JP2002302951A - Buried matter having water resistance providing layer, and bonding protecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide buried matter comprising a surface treatment agent layer to restrict bonding to hydrate of hydraulic composition, and having a water resistance providing agent layer having both water resistance and solubility in alkaline water to be capable of protecting the surface treatment agent layer while enabling it to sufficiently achieve its effect, and a bonding protecting method using that. SOLUTION: This buried matter gets in contact with the hydrate of the hydraulic composition. It comprises the surface treatment layer to restrict bonding to the hydrate of the hydraulic composition, and the water resistance providing layer provided on a base material surface in this order from the inner side. The water resistance providing layer is formed of resin of an acid value of 50-150 mgKOH/g as an essential condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buried object and an adhesion preventing method using the buried object. More specifically, the present invention relates to a buried object that comes into contact with a hydrate of a hydraulic composition, and a method for preventing adhesion between the buried object and the hydrate of the hydraulic composition.

[0002]

2. Description of the Related Art In a construction work related to a ground foundation structure such as a retaining wall in a construction work in a construction field or a civil engineering field, a buried object such as an H-shaped steel is used as a core material of the ground foundation structure. ing. As such buried objects, those having a surface treatment layer that suppresses the adhesion of the hydraulic composition to the hydrate on the surface thereof can suppress equipment, costs, days, etc. in foundation work and the like. Recently attracted attention.

[0003] For example, when an H-shaped steel or the like is used as a core material such as concrete constituting a ground foundation structure, that is, an embedded material, after the H-shaped steel is loosely inserted into a drilling hole, concrete is poured around the H-shaped steel and water is poured. It has been practiced to add (harden) or embed concrete in an excavation hole and hydrate the concrete after embedding H-shaped steel. The H-shaped steel embedded in the concrete hydrate is pulled out of the concrete hydrate so as not to hinder other underground works after the completion of the work and to be reused. At this time, since the H-shaped steel and the concrete hydrate are usually firmly adhered to each other, the drawing work requires equipment, cost, days, etc. When a buried object having a surface treatment layer for suppressing adhesion is used, the workability of drawing is improved and the efficiency of construction is improved.

[0004] As described above, a technique for facilitating the removal of a buried object from a hydraulic composition is disclosed in, for example, Japanese Patent Publication No. 5-1.
No. 9612 discloses that a polyvinyl alcohol (PVA) -based paste or the like is used as a rewetting binder for a rewetting lubricating layer obtained by kneading a water-absorbing polymer and a rewetting binder and drying and solidifying the mixture. Also, JP-A-63
JP-165615A relates to forming a film by applying a volatile film-forming resin and a superabsorbent resin, and using a latex obtained by suspending natural rubber, synthetic rubber or plastic in water as a volatile film-forming resin. It is disclosed for use.

In these techniques, the water-absorbent resin is attached to the surface of the base material. For example, the water-absorbent resin swells before the cement hardens and displaces the cement from the surface of the base material. Since water gradually disappears, the swollen water-absorbing resin shrinks, and a gap is formed between the hardened cement and the surface of the base material, thereby suppressing adhesion to the cement.

However, in the case of a substrate on which a coating film containing a water-absorbing resin is formed on the surface by these techniques, the coating film absorbs and swells before use, so that its effect cannot be sufficiently exhibited. was there. For example, building materials such as steel sheet piles are usually piled up and stored in outdoor material storage, etc., but at this time, the water-absorbent resin may swell due to rain, night dew, or moisture from the ground. there were. To prevent this, cover with a waterproof sheet,
It may be stored in an indoor storage space, but the efficiency of the construction is reduced and the cost is increased. In addition, when the embedded material is embedded in the hydraulic composition or when the hydraulic composition is cast, the adhesion of the coating film cannot be maintained, so that the embedded object is sufficiently effective when pulled out. There was a problem that it was not possible. Therefore, there is room for overcoming these problems and sufficiently demonstrating the effect of suppressing the adhesion between the surface of the embedded object and the hydrate of the hydraulic composition.

Japanese Patent Application Laid-Open No. 11-241339 discloses a surface treating agent containing a water-swellable resin and an alkali-water-soluble resin having an acid value of 15 mgKOH / g or more. A buried object to which a water resistance imparting agent is attached is disclosed. By using this buried material, it is possible to suppress the adhesion between the base material surface and the hydrate of the hydraulic composition to improve the efficiency of foundation work and the like, and to coat the buried material outdoors by overcoating. Even if it is stored, it is possible to prevent the surface treatment layer from absorbing water and swelling due to rain, night dew, moisture from the ground,
There is room for research to further improve the efficiency in foundation work and the like by further balancing the water resistance of the top coat and the dissolution time in cement (alkaline) water. In other words, the surface of the buried object is required to be water-resistant to prevent rain wetting during storage of the buried object and to maintain the adhesion when the hydraulic composition is poured. After being embedded in the composition, before the cement water decreases due to the cement hardening, the overcoat is dissolved by the cement water, and the water absorption swelling of the surface treatment layer needs to be performed,
There is room for the buried object to exhibit these effects more fully and to devise ways to broaden the applications.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention has a surface treatment layer for suppressing the adhesion of a hydraulic composition to a hydrate, and has a water resistance and a solubility in alkaline water. It is an object of the present invention to provide a buried object capable of sufficiently exerting its action while protecting a surface treatment layer, and a method for preventing adhesion using the same, since the water-proof imparting layer is compatible with Things.

[0009]

Means for Solving the Problems The present inventors have studied the buried object which comes into contact with the hydrate of the hydraulic composition,
When the surface treatment layer and the water resistance imparting layer that suppress the adhesion of the hydraulic composition to the hydrate are provided on the substrate surface from the inside in this order, the surface treatment layer is protected by the water resistance imparting layer, Although it is possible to take measures against rain wetting during storage of buried objects and measures to maintain adhesion during casting of hydraulic compositions, a water-resistant layer is formed by using a resin having an acid value of 50 to 150 mgKOH / g as essential. By doing so, it has been conceived that both the water resistance and the solubility in alkaline water can be achieved, and the above-mentioned problem can be successfully solved. In addition, it has been found that when the surface treatment layer is formed with a specific resin as an essential component, the effect of suppressing the adhesion between the buried object and the hydrate of the hydraulic composition is more sufficiently exerted, and such It was also found that an anti-adhesion method using a buried object that can fully exert its function while protecting the surface treatment layer can improve the efficiency of foundation work etc. in the construction field and civil engineering field, and reached the present invention It was done.

[0010] That is, the present invention relates to a buried object which comes into contact with a hydrate of a hydraulic composition, wherein the buried object comprises a surface treatment layer for suppressing the adhesion of the hydraulic composition to the hydrate and a water-resistant layer. The water resistance imparting layer is a buried product formed essentially of a resin having an acid value of 50 to 150 mgKOH / g.

The present invention also relates to a method for preventing adhesion, in which an embedded object is brought into contact with a hydraulic composition, and after the hydraulic composition is hydrated, the embedded object is separated from the hydrate of the hydraulic composition. The present invention also provides a method for preventing adhesion between a buried product using the above-mentioned buried product and a hydrate of a hydraulic composition. Hereinafter, the present invention will be described in detail.

The embedded object of the present invention exhibits the following effects (1) to (5) by providing the surface treatment layer and the water resistance imparting layer on the substrate surface from the inside in this order. That is, (1) the surface treatment layer that suppresses the adhesion of the hydraulic composition to the hydrate swells by absorbing cement water (alkaline water) in the hydraulic composition, and the hydraulic composition hydrates. The surface treatment layer swollen in accordance with the above is dried and shrunk, and a gap can be formed between the substrate surface and the hydraulic composition. Therefore, the substrate surface, the hydraulic composition and its hydrate (cured product) Can be suppressed.
When the surface treatment layer is formed with the water-swellable resin as an essential component, such an effect is more reliably exerted.

(2) The surface treatment layer is brought into close contact with the surface of the base material. However, since the alkali water-soluble resin having an acid value of 15 mgKOH / g or more is essentially formed, the water-swellable resin is The water-absorbing and swelling properties are not hindered, and the above-mentioned effect (1) can be sufficiently exhibited.

