JP2023091996A - Filler laminate for concrete structure, and concrete structure - Google Patents

Abstract

To provide a filler laminate for a concrete structure which has excellent interlayer adhesion and can retain excellent flexibility for a long time even under open air conditions, and a concrete structure in which a gap is filled by the filler laminate for a concrete structure.SOLUTION: The present invention relates to a filler laminate for concrete structures characterized by having a coating film (B) obtained from a water-based paint on an organic-inorganic composite hydrogel layer (A), and concrete structures characterized by having a gap filled by the filler laminate for concrete structures are used.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a filler laminate for a concrete structure and a concrete structure.

Conventionally, various fillers have been proposed for joints and cracks in concrete structures. However, it is difficult to adhere to complex-shaped parts and wet surfaces, and it cannot follow expansion and contraction due to seasonal fluctuations of structures, resulting in peeling and brittle fracture.

In order to address these problems, a filler for concrete structures comprising a polymer hydrogel formed from a polymer of a water-soluble organic monomer and a water-swellable clay mineral has been proposed (see, for example, Patent Document 1). However, this filler has the problem that it eventually turns into a brittle material and separates from the concrete structure as water evaporates under open air conditions.

Therefore, there has been a demand for a filler for concrete structures that can retain its flexibility for a long period of time even under atmospheric open conditions.

WO2017/169002

The problem to be solved by the present invention is to provide a filler laminate for a concrete structure that has excellent interlaminar adhesion and is capable of maintaining excellent flexibility for a long period of time even under atmospheric open conditions.

The present inventors have found that the above problems can be solved by a filler laminate for a concrete structure having a coating film obtained from a water-based paint on an organic-inorganic composite hydrogel layer, and have completed the present invention.

That is, the present invention provides a filler laminate for concrete structures, comprising a coating film (B) obtained from a water-based paint on an organic-inorganic composite hydrogel layer (A).

The filler laminate for concrete structures of the present invention has excellent interlayer adhesion and can maintain excellent flexibility for a long period of time. It can be used as a filling material for objects and as a repairing material for them.

The filler laminate for concrete structures of the present invention has a coating film (B) obtained from a water-based paint on an organic-inorganic composite hydrogel layer (A).

The hydrogel layer (A) preferably contains a polymer of a water-soluble organic monomer, a water-swelling clay mineral, and water, since it has excellent flexibility.

The polymer of the water-soluble organic monomer is obtained by polymerizing the water-soluble organic monomer. Examples of the water-soluble organic monomer include a monomer having a (meth)acrylamide group, a monomer having a (meth)acryloyloxy group, Examples include acrylic monomers having hydroxyl groups.

Examples of monomers having a (meth)acrylamide group include acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N-isopropylacrylamide, and N-cyclopropylacrylamide. , N,N-dimethylaminopropylacrylamide, N,N-diethylaminopropylacrylamide, acryloylmorpholine, methacrylamide, N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, N-methylmethacrylamide, N-ethyl methacrylamide, N-isopropylmethacrylamide, N-cyclopropylmethacrylamide, N,N-dimethylaminopropylmethacrylamide, N,N-diethylaminopropylmethacrylamide and the like.

Examples of the (meth)acryloyloxy group-containing monomer include methoxyethyl acrylate, ethoxyethyl acrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, methoxymethyl acrylate, and ethoxymethyl acrylate.

Examples of acrylic monomers having a hydroxyl group include hydroxyethyl acrylate and hydroxyethyl methacrylate.

Among these, from the viewpoint of solubility and physical properties of the resulting organic-inorganic hydrogel layer, it is preferable to use a monomer having a (meth)acrylamide group, such as acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N -Isopropylacrylamide and acryloylmorpholine are more preferably used, N,N-dimethylacrylamide and acryloylmorpholine are more preferably used, and N,N-dimethylacrylamide is particularly preferable from the viewpoint of easy progress of polymerization.

The water-soluble organic monomers described above may be used alone, or two or more of them may be used in combination.

If necessary, the water-soluble organic monomer polymer can be copolymerized with monomers other than the water-soluble organic monomer.

The content of the water-soluble organic monomer polymer in the hydrogel layer (A) is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. When the content of the polymer of the water-soluble organic monomer is 1% by mass or more, it is preferable because a hydrogel having excellent mechanical properties can be obtained. On the other hand, when the polymer (A) of the water-soluble organic monomer is 50% by mass or less, the hydrogel precursor composition can be easily prepared before polymerization, which is preferable.

The water-swelling clay mineral forms a three-dimensional network structure together with the polymer of the water-soluble organic monomer, and serves as a component of the hydrogel layer (A).

