JP7846498B2 - Aqueous composition and its cured product, a water-stopping agent raw material set, a water-stopping agent, and a method for stopping water leakage from a leaking part. - Google Patents

Description

This invention relates to an aqueous composition and cured product, a water-stopping agent raw material set, a water-stopping agent, and a method for stopping water leakage from a leaking area.

As a method for stopping water leakage from cracks in concrete structures or from the openings of pipes containing cables, various polymer-based waterproofing agents are known to be injected into the leaking area and allowed to harden.

Generally, to stop water leakage or seepage from concrete structures, liquid or slurry-type cement-based waterproofing agents are injected. When the crack width of the leak is large and the leakage volume is high, a method of injecting sodium silicate (water glass) or a mixture of sodium silicate and cement into the leak is used. For leaks with small crack widths or minute leaks, injecting fine-particle cement is common. However, with the method of injecting sodium silicate or a mixture of sodium silicate and cement, the gelled sodium silicate is brittle and shrinks significantly, making re-leakage likely after waterproofing. On the other hand, the method of injecting fine-particle cement has problems such as difficulty in rapid hardening, inability to penetrate deeply into minute cracks, and frequent crack formation due to self-shrinkage; solutions to these problems were desired.

In addition to the cement-based waterproofing agents mentioned above, polyurethane-based waterproofing agents are also used. Polyurethane-based waterproofing agents exhibit strong adhesion to the leaking material (concrete, wood, metal, etc.) after hardening. However, they may not be able to fully adapt to changes in external environmental conditions such as material temperature and vibration, potentially leading to the formation of new cracks at the adhesive joint.

On the other hand, (meth)acrylic acid ester-based waterproofing agents have been developed and are being used as an alternative to the above-mentioned waterproofing agents. All of the following patent documents disclose waterproofing agents that primarily contain polyalkylene glycol di(meth)acrylate to maintain the hydrophilicity of the waterproofing agent while achieving high molecular weight.

Patent No. 3970604 Patent No. 4916695 Patent No. 2722389 Japanese Unexamined Patent Publication No. 58-206680 Japanese Patent Publication No. 2004-115646 Japanese Patent Publication No. 2015-205981

(Meth)acrylic acid ester-based waterproofing agents suppress water leakage and exhibit a waterproofing effect when filled into the leak area. When performing waterproofing work using (meth)acrylic acid ester-based waterproofing agents at a leak site, the area near the leak is excavated with an excavator, an injection nozzle is attached, and an air-driven high-pressure injection machine is connected to the injection nozzle. The (meth)acrylic acid ester-based waterproofing agent is then injected at high pressure into the leak area through the injection nozzle.

According to our research, the hardness required for a waterproofing agent is preferably 50 or less. If the hardness of the waterproofing agent is too high, the hardened (meth)acrylic acid ester-based waterproofing agent clogs the tip of the injection nozzle during waterproofing work, often requiring a temporary interruption of the work and replacement of the injection nozzle. The (meth)acrylic acid ester-based waterproofing agents described in Patent Documents 1-6 have a hardness of 60 or higher, posing problems for workability at construction sites, and there is still room for improvement.

The present invention aims to provide an aqueous composition for obtaining a low-hardness acrylic ester-based water-stopping agent, in which the hardness of the cured (meth)acrylic acid ester-based water-stopping agent is 50 or less.

The present invention encompasses the following embodiments.

[1] An aqueous composition containing a difunctional allyl ether and a di(meth)acrylate,
An aqueous composition characterized in that the aforementioned bifunctional allyl ether is represented by the following formula (1).

[In the formula, ^R1 represents an alkylene group, and w represents an integer greater than or equal to 2.]

[2] The aqueous composition according to [1], characterized in that the content of the difunctional allyl ether is 40% by mass or less, based on the total amount of polymerization components in the aqueous composition.

[3] The aqueous composition according to [1] and [2], characterized in that, based on the total amount of polymerization components in the aqueous composition, the content of the difunctional allyl ether is 40% by mass or less, and the content of the di(meth)acrylate is 45% by mass or more.

[4] The aqueous composition according to [1] to [3], further containing a monofunctional monomer.

[5] The aqueous composition according to [4], wherein the content of monofunctional monomers is 50% by mass or less based on the total amount of polymerization components in the aqueous composition.

A water-stopping agent raw material set comprising: a first raw material which is an aqueous composition described in any of [6], [1], to [5]; and a second raw material which is a composition containing ascorbic acid or a derivative thereof.

[7] The water-stopping agent raw material set according to [6], further comprising a third raw material which is a composition containing a persulfate.

[8] The water-stopping agent raw material set according to [6] and [7], further comprising, separately from the first raw material, a fourth raw material which is an aqueous composition according to any one of [1] to [5].

A cured product of a mixture containing the aqueous composition described in any of [9], [1] to [5], ascorbic acid or a derivative thereof, and a persulfate.

[10] A method for stopping water leakage from a leaking part,
A mixing step to obtain a mixture containing an aqueous composition according to any one of [1] to [5], a composition containing ascorbic acid or a derivative thereof, and a composition containing a persulfate,
A method comprising an injection step of injecting the aforementioned mixture into the leaking portion.

[11] The process further includes placing a porous body in the leaking area before the injection step,
The method according to [10], wherein the injection step involves injecting the mixture into the porous body.

According to the present invention, because the hardness of the cured (meth)acrylic acid ester-based waterproofing agent is low, the injection nozzle does not clog when the waterproofing material is injected at the site of a leak, thus improving work efficiency.