(3) When the surface treatment layer is set to have high adhesion to the substrate surface but not high strength, it is possible to minimize peeling of the surface treatment layer due to a large scratching force. it can. (4) By using a solvent to form the surface treatment layer, since the surface treatment layer does not absorb and swell when applied, it is possible to apply a uniformly mixed product, Is low, and spray coating is also possible, which facilitates the coating operation. (5) Since the water resistance imparting layer is used as the top coat,
Improves water resistance, measures against rain when storing buried objects, maintains adhesion of surface treatment layer when casting hydraulic composition (prevents peeling), and ensures that surface treatment layer Water absorption swelling with alkaline water can be more sufficiently compatible.

[0015] The embedded object of the present invention has a surface treatment layer for suppressing adhesion of the hydraulic composition to the hydrate and a water resistance imparting layer on the substrate surface from the inside in this order. While maintaining the adhesion, the adhesion between the substrate surface and the hydrate of the hydraulic composition is suppressed. That is, in the embedded object of the present invention, the water-resistance imparting layer together with the surface treatment layer also exerts the function and effect of the present invention. Such a surface treatment layer and a water resistance imparting layer are formed by applying a surface treatment agent and a water resistance imparting agent, respectively.

The structure of the buried object of the present invention is not particularly limited as long as it has a surface treatment layer and a water resistance imparting layer on the substrate surface from the inside in this order. For example, it may or may not have another layered structure. In addition, as the coating form on the substrate surface of the buried object, all or a part of the substrate surface will be covered by the surface treatment layer and the water resistance imparting layer, and all or part of the surface treatment layer Is not particularly limited, as long as the function and effect of the present invention are exhibited, but is not particularly limited, and a base material that comes into contact with the hydrate of the hydraulic composition. By covering most of the surface with the surface treatment layer and the water resistance imparting layer, the effect of suppressing the adhesion of the hydraulic composition to the hydrate is more reliably exhibited.

First, the water resistance imparting layer which exhibits the function and effect of the present invention will be described. The water resistance imparting layer is formed essentially of a resin having an acid value of 50 to 150 mgKOH / g. That is, the acid value of the resin contained in the water resistance imparting agent is 50 mgKOH / g or more and 150 mKOH / g.
gKOH / g or less, and 60 mgKO
H / g or more and 120 mgKOH / g or less, preferably 70 mgKOH / g or more and 100 mgKO
Most preferably, it is H / g or less.

When the acid value of the resin contained in the above-mentioned water-resistance imparting agent is less than 50 mgKOH / g, the water resistance is very good, but the water-resistance imparting agent is further added on the surface treatment agent in the present invention. When the buried material (base material) is poured into the hydraulic composition, even if the hydraulic composition starts to harden and the water content starts to decrease, the water resistance imparting layer is not sufficiently dissolved. Since the water does not reach the treatment layer and the surface treatment layer cannot sufficiently absorb and swell, the effect of preventing adhesion between the surface of the embedded material (base material) and the hydrate (cured product) of the hydraulic composition is not sufficiently exhibited. . On the other hand, when the acid value of the resin contained in the water resistance imparting agent exceeds 150 mgKOH / g, the embedded material (base material) in which the water resistance imparting agent is further applied on the surface treatment agent of the present invention is washed with water. When poured into a hardening composition, the water-resistance imparting layer dissolves quickly, and the effect of preventing adhesion between the surface of the embedded material (base material) and the hydrate (cured product) of the hydraulic composition is as follows.
It is exhibited at the same level as when no water resistance imparting agent is applied, but there is a problem that the water resistance itself of the water resistance imparting layer is insufficient.

In the present invention, by specifying the water resistance imparting layer as described above, it is possible to exhibit its function and effect. For example, when the base material is stored, the surface treatment layer swells by absorbing water and the like from rain and night dew, ground, and can exert its effect sufficiently in the hydraulic composition. It is possible to suppress the disappearance, and it is possible to further suppress a decrease in the adhesion between the surface of the substrate and the surface treatment layer of the buried object. In other words, in the construction of the ground foundation structure, etc., both during storage of the base material before construction and during construction, the adhesion of the surface treatment layer is maintained (prevention of peeling), and the surface treatment layer is formed by the alkaline water in the hydraulic composition. It is possible to more reliably balance water absorption and swelling.

The resin contained in the water-resistance imparting agent is not particularly limited as long as the acid value is 50 to 150 mgKOH / g, and the surface treatment layer is sufficiently prevented from swelling before exerting its action. Preferably, for example, as a hydrophilic binder resin, α,
β-unsaturated carboxylic acid monomer copolymerized (meth)
Acrylic ester copolymers, polyurethanes, polyesters, polycarbonates, polyvinyl alcohol-based resins, polyvinyl acetate partial hydrolysates, ethylene-polyvinyl alcohol copolymers, and the like, and one or a mixture of two or more of these. Can be used. In addition, it is preferable that the water-resistance imparting agent contains a solvent in the same manner as the surface treatment agent described later to facilitate application to the substrate surface. Further, as other components, for example, wax or silicone-based water repellent A conventionally known water repellent such as an agent may be contained.

Among the resins having an acid value of 50 to 150 mg KOH / g, if the water resistance imparting layer is easily dissolved in the alkaline water (cement water) in the hydraulic composition, the function of the surface treatment layer will be sufficient. Alkaline water-soluble resins are preferred because they can exert their effects. The solubility of the alkaline water-soluble resin in alkaline water is not particularly limited as long as the characteristics of the present invention are not impaired. For example, 0.4
It is preferable that the resin is a resin that dissolves in an aqueous solution of NaOH having a concentration of% by weight and does not dissolve in neutral or acidic water. Such an alkaline water-soluble resin is not particularly limited as long as it has the above-mentioned solubility. For example, an α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith can be used. And the like.

The solubility of the above-mentioned alkaline water-soluble resin in alkaline water can also be evaluated, for example, by the weight reduction rate of the alkaline water-soluble resin in the following solubility test. That is, the solubility of the alkali water-soluble resin in the alkali water, which can be preferably used in the present invention, can be determined, for example, by obtaining a molded product of the alkali water-soluble resin having a shape of 5 mm or less (for example, using a twin-screw extruder. A cylindrical pellet shape of 3 mm in diameter and 3 mm in length as long as it can be formed, even if it is not pelletized, it may be a molded article cut to a size of 5 mm or less) 0.4 g of 10 g % Of NaOH aqueous solution, stirred at 25 ° C. for 24 hours, and can be obtained from the reduction rate of the weight of the alkali water-soluble resin molded body dissolved in alkaline water.

In the above-described solubility test in alkaline water, if there is any resin remaining without being dissolved after stirring for 24 hours, the resin is filtered off, washed with water, and the weight after drying is determined. Then, before being subjected to the solubility test, it can be determined by the rate of decrease from the weight of the original alkali water-soluble resin.
In other words, it can be determined by the ratio of (original weight-weight after solubility test) / (original weight) expressed in%.

The alkali water-soluble resin preferably has a solubility test value in alkaline water of 50 to 100% by weight. More preferably, 60 to 10
0% by weight. More preferably, 70 to 100% by weight
It is.

The alkaline water-soluble resin also includes
It is preferable that the polymer has a weight average molecular weight of 30,000 to 300,000 and a glass transition temperature of -20 to 120 ° C.

The surface treatment layer in the present invention is not particularly limited as long as it can suppress the adhesion between the substrate surface and the hydrate of the hydraulic composition. As a preferable form of such a surface treatment layer, for example, a form in which a water-swellable resin is essentially formed, or a form in which an alkali-water-soluble resin having an acid value of 15 mgKOH / g or more is formed as essential. Form.

When the surface treatment layer is formed essentially of a water-swellable resin, the buried material is embedded in a hydraulic composition such as cement, and then sufficiently absorbs and swells the alkaline water in the hydraulic composition. However, the surface treatment layer swollen as the hydraulic composition hydrates can sufficiently exhibit the effect of drying and shrinking. Furthermore, when an alkali water-soluble resin having an acid value of 15 mgKOH / g or more is formed as an essential component, that is, a water-swellable resin and an acid value of 15 mgKOH / g
/ G or more as an essential component, the alkali-water-soluble resin functions as a binder resin and dissolves in alkaline water, whereby the water-swellable resin more reliably exhibits its function. It becomes possible.

The water-swellable resin is not particularly limited as long as it is a resin which swells by absorbing water and has a water absorption ratio of ion exchange water to its own weight of 3 times or more.

