JPH0315951B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a water sealing agent that uses a polymeric substance and can harden into a water-insoluble elastic gel in a short period of time, and is used for stabilizing the ground, water springs, and water leaks. In addition to general civil engineering work such as prevention, the present invention relates to a water stop agent that is particularly suitable for use in preventing infiltration and water leakage in sewer pipe facilities. (Prior art) Conventionally, as a polymeric water-stopping agent used for stabilizing the ground and preventing spring water and water leakage, for example, Japanese Patent Application Laid-Open No. 58-206680 discloses the general formula

[Formula] (wherein R is a hydrogen atom or a methyl group, m is an integer of 2 or more)
100 parts by weight of polyethylene glycol acrylic esters, either alone or as a mixture, represented by the general formula (In the formula, R ₂ and R ₃ are hydrogen atoms or methyl groups, and n is a number from 2 to 50. An aqueous water stop agent has been proposed in which a polymerization catalyst is added after adding an acid salt. In addition, US Pat. No. 4,295,762 discloses that molecular weight
It has been proposed that a polymerization catalyst is added to an aqueous solution of a mixture of a water-soluble diacrylate ester of 300 or more polyoxyalkylene glycol and 2 to 50% by weight of a water-soluble vinyl monomer. . (Problems to be Solved by the Invention) However, the water sealing agent described in JP-A No. 58-206680 is not suitable for stabilizing the ground, preventing spring water,
Although it is suitable for civil engineering works such as water leakage prevention,
The performance of the cured gel, especially its strength, is still insufficient to apply it to the prevention of water infiltration and leakage from pipe connections and cracks in pipes in sewer pipe facilities. Furthermore, in the specification of US Pat. No. 4,295,762,
As a particularly preferable soil stabilizer, the molecular weight is 400~
600 range of polyoxyethylene glycol dimethacrylate, which includes acrylamide, methoxyethyl acrylate, ethoxyethyl acrylate, dimethylaminoethyl methacrylate, tetraethylene glycol diacrylate, hydroxypropyl acrylate, dimethylaminoethyl methacrylate, dimethyl sulfate 4 It has been proposed to copolymerize 2 to 50% by weight of water-soluble vinyl monomers such as alkaline earth or alkali metal salts of acrylic acid or methacrylic acid. Copolymers using ethylene glycol dimethacrylate generally have low strength, and when methoxyethyl acrylate, ethoxyethyl acrylate, tetraethylene glycol, diacrylate, or hydroxypropyl acrylate is selected as a copolymerization component, the resulting gel It has the disadvantage of causing severe syneresis of the body, and cannot be said to be suitable as a water-stopping agent. In general, water-stopping agents, especially water-stopping agents for preventing water intrusion and leakage in sewage pipe facilities, include:
General soil properties such as high chemical safety, good permeability into the ground, easy setting of curing time, and hardening gel is impermeable and strong enough to withstand excavation after construction. In addition to satisfying the performance required for stabilization, the cured gel has no syneresis, is difficult to swell when immersed in water, and has sufficient strength to last for a long period of time. It is necessary to have durability without breaking over a long period of time. In other words, soil stabilization by chemical injection is often a temporary measure to facilitate post-construction civil engineering work (soil excavation, etc.), and is used to simply temporarily stabilize soft ground. In many cases, it is sufficient to prevent spring water, water leakage, etc. for a certain period of time, so it is not strictly required that the cured gel itself has high strength or that the gel body has no syneresis or swelling properties. However, when performing water stoppage work on sewage pipe facilities as described above, chemical solutions are usually injected from inside the pipe into the joints and cracks of the pipe to form a gel. gel) becomes constantly exposed to running water, i.e. sewage. Therefore, the water sealing agent used in such cases should be such that the gel itself does not have syneresis, does not easily swell when immersed in water, has high strength, and will not break down even after long-term use. In addition to having a well-balanced combination of performances that are not necessarily strictly required in the case of soil stabilization as described above, such as having unprecedented durability, there are currently many types of sewage pipes made of concrete (Hyum pipes). Due to its use, it is essential that the gel body has resistance to alkali. The inventors of the present invention have conducted various studies in order to provide a water-stopping agent that has a well-balanced combination of properties that have not been proposed in the past, and have found that the following composition is suitable for that purpose. , arrived at the present invention. (Means for Solving the Problem) That is, the present invention provides “(a) general formula (In the formula, n is an integer of 18 or more and 40 or less.) 98 to 80 parts by weight of a compound represented by