The embodiments of the present invention will be described in detail below.

In this specification, a difunctional allyl ether means a compound having two allyl groups in its molecule, and a monofunctional allyl ether means a compound having one allyl group in its molecule. A polyfunctional (meth)acrylate means a compound having two or more (meth)acryloyl groups in its molecule, and a monofunctional (meth)acrylate means a compound having one (meth)acryloyl group in its molecule. "(meth)acrylate" refers to acrylate and its corresponding methacrylate, and "(meth)acrylic acid" refers to acrylic acid and its corresponding methacrylic acid. In this specification, an aqueous composition means a composition containing water. Polymerization components refer to acrylic monomer components necessary for forming the acrylic resin, which is a water-stopping agent. Polymerization-involved components refer to catalytic components necessary for forming the acrylic resin.

The water-stopping agent in one embodiment of the present invention is prepared from a water-stopping agent raw material set comprising a first raw material, a second raw material, a third raw material, and a fourth raw material, each separately, and is a cured product of a mixture containing these raw materials.

The first raw material is, in one embodiment, an aqueous composition containing a bifunctional allyl ether represented by the following formula (1) and a di(meth)acrylate salt.

In formula (1), the alkylene group represented by R ¹ may be linear or branched. The number of carbon atoms in the alkylene group may be 2 to 30, 2 to 20, or 2 to 10. The alkylene group represented by R ¹ may be a methylene group or a propylene group.

In formula (1), W is an integer of 2 or greater, preferably 3 or greater, more preferably 4 or greater, and more preferably 50 or less, 40 or less, 30 or less, 20 or less, or 10 or less.

Commercially available difunctional allyl ethers may be used. Examples of commercially available polyalkylene glycol diallyl ethers include Unisafe PKA-5018, Uniox AA-480R, and Uniox AA-800 (all manufactured by NOF Corporation).

From the viewpoint of adjusting the hardness of the cured product, the content of the difunctional allyl ether is preferably 40% by mass or less, 38% by mass or less, or 36% by mass or less, based on the total amount of polymerization components in the aqueous composition. From the viewpoint of adjusting the hardness of the cured product, the content of the difunctional allyl ether is preferably 2% by mass or more, 4% by mass or more, or 6% by mass or more, based on the total amount of polymerization components in the aqueous composition.

The first raw material, an aqueous composition, may further contain a polyfunctional (meth)acrylate in addition to the above. The polyfunctional (meth)acrylate may be, for example, a di(meth)acrylate (two-functional (meth)acrylate) or a tri(meth)acrylate (three-functional (meth)acrylate). The polyfunctional (meth)acrylate may be used individually or in combination of two or more types.

The di(meth)acrylate mentioned above is preferably the di(meth)acrylate represented by the following formula (2).

In the formula, ^R2 and ^R3 each independently represent a hydrogen atom or a methyl group, and ^R4 represents a divalent organic group.

Examples of divalent organic groups represented by R ⁴ include the groups represented by the following formulas (3) and (4).

In the formula, p represents an integer between 2 and 30, and q represents an integer between 2 and 50.

In equation (3), p is an integer greater than or equal to 2, and preferably less than or equal to 30, 25, 20, 10, 5, or 3. p is particularly preferably 2.

In equation (3), q is an integer of 2 or greater, preferably 3 or greater, more preferably 4 or greater, and more preferably 50 or less, 40 or less, 30 or less, 20 or less, or 10 or less.

The bifunctional (meth)acrylate represented by formula (2) is preferably polyethylene glycol di(meth)acrylate (a compound in which ^R4 in formula (2) is the group represented by formula (3) and p in formula (3) is 2).

The tri(meth)acrylate may be, for example, a tri(meth)acrylate represented by the following formula (5) (alkoxylated glycerin tri(meth)acrylate).

In the formula, ^R5 , ^R6 , and ^R7 each independently represent an alkylene group, and x, y, and z each independently represent a positive integer.

In formula (5), the alkylene groups represented by ^R5 , ^R6 , and ^R7 may be linear or branched. The number of carbon atoms in the alkylene group may be 2 to 30, 2 to 20, or 2 to 10. The alkylene groups represented by ^R5 , ^R6 , and ^R7 may be methylene groups or propylene groups.

In equation (5), the sum of x, y, and z is preferably 3 to 30, more preferably 5 to 28, and even more preferably 8 to 25.

The difunctional (meth)acrylates mentioned above can also be commercially available. Examples of commercially available di(meth)acrylates include: Brembo PDE-100, Brembo PDE-150, Brembo PDE-200, Brembo PDE-400, Brembo PDE-600, Brembo PDP-400N, Brembo PDT-650, Brembo ADE-200, Brembo ADE-300, Brembo ADE-400A, Brembo ADP-400, Brembo ADT-250, Brembo GMR-R, Brembo GMR-M, and Brembo GA. Examples include M, Bremmer GAM-R, Bremmer PDBE-200A, Bremmer PDBE-250, Bremmer PDBE-450A, Bremmer PDBE-1300 (all manufactured by NOF Corporation), NK Ester 4G, NK Ester 9G, NK Ester 14G, NK Ester 23G, NK Ester A-200, NK Ester A-400, NK Ester A-600, NK Ester A-BPE-30, and NK Ester BPE-1300N (all manufactured by Shin-Nakamura Chemical Co., Ltd.).

Examples of commercially available tri(meth)acrylates include NK Ester A-GLY-9E and NK Ester A-GLY-20E (both manufactured by Shin-Nakamura Chemical Co., Ltd.).