Examples of the water-swellable resin include cross-linked poly (meth) acrylic acid, cross-linked poly (meth) acrylate, cross-linked poly (meth) acrylate having a sulfonic acid group, and polyoxyalkylene. Cross-linked poly (meth) acrylate, cross-linked poly (meth) acrylamide, cross-linked copolymer of (meth) acrylate and (meth) acrylamide, hydroxyalkyl (meth) acrylate and (meth) Cross-linked copolymer with acrylate, cross-linked polydioxolane, cross-linked polyethylene oxide, cross-linked polyvinyl pyrrolidone, cross-linked sulfonated polystyrene, cross-linked polyvinyl pyridine, saponified starch-poly (meth) acrylonitrile graft copolymer, starch- Poly (meth) acrylic acid (salt) graft-crosslinked copolymer, poly Reaction products of alkenyl alcohol and maleic acid (salt), cross-linked polyvinyl alcohol sulfonate, polyvinyl alcohol - acrylic acid graft copolymers, polyisobutylene maleic acid (salt) cross-linked polymer, and the like. These may be used alone or in combination of two or more.

The preferred form of the water-swellable resin is a water-swellable resin having a nonionic group and / or a sulfonic acid (salt) group, and more preferably a water-swellable resin having an amide group or a hydroxyalkyl group. And a cross-linked copolymer of (meth) acrylate and (meth) acrylamide, and a cross-linked copolymer of hydroxyalkyl (meth) acrylate and (meth) acrylate. be able to. A particularly preferred embodiment is a water-swellable resin having a polyoxyalkylene group. For example, a copolymerized crosslinked product of a (meth) acrylate ester having a methoxypolyoxyalkylene group and a (meth) acrylate salt And the like. In these embodiments, the water absorption of alkaline water is improved, but a water-swellable resin having a methoxypolyoxyalkylene group is particularly excellent.

As the water-swellable resin, a resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer and, if necessary, a monomer component containing a crosslinking agent can be used. . In this case, the water-swellable resin is preferable because it is excellent in water absorbability and generally inexpensive. The ethylenically unsaturated monomer that forms such a water-swellable resin and the crosslinking agent used as necessary are not particularly limited, but as the ethylenically unsaturated monomer, One or more of the exemplified monomers may be used.

(Meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, vinylsulfonic acid, (meth) allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, −
(Meth) acryloylethanesulfonic acid, 2- (meth)
Acryloylpropanesulfonic acid and alkali metal salts and ammonium salts of these monomers; N, N-dimethylaminoethyl (meth) acrylate and its quaternary products; (meth) acrylamide, N, N-dimethyl (meth) ) Acrylamide, 2-hydroxyethyl (meth) acrylamide, diacetone (meth) acrylamide, N
-(Meth) acrylamides such as isopropyl (meth) acrylamide and (meth) acryloylmorpholine, and derivatives of these monomers; hydroxyalkyl such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate (Meth) acrylates; polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, and methoxypolypropylene glycol mono (meth) acrylate; N -Vinyl-2-pyrrolidone,
N-vinyl monomers such as N-vinyl succinimide;
N-vinylamide monomers such as vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide; vinyl methyl ether and the like.

The preferred form of the ethylenically unsaturated monomer is a nonionic group and / or a sulfonic acid (salt).
And an ethylenically unsaturated monomer having a group, for example, 2- (meth) acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid,
(Meth) acrylamide, hydroxyalkyl (meth)
Acrylate, methoxypolyethylene glycol mono (meth) acrylate and the like can be exemplified. In addition, a particularly preferred embodiment includes an ethylenically unsaturated monomer having a polyoxyalkylene group. When the ethylenically unsaturated monomer in these forms is used, the water absorbability of the water-swellable resin with respect to alkaline water is improved. However, it is particularly preferable to use methoxypolyethylene glycol mono (meth) acrylate.

When two or more ethylenically unsaturated monomers are used in combination as the monomer component forming the water-swellable resin, the total amount of all the monomer components forming the water-swellable resin is 100%.
It is preferable that the proportion of the ethylenically unsaturated monomer having a nonionic group and / or sulfonic acid (salt) group is 1% by weight or more based on the weight%. When the amount is less than 1% by weight, the effect of water absorption due to the formation of an ethylenically unsaturated monomer having a nonionic group and / or a sulfonic acid (salt) group may be reduced. More preferably, it is at least 10% by weight.

The combination when two or more of the above ethylenically unsaturated monomers are used in combination is not particularly limited. For example, a combination of an alkali metal (meth) acrylate such as sodium acrylate and acrylamide, )
A combination of an alkali metal acrylate and methoxypolyethylene glycol mono (meth) acrylate is preferred.

The polymerization method for producing the above-mentioned water-swellable resin and the additives such as an initiator used for the polymerization are not particularly limited, and the polymerization can be carried out by a commonly used method. The weight-average molecular weight and shape of the water-swellable resin thus obtained, the average particle size, and the like may be appropriately set according to the composition of the surface treatment agent, the pH of alkaline water, the working environment, and the like, and are particularly limited. is not. For example, the average particle diameter is preferably 30 to 800 μm. If it exceeds 800 μm, when the water-swellable resin is mixed with the solvent solution of the binder resin, the particles of the water-swellable resin may be easily settled because the particles are too large. If the particles are too small, they may be easily scattered as fine powder, which may make handling difficult. More preferably, 30 to
600 μm, more preferably 30 to 400 μm
It is.

The alkaline water-soluble resin having an acid value of 15 mgKOH / g or more is not particularly limited as long as the acid value is 15 mgKOH / g or more. As a binder resin, a water-swellable resin is sufficiently fixed on a substrate. It preferably has a function. Examples of the type of such an alkali water-soluble resin include, for example, a hydrophilic binder resin capable of forming the above-mentioned water resistance imparting layer, and the like.
Species or a mixture of two or more can be used. The solubility in alkaline water of an alkaline water-soluble resin having an acid value of 15 mgKOH / g or more is not particularly limited as long as the characteristics of the present invention are not impaired. It is preferable to show the same solubility as an alkali water-soluble resin capable of forming a polymer. That is, it is preferably a resin that dissolves in a 0.4% by weight NaOH aqueous solution and does not dissolve in neutral or acidic water,
For example, a copolymer of an α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith may be used.

A preferred form of the alkali water-soluble resin having an acid value of 15 mgKOH / g or more is, for example, an acid value of 40 to 500 mgKOH / g. More preferably, it is 50 to 300 mgKOH / g. Also, as in the case of the water resistance imparting layer, the value of the solubility test in alkaline water is preferably 50 to 100% by weight. More preferably, 60 to 100% by weight
It is. More preferably, it is 70 to 100% by weight.
Further, it is preferable that the polymer has a weight average molecular weight of 30,000 to 300,000 and a glass transition temperature of -20 to 120 ° C.

In the present invention, in order to form the surface treatment layer, an isocyanate group-terminated urethane prepolymer having a binder function for the substrate surface and a water-absorbing swelling property for alkaline water can be used as the water-absorbing binder resin. Such an isocyanate group-terminated urethane prepolymer is cured by moisture and crosslinks, and adheres to the substrate surface.

As the isocyanate group-terminated urethane prepolymer, for example, a polymer obtained by essentially reacting a polyether polyol and / or a polyester polyol with an organic polyisocyanate can be used. These may be used alone, respectively.
More than one species may be used in combination. In the present invention, the isocyanate group-terminated urethane prepolymer swells by absorbing water. For example, a polymer having a water absorption capacity (water absorption swelling ratio) of 3 times or more relative to its own weight of ion-exchanged water may be used. preferable.

The polyether polyol is not particularly limited. For example, one or more alkylene oxides are added to at least one selected from the group consisting of low molecular polyols, polyhydric phenols and amines. Examples include an alkylene oxide adduct and a ring-opened polymer of an alkylene oxide. Examples of the addition form of such a polyether polyol include, for example, a block form,
There is no particular limitation such as a random shape.

Examples of the low molecular polyol include:
Bifunctional polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, and cyclohexylene glycol; and trifunctional or higher polyols such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, and souce, and the like. As the polyhydric phenols, for example,
Examples of the amines include alkanolamines such as triethanolamine and N-methyldiethanolamine; aliphatic polyamines such as ethylenediamine and diethylenetriamine; aromatic diamines such as tolylenediamine and diphenylmethanediamine. And the like.