Examples of the water-swelling clay mineral include, but are not limited to, water-swelling smectite and water-swelling mica.

Examples of the water-swellable smectite include water-swellable hectorite, water-swellable montmorillonite, and water-swellable saponite.

Examples of the water-swellable mica include water-swellable synthetic mica.

Among these, from the viewpoint of the stability of the hydrogel precursor composition, it is preferable to use water-swellable hectorite and water-swellable montmorillonite, and it is more preferable to use water-swellable hectorite.

The water-swelling clay mineral may be naturally derived, synthesized, or surface-modified. Examples of surface-modified water-swelling clay minerals include phosphonic acid-modified hectorite and fluorine-modified hectorite. It is preferred to use lights.

Examples of the phosphonic acid-modified hectorite include pyrophosphate-modified hectorite, etidronic acid-modified hectorite, alendronic acid-modified hectorite, methylenediphosphonic acid-modified hectorite, and phytic acid-modified hectorite. These phosphonic acid-modified hectorites may be used alone or in combination of two or more.

The water-swelling clay minerals described above may be used alone, or two or more of them may be used in combination.

The content of the water-swellable clay mineral in the hydrogel layer (A) is preferably 1% by mass or more, more preferably 2% by mass or more, because the mechanical properties of the obtained hydrogel are further improved. preferable. In addition, the content of the water-swelling clay mineral in the hydrogel layer (A) is preferably 20% by mass or less, and 10% by mass, because the increase in viscosity of the hydrogel precursor composition can be further suppressed. The following are more preferable.

In addition, the hydrogel layer (A) may contain an organic solvent other than water, has a small change in mass even under atmospheric open conditions, and can stably maintain mechanical properties such as substrate adhesion and breaking strength. Since a hydrogel can be obtained, the volatility is preferably 0.1 g or less per 1 cm ² hour in an open system at 60 ° C. 1 atm (0.1 g/cm ² hr 60 ° C. 1 atm or less), 0.05 g or less is more preferable, and 0.01 g or less is even more preferable. Specifically, since solvents that are easily miscible with water are preferable, glycerin (0.001 g or less/cm ² ·hr · 60 ° C. · 1 atm), diglycerin (0.001 g or less / cm ² · hr · 60 ° C. · 1 atm ), ethylene glycol (0.01 g or less/cm ² hr, 60°C, 1 atm), propylene glycol (0.001 g or less/cm ² hr, 60°C, 1 atm), polyethylene glycol (0.001 g or less/cm ² ·hr·60°C·1 atm), polyhydric alcohols having a volatility of 0.01 g or less per 1 cm ² ·1 hour in an open system of 60°C and 1 atm are more preferable, and glycerin and diglycerin are more preferable. These organic solvents may be used alone or in combination of two or more. Moreover, it is desirable that these organic solvents are uniformly contained in the organic-inorganic composite hydrogel of the present invention.

The mass ratio (water/organic solvent) between the water and the organic solvent in the hydrogel layer (A) is an organic solvent that has a small change in mass even under open-air conditions and is excellent in various physical properties such as substrate adhesion and breaking strength. It is important to be between 60/40 and 20/80, preferably between 50/50 and 30/70, to obtain an inorganic hydrogel.

As a method for producing the hydrogel layer (A), since a hydrogel having a three-dimensional network structure can be easily obtained, a water-soluble organic monomer, a water-swellable clay mineral, water, and, if necessary, an organic solvent are mixed. A method of polymerizing the water-soluble organic monomer in a hydrogel precursor composition containing a liquid, a polymerization initiator, and a polymerization accelerator is preferred. The obtained polymer of the water-soluble organic monomer forms a three-dimensional network structure together with the water-swellable clay mineral, and becomes a component of hydrogel.

The polymerization initiator preferably has a solubility in water of 50 g/100 ml or more at 20° C. because the polymerization of the water-soluble organic monomer can proceed sufficiently even in an air atmosphere.

Examples of the polymerization initiator include water-soluble peroxides and water-soluble azo compounds having a solubility in water of 50 g/100 ml or more at 20°C.

Examples of the water-soluble peroxide include ammonium persulfate, sodium persulfate, t-butyl hydroperoxide and the like.

Examples of the water-soluble azo compound include 2,2'-azobis(2-methylpropionamidine) dihydrochloride and 4,4'-azobis(4-cyanovaleric acid).

Among these, water-soluble peroxides are preferably used, and ammonium persulfate and sodium persulfate are more preferably used, from the viewpoint of interaction with the water-swelling clay mineral.