In one embodiment, the first raw material requires diacrylate and dimethacrylate. Diacrylate and dimethacrylate impart elasticity and moisture retention to the cured aqueous composition. Diacrylate is often used when a faster reaction rate is desired, while dimethacrylate is often used when a slower reaction rate is desired. Examples of diacrylate and dimethacrylate include alkaline earth metal salts such as magnesium and calcium, and metal salts such as zinc and aluminum. From the viewpoint of enhancing elasticity and moisture retention in the cured product, magnesium salts, calcium salts, and zinc salts are preferred.

The content of di(meth)acrylate salts is 45% by mass or more, based on the total amount of polymerization components in the aqueous composition, from the viewpoint of enhancing the elasticity and moisture retention of the cured product. Preferably, the content of di(meth)acrylate salts is 45% by mass or more, 47% by mass or more, or 49% by mass or more, based on the total amount of polymerization components in the aqueous composition. Preferably, the content of di(meth)acrylate salts is 99% by mass or less, 98% by mass or less, or 97% by mass or less, based on the total amount of polymerization components in the aqueous composition.

The content of di(meth)acrylate may be 60% or more by mass, 62% or more by mass, or 64% or more by mass, based on the total amount of the aqueous composition. The content of di(meth)acrylate may be 99% or less by mass, 98% or less by mass, or 97% or less by mass, based on the total amount of the aqueous composition.

The first raw material may further contain at least one monofunctional monomer selected from the group consisting of monofunctional (meth)acrylates represented by formula (6) and monofunctional allyl ethers represented by formula (7). (Hereinafter, these will be collectively referred to as "monofunctional monomer X.")

In the formula, ^R8 represents a hydrogen atom or a methyl group, and ^R9 represents a monovalent group having an oxyalkylene group, a glyceryl group, or a glycidyl group.

In the formula, R ¹⁰ represents a monovalent group having an oxyalkylene group, a glyceryl group, or a glycidyl group.

The monovalent group having oxyalkylene groups represented by ^R9 and ^R10 is preferably the group represented by the following formula (8).

In the formula, ^R11 represents a hydrogen atom or an alkyl group, m represents an integer from 2 to 30, and n represents an integer from 1 to 50.

When ^R11 is an alkyl group, the alkyl group represented by ^R11 may be linear or branched. The number of carbon atoms in the alkyl group represented by ^R11 is preferably 1 or more, and more preferably an integer of 50 or less, 30 or less, 25 or less, 20 or less, 10 or less, 5 or less, or 3 or less. The alkyl group represented by ^R11 may be a methyl group or an ethyl group.

m is preferably an integer of 2 or more, and more preferably an integer of 30 or less, 25 or less, 20 or less, 10 or less, 5 or less, or 3 or less. m is particularly preferably 2. In multiple -(C _m H _2m -O)- contained within the same molecule, each m may be a different number.

The number n represents the degree of polymerization of the oxyalkylene portion in the monofunctional (meth)acrylate represented by formula (6) or the allyl ether represented by formula (7), and is an integer from 1 to 50. n is preferably an integer of 2 or more, more preferably 3 or more, and even more preferably 4 or more, and also preferably an integer of 50 or less, 40 or less, 30 or less, 20 or less, or 10 or less. When n is an integer of 1 or more, the water solubility of the aqueous composition is further improved, making it easier to prepare the water-stopping agent, and furthermore, the strength of the cured product can be improved by increasing the crosslinking density of the resulting cured product. On the other hand, when n is an integer of 50 or less, the distance between polymerizable double bonds does not become too long when the cured product is prepared, thus suppressing a decrease in the strength of the cured product.

^R9 and ^R10 may be glyceryl groups, i.e., groups represented by the following formula (9).

When the monofunctional monomer X is a monofunctional (meth)acrylate represented by formula (6), the monofunctional (meth)acrylate is a polyalkylene glycol (meth)acrylate (a compound in which R ⁹ is the group represented by formula (8) in formula (6), R ¹¹ is a hydrogen atom in formula (8), and n is 2 or more), alkoxypolyalkylene glycol (meth)acrylate (a compound in which R ⁹ is the group represented by formula (8) in formula (6), R ¹¹ is an alkyl group in formula (8), and n is 2 or more), hydroxyalkyl (meth)acrylate (a compound in which R ⁹ is the group represented by formula (8) in formula (6), R ¹¹ is a hydrogen atom in formula (8), and n is 1), alkoxyalkyl (meth)acrylate (a compound in which R ⁹ is the group represented by formula (8) in formula (6), and R 11 is a hydrogen atom in formula (8), This may be a compound in which ¹¹ is an alkyl group and n is 1), glycidyl (meth)acrylate (a compound in which R ⁹ is a glycidyl group in formula (6)), or glycerin (meth)acrylate (a compound in which R ⁹ is a glyceryl group in formula (6)).

Examples of polyalkylene glycol (meth)acrylates include polyethylene glycol (meth)acrylate (a compound in formula (8) where m is 2), polypropylene glycol (meth)acrylate (a compound in formula (8) where m is 3), polyethylene glycol-polypropylene glycol (meth)acrylate (a compound having a group with m 2 and a group with m 3 in formula (8)), polyethylene glycol-polytetramethylene glycol (meth)acrylate (a compound in formula (8) having a group with m 2 and a group with m 4), and propylene glycol-polybutylene glycol (meth)acrylate (a compound having a group with m 3 and a group with m 4 in formula (8)).