Examples of the alkylene oxide include alkylene oxides having 2 to 4 carbon atoms such as ethylene oxide, propylene oxide and butylene oxide. Examples of the ring-opened polymer of the alkylene oxide include polytetramethylene ether glycol formed by ring-opening polymerization and hydrolysis of tetrahydrofuran.

The average hydroxyl group equivalent of the above polyether polyol is not particularly limited.
It is preferably 0. If it is less than 800, the expansion coefficient may not be sufficient, and if it is more than 4000, the shape retention and the like at the time of water absorption and swelling may be reduced. More preferably, it is 1000-3000.

Among the above polyether polyols, preferred are ethylene oxide adducts of polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin (polyoxyethylene polyols) and / or adducts of ethylene oxide and propylene oxide. [Oxyethylene / oxypropylene copolymer polyether polyol (copolyether polyol)]. More preferably, it is a copolymerized polyether polyol. In addition, other than these, other polyether polyols, for example, polyoxypropylene polyol, etc. can be used in combination.

The polyether polyol preferably has 30% by weight or more of oxyethylene groups. That is, the weight of ethylene oxide is preferably 30% by weight or more based on 100% by weight of the total weight of all alkylene oxides forming the polyether polyol. Thereby, the water absorption swelling ratio of the isocyanate group-terminated urethane prepolymer is increased, and the effect of the present invention can be more sufficiently exerted.

The polyester polyol is not particularly limited as long as it is a known polyester polyol produced from a dibasic acid and a diol or a dibasic acid anhydride and an oxyalkylene compound. Examples of diols such as aliphatic dibasic acids such as succinic acid and adipic acid, and aromatic dibasic acids such as phthalic acid and terephthalic acid include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, and propylene. Glycol, neopentyl glycol, and the like, which are obtained by combining these dibasic acids and diols and reacting them (under an OH group excess condition to make a terminal OH group).
In order for the urethane after the reaction to have water absorption, it is preferable that the polyester polyol also has high hydrophilicity.As the dibasic acid, an aliphatic dibasic acid is more preferable than an aromatic dibasic acid, and a carbon such as adipic acid is also used. Those having a small number are preferred, and the diol is preferably ethylene glycol or the like.

The organic polyisocyanate is not particularly restricted but includes, for example, aliphatic polyisocyanates and aromatic polyisocyanates. The aliphatic polyisocyanate is a polyisocyanate in which all isocyanate groups are bonded to non-aromatic hydrocarbon atoms, and is, for example, an aliphatic group having 2 to 12 carbon atoms (excluding carbon in the isocyanate group). Polyisocyanate, C4 to C15 alicyclic polyisocyanate, C8 to C
Twelve araliphatic (aliphatic having aromatic nuclei) polyisocyanates and modified products of these polyisocyanates. Examples of the modified product include a modified product having a carbodiimide group, a uretdione group, a uretoimine group, a urea group, a buret group, and / or an isocyanurate group.

Specific examples of the chemical name of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, , 2,4-trimethylhexanediisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6- Diisocyanate hexanoate; isophorone diisocyanate (IPDl), dicyclohexylmethane diisocyanate (hydrogenated MDl), cyclohexylene diisocyanate, methylcyclohexane Silylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) 4-cyclohexene-1,2-dicarboxylate; xylylene diisocyanate, diethylbenzene diisocyanate; water-modified HDI, trimerized IPDI, and the like. . Among them, HDI, IPDI or hydrogenated MD
Preferably, I is used.

The aromatic polyisocyanate is a polyisocyanate in which all isocyanate groups are bonded to aromatic hydrocarbon atoms. Specific chemical names include, for example, tolylene diisocyanate (TD)
I), 4,4'-diphenylmethane diisocyanate (TDI), crude MDI, and MDI modified to have a carbodiimide group, uretdione group, uretonimine group and the like as described in JP-B-55-27098. Is mentioned. Among these, TDI or M
Preferably, DI is used.

The above isocyanate group-terminated urethane prepolymer may be produced in one step by reacting a polyether polyol and / or a polyester polyol with an organic polyisocyanate. After obtaining a hydroxyl-terminated urethane prepolymer from a system-based polyisocyanate and excess polyether polyol and / or polyester polyol,
By reacting aromatic polyisocyanate,
Examples include a form of manufacturing in two stages. In the mode (2), an aliphatic group derived from an aliphatic polyisocyanate is bonded to an NH group of a urethane bond, and an isocyanate group-terminated urethane prepolymer having an isocyanate group derived from an aromatic polyisocyanate can be obtained. become.

In the embodiment (1), the molar ratio (NCO / OH ratio) between the isocyanate group and the hydroxyl group in the polyether polyol and / or polyester polyol and the organic polyisocyanate is, for example, 1.4 /
It is preferable to set it to 1 to 3/1. If it is less than 1.4 / 1, the adhesion of the surface treatment layer to the substrate surface may not be sufficient, and if it exceeds 3/1, the water absorption swelling rate may not be sufficient. More preferably, 1.6 / 1
２．５2.5 / 1. The reaction conditions include, for example, a reaction temperature of 60 to 100 ° C. and a reaction time of 4-1.
Preferably, it is 2 hours. More preferably, 70-
90 ° C. for 6 to 10 hours.

In the above-mentioned embodiment (2), the molar ratio (NCO / OH ratio) between the isocyanate group and the hydroxyl group is set to 1 / 1.2 to 1/8 when obtaining the hydroxyl group-terminated urethane prepolymer. preferable. More preferably, 1 / 1.5 to 1
/ 4. If it exceeds 1 / 1.2, the hydroxyl group-terminated urethane prepolymer will have a high viscosity and may be difficult to handle. If it is less than 1/8, the alkali resistance may decrease. In this case, the reaction temperature is 60-130.
C. and the reaction time is preferably 4 to 20 hours. More preferably, the temperature is set to 70 to 120 ° C. for 6 to 15 hours. The amount of the solvent used is preferably, for example, 0 to 120 parts by weight based on 100 parts by weight of the urethane prepolymer having a hydroxyl group. More preferably, it is 10 to 80 parts by weight. As the average hydroxyl equivalent of the obtained hydroxyl-terminated urethane prepolymer,
For example, it is preferably 900 to 25000. More preferably, it is 1300-9300.

In the above embodiment (2), the molar ratio of the isocyanate group to the hydroxyl group (NCO /
The OH ratio is preferably, for example, 1.4 / 1 to 3/1. More preferably, 1.6 / 1 to 2.5
/ 1. The reaction conditions between the hydroxyl-terminated urethane prepolymer and the aromatic polyisocyanate include, for example, a reaction temperature of 60 to 100 ° C. and a reaction time of 4 to 100 ° C.
It is preferably 12 hours. More preferably, 70
To 90 ° C. for 6 to 10 hours.

The reaction for obtaining the isocyanate group-terminated urethane prepolymer can be carried out in a solvent. As the solvent, for example, a polar solvent having no active hydrogen is preferably used. For example, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; etherified or esterified cellosolves such as dimethyl cellosolve and methyl cellosolve acetate; One or more kinds of solvents and the like can be used. The amount of the solvent used is preferably 0 to 70 parts by weight based on 100 parts by weight of the total of the polyether polyol and / or polyester polyol and the organic polyisocyanate. More preferably, it is 0 to 50 parts by weight.

In order to make the above reaction proceed, the reaction can be carried out in the presence of a catalyst. As such a catalyst, a conventionally known catalyst that generally promotes the reaction between an isocyanate group and an active hydrogen compound can be used, and examples thereof include organic metal catalysts such as dibutyltin dilaurate, lead octylate, and stannas octoate. And one or more of tertiary amine compounds such as triethylenediamine.