(b) A water stop agent made by adding a polymerization catalyst to a mixture of 2 to 20 parts by weight of an electrolyte vinyl monomer. ”. Below, to explain the present invention, the general formula used as the main component in the water stopper of the present invention is: (In the formula, n is an integer of 18 or more and 40 or less.) The compound (hereinafter referred to as component (a)) is specifically a dimethacrylate of polyethylene glycol, and the polyethylene glycol moiety is It is a crosslinking monomer having a degree of polymerization n in the range of 18 to 40. A similar compound to component (a) is polyethylene glycol diacrylate, but the gel obtained by polymerizing this diacrylate has an ester moiety that is easily hydrolyzed, easily disintegrates under alkaline conditions, and It was found that the gel body obtained by polymerizing dimethacrylate of polyethylene glycol does not disintegrate even under alkaline conditions and maintains sufficient strength. Therefore, it is significant to use polyethylene glycol dimethacrylate as a crosslinking component of a water stopper applied to humid pipes mainly made of concrete. In the present invention, it is necessary to use polyethylene glycol dimethacrylate whose polyethylene glycol moiety has a degree of polymerization n in the range of 18 to 40. In dimethacrylate of polyethylene glycol, as the degree of polymerization (hereinafter sometimes simply referred to as n or the number of n) of the polyethylene glycol moiety decreases, hydrophilicity is lost and the water solubility of the monomer decreases, and the polymer tends to exhibit syneresis and is also susceptible to strain. On the other hand, as the n number increases, the hydrophilicity improves and the water solubility of the monomer increases, and the polymer does not show syneresis and tends to be resistant to strain. As the spacing between double bonds becomes longer, the crosslinking density of the polymer tends to decrease and the gel strength tends to decrease. Therefore, when using polyethylene glycol dimethacrylate as a crosslinking component of a water sealant, it is necessary to select an appropriate number of n.
According to the research of the present inventors, surprisingly,
It has been found that in compounds where n number is 18 to 40, the strength of the polymer is specifically increased. Then, the gel body obtained by adding an appropriate amount of electrolyte vinyl monomer to polyethylene glycol dimethacrylate having such n number alone or in a mixture and copolymerizing it not only has further increased strength, but also It has alkali resistance, shows no syneresis, is resistant to strain, and
There is little swelling when the gel body is immersed in water, etc.
It was found that it is suitable as a water stop agent. The present invention was completed based on this knowledge. Dimethacrylate of polyethylene glycol having an n number of 18 to 40, that is, in the water stopper of the present invention
The reason why the strength of the gel body obtained by polymerizing component (a) is specifically high is as follows.
Although it is not clear, when n is less than 18, an intramolecular cyclization reaction occurs between two polymerizable double bonds, making it difficult to cause an effective intermolecular cross-reaction, whereas when n exceeds 40, The crosslinking density of the polymer decreases and the gel strength decreases, but when n is 18 to 40, the intermolecular crosslinking reaction efficiency is the highest, and the crosslinking density is appropriate and the polyethylene glycol chains between double bonds are has appropriate flexibility to meet the purpose of use as a water sealing agent,
It is also presumed that a strong elastic gel body is produced in combination with good copolymerizability with the electrolyte vinyl monomer. Component (a) used in the present invention is a liquid or solid substance with low toxicity and excellent water solubility, and the aqueous solution has low viscosity and has good permeability into sewer pipe connections, cracks, and the ground. Also, it has good polymerizability and the curing time can be easily set. In the present invention, examples of the component (a) that is usually suitably used include PEG #1000 dimethacrylate, PEG #1540 dimethacrylate, and the like. In addition, in the present invention, any known crosslinking component may be used, such as methylenebisacrylamide, 1,3-di(acrylamidomethyl)-2-imidazolidone,
It is also possible to mix and use one or more types of hexahydro-1,3-triacryl-S-triazine and the like with component (a). In the present invention, the electrolyte monomer used to copolymerize with component (a) (hereinafter referred to as component (b))
