JP3273040B2 - Release method of movable formwork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a chimney, a pier,
Alternatively, the present invention relates to a method for releasing a movable mold used to construct a hydraulic composition by a unit length when constructing a concrete structure which extends horizontally or vertically, such as a tunnel or a sewer.

[0002]

2. Description of the Related Art Conventionally, concrete is cast using a movable formwork, and after a certain degree of strength is obtained, the next concrete is cast on the surface of a cured concrete product. A concrete structure is constructed by sliding a mold to a place, releasing the mold, placing new concrete in a newly created space, and continuing the concrete.

[0003] However, the movable form and the surface of the hardened concrete are strongly adhered to each other, and a very large force is required to slide the form. Therefore, a large-scale device and a large amount of power are required. There are drawbacks needed.

[0004] As a conventional technique, it has been proposed to apply a lubricating oil such as wax or grease to a mold in advance to reduce the adhesive force between the hardened concrete and the mold. Although this method slightly reduces the power required to move the formwork, the rate of the reduction is extremely insufficient.

Japanese Unexamined Patent Publication (Kokai) No. 2-112561 proposes a method for releasing a concrete form in which a substance containing a water-absorbing resin and / or a glue material is interposed on a contact surface between concrete and the concrete form. Although the frictional force can be reduced by this method, the glue material shown in this method is a water-soluble resin. There is a drawback that peeling off occurs and the predetermined performance cannot be exhibited. The mold is used by spraying a mixture of an aqueous solution of a water-soluble resin in water and a water-absorbent resin, for example. Such a mixture becomes gel-like due to the absorption of water by the water-absorbent resin. The application work is extremely difficult due to clogging and the like, and it is very difficult to handle even with a brush or the like. Furthermore, once the water-absorbent resin has absorbed water, drying is very slow, and after spraying the mixture onto a mold or a non-woven fabric, the mixture is dried to obtain adhesion between the mixture and the mold or the mixture and the non-woven fabric. There is a disadvantage that it takes a lot of time and effort to complete. In addition, if used with insufficient drying, it will not only be difficult to work due to stickiness and slippage, but also because of the low strength of the mixture of the water-absorbent resin and the glue material, it will fall off from the formwork, rope, etc. The mixture may fall off the mold due to rubbing or contact with other materials. Furthermore, the adhesion of the water-absorbent resin to the form is insufficient, and the water-absorbent resin is peeled off from the form while the concrete is still flowing after casting the concrete, and the concrete rises to the upper layer of the concrete and has a predetermined effect. There is a disadvantage that is not exhibited.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide neutral water such as rainwater between a movable mold and a hydraulic composition. By easily producing an anti-adhesive layer with sufficient adhesion to the mold without being peeled off even by water wetting, etc., the movable mold and the cured product of the hydraulic composition can be easily and stably formed. The present invention is to provide a mold releasing method for a mold, in which the adhesive force and frictional force between the molds are reduced, and the movable mold is easily released by sliding along the surface of the cured product.

[0007]

Means for Solving the Problems In order to solve the above-mentioned conventional problems, the inventor of the present invention has intensively studied an anti-adhesion material interposed between a mold and a hydraulic composition to prevent the adhesion between the two. . As a result, the water-absorbing resin and the alkali water-soluble resin or the acid value of 40 mgKOH / g to 500 mgK
An anti-adhesion material containing a mixture of OH / g and a resin (both resins may be collectively referred to as a binder resin) is adhered to the surface of the movable mold that comes into contact with the hydraulic composition, or The anti-adhesion material, which is formed by bonding the anti-adhesion material to a substrate such as cloth, paper, and plastic film, suppresses the adhesion between the mold and the cured product of the hydraulic composition by attaching the sheet to the surface of the mold. It was found that the formwork could be moved with very little power, and that it did not peel off due to wetness with neutral water such as rainwater as an anti-adhesion material. The invention has been completed.