The above isocyanate-terminated urethane prep
The NCO% of the rimer should be 0.05-7%
Is preferred. More preferably, it is 0.1 to 4%. Up
The isocyanate group-terminated urethane according to the embodiment (2)
In the case of repolymers, the aliphatic poly
Mole of lysocyanate and aromatic polyisocyanate
The ratio should be, for example, 1 / 0.7 to 1/20
Is preferred. More preferably, it is 1 / 0.8 to 1/9.
You. Also, isocyanate group-terminated urethane prepolymer
Concentration of urethane bond to aliphatic group in solid content of
For example, 2.5 × 10^-Five~ 1.0 × 10^-3mol
/ G. More preferably, 7.0 ×
10^-Five~ 6.5 × 10^-1mol / g. Aromatic nuclei
As the combined urethane bond concentration, for example, 5.5 × 1
0^-Five~ 3.0 × 10^-3mol / g is preferred
No. More preferably, 1.5 × 10^-Four~ 2.0 × 10 ^-3
mol / g.

When the above-mentioned isocyanate group-terminated urethane prepolymer is used, another isocyanate group-terminated urethane prepolymer can be used in combination, if necessary. Other isocyanate group-terminated urethane prepolymers include, for example, isocyanate group-terminated urethane prepolymers described in JP-A-58-39088. It is preferable to use an isocyanate group-terminated urethane prepolymer in an amount of 20% by weight or more. More preferably, it is 50% by weight or more.

It is preferable that the surface treatment agent applied to the buried object of the present invention contains a solvent. As such a solvent, a known solvent used for ordinary paints and the like can be used, and is not particularly limited. Examples thereof include alcohols such as methanol, ethanol, and isopropyl alcohol; and aromatic hydrocarbons such as benzene and toluene. Ketones such as acetone and methyl ethyl ketone; aliphatic esters such as ethyl acetate and butyl acetate; ethylene glycol derivatives such as ethylene glycol and ethylene glycol monomethyl ether; propylene glycol monomethyl ether;
One or more of propylene glycol derivatives such as propylene glycol monomethyl ether acetate may be used. Further, when an isocyanate group-terminated urethane prepolymer is used to form the surface treatment layer, it is preferably one that does not hinder the formation of the surface treatment layer on the substrate surface by moisture curing. And a solvent that can be used in the reaction for obtaining the above-mentioned isocyanate group-terminated urethane prepolymer. In the present invention, when a solvent is used, the viscosity of the surface treatment agent or the water resistance imparting agent is reduced, and spray coating or the like is also possible, thereby facilitating the coating operation. In the present invention, a solvent contained in the resin can be used as the solvent.

Among the above solvents, it is preferable to use a solvent having a boiling point, safety and the like suitable for application to the surface of a substrate. If a solvent with a low boiling point is selected, it has a quick drying property, and a surface treatment layer can be formed in a short time, so that thick coating and the like can be easily performed, and if a solvent with a high boiling point is selected, the drying speed is adjusted, Workability in on-site work such as summertime can be made favorable. By using the solvent in this way,
There is no swelling due to water absorption of the surface treatment agent that occurs when a medium containing water is used, and the coating agent is not gelled, thereby facilitating the coating operation. If a highly volatile solvent such as methyl ethyl ketone or methanol is used, it is dried in about 10 minutes,
To dry much faster than when water is used as a medium, the next operation or step can be moved quickly,
The construction period or the time required for application to the substrate surface can be significantly reduced.

The above-mentioned surface treating agent may or may not contain other additives such as other resins, pigments, various stabilizers and various fillers as long as the function and effect are not impaired. Is also good. For example, in order to be able to easily determine that the surface treatment layer is formed, for the purpose of coloring, a pigment may be mixed, or if necessary, various additives for other uses may be mixed. Good.

The total amount of the water-swellable resin and the binder resin or the weight ratio of the water-absorbing binder resin to 100% by weight of all the components constituting the surface treatment agent in the present invention is, for example, 100% by weight of the surface treatment agent. For
It is preferably at least 50% by weight. If it is less than 50% by weight, the function and effect of the present invention may be impaired.
It is more preferably at least 70% by weight, particularly preferably at least 80% by weight.

The weight ratio of each component in the surface treatment agent applied to the buried object of the present invention is not particularly limited. For example, in order to surely exert the effect of the surface treatment agent, 100 parts by weight of the surface treatment agent is required. %, When the water-swellable resin and the binder resin are essential components, the water-swellable resin is 5 to 60% by weight and the binder resin is 10 to 70% by weight.
5% to 70% by weight of a solvent, and 0 to 50% of other additives.
% By weight. More preferably, the water-swellable resin is 10 to 50% by weight, and the binder resin is 10 to 6% by weight.
0% by weight, 10-60% by weight of solvent, 0-% of other additives
30% by weight. When a water-absorbing binder resin is used as an essential component, the water-absorbing binder resin has a content of 30 to 1%.
00% by weight, 0 to 70% by weight of solvent, 0 to 0% of other additives
Preferably it is 50% by weight. More preferably, the water-absorbing binder resin is 50 to 100% by weight, and the solvent is 0 to 100% by weight.
50% by weight, other additives 0-30% by weight.

The embedded object of the present invention has a surface treatment layer and a water resistance imparting layer on the substrate surface in this order by applying the surface treatment agent and the water resistance imparting agent to the substrate surface.
The function and effect can be exerted. Examples of the method of applying to the surface of the base material include (1) applying a surface treatment agent and a water resistance imparting agent in this order to the surface of the base material, And (2) applying a surface treatment agent and a water resistance imparting agent in this order to form a surface treatment layer and a water resistance imparting layer in this order from the inside. (3) attaching the surface-treated layer and the water-resistance-imparting layer in the form of a film to the substrate surface from the inside in this order, Pasting.

The method for applying the surface treatment agent and the water resistance imparting agent is not particularly limited, and for example, a commonly used coating method for a paint can be used.
The coating may be performed by using a roller or the like, or may be performed by spraying using a spray device such as lithiligan. Also,
It is applied to the surface of the substrate or the sheet so as to correspond to the portion (place) where the adhesion between the surface of the substrate and the hydrate of the hydraulic composition is to be prevented, but may be applied to other portions. The coating amount is not particularly limited. For example, in the case of a surface treatment agent, it is preferably 40 to 700 g / m ² .
If it is less than 40 g / m ² , the effects of the present invention may not be sufficiently exerted, and 700 g / m ^2.
If it exceeds, the time until application and drying is prolonged, which may be economically disadvantageous. More preferably, it is 50 to 500 g / m ² , still more preferably, 7 g / m ^2.
0 to 300 g / m ² . In the case of a water resistance imparting agent, about 50 g / m ² is sufficient. In the case where the surface treatment agent contains a water-absorbing binder resin, the surface treatment layer undergoes moisture curing when forming the surface treatment layer. However, the curing conditions are not particularly limited. For example, the curing condition is normal temperature (25 ° C.). It is preferable to set it for 5 hours to 2 days. The surface of the base material may be subjected to another surface treatment, or may be coated with an undercoat or the like.

When the above-mentioned surface treating agent or water-resistance imparting agent is applied to a sheet and the above-mentioned sheet is adhered to the surface of a substrate, for example, a sheet of cloth, paper, plastic film or the like can be used. In this case, it is preferable to apply a pressure-sensitive adhesive on the back surface of the sheet, since it is easy to attach the sheet to the surface of the base material. The pressure-sensitive adhesive is not particularly limited. For example, a commonly used acrylic pressure-sensitive adhesive may be used, or if a grease oil or the like is used, it is easy to peel off and re-attach when a mistake is made at a construction site. Is preferable.

When the buried object of the present invention is used, the above-described functions and effects are exhibited. However, the buried object is brought into contact with the hydraulic composition, and after the hydraulic composition is hydrated, the buried substance is hydrated. An anti-adhesion method for separating the hydrate of the hydraulic composition and the hydrate of the hydraulic composition, the method of preventing the adhesion between the hydrate of the hydraulic composition and the buried product using the buried product of the present invention,
The present invention is effective for exhibiting the function and effect of the present invention to improve the efficiency in various foundation works and the like. Such a method for preventing adhesion of a buried object is also one of the present invention.

The above-mentioned embedded material means a substrate which comes into contact with the hydrate of the hydraulic composition, that is, a substrate which is embedded in the hydraulic composition. A substrate before being embedded, (2) a substrate embedded in the hydraulic composition, (3) a substrate extracted from the hydraulic composition, and the like. That is, the above-mentioned buried object means the base material in these states. Further, the buried material of the present invention may be in contact with at least the hydrate of the hydraulic composition. That is, it is not necessary that the entire buried object is buried in the hydraulic composition, and it is sufficient that at least a part of the buried object is buried in the hydraulic composition.