Examples of alkoxypolyalkylene glycol (meth)acrylates include methoxypolyethylene glycol (meth)acrylate (a compound in formula (8) where R ¹¹ is a methyl group and m is 2) and methoxypolypropylene glycol (meth)acrylate (a compound in formula (8) where R ¹¹ is a methyl group and m is 3).

Examples of hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate. Examples of alkoxyalkyl (meth)acrylates include 2-methoxyethyl (meth)acrylate.

The monofunctional (meth)acrylate may be at least one selected from the group consisting of polyethylene glycol (meth)acrylate and alkoxy polyethylene glycol (meth)acrylate. In the case of polyethylene glycol (meth)acrylate or alkoxy polyethylene glycol (meth)acrylate, the ester portion of the cured product obtained by polymerization is less susceptible to hydrolysis, and for example, the ester portion is less likely to break down even under alkaline conditions. Therefore, the resulting cured product can maintain sufficient strength.

The alkoxypolyalkylene glycol (meth)acrylate may be at least one selected from the group consisting of methoxypolyethylene glycol (meth)acrylate and methoxypolypropylene glycol (meth)acrylate. Preferably, the alkoxypolyalkylene glycol (meth)acrylate is methoxypolyethylene glycol (meth)acrylate.

The monofunctional (meth)acrylates mentioned above can be commercially available. Examples of commercially available polyalkylene glycol (meth)acrylates include Bremmer (registered trademark, hereinafter the same) PE-90, Bremmer PE-200, Bremmer PE-350, Bremmer PE-350G, Bremmer PP-1000, Bremmer PP-500, Bremmer PP-800, Bremmer 50PEP-300, Bremmer 70PEP-350B, Bremmer 55PET-800, Bremmer 10PPB-500B, Bremmer AE-90U, Bremmer AE-200, Bremmer AE-400, Bremmer AP-200, Bremmer AP-400, Bremmer AP-550, and Bremmer AP-800 (all manufactured by NOF Corporation).

Examples of commercially available alkoxy polyalkylene glycol (meth)acrylates include NK Ester M-20G, NK Ester M-40G, NK Ester M-90G, NK Ester M-130G, NK Ester M-230G, NK Ester AM-30G, NK Ester AM-90G, NK Ester AM-130G, and NK Ester AM-230G (all manufactured by Shin-Nakamura Chemical Co., Ltd.).

Examples of commercially available hydroxyalkyl (meth)acrylates include Acrylics (registered trademark, hereinafter the same) HEA (manufactured by Toagosei Co., Ltd.). Examples of commercially available alkoxyalkyl (meth)acrylates include Acrylics C-1 (manufactured by Toagosei Co., Ltd.). Examples of commercially available glycidyl (meth)acrylates include Bremmer G, Bremmer GH, and Bremmer GS (all manufactured by NOF Corporation). Examples of commercially available glycerin (meth)acrylates include Bremmer GLM and Bremmer GLM-R (both manufactured by NOF Corporation).

When the monofunctional monomer X is an allyl ether (monoallyl ether) represented by formula (7), the allyl ether may be, for example, a polyalkylene glycol allyl ether (a compound in which R ¹⁰ is the group represented by formula (8) in formula (7) and R ¹¹ is a hydrogen atom in formula (8)), an alkoxy polyalkylene glycol allyl ether (a compound in which R ¹⁰ is the group represented by formula (8) in formula (7) and R ¹¹ is an alkyl group in formula (8)), an allyl glycidyl ether (a compound in which R ¹⁰ is a glycidyl group in formula (7)), or a glycerin monoallyl ether (a compound in which R ¹⁰ is a glyceryl group in formula (7)).

Examples of polyalkylene glycol allyl ethers include polyethylene glycol allyl ether (a compound in formula (8) where m is 2), polypropylene glycol allyl ether (a compound in formula (8) where m is 3), and polyethylene glycol-polypropylene glycol allyl ether (a compound having a group with m = 2 and a group with m = 3 in formula (8)).

Examples of alkoxypolyalkylene glycol allyl ethers include methoxypolyethylene glycol allyl ether (a compound in formula (8) where R ¹¹ is a methyl group and m is 2), butoxy-polyethylene glycol-polypropylene glycol-allyl ether (a compound in formula (8) where R ¹¹ is a butyl group and has a group with m = 2 and a group with m = 3).

The allyl ethers mentioned above can be commercially available. Examples of commercially available polyalkylene glycol allyl ethers include Uniox (registered trademark, hereinafter the same) PKA-5001, Uniox PKA-5002, Uniox PKA-5003, Uniox PKA-5004, Uniox PKA-5005, Unisafe PKA-5011, Unisafe PKA-5012, Unilube (registered trademark) PKA-5013, and Unisafe PKA-5014TF (all manufactured by NOF Corporation).

Examples of commercially available alkoxy polyalkylene glycol allyl ethers include Uniox PKA-5006, Uniox PKA-5007, Uniox PKA-5008, Uniox PKA-5009, Uniox PKA-5010, Unisafe PKA-5015, Unisafe PKA-5016, and Unisafe PKA-5017 (all manufactured by NOF Corporation).

The content of monofunctional monomer X is 50% by mass or less, based on the total amount of polymerization components in the aqueous composition, from the viewpoint of adjusting the swelling properties of the cured product in water. Preferably, the content of monofunctional monomer X is 50% by mass or less, 48% by mass or less, or 46% by mass or less, based on the total amount of polymerization components in the aqueous composition. Preferably, the content of monofunctional monomer X is 0.1% by mass or more, 0.2% by mass or more, or 0.3% by mass or more, based on the total amount of polymerization components in the aqueous composition.