According to the above method, a layer of a water-absorbing resin swollen by absorbing water is formed between the mold and the hydraulic composition. The swelled layer of the water-absorbing resin can suppress the adhesion between the two. In addition, when the mold is slid and released from the cured product of the hydraulic composition, the swelled water-absorbing resin exerts a lubricating effect, so that the building member becomes slippery. Therefore, the labor (tensile force) in the drawing operation can be further reduced,
Workability of the work can be improved.

The anti-adhesion material used for the contact surface between the movable mold of the present invention and the hydraulic composition is an alkali water-soluble resin or an acid value of 40 mgKOH / g to 500 mg.
The resin of mg KOH / g (hereinafter, both resins may be collectively referred to as a binder resin) holds, for example, a predetermined amount of a water-absorbing resin at a position where an anti-adhesion effect is desired in a movable mold. Used as a binder to keep it.

[0010] The anti-adhesion material of the present invention mainly comprises a water-absorbing resin and a binder resin. Other additives may be added as long as the desired effect is not impaired. More preferably, the binder resin is made of an alkali water-soluble resin. Even in this case, other binder resins may be blended as long as the solubility of the binder resin of the present invention in alkaline water is not hindered. However, preferably, the blending amount of the other binder resin is 30-0% by weight. Further, the above-mentioned alkali water-soluble resin is sometimes referred to as an alkali-soluble resin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An alkaline water-soluble resin, which is a binder resin constituting an anti-adhesion material interposed between a mold and a hydraulic composition, is dissolved in a 0.4% by weight aqueous solution of sodium hydroxide. It is a resin that does not dissolve in neutral or acidic water. The type of the alkali water-soluble resin is not particularly limited as long as it has the solubility specified above. For example, an α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith can be used. Copolymers can be mentioned.

Although the solubility in alkaline water is as described above, the degree of solubility is not particularly limited, but the preferable solubility of the alkali water-soluble resin as a binder resin that can be preferably used in the present invention will be described later. . In addition, the term “alkali water-soluble resin” of the present invention may be expressed as an alkali-soluble resin in another expression. Since it is more clear to use an alkali water-soluble resin,
In the present invention, an alkali water-soluble resin is used.

The α, β-unsaturated carboxylic acid used in the production of the binder resin of the present invention includes, for example, α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid and fumaric acid. Acids; α, β-unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride; maleic acid monoester, fumaric acid monoester,
Α, β-unsaturated dicarboxylic acid monoesters such as itaconic acid monoester. The above α, β-
The unsaturated carboxylic acid may be only one kind or two or more kinds. Among them, acrylic α, β-
Acrylic acid and / or methacrylic acid, which are unsaturated carboxylic acids, are preferably used because they are inexpensive and have good copolymerizability with other unsaturated monomers.

The binder resin of the present invention comprises the above α, β
A copolymer obtainable by polymerization using an unsaturated monomer component comprising an unsaturated carboxylic acid monomer and another monomer copolymerizable therewith.

The ratio of the α, β-unsaturated carboxylic acid in the binder resin is defined as the ratio of the unsaturated monomer comprising the above α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith. When the monomer component is 100% by weight, a binder resin obtained by polymerizing an unsaturated monomer component is preferably used in an amount of 7 to 80% by weight based on the total amount of the unsaturated monomer component. More preferably, this component ratio is 7 to 50% by weight. More preferably, it is 9 to 30% by weight.

That is, α, β-
The ratio of the structure derived from the unsaturated carboxylic acid is preferably 7
~ 80% by weight. More preferably, it is 7 to 50% by weight.
More preferably, it is 9 to 30% by weight.