The shape, length, material and the like of the above-mentioned buried object are not particularly limited. For example, H-section steel,
Columnar substrates such as I-beams, steel columns, concrete piles, poles, etc.
Examples include a cylindrical columnar base such as a tubular pile (hollow pile), a steel sheet pile (sheet pile) or a corrugated sheet which is a long plate-like pile, and among these, a steel sheet pile, an H-shaped steel, It is preferably a steel pipe pile or a cylindrical columnar substrate.

In the present invention, when the above-mentioned buried object constitutes a structure such as a ground foundation structure such as a retaining wall or a foundation, and the above-mentioned structure is constituted by at least the buried object and the hydraulic composition, Examples of the hydraulic composition constituting the above structure include various types of concrete, various types of mortar, and the like, but are not particularly limited. Examples of the form of such a hydraulic composition include water and a composition containing a material such as cement that hardens with water, and more specifically, water and cement such as Portland cement or mixed cement. And a composition containing, if necessary, an aggregate such as sand or gravel, a cement admixture, an admixture, a reinforcing material and the like. In this case, the type and combination of cement, aggregate, admixture, admixture, reinforcing material, and the like contained in the hydraulic composition, that is, the composition of the hydraulic composition is not particularly limited.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
4 will be described by way of example. In addition, FIG.
FIG. 4 is a schematic cross-sectional view of a case where the surface treatment layer is formed essentially of a water-swellable resin and a binder resin among the embedded materials in which the surface treatment layer and the water resistance imparting layer are formed on the substrate surface. , But we ’ve described these cases,
In the case where the surface treatment layer is formed with the water-absorbing binder resin as an essential component, the water-absorbing binder resin forms a surface treatment layer instead of the water-swellable resin and the binder resin and exerts its function.

FIGS. 1 to 4 are conceptual cross-sectional views illustrating an embodiment of a buried object according to the present invention. In FIG. 1, the hydraulic composition 2
FIG. 2 is a conceptual cross-sectional view of a part of a buried object 1 embedded in the vicinity of a surface of a base material. In FIG. 1 (1), the hydraulic composition 2 contains alkaline water and is in a state where hydration has not progressed, the water resistance imparting layer 7 is in a state where it has not yet been dissolved by alkaline water, and The treatment layer 3 is in a state where the alkaline water has not been sufficiently absorbed, and in (2), the hydration of the hydraulic composition 2 proceeds and the dissolution of the water resistance imparting layer 7 with the alkaline water proceeds. And the water-swellable resin in the surface-treated layer 3 is also in a state in which the water-swellable swelling has progressed,
In (3), the hydration of the hydraulic composition 2 is completed and the aqueous composition does not contain alkaline water, and the water-swellable resin that has absorbed and swollen is dried and hydrated with the surface treatment layer 3. 2
Is a state in which a gap is formed between them. In this way, the surface treatment layer 3 is protected by the water resistance imparting layer 7 until the state of FIG. The function of (3) is exhibited, and adhesion between the substrate surface and the hydraulic composition 2 is suppressed by the gap formed in the state of (3), and the embedded object 1 is hydrated with the hydraulic composition 2. It can be easily removed from the object. Further, even when the embedded object 1 is removed from the hydraulic composition 2 in the state shown in (2), the presence of the water-absorbed and swollen surface treatment layer 3 between the embedded object 1 and the hydraulic composition 2, This can be easily performed. In the figure, among the states in which the water resistance imparting layer 7 is formed,
The state in which the water resistance imparting layer 7 is not dissolved by the alkaline water is indicated by a thick line on the surface treatment layer 3, and the state in which part or all of the water resistance imparting layer 7 is dissolved is indicated by a thin line on the surface treatment layer 3. I have. This is the same in the following drawings.

FIGS. 2 (1) to 2 (3) exemplify a ground substructure formed in the ground 4. FIG. The ground substructure of FIG. 2A is formed of the hydraulic composition 2 and the buried object 1, and a surface treatment agent is applied to the surface of the base material of the buried object 1 prior to the formation of the ground substructure. Then, a water resistance imparting agent is applied to form the surface treatment layer 3 and the water resistance imparting layer 7. In this case, as a method of forming the ground foundation structure, for example, after forming an excavation hole in the ground 4 and loosely inserting the buried object 1, the hydraulic composition 2 is poured around the buried object 1. Alternatively, the embedding can be performed by embedding the buried object 1 in the hydraulic composition 2 that has been cast into a borehole. In such a ground substructure, an operation of removing the buried object 1 from the hydraulic composition 2 or its hydrate is performed.

The ground foundation structure shown in FIGS. 2 (2) and 2 (3) is formed of a hydraulic composition 2 and a tubular buried object 1a.
A surface treatment agent is applied to the upper (pile head) base material surface on the inner surface of the buried object 1a prior to formation of the ground substructure, and then a water resistance imparting agent is applied to the surface treatment layer 3 and the water resistance. The application layer 7 is formed. In this case, as a method of forming the ground foundation structure, for example, the method can be performed by embedding the buried object 1a in the hydraulic composition 2 that has been cast into an excavation hole. In such a ground foundation structure,
After the hydraulic composition 2 is hydrated, an operation of peeling off the hydrate of the hydraulic composition 2 from the pile head 2a on the inner surface of the buried object 1a is performed, and will be used for later foundation work. In addition,
2 (1) to 2 (3) show a state in which the water-swellable resin in the surface treatment layer 3 has swollen by water.

In the present invention, in the embodiment shown in FIGS. 2A to 2C, the water resistance imparting layer 7 and the surface treatment layer 3 act as shown in FIGS. 1A to 1C. Thereby, the work of pulling out the embedded material from the hydraulic composition or its hydrate can be performed efficiently and easily.

In the embodiment shown in FIGS. 1 and 2, since the surface treatment layer 3 gradually absorbs water from the surface, the water swelling ratio of the water-swellable resin is large near the surface of the surface treatment layer 3.
In some cases, the water-swelling resin existing near the substrate surface also gradually absorbs and swells. That is, in the present invention, when the water-swellable resin present in the surface treatment layer 3 absorbs and swells, a part thereof may be in a state of absorbing and swelling, or the whole may be in a state of absorbing and swelling. Also,
The conceptual diagram shows that the thickness of the surface treatment layer 3 is larger when the water-swellable resin swells than when it is dried. Actually, the thickness of the surface treatment layer 3 is several times to several tens times or more at the time of swelling with water absorption and at the time of drying. This is the same in the following embodiments and the like.

In the various structures described above, when the buried object is pulled out of the hydraulic composition, a cavity (hole) having the same shape as that of the buried object is formed in the structure.
The cavity can be used, for example, as a drain, electric wire,
It can be used as a pipe for inserting a gas pipe, a water pipe, or the like. In addition, the various structures may be bases for installing road signs and the like. That is, after the structure is formed using the embedded object of the road sign desired to be installed, the embedded object is pulled out and the road sign is inserted, whereby the road sign can be installed.

According to an embodiment of the present invention, after digging the ground and installing or constructing various structures below the ground surface,
A method for constructing an underground structure by backfilling with a backfill material in which a cement-based or lime-based solidified material is mixed, wherein the underground structure using the buried object of the present invention as a retaining wall or a member constituting the retaining wall is provided. Construction method. Such a method of constructing an underground structure is one of the preferred embodiments of the present invention.
One.

In the above method for constructing an underground structure, for example, a trench is excavated as a preliminary step, but prior to the excavation, along the outer periphery of the excavation area to prevent the ground outside the excavation area from loosening or collapse. An earth retaining wall made of steel sheet pile or the like will be constructed. After that, various underground structures are constructed inside the trench, the cut-out portion is backfilled with backfill material, and finally the retaining wall is removed by drawing or the like. here,
The water-resistance imparting layer protects the surface treatment layer, and the surface treatment layer exists between the earth retaining wall or a member constituting the earth retaining wall and the backfill material, and a part or all of the water resistance imparting layer is dissolved. Therefore, the separation of the surface treatment layer on the retaining wall or the member constituting the retaining wall can be prevented, and the material constituting the retaining wall or the retaining wall and the backfill material by swelling of the water-swellable resin. Since it is possible to prevent adhesion to the underground structure, it is possible to improve the efficiency of foundation work and the like even in such a method of constructing an underground structure.