The content of monofunctional monomer X may be 20% by mass or less, 19% by mass or less, or 18% by mass or less, based on the total amount of the aqueous composition. The content of monofunctional monomer X may be 0.1% by mass or more, 0.2% by mass or more, or 0.3% by mass or more, based on the total amount of the aqueous composition.

The first raw material, an aqueous composition, may optionally contain other additives. Examples of other additives include glycols, such as ethylene glycol and propylene glycol. Additionally, to adjust the pH, examples include sodium hydroxide and potassium hydroxide. These other additives may be used individually or in combination of two or more.

The content of the polymerization component in the aqueous composition is preferably 15% by mass or more, more preferably 16% by mass or more, even more preferably 17% by mass or more, preferably 50% by mass or less, more preferably 49% by mass or less, and even more preferably 48% by mass or less, based on the total amount of the aqueous composition.

The pH of the aqueous composition is preferably 7.0 or lower, and as close to 7.0 as possible, from the viewpoint of accelerating the polymerization reaction to obtain the cured product. The pH of the aqueous composition is preferably 5.0 or higher, more preferably 5.1 or higher, even more preferably 5.2 or higher, and also preferably 7.0 or lower, more preferably 6.9 or lower, and even more preferably 6.8 or lower.

The second raw material is, in one embodiment, a composition containing ascorbic acid or a derivative thereof. Derivatives of ascorbic acid include salts such as sodium ascorbate, potassium ascorbate, and calcium ascorbate; inorganic acid esters of ascorbic acid such as ascorbic acid phosphate; and glycosides of ascorbic acid such as ascorbic acid-2-glucoside. Furthermore, examples include erythorbic acid, salts such as sodium erythorbate, potassium erythorbate, and calcium erythorbate; inorganic acid esters of erythorbic acid such as erythorbic acid phosphate; and glycosides of erythorbic acid such as erythorbic acid-2-glucoside.

The second raw material may be provided in the raw material set in solid form, such as a powder, or in aqueous solution. If the second raw material is in solid form, such as a powder, the powder may be dissolved in the first raw material, or it may be dissolved in an aqueous solution before use and then mixed with the first raw material. If the second raw material is an aqueous solution, the content of ascorbic acid or its derivative is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, preferably 25% by mass or less, more preferably 24% by mass or less, and even more preferably 23% by mass or less, based on the total amount of the aqueous solution.

The second raw material may further contain other additives as needed. Examples of other additives include sodium thiosulfate, rongalit, potassium sulfite, sodium sulfite, sodium bisulfite, pyrosulfite, and ferrous sulfate. These other additives may be used individually or in combination of two or more.

The water-stopping agent raw material set may further include a composition containing a persulfate as a third raw material, separate from the first and second raw materials. The salt in the persulfate may be an alkali metal salt such as ammonium, sodium, or potassium, and preferably a sodium salt or a potassium salt.

The third raw material may be provided in the raw material set in solid form, such as a powder, or as an aqueous solution. When the third raw material is dissolved in water for use, or when it is included in the raw material set as an aqueous solution, the persulfate content is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, preferably 40% by mass or less, more preferably 39% by mass or less, and even more preferably 38% by mass or less, based on the total amount of the aqueous solution.

The third raw material may further contain other additives as needed. Examples of other additives include sodium perchlorate and hydrogen peroxide. These other additives may be used individually or in combination of two or more.

The water-stopping agent raw material set may further include, as a fourth raw material, an aqueous composition containing the above-mentioned bifunctional allyl ether and the above-mentioned di(meth)acrylate, separately from the first, second, and third raw materials.

The fourth raw material may further contain other polyfunctional (meth)acrylates other than the bifunctional allyl ether described above, and may further contain other additives as needed. These other additives may be the same as those used in the first raw material described above. The fourth raw material may have the same composition as the first raw material or a different composition.

The water-stopping agent raw material set according to this embodiment allows for long-term storage because the first and second raw materials, as well as the third and fourth raw materials, can be stored separately.

The water-stopping agent raw material set may further include, in addition to the raw materials described above, other raw materials such as corrosion inhibitors, cationic electrolyte monomers, cements, and incinerator ash. These raw materials may be included in the water-stopping agent raw material set as separate raw materials from the first to fourth raw materials, or they may be contained within any of the first to fourth raw materials.

The corrosion inhibitor may be one or more selected from the group consisting of carboxylic acids and their salts, phosphoric acid and its salts, phosphoric acid esters, nitrites and their salts, and amines and their salts. By adding the corrosion inhibitor, the water-stopping agent exhibits a strong corrosion inhibitory effect on metals, particularly commonly used iron-based materials such as steel.

The cationic electrolyte monomer may be dimethylaminoethyl (meth)acrylate and its salts and quaternaries, diethylaminoethyl (meth)acrylate and its salts and quaternaries, dimethylaminopropyl (meth)acrylamide and its salts and quaternaries, etc. As salts of these, salts with inorganic salts such as hydrochloric acid and sulfuric acid, or salts with di(meth)acrylic acid are used. As quaternaries, quaternaries with methyl chloride, dimethyl sulfuric acid, etc., or complex salts thereof are used. The cationic electrolyte monomer may be used individually or in combination of two or more.

The cements may include various types of portrant cement, blast furnace cement, silica cement, fly ash cement, jet cement, alumina cement, slag cement, etc. The incinerated ash may include fly ash, silica fume, blast furnace slag, gypsum, sewage treatment sludge, etc. The cements and incinerated ash may be used individually or in combination of two or more types.