When the proportion of the α, β-unsaturated carboxylic acid is less than 7% by weight, the acid value of the binder resin becomes low, and the carboxyl group in the polymer is changed to water (in the hydraulic composition) which exhibits alkalinity. (Hereinafter, it may be referred to as “alkali water”.) The salt is formed by neutralization, and the degree of improvement in the hydrophilicity of the polymer becomes small, so that the solubility in alkali water becomes poor. On the other hand, when the proportion exceeds 80% by weight, there is a problem in water resistance to neutral and acidic water. For this reason, the acid value of the polymer is preferably 40 mgKOH / g or more, more preferably 50 mgKOH / g or more in order to have appropriate solubility in alkaline water.
More preferably, it is 70 mgKOH / g or more. In order to maintain the water resistance, it is preferably at most 500 mgKOH / g, more preferably at most 300 mgKOH / g. More preferably, 200 mg KOH
/ G or less.

Examples of other monomers include those having 1 to 18 carbon atoms such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and stearyl methacrylate. Esters of monohydric alcohols with (meth) acrylic acid; acrylonitrile,
Nitrile group-containing vinyl monomers such as methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; hydroxyl-containing vinyl monomers such as hydroxyethyl acrylate and hydroxypropyl methacrylate; glycidyl methacrylate and the like Epoxy group-containing vinyl monomers; metal salts of α, β-unsaturated carboxylic acids such as zinc acrylate and zinc methacrylate; styrene, α
-Aromatic vinyl monomers such as methylstyrene; aliphatic vinyl monomers such as vinyl acetate; halogen-containing vinyl monomers such as vinyl chloride, vinyl bromide, vinyl iodide, and vinylidene chloride; allyl ether Maleic acid derivatives such as dialkyl esters of maleic acid; fumaric acid derivatives such as dialkyl esters of fumaric acid; maleimide derivatives such as maleimide, N-methylmaleimide, stearylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide; itaconic acid Itaconic acid derivatives such as dialkyl esters, itaconamides, itaconic imides and itaconamide esters; alkenes such as ethylene and propylene; and dienes such as butadiene and isoprene.

The amount of the other monomer component used as a raw material in the case of producing the binder resin of the present invention, that is, the binder resin obtained by polymerizing the above-mentioned unsaturated monomer component, is as follows. an unsaturated monomer component comprising a β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith;
As 00% by weight, preferably 93 to 20% by weight based on all components of the unsaturated monomer. More preferably, it is 93 to 50% by weight. More preferably, it is 91 to 70% by weight.

The other monomer may be only one kind,
Two or more types may be used. Of these, alkyl acrylates and / or methacrylates are readily available in the form of esters having various properties, and by appropriately combining them, the degree of solubility of the binder resin in alkaline water and the flexibility thereof can be improved. It is preferably used because it can control the degree of adhesion and the degree of adhesion to base materials such as molds, papers, films, and various cloths, and has good copolymerizability. In this sense, the above-mentioned alkyl (meth) acrylate is preferably used in an amount of from 30% by weight to 100% by weight, and more preferably from 50% by weight to 100% by weight, based on 100% by weight of the other monomer components. More preferably, it is used. More preferably 60
-100% by weight, more preferably 70-100% by weight
It is. That is, the use of an acrylic monomer as another monomer is a preferred embodiment as a form of the alkali water-soluble resin as the binder resin of the present invention.

(Meth) acrylic monomers such as (meth) acrylic acid and (meth) acrylic acid ester have the preferable properties described above, and can be obtained easily and at low cost. Therefore, as the binder resin, the ratio of the structural unit derived from the (meth) acrylic monomer is 5% of the polymer.
A (meth) acrylic polymer occupying 0% by weight or more is preferred. More preferably, it is 60% by weight. More preferably, it is 70% by weight.

Although the glass transition temperature of the binder resin is not particularly limited, it should have a glass transition temperature of -20 ° C to 120 ° C from the viewpoint of coexistence with the mold and toughness of the anti-adhesive layer. Is preferred. Glass transition temperature is-
When the temperature is lower than 20 ° C., the anti-adhesion material is likely to be sticky, and particularly when processed into a sheet, blocking may occur. Further, the strength of the anti-adhesion material is insufficient, so that the anti-adhesion material layer formed on the base material, the mold, or the like is easily damaged, which is not preferable. From this, it is more preferable that the glass transition temperature is 0 ° C. or higher.