An outline of the method of building the underground structure will be described with reference to FIG. In FIG. 3, the state of the foundation work in the construction of the underground structure 5 is shown as a conceptual sectional view. First, the surface treatment layer 3 and the water resistance imparting layer 7 according to the present invention are formed in this order from the inside on the base material surface of the construction member 1b such as a steel sheet pile, and the construction member 1b is built into the ground 4 and After the wall is formed, the ground 4 between the retaining walls is excavated to form a groove. Thereafter, the underground buried object 5 is installed in the excavated ground 4 and backfilled with the cement-based backfill material 2b, and further, a backfill material 6 such as soil used as necessary.
After that, the surface treatment layer 3 is formed, and the construction member 1b such as a steel sheet pile in which a part or the whole of the water resistance imparting layer 7 is dissolved is pulled out and removed. Thus, the surface treatment layer 3 formed on the construction member 1b such as a steel sheet pile or the like.
With the water resistance imparting layer 7, the construction member 1b such as a steel sheet pile constituting the earth retaining wall can be easily built in the ground or pulled out and removed from the ground while protecting the surface treatment layer 3. .

According to an embodiment of the present invention, the hydraulic composition is further cast using a movable mold, and after the hydraulic composition is cured, the movable mold is placed on the surface of the cured product of the hydraulic composition. This is a method for releasing a movable mold that slides along the movable mold, and includes a method for releasing a movable mold that uses the embedded object of the present invention as the movable mold. Such a method of releasing the movable mold form is one of preferred embodiments of the present invention.

In the method for releasing the movable mold form, for example, when constructing a concrete structure which extends long in the horizontal or vertical direction such as a chimney, a pier or a tunnel, a sewer, the hydraulic composition In order to construct the concrete, concrete is cast using a movable formwork. Then, after a certain level of strength is obtained, the movable mold is slid over the surface of the hardened concrete to the place where the next concrete is to be poured, and the mold is released. Casting is carried out, and concrete is constructed to construct a concrete structure. Here, the water resistance imparting layer protects the surface treatment layer, and the surface treatment layer exists between the movable mold and the hydraulic composition,
Since part or all of the water resistance imparting layer is dissolved, peeling of the surface treatment layer on the mold side can be prevented, and adhesion between the mold and the ground due to swelling of the water-swellable resin. Can be prevented, the surface treatment layer on the movable mold can be prevented from peeling, and the movable mold can be easily slid.

The movable mold is not particularly limited as long as it retains its shape until the hydraulic composition exhibits a predetermined strength and slides on the surface of the cured product after curing to release the mold. However, examples thereof include a form for a slip form method, a form for a jump form method, a machine used for various shield methods, and other sliding form forms.

The outline of the method for releasing the movable mold form will be described with reference to FIG. FIG. 4 is a conceptual cross-sectional view illustrating the construction of the hydraulic composition structure. First, using a movable mold 1c in which a surface treatment layer 3 and a water resistance imparting layer 7 according to the present invention are formed in this order from the inside on the surface of a base material, an existing hydraulic composition is cast and cured. After sliding the movable mold 1c on the upper part of 2c, a new hydraulic composition 2d is poured into the newly created space. Thus, the surface treatment layer 3 in the movable mold 1c
The water-resistance imparting layer 7 protects the surface treatment layer 3 and suppresses the adhesion between the movable mold and the hydraulic composition, and the water-swellable resin 3a in the swollen surface treatment layer 3 becomes wet. Since the movable mold can be easily slid by exerting the effect, it becomes easy to construct the hydraulic composition structure by handing over the hydraulic composition.

[0085]

EXAMPLES The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In the examples, “parts” means “parts by weight” unless otherwise specified.

Production Example 1 A water-swellable resin was prepared by the following method. That is, a kneader equipped with a table-top jacket having a capacity of 1.5 L and having a thermometer and a blade (stirring blade), the inner surface of which is lined with ethylene trifluoride, was used as a reactor, and methoxypolyethylene glycol methacrylate was added to the reactor. (Molecular weight 512) 60.18 g, methacrylic acid (molecular weight 86.09) 3.76 g, sodium methacrylate (molecular weight 108) 210.69 g, polyethylene glycol diacrylate 1.3 g as a cross-linking agent, and ion exchange as a solvent 352.37 g of water was charged. The proportion of the crosslinking agent in the monomer component is 0.14 mol%.

By flowing warm water of 50 ° C. through the jacket, the above aqueous solution was stirred under a nitrogen gas stream while stirring.
Heated to ° C. Then, 2,2'-azobis- (2-amidinopropane) dihydrochloride (molecular weight 2
71.27, Chemical product V-50 manufactured by Wako Pure Chemical Industries, Ltd.)
Was added and stirred for 10 seconds, then the stirring was stopped and the mixture was allowed to stand. The ratio of the polymerization initiator to the monomer component is 0.2 mol%.

The polymerization reaction was started immediately after the addition of the polymerization initiator, and the internal temperature reached 100 ° C. (peak temperature) after 90 minutes. Thereafter, the contents were aged for an additional 30 minutes while flowing hot water at 80 ° C. through the jacket. Thus, a hydrogel was obtained. After completion of the reaction, the hydrogel was disintegrated by rotating a blade until the hydrogel became fine, and then the hydrogel was taken out by inverting the reactor. The obtained hydrogel was dried at 140 ° C. for 3 hours using a hot-air circulation dryer. After drying, the dried product was pulverized using a desktop simple pulverizer (manufactured by Kyoritsu Riko Co., Ltd.). Thereby, a water-swellable resin (1) having an average particle diameter of 160 μm was obtained.

Production Example 2 0.45 kg of acrylic acid and 2.3 of ethyl acrylate were placed in a 50 L capacity tank reactor equipped with a thermometer and a dropping device.
kg, 0.25 kg of methyl methacrylate, 12 g of 2,2'-azobis- (2,4-dimethylvaleronitrile) as a polymerization initiator, and methyl alcohol 3 as a solvent
kg. In addition, acrylic acid 1.0
A mixed solution consisting of 5 kg, 2.2 kg of methyl acrylate, 3.75 kg of methyl methacrylate, 26 g of 2,2'-azobis- (2,4-dimethylvaleronitrile), and 7 kg of methyl alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring in a nitrogen gas atmosphere and reacted for 20 minutes. Thereby, the polymerization rate of the content was adjusted to 72%. Subsequently, while maintaining the internal temperature at 65 ° C., the above mixed solution was dropped uniformly from the dropping device over 2 hours. After completion of the dropwise addition, the content was aged at 65 ° C. for another 3 hours. After the reaction was completed, 10 kg of methyl alcohol was mixed with the contents to obtain a 33% by weight methyl alcohol solution of the binder resin (1).

The weight average molecular weight of the obtained binder resin (1) was 120,000, and the acid value was 115 mgKOH / g. As a result of performing differential scanning calorimetry on the binder resin (1), the binder resin (1) had two glass transition temperatures in the range of -80 ° C to 120 ° C.

Production Example 3 Newpole PE75 [trade name, manufactured by Sanyo Chemical Industries, Ltd., polypropylene glycol / polyethylene glycol = 5]
0/50 (weight ratio)] to 100 parts of TDI-80
(Trade name, mixing ratio of 2,4-isomer and 2,6-isomer 8
20.4 parts [NCO / OH = 2.4 (molar ratio)] of 0/20 tolylene diisocyanate) was added thereto, and the mixture was reacted at 80 ° C. for 8 hours. 1) was obtained.

Production Example 4 0.37 kg of acrylic acid and 2.3 of ethyl acrylate were placed in a 50 L capacity tank reactor equipped with a thermometer and a dropping device.
kg, 0.43 kg of methyl methacrylate, 12 g of 2,2'-azobis- (2,4-dimethylvaleronitrile) as a polymerization initiator, and methyl alcohol 3 as a solvent
kg. In addition, acrylic acid 0.8
A mixed solution consisting of 6 kg, 2.2 kg of methyl acrylate, 3.94 kg of methyl methacrylate, 24 g of 2,2'-azobis- (2,4-dimethylvaleronitrile) and 7 kg of methyl alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring in a nitrogen gas atmosphere, and reacted for 20 minutes. Thereby, the polymerization rate of the content was adjusted to 72%. Subsequently, while maintaining the internal temperature at 65 ° C., the above mixed solution was dropped uniformly from the dropping device over 2 hours. After completion of the dropwise addition, the content was aged at 65 ° C. for another 3 hours. After the completion of the reaction, a 33% by weight methyl alcohol solution of the water resistance imparting resin (1) was obtained by mixing the content with 10 kg of methyl alcohol.