Next, a water-stopping agent according to one embodiment will be described. The water-stopping agent according to this embodiment consists of a cured product of a mixture containing the above-mentioned difunctional allyl ether and di(meth)acrylate, ascorbic acid or its derivative, and a persulfate. The cured product contains structural units derived from the difunctional allyl ether, structural units derived from di(meth)acrylate, and structural units derived from ascorbic acid or its derivative. It may further contain structural units derived from polyfunctional (meth)acrylate, monofunctional (meth)acrylate, and structural units derived from monofunctional allyl ether. The persulfate acts as a polymerization initiator to initiate the polymerization reaction of the difunctional allyl ether and di(meth)acrylate, while the ascorbic acid or its derivative acts as a polymerization accelerator to promote the polymerization reaction of the difunctional allyl ether and di(meth)acrylate. This cured product is obtained by mixing each of the raw materials in the above-mentioned raw material set.

The aqueous composition, ascorbic acid or its derivative, and persulfate used as raw materials for the cured product may be the same as those used as the first, fourth, second, and third raw materials described above.

In the cured product, the content of structural units derived from the difunctional allyl ether is 40% by mass or less, 39% by mass or less, or 38% by mass or less, based on the total amount of polymerization-involved components in the cured product. The content of structural units derived from polymerizable monomer X is preferably 0.5% by mass or more, 0.6% by mass or more, or 0.7% by mass or more, based on the total amount of polymerization-involved components in the cured product.

In the cured product, the content of structural units derived from di(meth)acrylate salts is 40% by mass or more, 42% by mass or more, or 44% by mass or more, based on the total amount of polymerization-involved components in the cured product. Alternatively, the content of structural units derived from di(meth)acrylate salts is 99% by mass or less, 98% by mass or less, or 97% by mass or less, based on the total amount of polymerization-involved components in the cured product.

In the cured product, the content of structural units derived from ascorbic acid or its derivatives is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, preferably 20% by mass or less, more preferably 19% by mass or less, and even more preferably 18% by mass or less, based on the total amount of polymerization-involved components in the cured product.

When the cured product further contains the monofunctional (meth)acrylate and monofunctional allyl ether described above, the content of structural units derived from the monofunctional (meth)acrylate is preferably 0.1% by mass or more, 0.2% by mass or more, or 0.3% by mass or more, based on the total amount of polymerization-involved components in the cured product. The content of the monofunctional allyl ether is preferably 50% by mass or less, 49% by mass or less, or 48% by mass or less, based on the total amount of polymerization-involved components in the cured product.

The cured product is a gel-like cured product containing water. From the viewpoint of increasing the strength of the cured product, the content of polymerization-involved components in the cured product is preferably 10% by mass or more, more preferably 11% by mass or more, and even more preferably 12% by mass or more, based on the total amount of the cured product. From the viewpoint of facilitating the dissolution of the raw materials for the cured product and facilitating the preparation of the cured product, the content of polymerization-involved components in the cured product is preferably 90% by mass or less, more preferably 89% by mass or less, and even more preferably 88% by mass or less, based on the total amount of the cured product.

The water content in the cured product may be 40% by mass or more, 41% by mass or more, or 42% by mass or more, and may be 95% by mass or less, 94% by mass or less, or 93% by mass or less, based on the total amount of cured product.

According to this embodiment, the water-stopping agent does not significantly reduce the residual chlorine concentration in the water during water-stopping. Therefore, it can be used not only in sewage facilities but also in water supply facilities. The water-stopping agent can adjust the reduction in residual chlorine in the water after leaching to less than 0.7 mg/L, even under conditions without conditioning treatment, as per the leaching test items for water supply equipment and materials, a standard established by the Japan Water Works Association.

According to this embodiment, the amount of amines leaching into the water during water sealing can be reduced to a concentration suitable for use as a water sealing material in water supply facilities, thus providing excellent safety. For example, the water sealing agent can reduce the concentration of amines in the water after leaching to less than 0.01 mg/L, as measured by high-performance liquid chromatography (detection limit 0.002 ppm), without the need for conditioning treatment (operations to stabilize leaching from hardened materials), as specified in the leaching test for water supply equipment and materials, a standard established by the Japan Water Works Association.

Next, a method for stopping water leakage from a leaking area using a water-stopping agent consisting of the cured material described above (hereinafter sometimes simply referred to as the "water-stopping method") will be described. One embodiment of the water-stopping method comprises a mixing step of obtaining a mixture containing the aqueous composition described above, a composition containing ascorbic acid or its derivative, and a composition containing a persulfate, and an injection step of injecting the mixture into the leaking area.

In one embodiment, the mixing process is carried out by the following method. First, a mixture (Solution A) is obtained by mixing the above-mentioned aqueous composition (First Raw Material) and a composition containing ascorbic acid or its derivative (Second Raw Material). A mixture (Solution B) is obtained by mixing a composition containing persulfate (Third Raw Material) and the above-mentioned aqueous composition (Fourth Raw Material), which is separate from the First Raw Material. Then, Solution A and Solution B are mixed to obtain a mixture of the above-mentioned raw materials. As a method for mixing Solution A and Solution B, for example, Solution A and Solution B can be sent through a Y-shaped pipe or a double-walled pipe and mixed at the junction of the Y-shaped pipe and the tip of the double-walled pipe. Preferably, Solution A and Solution B are mixed in a volume ratio of 1:1.