If the glass transition temperature is 120 ° C. or higher, the anti-adhesion layer becomes too hard, and the adhesion to the base material and the mold and the flexibility of the anti-adhesion material become poor. It is not preferable because it easily falls off from the frame or the like. From this, it is more preferable that the glass transition temperature is 100 ° C. or less, and if the glass transition temperature is between 0 ° C. to 20 ° C. and 20 ° C. to 100 ° C., respectively, the softening component and the shape maintaining component are Good balance is more preferable.

The weight average molecular weight of the binder resin is not particularly limited, but is preferably in the range of 30,000 to 300,000, and more preferably in the range of 50,000 to 200,000. By using the resin having the above-mentioned weight average molecular weight, it becomes easy to balance the toughness of the anti-adhesion material with the solubility in alkaline water.

The alkali water-soluble resin, which can be preferably used in the present invention, is soluble in alkaline water, and the desired effect of the present invention is to prevent the adhesion between the backfill material having solidification and the retaining wall. There is no particular limitation as long as there is no problem in the effect.

For example, it can be specified by the weight reduction rate of the alkali water-soluble resin in the following solubility test. The solubility of the alkali water-soluble resin that can be preferably used in the present invention in alkaline water is, for example, a molded product of the alkali water-soluble resin having a shape of 5 mm or less (for example, a 3 mm pellet shape as described in Examples, pellets). Even if it is not converted, it may be cut to a size of 5 mm or less.) 10 g of 0.4% by weight of NaO
H is added to 500 g of an aqueous solution of H, and stirred at 25 ° C. for 24 hours.

That is, if any resin remains without being dissolved after stirring for 24 hours, the resin is filtered, washed with water, and the weight after drying is determined. Before being subjected to the solubility test, it can be determined by a reduction rate from the weight of the original alkali water-soluble resin. That is, <original weight−weight after solubility test> / <
Original weight> can be determined in terms of%.

The alkaline water-soluble resin of the present invention includes:
This value is preferably between 50% and 100%. More preferably, it is 60-100%. More preferably, it is 70-100% by weight. The unsaturated monomer components described above may be appropriately combined depending on the application conditions, the type and physical properties of the water-absorbing resin to be mixed, and the solubility may be set within this range.

The anti-adhesion material of the present invention comprises a water-absorbing resin and a binder resin. If there is no problem, other additives or the like may be added up to 20-0% by weight based on 100% by weight of the adhesion preventing material.

The usage ratio of the water-absorbent resin and the binder resin in the anti-adhesive material of the present invention is the form of the mold release method used, the form of the movable mold, and the use of a casting mold. It may be determined according to the hydraulic composition or the like, and is not particularly limited. For example, as a usage ratio of the water-absorbing resin and the binder resin in the anti-adhesion material of the present invention, a ratio of 5 to 80% by weight of the water-absorbing resin and 95 to 20% by weight of the binder resin is preferable. Further, more preferably, the water-absorbing resin,
10-70% by weight and 90-30% by weight of binder resin. Mixing both at this ratio is one of the preferred embodiments of the anti-adhesion material of the present invention.

The binder resin is preferably produced by solution polymerization in an organic solvent. In this method, a water-absorbing resin is directly mixed with a solution containing a binder resin obtained by solution polymerization to prepare a coating for forming an anti-adhesive material, and then applied,
This is because by drying, an anti-adhesion material layer can be easily formed on the surface of the mold. These coatings
A brush, a roller or the like may be used, or a spray coating may be performed using a ricin gun or the like. Further, by applying the coating material to a base material such as paper, film, cloth or the like, a sheet-like processed product of an anti-adhesion material can be easily obtained, and this may be attached to a form. Examples of the polymerization method include anionic polymerization, cationic polymerization, and radical polymerization, and radical polymerization is preferred.