The obtained water resistance imparting resin (1) had a weight average molecular weight of 140,000 and an acid value of 95 mgKOH / g. As a result of performing differential scanning calorimetry on the water resistance imparting resin (1), the water resistance imparting resin (1) had two glass transition temperatures in the range of -80 ° C to 120 ° C.

Comparative Production Example 1 0.16 kg of acrylic acid and 2.3 of ethyl acrylate were placed in a 50 L capacity tank reactor equipped with a thermometer and a dropping device.
kg, 0.64 kg of methyl methacrylate, 12 g of 2,2'-azobis- (2,4-dimethylvaleronitrile) as a polymerization initiator, and methyl alcohol 3 as a solvent
kg. In addition, acrylic acid 0.3
A mixed solution comprising 6 kg, 2.2 kg of methyl acrylate, 4.4 kg of methyl methacrylate, 25 g of 2,2'-azobis- (2,4-dimethylvaleronitrile), and 7 kg of methyl alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring in a nitrogen gas atmosphere, and reacted for 20 minutes. Thereby, the polymerization rate of the content was adjusted to 72%. Subsequently, while maintaining the internal temperature at 65 ° C., the above mixed solution was dropped uniformly from the dropping device over 2 hours. After completion of the dropwise addition, the content was aged at 65 ° C. for another 3 hours. After completion of the reaction, a 33% by weight methyl alcohol solution of the comparative water resistance imparting resin (1) was obtained by mixing the content with 10 kg of methyl alcohol.

The comparative water resistance imparting resin (1) thus obtained had a weight average molecular weight of 140,000 and an acid value of 40 mg KOH /
g. As a result of performing differential scanning calorimetry on the comparative water resistance imparting resin (1), the comparative water resistance imparting resin (1) has two glass transition temperatures in the range of -80 ° C to 120 ° C. I was

Comparative Production Example 2 0.64 kg of acrylic acid and 2.3 of ethyl acrylate were placed in a 50 L capacity tank reactor equipped with a thermometer and a dropping device.
kg, 0.16 kg of methyl methacrylate, 12 g of 2,2'-azobis- (2,4-dimethylvaleronitrile) as a polymerization initiator, and methyl alcohol 3 as a solvent
kg. In addition, acrylic acid 1.4 was added to the dropping device.
A mixed solution composed of 4 kg, 2.2 kg of methyl acrylate, 3.32 kg of methyl methacrylate, 26 g of 2,2'-azobis- (2,4-dimethylvaleronitrile), and 7 kg of methyl alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring in a nitrogen gas atmosphere, and reacted for 20 minutes. Thereby, the polymerization rate of the content was adjusted to 72%. Subsequently, while maintaining the internal temperature at 65 ° C., the above mixed solution was dropped uniformly from the dropping device over 2 hours. After completion of the dropwise addition, the content was aged at 65 ° C. for another 3 hours. After completion of the reaction, a 33% by weight methyl alcohol solution of the comparative water resistance imparting resin (2) was obtained by mixing the content with 10 kg of methyl alcohol.

The obtained water resistance imparting resin for comparison (2) had a weight average molecular weight of 130,000 and an acid value of 160 mg KOH.
/ G. As a result of performing differential scanning calorimetry on the comparative water resistance imparting resin (2), the comparative water resistance imparting resin (2) has two glass transition temperatures in the range of -80 ° C to 120 ° C. I was

Example 1 50 parts of the water-swellable resin (1) obtained in Production Example 1, 150 g of a 33% methanol solution of the binder resin (1) obtained in Production Example 2, and 50 g of 2-butanone were thoroughly mixed and stirred. ,
A surface treating agent (1) was obtained. The surface treating agent (1) was applied to a steel plate having a thickness of 3 mm, a width of 30 mm, and a length of 300 mm at a coating amount of 400 g / m ² when dried, dried at room temperature for 1 hour, and further produced thereon. The water-resisting resin obtained in the above was applied at a coating amount of 100 g / m ² when dried, and
After drying for a time, a water resistant friction cut steel sheet (1) was obtained. Next, the water resistant friction cut steel sheet (1) was
After being immersed in ion-exchanged water at 0 ° C. for 24 hours, the appearance was evaluated, and the results are summarized in Table 1.

Further, a polypropylene cylinder having a diameter of 80 mm and a height of 250 mm was filled with a cement milk having the composition shown in Table 2 to a height of 150 mm, and a water-resistant friction-cut steel plate (1) was set upright thereat at room temperature. (About 20 ° C.) for 7 days. After hardening for 7 days, the steel sheet was manually pulled out using only a 490N spring and the pulling force was measured. Table 1 summarizes the results.

Example 2, Comparative Examples 1 to 4 The same operation as in Example 1 was carried out except that the surface treating agent and the water-resistance imparting resin described in Table 1 were used, and the results of water resistance and anti-adhesion were obtained. Was. Table 1 summarizes the results.

[0105]

[Table 1]

[0106]

[Table 2]

[0107]

【The invention's effect】

Since the buried product of the present invention has the above-mentioned structure, it has a surface treatment layer for suppressing the adhesion of the hydraulic composition to the hydrate, and has a water resistance and a solubility in alkaline water. Has a water resistance imparting layer that is compatible with the above, so that its action can be sufficiently exhibited while protecting the surface treatment layer. In addition, using the method for preventing adhesion between a buried product and a hydrate of a hydraulic composition according to the present invention is effective for suppressing the cost for foundation work and the like and for quickly completing the work.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view for explaining the function and effect of a surface treatment layer and a water resistance imparting layer in an embodiment of the present invention.

FIG. 2 is a conceptual cross-sectional view illustrating an embodiment of the present invention, and is a conceptual cross-sectional view showing a ground foundation structure using a buried object of the present invention.

FIG. 3 is a conceptual cross-sectional view illustrating an embodiment of the present invention, and is a conceptual cross-sectional view for explaining a method of building an underground structure.

FIG. 4 is a conceptual cross-sectional view illustrating an embodiment of the present invention, and is a schematic cross-sectional view for explaining a method of releasing a movable mold.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 buried object 1a tubular buried object 1b construction member such as steel sheet pile 1c movable formwork 2 hydraulic composition 2a pile head 2b cement-based backfill material 2c existing hydraulic composition 2d newly cast Hydraulic composition 3 Surface treatment layer 3a Water-swellable resin 3b Binder resin 4 Ground 5 Underground buried material 6 Backfill material such as soil used as necessary 7 Water resistance imparting layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Hattori 4-1-1, Koraibashi, Chuo-ku, Osaka-shi, Osaka F-term in Nippon Shokubai Co., Ltd. (Reference) 2D049 FA04 FB03 FB12 FB13 FB14 2D050 AA06 AA12 AA13 DA10

Claims (5)

[Claims] 1. A buried material that comes into contact with a hydrate of a hydraulic composition, wherein the buried material is a surface treatment layer and a water-resistance imparting layer that suppress adhesion of the hydraulic composition to the hydrate. And the water resistance imparting layer has an acid value of 50
A buried product characterized by being formed essentially with a resin of up to 150 mgKOH / g. 2. The embedded object according to claim 1, wherein the surface treatment layer is formed essentially of a water-swellable resin. 3. The surface treatment layer has an acid value of 15 m.
3. The buried product according to claim 2, wherein the buried product is formed essentially of an alkali water-soluble resin having a gKOH / g or more. 4. An anti-adhesion method for bringing an embedded object into contact with a hydraulic composition, separating the embedded object and the hydrate of the hydraulic composition after the hydraulic composition is hydrated, and comprising: Item 1,
4. A method for preventing adhesion between a buried object and a hydrate of a hydraulic composition, characterized by using the embedded object according to 2 or 3. 5. The buried object and the hydrate of the hydraulic composition according to claim 4, wherein the buried object is a steel sheet pile, an H-shaped steel, a steel pipe pile, or a cylindrical columnar substrate. How to prevent adhesion.