In the injection process, the mixture of liquids A and B obtained in the mixing process is injected under high pressure into the leak and its vicinity through an injection nozzle installed at the leak. Regarding the details of the injection, depending on the leak situation, after injecting the mixture under high pressure for several tens of seconds, the injection is temporarily stopped, and the reaction time required for the injected mixture to harden into a solid is waited for. After a sufficient reaction time has elapsed, the mixture is injected again under high pressure, and the hardened material that hardened first is pushed into the void inside the leak with the subsequently injected mixture. This hardening process is performed approximately 1 to 20 times per injection nozzle, filling the void in the leak with the hardened material as much as possible.

The interval between high-pressure injection of the mixed solution depends on the reaction time of the hardened material, the leakage situation, the water-stopping situation, and the operator, but it is repeated at intervals of 0.5 to 10 minutes. Even when the mixed solution is not being injected under high pressure, polymerization reactions proceed in the mixed solution at the confluence of the Y-pipe, the tip of the double pipe, and inside the injection nozzle, similar to the leakage void, and hardened material is formed. As the reaction time of the mixture of liquids A and B elapses, the polymerization reaction of the hardened material enters its later stages, and the hardness of the hardened material increases, approaching the same hardness as measured by the FP hardness tester. After 5 minutes or more, the polymerization reaction of the hardened material is almost complete, and the hardness of the hardened material becomes approximately the same as the hardness measured by the FP hardness tester. In such cases, if the hardened material has high hardness, even if the mixed solution is injected again under high pressure, the hardened material often clogs the Y-shaped pipe junction, the end of the double pipe, and the injection nozzle, preventing the mixed solution from being injected under high pressure into the leak. This necessitates replacing the Y-shaped pipe junction, the end of the double pipe, and the injection nozzle, thus temporarily suspending the water-stopping work.

Generally, when the hardness of the cured acrylic ester-based waterproofing agent is measured with an FP hardness tester and is between 60 and 90, the hardened material can be pushed out with the mixed solution within 3 minutes of high-pressure injection, allowing the waterproofing work to continue. However, if the situation remains unchanged for more than 3 minutes after high-pressure injection, the hardened material at the Y-pipe junction, the tip of the double pipe, and inside the injection nozzle will have completed its reaction, and its hardness will be the same as the FP hardness tester's measurement of 60-90. Therefore, even if the mixed solution is injected at high pressure, the hardened material cannot be pushed out. In this case, the injection work must be interrupted, the injection nozzle replaced, and the high-pressure injection work must be resumed. If the hardened material hardness is 80 or higher, even after 1 minute, the hardened material cannot be pushed out from the injection nozzle even if the mixed solution is injected at high pressure. Therefore, the waterproofing work must be interrupted each time, making it unsuitable for use on site.

The hardness of cured acrylic ester-based waterproofing agents is generally 60-90 when measured with an FP-type hardness tester (manufactured by Polymer Instruments Co., Ltd.). For example, the hardness of the cured product of Vandeflexin (manufactured by Hodogaya Building Materials Co., Ltd.) is 60-70, the hardness of the cured product of Flexin Kyoku (manufactured by Hodogaya Building Materials Co., Ltd.) is 70-80, and the hardness of the cured products of FlexiQuick (manufactured by Mitsubishi Chemical Corporation) and Chatani Sangyo Co., Ltd. is 80-90.

According to this embodiment of the waterproofing agent, the cured product using the aqueous composition of the present invention has a hardness of 50 or less as measured by an FP hardness tester. Therefore, during waterproofing work, the cured product does not clog the injection nozzle, eliminating the need to replace the injection nozzle, thus significantly improving work efficiency.

The injected mixture hardens, stopping the water leak at the point of leakage. When injecting the mixture, for example, if the leak is in a concrete wall, high pressure injection is necessary, so an air piston plunger pump or similar device is used. On the other hand, if the leak is in a cable conduit opening, for example, low pressure injection is possible, and this is done by using a low-pressure regulated air compressor or compressed gas cylinder to pump the liquid from a container.

In other embodiments, the water-stopping method may further include a step of placing a porous body at the water leak before the injection step. In this case, the mixture is injected into the porous body during the injection step to impregnate it. The water-stopping method according to this embodiment is suitable for water leaks at cable conduit openings. The porous body impregnated with the mixture can also be used as a water-stopping sealant, such as a water-stopping plate.

The porous material preferably has excellent mechanical strength, elasticity, and weather resistance, as well as excellent permeability of the waterproofing agent (mixture). It may be a foam with an open-cell structure, or a fibrous mass formed by intertwined fibers. The porous material is preferably a urethane foam. The shape of the porous material is not particularly limited, but when placed at a leak in a cable conduit opening, it is preferably cylindrical, and when placed at a leak in a joint between concrete structures, it is preferably sheet-shaped.

In this embodiment, two or more porous bodies may be used. For example, in the case of a single cable leak at a cable conduit opening, the water-stopping method may involve placing a cylindrical porous body, which has been processed by drilling holes to match the cable shape, at the leak and injecting the mixture into this porous body. If the cable is a multi-cable, the water-stopping method may involve using two or more porous bodies and injecting the mixture into the gaps between them. This makes the method simpler and provides a better water-stopping effect.

The water-stopping methods according to these embodiments enable easy stopping of water leakage in concrete structures, cable conduit openings, and the like. Areas sealed using these embodiments exhibit excellent chemical resistance, water pressure resistance, freeze-thaw resistance, and drying shrinkage resistance.

The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to these examples.