In addition, the said polymerization initiator may be used independently and may use 2 or more types together.

The molar ratio of the polymerization initiator to the water-soluble organic monomer in the hydrogel precursor composition is 0.01 to 0.01 because the polymerization of the water-soluble organic monomer can be sufficiently progressed even in an air atmosphere. A range of 0.1 is preferred, and a range of 0.01 to 0.05 is more preferred.

Examples of the polymerization accelerator include tertiary amine compounds, thiosulfates, and ascorbic acids.

Examples of the tertiary amine compound include N,N,N',N'-tetramethylethylenediamine and 3-dimethylaminopropionitrile.

Examples of the thiosulfate include sodium thiosulfate and ammonium thiosulfate.

Examples of the ascorbic acids include L-ascorbic acid and sodium L-ascorbate.

Among these, tertiary amine compounds are preferably used, and N,N,N',N'-tetramethylethylenediamine is more preferably used, from the viewpoint of affinity and interaction with water-swelling clay minerals.

In addition, the said polymerization accelerator may be used independently and may use 2 or more types together.

The content of the polymerization accelerator in the hydrogel precursor composition is preferably 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass. When it is 0.01% by mass or more, it is preferable because the synthesis of the organic monomer of the obtained hydrogel can be promoted efficiently. On the other hand, when the amount is 1% by mass or less, the hydrogel precursor composition can be used without agglomeration before polymerization, and the handleability is improved, which is preferable.

The hydrogel precursor composition may further contain an organic cross-linking agent, a preservative, a thickening agent, etc., if necessary.

The polymerization temperature of the water-soluble organic monomer is preferably 10 to 80°C, more preferably 20 to 80°C. A polymerization temperature of 10° C. or higher is preferable because the radical reaction can proceed in a chain reaction. On the other hand, a polymerization temperature of 80° C. or lower is preferable because water can be polymerized without boiling.

The polymerization time varies depending on the types of the polymerization initiator and the polymerization accelerator, but is carried out from several tens of seconds to 24 hours. In particular, in the case of radical polymerization using heat or redox, the time is preferably 1 to 24 hours, more preferably 5 to 24 hours. A polymerization time of 1 hour or more is preferable because the polymer of the water-swelling clay mineral and the water-soluble organic monomer can form a three-dimensional network. On the other hand, since the polymerization reaction is almost completed within 24 hours, the polymerization time is preferably 24 hours or less.

The coating film (B) is obtained by applying a water-based paint on the hydrogel layer (A). The layer (A) and the coating film (B) exhibit excellent interlayer adhesion.

The water-based paint has a resin dissolved or dispersed in an aqueous medium.

The resin is not particularly limited as long as it is used for coating film formation, and examples thereof include acrylic resins, urethane-modified acrylic resins, urethane resins, polyester resins, alkyd resins, epoxy ester resins, and epoxy resins. . Among these, acrylic resins such as acrylic resins and urethane-modified acrylic resins are preferable because they have excellent affinity with the hydrogel layer (A) and excellent interlayer adhesion. In addition, these resins may be used independently and may use 2 or more types together.

Moreover, the resin preferably has a hydrophilic group, since the solubility and dispersibility in the aqueous medium are further improved.

Examples of the hydrophilic group include an anionic group, a cationic group, and a nonionic group.

In addition, by introducing a crosslinkable functional group into the resin, it can be used as a two-liquid curing water-based paint.

Examples of the aqueous medium include water, hydrophilic organic solvents, and mixtures thereof. Since the affinity with the hydrogel (A) is excellent, water or a mixture of water and a hydrophilic organic solvent can be used. is preferred.

The hydrophilic organic solvent is preferably a water-miscible organic solvent that is miscible with water without separating. Solvents are preferred. Examples of these water-miscible organic solvents include alcohol solvents such as methanol, ethanol, propanol, butanol, 3-methoxybutanol and 3-methyl-3-methoxybutanol; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol monomethyl ether; Ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monoisopropyl ether , diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether and other glycol ethers Examples include solvents. These water-miscible organic solvents may be used alone or in combination of two or more.

The mass ratio (resin/aqueous medium) of the resin and the aqueous medium in the water-based paint is preferably 20/80 to 60/40, and 30/70 to 50/ 50 is more preferred.

The water-based paint preferably contains a hydrophilic plasticizer because the interlayer adhesion between the hydrogel layer (A) and the coating film (B) is further improved.

As the hydrophilic plasticizer, polyol plasticizers such as glycerin, diglycerin, ethylene glycol, propylene glycol, and polyethylene glycol are preferable because they have excellent affinity with the hydrogel layer (A). Diglycerin is preferred.