There are various types of methacrylates, and preferred examples include acrylic acid, acrylates, methacrylic acid, methacrylates, 2-acrylamido-2-methylpropanesulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid. acid salt, dimethylaminoethyl methacrylate, dimethylaminoethyl methacrylate salt, quaternized product of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diethylaminoethyl methacrylate salt, quaternized product of diethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl Acrylate salt, quaternized product of dimethylaminoethyl acrylate, diethylaminoethyl acrylate, diethylaminoethyl acrylate salt, quaternized product of diethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide salt, dimethylaminopropyl methacrylamide Quaternary product, diethylaminopropyl methacrylamide, diethylaminopropyl methacrylamide salt, quaternized product of diethylaminopropyl methacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide salt, quaternized product of dimethylaminopropylacrylamide, diethylaminopropyl Examples include acrylamide, diethylaminopropylacrylamide salts, and quaternized products of diethylaminopropylacrylamide. These components (b) can be used not only individually, but also in a mixture. In the present invention, component (b) needs to be added in a small amount to component (a), and the preferred ratio is usually (a)/(b) = 98/2 to 80/20 ( weight ratio). If the ratio of components (a) and (b) used is within this range, the gel obtained by copolymerizing the mixture will not exhibit syneresis properties due to the incorporation of highly hydrophilic electrolyte monomers, and Swelling when immersed in water can be suppressed. In a mixture of (a) and (b), if the amount of component (b) used is less than 2% by weight, the gel body tends to show syneresis, while if it exceeds 20% by weight, it is a crosslinking component.
As the content of the components decreases, the crosslinking density of the gel body decreases, resulting in a decrease in gel strength.At the same time, the content of hydrophilic electrolyte monomer increases, which increases the water absorbency of the gel body, making it difficult to immerse in water. This is not preferable because it tends to swell, resulting in a decrease in water resistance. The acrylates and methacrylates used as component (b) include sodium salts, calcium salts, magnesium salts, aluminum salts, etc. Among these, sodium salts are prepared by dissolving acrylic acid, methacrylic acid, etc. and sodium hydroxide in aqueous solution. A homogeneous solution without precipitates can be obtained by mixing the mixture in the solution. On the other hand, calcium and magnesium salts are
Similarly, it can be obtained by mixing acrylic acid, methacrylic acid, etc. with calcium and magnesium hydroxides in an aqueous solution, but a step is required to remove some of the precipitate that is formed at this time.
Although their preparation involves various complications, these calcium salts and magnesium salts are advantageous compared to sodium salts because they cause less swelling when the gelled mixture of (a) and (b) is immersed in water. be. Therefore, without using the calcium salts, magnesium salts, etc. of acrylic acid and methacrylic acid obtained through such complicated work, the present inventors have developed a method that has low swelling property in water as in the case where these salts are used. As a result of various studies in an attempt to obtain a gelled product of the mixture (a) and (b), we found that a method similar to the technique described in Japanese Patent Publication No. 46-28418 filed by the present applicant, that is, a method in which components (a) and An aqueous solution (a) of a mixture of sodium salts of acrylic acid and methacrylic acid, and an aqueous solution (a) of a mixture of at least one member selected from the group consisting of magnesium sulfate, magnesium chloride, and calcium chloride (hereinafter referred to as component (c)) and a polymerization catalyst. By preparing two liquids, and mixing them together to form a gel during construction,
Not only can this objective be achieved, but in this case, by using component (c) in excess (amount greater than the stoichiometric amount) relative to acrylic acid or methacrylic acid, it is possible to reduce swelling in water. It was found that a gel body was obtained. Therefore, when using the water stopper of the present invention, it is desirable to adopt such measures as necessary. In addition, as component (b), 2-acrylamide-2
- When using methylpropanesulfonate, in the same way as in the above case, an aqueous solution of a mixture of component (a) and sodium salt of 2-acrylamido-2-methylpropanesulfonic acid is polymerized with component (c). By preparing two liquids, an aqueous solution of a catalyst mixture, and gelling the two liquids by mixing them at the time of construction.