The radical polymerization initiator used in the radical polymerization is not particularly limited, but specific examples thereof include 2,2′-azobisisobutyronitrile and 2,2 ′
Azo-based initiators such as -azobis (2,4-dimethylvaleronitrile); and peroxide-based initiators such as benzoyl peroxide and di-t-butyl peroxide. Two or more of these radical polymerization initiators may be used in combination.

The solvent used in the solution polymerization is not particularly limited as long as it does not hinder the radical polymerization reaction.
For example, alcohols such as methanol, ethanol and isopropyl alcohol; aromatic hydrocarbons such as benzene and toluene; ketones such as acetone and methyl ethyl ketone; aliphatic esters such as ethyl acetate and butyl acetate;
Examples thereof include ethylene glycol derivatives such as ethylene glycol and ethylene glycol monomethyl ether, and propylene glycol derivatives such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate. Two or more of these solvents may be used in combination. Also, later, formwork or cloth,
It is preferable to select a solvent having a preferable boiling point, safety and the like for application to a substrate on paper, a plastic film or the like as a solvent for polymerization. If a solvent having a low boiling point is selected, it has a quick drying property, and a coating film can be formed in a short time, so that a thick coating or the like can be easily performed. If a solvent having a high boiling point is selected, the working time can be lengthened. By using an organic solvent,
When an aqueous medium is used, the water-absorbent resin does not swell due to water absorption, and does not become a gel, thereby facilitating the coating operation. In addition, if a highly volatile solvent such as methyl ethyl ketone or methanol is used, it will dry in about 10 minutes, and it will dry much faster than the case where water is used as a medium, so that it can move to the next operation quickly, Can be shortened.

Examples of the reaction vessel used for producing the raw material polymer include a tank reactor, a kneader, and a tubular reactor such as a static mixer. These reactors can be used together if necessary. A dropping tank is also used as needed. The pressure in the reaction vessel may be any of reduced pressure, normal pressure, and pressurized.

The water-absorbing resin constituting the anti-adhesion material may be any resin that swells by absorbing water and has a water absorption ratio of ion exchange water to its own weight of 3 times or more. Specific examples of the water-absorbent resin include, for example, a cross-linked poly (meth) acrylic acid, a cross-linked poly (meth) acrylate, a cross-linked poly (meth) acrylate having a sulfonic acid group, polyoxy Crosslinked poly (meth) acrylate having an alkylene group, crosslinked poly (meth) acrylamide, crosslinked copolymer of (meth) acrylate and (meth) acrylamide, hydroxyalkyl (meth) acrylate and (meth) ) Crosslinked copolymer with acrylate, crosslinked polydioxolane, crosslinked polyethylene oxide, crosslinked polyvinylpyrrolidone, crosslinked sulfonated polystyrene, crosslinked polyvinylpyridine, saponified starch-poly (meth) acrylonitrile graft copolymer, starch -Poly (meth) acrylic acid (salt) graft-crosslinked copolymer, polyvinyl Reaction products of alcohols with maleic acid (salt), cross-linked polyvinyl alcohol sulfonate, polyvinyl alcohol - acrylic acid graft copolymers, polyisobutylene maleic acid (salt) cross-linked polymer, and the like. One of these water-absorbing resins may be used alone, or two or more thereof may be used in combination.

Of the above-mentioned water-absorbing resins, a water-absorbing resin having a nonionic group and / or a sulfonic acid (salt) group is more preferable, and a water-absorbing resin having an amide group or a hydroxyalkyl group is more preferable. Examples of the water-absorbing resin include a crosslinked copolymer of (meth) acrylate and (meth) acrylamide, and a crosslinked copolymer of hydroxyalkyl (meth) acrylate and (meth) acrylate. Can be Further, a water absorbent resin having a polyoxyalkylene group is particularly preferred. Examples of the water-absorbing resin include a cross-linked copolymer of a (meth) acrylate having a methoxypolyoxyalkylene group and a (meth) acrylate. A water-absorbing resin having a methoxypolyoxyalkylene group is particularly excellent in water absorption with respect to alkaline water. Therefore, by using the water-absorbing resin, the adhesive strength between the mold and the mold can be more reliably reduced.