The content of the hydrophilic plasticizer is preferably 1 to 30% by mass, more preferably 3 to 20% by mass of the resin, because the interlayer adhesion between the hydrogel layer (A) and the coating film (B) is further improved. % is more preferred.

In addition, the water-based paint may optionally contain surfactants, leveling agents, rheology control agents, ultraviolet absorbers, antioxidants, antifoaming agents, light stabilizers, weather stabilizers, heat stabilizers, pigments, etc. Various additives can be contained.

As a method for coating the hydrogel layer (A) with the water-based paint, various known coating methods can be used. Application by brush, spray or roller is preferred.

In addition, as a method of forming a coating film after applying the water-based paint, there is a method of curing at room temperature for about 0.5 to 7 days, but heating to 40 to 80 ° C. and shortening the curing time. can also

The coating amount of the water-based paint is excellent in interlayer adhesion with the hydrogel layer (A), and can further suppress water evaporation from the hydrogel layer (A). Although it is preferable to form a thick layer, the drying property becomes slow when the coating amount is large, so 0.05 to 0.5 kg/m ² is preferable.

As the method for manufacturing the filler laminate for a concrete structure of the present invention, it is possible to easily fill even a complicated shape part, etc., and the workability at civil engineering construction sites, building construction sites, etc. is further improved. A preferred method is to inject the hydrogel precursor composition into the gaps or onto the surface of a concrete structure, generate the organic-inorganic composite hydrogel in the gaps or on the surface, and apply the water-based paint thereon.

Due to its affinity with concrete, the filler laminate for concrete structures of the present invention enters into the porous structure and adheres to it by capillary action.

INDUSTRIAL APPLICABILITY The filler laminate for a concrete structure of the present invention can be used for various industrial materials because it has excellent interlaminar adhesion and can maintain excellent flexibility for a long period of time even under atmospheric open conditions. For example, it can be used as a filling material for concrete structures such as tunnels, roads, bridges, tracks, buildings, revetments, water supply and sewage systems, and as a repairing material for them.

EXAMPLES The present invention will be described in more detail below with specific examples, but the present invention is not limited to these examples.

(Preparation Example 1: Preparation of hydrogel precursor composition (1))
In a flat-bottom glass container, 40 g of pure water, 63 g of purified glycerin, 4.8 g of phosphonic acid-modified synthetic hectorite ("Laponite RDS" manufactured by BYK-Chemie Japan Co., Ltd.), 20 g of dimethylacrylamide (hereinafter abbreviated as "DMAA"), 20 mg of N,N'-methylenebisacrylamide was added and stirred to prepare a uniform transparent composition (1). The viscosity of this composition (1) after being kept in a constant temperature bath at a water temperature of 25° C. was measured using a Brookfield viscometer (“VISCOMETER TV-20” manufactured by Toki Sangyo Co., Ltd.), and was 50 mPa·s. .
Next, 12.6 g of purified glycerin and 80 μL of tetramethylethylenediamine (hereinafter abbreviated as “TEMED”) were placed in another flat-bottomed glass container and stirred to prepare a uniform TEMED solution.
The entire amount of the composition (1) was placed in a 200 mL glass beaker, and 0.5 g of sodium persulfate (hereinafter abbreviated as "NPS") was added and stirred until dissolved. Further, the TEMED solution prepared above was added, and stirring was continued until the mixture was uniformly mixed to prepare a hydrogel precursor composition (1).

(Preparation Example 2: Preparation of hydrogel precursor composition (2))
In the same manner as in Preparation Example 1, except that 20 mg of N,N'-methylenebisacrylamide used in Preparation Example 1 was changed to 0.05 g of polyethylene glycol diacrylate ("Light Acrylate 4EG-A" manufactured by Kyoeisha Chemical Co., Ltd.). A hydrogel precursor composition (2) was prepared.

An acrylic emulsion (“Barnock WE-317” manufactured by DIC Corporation, non-volatile matter: 45% by mass, solvent: water) was used as a water-based paint (1).

A urethane-modified acrylic emulsion (“Boncoat HY-364” manufactured by DIC Corporation: 45% by mass of non-volatile matter, solvent: water) was used as the water-based paint (2).

Add 5 parts by mass of glycerin to 100 parts by mass of acrylic emulsion (“Barnock WE-317” manufactured by DIC Corporation, non-volatile content: 45% by mass, solvent: water), stir until uniformly mixed, water-based paint (3) was prepared.