- A gel body with less swelling in water is obtained than when sodium salt of acrylamide-2-methylpropanesulfonic acid is used. This gel body has less swelling property in water and is superior in water resistance than the gel body obtained when the above-mentioned sodium salts of acrylic acid and methacrylic acid are used together with the component (c). In the present invention, as described above, as component (b), cationic vinyl monomers such as dialkylaminoalkyl acrylate, dialkylaminoalkyl methacrylate, dialkylaminoalkylacrylamide, and dialkylaminoalkylmethacrylamide are used alone or in mixtures thereof;
Salts such as sulfates and hydrochlorides of these monomers, or quaternized products of these monomers such as dimethyl sulfate and methyl chloride are used. It is recognized that the strength of the solidified body obtained by injecting and curing is particularly increased. This is thought to be due to the strong bonding force between the cation groups in the crosslinked polymer structure and the sand particles. Since the water stopper of the present invention is generally used at room temperature, it is desirable to use a redox catalyst as the polymerization catalyst for copolymerizing the mixtures (a) and (b).
Among cationic vinyl monomers, when one having a tertiary amine is used, (a) can be obtained at room temperature by using only the oxidizing agent component (peroxide) without using the reducing agent component of the catalyst. (b) The mixture can be copolymerized and gelled. Furthermore, among cationic vinyl monomers, dialkylaminoalkylacrylamide and dialkylaminoalkylmethacrylamide are difficult to hydrolyze even under alkaline conditions due to their structure.
Decomposition of the cationic group and vinyl group is difficult to occur and it is stable. Therefore, an alkaline solution obtained by mixing a solution containing these monomers with an amine, etc., which is a reducing agent component of a redox catalyst, does not change over time even when stored for a long period of time, and the oxidizing agent component can be added to this solution. The properties of the gel body obtained by adding it are always stable and have stable water-stopping properties for a long period of time after curing. Therefore, in this respect, it can be said that the water stopper of the present invention in which dialkylaminoalkylacrylamide or dialkylaminoalkylmethacrylamide is used as component (b) is particularly preferable. When using the water stopper of the present invention, the mixture of (a) and (b) is preferably used as an aqueous solution, usually at a concentration of 3 to 60% by weight, from the viewpoint of effectiveness. In this case, the oxidizing agent component of the redox catalyst used is preferably ammonium persulfate, potassium persulfate, etc., and the reducing agent component is, for example, sodium thiosulfate, Rongarite, sodium sulfite, triethanolamine,
Examples include hexamethylenetetramine, ferrous sulfate, tartaric acid, citric acid, and the like. The amount of redox catalyst used can be changed depending on the desired curing time, but usually (a),
(b) ranging from 0.1 to 100% by weight, based on the mixture; Next, the present invention will be explained using Examples and Comparative Examples. (Example) Examples 1 to 11 and Comparative Examples 1 to 11 To 10 g of a mixture of both components (a) and (b) in the proportions shown in Table 1, a polymerization catalyst (ammonium persulfate and triethanolamine) and water were added. and magnesium sulfate (MgSo ₄ .
A predetermined amount of 7H ₂ O) was added to bring the total volume to 100 ml, and the drug solution was gelled in a cylindrical container with a diameter of 50 mm. Table 1 shows the results of examining the curing time of the chemical solution, syneresis, fracture strain, fracture strength, swelling property, alkali resistance, etc. of the resulting gel body. Each of these performances was measured by the following method. Γ curing time...Time required for the chemical solution to gel at 20℃
Measured under. Γ Syneresis: The amount of syneresis water after 1 day of gelation was observed with the naked eye. Γ fracture property, fracture strength...values obtained by uniaxially compressing a gel body. Γ Swelling property: The degree of weight increase when the gel body was immersed in 100 to 200 times the amount of water for 10 days was expressed as the degree of swelling. In addition, the swelling degree here is defined as follows. Swelling degree Weight of gel body after 10 days immersion in water/weight of original gel body Γ Alkali resistance...5% of 100 to 200 times the amount of gel body
These are the results of visual observation of the state when immersed in a NaOH aqueous solution for 10 days. For comparison, various compositions different from the water stopper of the present invention were gelled by the same method as above, and the obtained gel bodies were subjected to similar tests. Table 2 shows the results. .