Further, as the water-absorbing resin according to the present invention, a resin obtained by polymerizing a monomer component containing a water-soluble ethylenically unsaturated monomer and, if necessary, a crosslinking agent is used. be able to. A water-absorbing resin obtained by (co) polymerizing an ethylenically unsaturated monomer is more excellent in water absorption with water, and is generally inexpensive. In addition, the above-mentioned crosslinking agent is not particularly limited.

The above ethylenically unsaturated monomers include:
Specifically, for example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, vinylsulfonic acid, (meth) allylsulfonic acid,
2- (meth) acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid,
2- (meth) acryloylpropanesulfonic acid, and alkali metal salts and ammonium salts of these monomers;
N, N-dimethylaminoethyl (meth) acrylate,
And quaternary compounds thereof; (meth) acrylamide, N,
(Meth) acrylamides such as N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, diacetone (meth) acrylamide, N-isopropyl (meth) acrylamide, (meth) acryloylmorpholine, and monomers thereof A hydroxyalkyl (meth) acrylate such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono ( Polyalkylene glycol mono (meth) acrylates such as meth) acrylate and methoxy polypropylene glycol mono (meth) acrylate; N-vinyl-
N-vinyl monomers such as 2-pyrrolidone and N-vinylsuccinimide; N-vinylformamide, N-vinyl-N
-Methylformamide, N-vinylacetamide, N-
N-vinylamide monomers such as vinyl-N-methylacetamide; vinyl methyl ether; and the like, but are not particularly limited. These ethylenically unsaturated monomers may be used alone or in combination of two or more.

Among the ethylenically unsaturated monomers exemplified above, an ethylenically unsaturated monomer having a nonionic group and / or a sulfonic acid (salt) group is more preferable. Examples of the monomer include 2- (meth) acrylamide-2
-Methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2- (meth) acryloylpropanesulfonic acid, (meth) acrylamide, hydroxyalkyl (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate and the like. . Further, an ethylenically unsaturated monomer having a polyoxyalkylene group is particularly preferred. The water-absorbing resin obtained by polymerizing a monomer component containing methoxypolyethylene glycol mono (meth) acrylate is particularly excellent in water absorption with respect to alkaline water.

When two or more ethylenically unsaturated monomers are used in combination as a monomer component, a more preferable combination is, for example, a combination of an alkali metal (meth) acrylate such as sodium acrylate and acrylamide. And a combination of an alkali metal salt of (meth) acrylic acid and methoxypolyethylene glycol mono (meth) acrylate, but are not particularly limited.

By polymerizing the above monomer components,
A water absorbent resin is obtained. The method for polymerizing the monomer components, that is, the method for producing the water-absorbent resin, is not particularly limited. The average molecular weight and shape of the water-absorbent resin, the average particle size, etc. may be set according to the composition of the anti-adhesion material, the pH of the alkaline water, the working environment, etc. When a substance having a large particle size is used, the water-absorbent resin particles easily sink when the water-absorbent resin is mixed with the organic solvent solution of the alkali-soluble resin, so that the average particle diameter is 30 to 80.
It is preferable to use a water absorbent resin having a thickness of 0 μm,
It is more preferable to use a water absorbent resin of 0 μm,
It is most preferable to use a 400 μm water absorbent resin.

The anti-adhesion material of the present invention comprises a mixture of the above water-absorbing resin and a binder resin. When this adhesion preventing material is present between the mold and the hydraulic composition, the binder resin is dissolved by the alkaline water contained in the hydraulic composition. Since the water-absorbing resin absorbs the alkaline water and swells, the hydraulic composition at the contact portion is displaced. Since the binder resin used as a binder for holding the desired amount of the water-absorbent resin in the desired place does not disturb the swelling of the water-absorbent resin because it is dissolved in alkaline water, the water-absorbent resin is originally used. Can exhibit sufficient water absorption performance to form a sufficient gap between the mold and the hydraulic composition, thereby suppressing adhesion between the two.