(Example 1)
Two flat plates of mortar (70 mm×70 mm×20 mm) were arranged so that their flat surfaces were parallel to each other, and two spacers made of polypropylene having a width of 40 mm were inserted between them. The two spacers were separated by 30 mm to form a space for filling with hydrogel, and the mortar plate and the entire spacer were fixed with aluminum tape. 110 g of the hydrogel precursor composition (1) obtained above was poured into this mold and allowed to stand for 20 minutes to prepare an organic-inorganic composite hydrogel, after which the mold was removed to obtain an H-shaped specimen. On the organic-inorganic composite hydrogel of the H-shaped specimen, the water-based paint (1) obtained above was applied with a brush (application amount: 0.3 kg/m ² ), left to stand for 24 hours, and filled for concrete structures. A mortar-gel-mortar structure (H-type specimen) was obtained as a material layer (1) and a concrete structure (1).

[Evaluation of interlayer adhesion]
The H-shaped specimen of the concrete structure (1) obtained above is stretched at a speed of 5 mm / min to an elongation of 50%, and then stretched to an elongation of 0% (original position) at the same speed. returned. After repeating this cycle five times, the film was further stretched to an elongation of 50%.
○: No abnormality ×: Delamination is observed in the coating film

[Evaluation of flexibility]
The H-shaped specimen of the concrete structure (1) obtained above was stretched by 50% at a speed of 5 mm/min, and the specimen was allowed to stand for 90 days. Evaluated by
○: No abnormality ×: The flexibility of the filler laminate is reduced, and peeling from the mortar is observed

(Example 2)
In the same manner as in Example 1 except that the water-based paint (1) used in Example 1 was changed to the water-based paint (2), mortar was used as the concrete structure filler layer (2) and the concrete structure (2). - After obtaining the gel-mortar structure (H type specimen), each performance was evaluated.

(Example 3)
In the same manner as in Example 1, except that the hydrogel precursor composition (1) used in Example 1 was changed to the hydrogel precursor composition (2), a concrete structure filler layer (3) and a concrete structure After obtaining a mortar-gel-mortar structure (H type specimen) as the body (3), each performance was evaluated.

(Example 4)
In the same manner as in Example 1 except that the water-based paint (1) used in Example 1 was changed to the water-based paint (3), mortar was used as the concrete structure filler layer (4) and the concrete structure (4). - After obtaining the gel-mortar structure (H type specimen), each performance was evaluated.

(Comparative example 1)
A mortar-gel-mortar structure (H-type specimen) was obtained as a concrete structure (R1) in the same manner as in Example 1, except that the water-based paint (1) applied in Example 1 was not applied. Flexibility was then evaluated.

(Comparative example 2)
A concrete structure filler layer ( R2) and a mortar-gel-mortar structure (H-type specimen) as a concrete structure (R2) were obtained, and each performance was evaluated.

The operations of the above Examples and Comparative Examples were performed in a test room under the conditions of 23° C. and 50% RH.

Table 1 shows the compositions and evaluation results of Examples 1 to 4.

Table 2 shows the compositions and evaluation results of Comparative Examples 1 and 2.

It was confirmed that the filler layers for concrete structures of the present invention of Examples 1 to 4 have excellent interlayer adhesion and can maintain excellent flexibility for a long period of time.

On the other hand, Comparative Example 1 is an example in which no coating film is provided on the organic-inorganic composite hydrogel layer (A), but it was confirmed that the flexibility could not be maintained for a long period of time.

Comparative Example 2 is an example having a coating film obtained from a solvent-based coating material on the organic-inorganic composite hydrogel layer (A). was confirmed.

Claims (6)

A filler laminate for a concrete structure, comprising a coating film (B) obtained from a water-based paint on an organic-inorganic composite hydrogel layer (A). 2. The filler laminate for a concrete structure according to claim 1, wherein said organic-inorganic composite hydrogel layer (A) contains a polymer of water-soluble organic monomers, a water-swelling clay mineral, and water. The organic-inorganic composite hydrogel layer (A) has a volatility of 0.1 g or less per 1 cm ² hour in an open system at 60 ° C. 1 atm (0.1 g / cm ² hr 60 ° C. 1 atm or less). 3. The filler laminate for concrete structures according to claim 2, which contains a certain low-volatility solvent. The filler laminate for concrete structures according to claim 2 or 3, wherein the water-swellable clay mineral contains phosphonic acid-modified hectorite. The filler laminate for a concrete structure according to any one of claims 1 to 4, wherein the water-based paint contains an acrylic resin. A concrete structure having gaps filled with the filler laminate for a concrete structure according to any one of claims 1 to 5.