【table】

【table】

【table】

[Table] Examples 12 to 17 and Comparative Examples 11 to 14 A water stop chemical solution having the composition shown in Table 3 was infiltrated into Toyoura standard sand and solidified, resulting in a diameter of 50 m/m and a height of
Table 3 also shows the results of measuring the unconfined compressive strength of the 100 m/m gel body.

【table】

[Table] (Effects of the Invention) The water stopper of the present invention has excellent properties as described below. (1) The polyethylene glycol dimethacrylate ester used as component (a), whose polyethylene glycol moiety has a degree of polymerization in the range of 18 to 40, has a polyethylene glycol chain between two polymerizable double bonds that acts as a water stopper. This is optimal and results in a gel body that is strong and resistant to strain. (2) The dimethacrylate ester of polyethylene glycol used as component (a) has hydrolysis resistance, and a gel body that is durable even under alkaline conditions can be obtained. (3) By mixing and using components (a) and (b) in the specific ratio specified in the present invention, the resulting gel body has no syneresis and is difficult to swell when immersed in water. Impervious to water and high strength. (4) Components (a) and (b) have low toxicity, high polymerizability, and high water solubility, and are used as a safe, easy-to-set curing time, and highly penetrating agent when performing water stoppage work as an aqueous solution. I can do things. For this reason, the water stop agent of the present invention is suitably used as a water stop agent for preventing water infiltration and water leakage in, for example, sewage pipe facilities by utilizing the above-mentioned properties.

Claims (1)

[Claims] 1 (a) General formula (In the formula, n is an integer of 18 or more and 40 or less.) 98 to 80 parts by weight of a compound represented by
(b) A water stop agent made by adding a polymerization catalyst to a mixture of 2 to 20 parts by weight of an electrolyte vinyl monomer. 2 (b) Component is acrylic acid, acrylate, methacrylic acid, methacrylate, 2-acrylamide.
2-Methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonate, dimethylaminoethyl methacrylate, dimethylaminoethyl methacrylate salt, quaternized product of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diethylaminoethyl methacrylate salt, diethylamino Quaternary product of ethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl acrylate salt,
Quaternary product of dimethylaminoethyl acrylate, diethylaminoethyl acrylate, diethylaminoethyl acrylate salt, quaternary product of diethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, dimethylaminopropyl methacrylamide salt, quaternary product of dimethylaminopropyl methacrylamide diethylaminopropyl methacrylamide, diethylaminopropyl methacrylamide salt, quaternized product of diethylaminopropyl methacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylacrylamide salt, quaternized product of dimethylaminopropylacrylamide, diethylaminopropylacrylamide, diethylaminopropyl The water stop agent according to claim 1, which is one or more selected from the group consisting of an acrylamide salt and a quaternized product of diethylaminopropylacrylamide. 3. The water stop agent according to claim 1 or 2, which is used to prevent infiltration and water leakage in sewer pipe facilities. 4 (a) General formula (In the formula, n is an integer of 18 or more and 40 or less.) 98 to 80 parts by weight of a compound represented by
(b) a mixture of sodium salts of acrylic acid, methacrylic acid, or 2-acrylamido-2-methylpropanesulfonic acid; (c) at least one member selected from the group consisting of magnesium sulfate, magnesium chloride, and calcium chloride; and a polymerization catalyst. Waterproofing agent made by adding. 5. The water stop agent according to claim 4, wherein the amount of component (c) used is greater than the stoichiometric amount relative to component (b). 6. The water stop agent according to claim 4 or 5, which is used to prevent water intrusion and leakage in sewage facilities.