<Preparation of the first raw material>
[Examples 1-26, Comparative Examples 1-9]
In the examples and comparative examples, aqueous compositions were prepared using the following materials based on the compositions shown in Tables 1 to 6. In Tables 1 to 6, the content of A-1 refers to the total content of A-1a and A-1b, the content of A-2 refers to the total content of A-2a, A-2b, and A-2c, and the content of A-3 refers to the total content of A-3a, A-3b, A-3c, A-3d, A-3e, and A-3f.

<Bifunctional allyl ether represented by formula (1)>
(A-1a)(A-1b): Bifunctional allyl ethers represented by the following formula (1) ( ^R1 = _C2H4 , _W≈10 , product name: Uniox AA-480R, manufactured by NOF Corporation) ( ^R1 _{= C2H4} , W≈16, product name: Uniox AA-800, manufactured by NOF Corporation)

(A-2a): 35% by mass aqueous solution of magnesium diacrylate (product name: MA-35, manufactured by Asada Chemical Industries, Ltd.) (A-2b): 25% by mass aqueous solution of calcium diacrylate (product name: CA-25, manufactured by Asada Chemical Industries, Ltd.) (A-2c): 30% by mass aqueous solution of zinc diacrylate (product name: ZA-30, manufactured by Asada Chemical Industries, Ltd.)

<Polymerizable monomers represented by formula (6) or formula (7)>
(A-3a): Methoxypolyethylene glycol methacrylate represented by the following formula (3A) (n ≈ 13, product name: NK Ester M-130G, manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

(A-3b): Methoxypolyethylene glycol acrylate represented by the following formula (3B) (n ≈ 13, product name: NK Ester AM-130G, manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

(A-3c): Hydroxypolyethylene glycol methacrylate represented by the following formula (3C) (n ≈ 8, product name: Bremmer PE-350, manufactured by NOF Corporation)

(A-3d)(A-3e)(A-3f): Hydroxypolyalkylene glycol allyl ether represented by the following formula (3D) (n≒4, product name: Uniox PKA-5001, manufactured by NOF Corporation) (n≒9, product name: Uniox PKA-5003, manufactured by NOF Corporation) (n≒30, product name: Uniox PKA-5005, manufactured by NOF Corporation)

<Polyfunctional (meth)acrylate> (A-4): Polyethylene glycol diacrylate represented by the following formula (4) (q ≈ 13, product name: NK Ester A-600, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

(A-5): 4% by mass aqueous solution of sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) (A-6): Tap water

<Preparation of hardened material (water-stopping agent)>
Solution A was prepared by mixing 106 g of the first raw material with 10 g of an aqueous solution of the second raw material, adjusted to the aqueous solution mass percentage listed in Tables 7 to 12 based on the total amount of the second raw material. Solution B was prepared by mixing 106 g of the fourth raw material with a third raw material, which is an aqueous solution adjusted to the aqueous solution mass percentage listed in Tables 7 to 12 using 10 g of water. The mixtures of Solution A and Solution B were immediately poured into a plastic container and stirred to obtain a cured product.

[Second ingredient]
(2-1): L-ascorbic acid aqueous solution (2-2): L-sodium ascorbate aqueous solution (2-3): Erythorbic acid aqueous solution (2-4): Sodium erythorbate aqueous solution [Third raw material]
(3-1): Ammonium persulfate solution (3-2): Sodium persulfate solution (3-3): Potassium persulfate solution

The combinations of the first to fourth raw materials in the examples and comparative examples are shown in Tables 7 to 12. The first and fourth raw materials are indicated by their formulation numbers in Tables 1 to 6 above. For the second and third raw materials, the type of raw material is shown in the upper row, and its aqueous solution mass % is shown in parentheses in Tables 7 to 12.

<Evaluation>
The hardness of the cured products of the examples and comparative examples was measured, and the results are shown in Table 1.
[Hardness measurement]
Hardness was measured by preparing a cured product (volume 77 ^cm³ ) using the formulations described in Table 1, and then measuring the hardness of the cured product using an FP-type hardness tester (manufactured by Polymer Instruments Co., Ltd.).

Claims (6)

A water-stopping agent raw material set comprising: a first raw material which is an aqueous composition containing a bifunctional allyl ether and a di(meth)acrylate; a second raw material which is a composition containing ascorbic acid or erythorbic acid or their salts, inorganic acid esters or glycosides; and a third raw material which is a composition containing a persulfate.
A water-stopping agent raw material set characterized in that the aforementioned bifunctional allyl ether is represented by the following formula (1).
[In the formula, ^R1 represents an alkylene group, and w represents an integer greater than or equal to 2.] A water-stopping agent raw material set according to claim 1, comprising the first raw material according to claim 1, further containing a monofunctional monomer. The water-stopping agent raw material set according to claim 1 or 2, further comprising a fourth raw material which is an aqueous composition according to claim 1 or 2, separately from the first raw material. A cured product of a mixture containing the aqueous composition according to any one of claims 1 to 3 , ascorbic acid or erythorbic acid or a salt thereof, an inorganic acid ester or glycoside , and a persulfate. A method for stopping water leakage from a leaking area,
A mixing step to obtain a mixture containing the aqueous composition according to any one of claims 1 to 3 , a composition comprising ascorbic acid or erythorbic acid or salts thereof, inorganic acid esters or glycosides , and a composition comprising a persulfate;
A method comprising an injection step of injecting the aforementioned mixture into the leaking portion. The process further includes placing a porous body in the leaking area before the injection step,
The method according to claim 5 , wherein the injection step involves injecting the mixture into the porous body.