nitrilotrispropionamide, triethylamine, trimethylamine, N,N,N',N'-tetramethylethylenediamine; Examples include secondary amines such as tanolamine, morpholine, and piperazine, polyethylene polyamines such as triethylenetetramine and tetraethylenepentamine, polyethyleneimine, dimethylaminoethylated polyacrylamide, and polymeric amines such as polydimethylaminoethyl methacrylate. Triethanolamine, ferrous sulfate, a combination of ferrous sulfate and a chelating agent, etc. are preferably used. These reducing agent components can be used alone or in combination of two or more.

On the other hand, oxidizing agent components include ammonium persulfate, sodium persulfate, potassium persulfate, ammonium perchlorate, sodium chlorate, potassium perchlorate, hydrogen peroxide, etc., but persulfates are particularly preferred. used.

The amount of the redox catalyst used in the present invention is determined as appropriate depending on the intended curing time.

In order to obtain a curing time of several seconds to several hours, it is usually sufficient to use 0.1 to 100 parts by weight based on 100 parts by weight of the water-soluble upper layer.

The water-soluble alkaline substance used in the present invention makes the DH of the immersion liquid at least weakly acidic or alkaline when a gel body obtained by gelling a chemical solution consisting of a water-soluble monomer and a redox catalyst is immersed in water. Used to maintain.

From the gel body produced by the gelation of the used chemical solution, the acidic substance produced by the redox reaction and contained in the gel body is eluted into water, and the generated strongly acidic water deteriorates underground buried objects and underground structures. In order to prevent this, a water-soluble alkaline substance is added to the chemical solution in the present invention.

The water-soluble alkaline substance used in the present invention includes N
a, silicates of alkalis such as + Li+ NH4.

Aluminate, hydroxide, carbonate, bicarbonate.

Phosphoric acid-hydrogen salt, phosphate, condensed phosphate, metaphosphoric acid (trimetaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid, etc.) salt, polyphosphoric acid (tripolyphosphoric acid, birophosphoric acid, etc.) salt, borate, metaborate , sodium carbonate-
At least one compound selected from the group consisting of double salts such as potassium can be used.

Note that a hydrogen carbonate, a borate, or a metaborate having an aqueous solution pi in a neutral range and a buffering effect is preferably used.

The amount of water-soluble alkaline substance used in the present invention is determined by adjusting the pH of the immersion liquid after the acidic substance is eluted into the immersion liquid of the gel body produced by gelation of the chemical solution to a weakly acidic or alkaline state, preferably a neutral to slightly alkaline range. The amount can be within the range of .

The amount should be at least equivalent to the neutralization equivalent to the acid groups contained in the redox catalyst component used.

In the present invention, the water-soluble alkaline substance is A liquid or A liquid.
The water-soluble alkaline substance exhibiting strong alkalinity is preferably added to the B solution.

The water stopper composition of the present invention may further contain a metal rust preventive agent and a reinforced concrete rust preventive agent as other additives.

One embodiment of the method for preparing and using the water stopper composition of the present invention is as follows.

First, a solution in which a water-soluble monomer and a reducing agent component of a redox catalyst are dissolved in water (liquid A), and a solution in which an oxidizing agent component of a redox catalyst and a water-soluble alkaline substance are dissolved in water (liquid A) are prepared.
B' solution) was prepared separately, and then A and B'
By mixing both liquids, the water stopper composition of the present invention can be obtained.

The obtained chemical solution can be used by various methods such as injection, spraying, or mixing with soil.

[Effects of the present invention]

When the formed gel body is immersed in water, the water stopper composition of the present invention makes the pi of the immersion liquid weakly acidic or alkaline, and does not become strongly acidic.

Therefore, it does not corrode metal and can suppress deterioration of underground objects and concrete structures.

〔Example〕

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

Examples 1 to 9 and Comparative Examples 1 to 7゜10 g of acrylamide and 0.5 g of methylenebisacrylamide as water-soluble monomers and various reducing agent components shown in Table 1 were dissolved in water, and various types of A liquid were prepared. 50 cc each was obtained.

On the other hand, 1 g of ammonium persulfate as an oxidizing agent component and various water-soluble alkaline substances shown in Table 1 were dissolved in water to obtain 50 cc of each of various B° solutions.

For comparison, a solution B was prepared by dissolving only 1 g of ammonium persulfate as an oxidizing agent component in water to make 50 cc without adding a water-soluble alkaline substance.

Each pH of liquid A, liquid B, and liquid B° alone, AB or AB' mixture at 20°C.

Table 1 shows the measurement results of gel time.

Also, add 100 cc of each of the obtained gel bodies to 1 liter of water.
00 cc and stirred in a mixer for 30 seconds to speed up elution from the gel body to form a slurry, into which a cast iron test piece (30 x 40 x 1) was immersed. Table 1 shows the pH of the immersion solution after - days and the state of rust on the test piece after one week.

When a water-soluble alkaline substance is not used, 9H of the immersion solution of the obtained gel body is p) before gelation of the A-B mixture solution.
In all cases, the pH value was significantly lower than that of 1 (excluding cases where the pH value was unknown because the gel time was short and pH measurement was not possible) and exhibited strong acidity.

The immersed cast iron test pieces were corroded, and rust was observed in all of them. (Comparative Examples-1 to 6).

On the other hand, when the water-soluble alkaline substance of the present invention is used, the pH of the gel body immersion liquid becomes alkaline,
No rust was observed on any of the immersed cast iron test pieces, indicating that corrosion could be suppressed. (Examples-1 to 6
．． 9).

Comparative Example 7 is a case where trisodium phosphate was used as the water-soluble alkaline substance.

Trisodium phosphate is known to prevent corrosion of metals caused by aqueous ammonium persulfate solutions, and the amount used is usually 0.25 to 0.5% equivalent to the liquid (
If the liquid volume is 50cc, it is 0.125 to 0.25
g).

No corrosion was observed in the cast iron test piece immersed in Solution B to which 0.5 g of trisodium phosphate was added in an amount greater than this amount even after one week had passed.

However, as shown in Comparative Example 7, the pH of the immersion liquid for the obtained gel body decreased to 4.5, and corrosion of the cast iron test piece was observed.

Example 7 was a case in which sodium hydroxide was further used in combination with Comparative Example 7, and corrosion of the cast iron test piece could be prevented.

In addition, in Example 8, the amount of trisodium phosphate added was further increased, and corrosion of the cast iron test piece could be prevented by increasing the pn of the gel immersion liquid.

In addition, when adding the water-soluble alkaline substance of the present invention,
No adverse effect on the gel time of the chemical solution or the properties of the resulting gel body was observed.

Claims (1)

[Claims] 1. A water-stopping agent composition comprising a combination of a water-soluble polymerizable monomer and a redox catalyst in the presence of an aqueous medium, the composition comprising a water-soluble alkaline substance.