The binder resin in the anti-adhesion layer does not dissolve or swell even when it comes into contact with water exhibiting a neutral or acidic pH such as rain. When the binder resin is an acrylic resin having an acid value, the interaction with the base material is large due to the presence of the carboxyl group, and the adhesion to the mold and various base materials is strong. In the case of using a material having the adhesive agent, a tough anti-adhesive material layer that is difficult to peel off can be formed on the surface of the mold due to the toughness of the anti-adhesive material derived from the material. That is, the binder resin of the present invention has a p value in a neutral region or an acidic region such as rainwater.
H is not damaged by contact with water and has excellent water resistance to neutral water. Furthermore, it has excellent friction resistance and impact resistance. Even if it does, there is no problem in transportation and storage at the site, and furthermore, there is no possibility that the anti-adhesion material layer will be peeled off even when it is wet by water or impact during construction.

Examples of the hydraulic composition to be used include various types of concrete and various types of mortar, but are not particularly limited, and a composition having properties required in the corresponding work may be used. The hydraulic composition becomes a cured product by hydration. In addition, types and combinations of cement, admixture, admixture, aggregates such as sand and gravel, and reinforcing materials contained in the hydraulic composition, that is, the composition of the hydraulic composition is not particularly limited. .

The movable mold is not particularly limited as long as it retains its shape until the hydraulic composition exhibits a predetermined strength and slides the surface of the cured product after curing to release the mold. Specifically, there are 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.

An embodiment of the present invention will be described in more detail with reference to FIGS.

[0047]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The acid value of the binder resin is JIS K69
01 "Liquid unsaturated polyester resin test method" was measured based on the test method described in the applicable clause 4.3. However,
When the binder resin did not dissolve in the solvent specified in the test method, the measurement was carried out in accordance with the above test method, using an appropriate solvent to dissolve the binder resin.

The measurement of the glass transition temperature of the binder resin is as follows.
It was measured according to "JIS K 7121 Plastic transition temperature measuring method" in a nitrogen atmosphere using a DSC220C manufactured by Seiko Instruments Inc. In addition, the condition adjustment of the test specimen was performed according to 3. According to (3).

Example 1 A water-absorbing 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 provided with 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 used as the reactor. (Molecular weight 512) 55.18 g, methacrylic acid (molecular weight 86.09) 3.76 g, sodium methacrylate (molecular weight 108) 215.69 g, polyethylene glycol diacrylate 1.4 as a crosslinking agent
g, and 352.37 g of ion-exchanged water as a solvent were charged. The ratio of the crosslinking agent in the monomer component is 0.15
Mol%.

By flowing warm water at 50 ° C. through the jacket, the above aqueous solution is stirred under a stream of nitrogen gas for 50 hours.
Heated to ° C. Next, 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 30 minutes while flowing warm water of 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.). Thus, a water-absorbent resin having an average particle diameter of 150 μm was obtained.

On the other hand, a binder resin was prepared by the following method. That is, a capacity 50 having a thermometer and a dropping device.
0.45kg of acrylic acid, 2.4kg of ethyl acrylate, 0.15k of methyl methacrylate
g, 2,2′-azobis- (2,4-
12 g of dimethylvaleronitrile) and 3 kg of methyl alcohol as a solvent were charged. In addition, 1.05 kg of acrylic acid, methyl acrylate 2.1
kg, 3.85 kg of methyl methacrylate, 28 g of 2,2′-azobis- (2,4-dimethylvaleronitrile),
And a mixed solution consisting of 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 a further predetermined time. After completion of the reaction, a 33% by weight methyl alcohol solution of a binder resin was obtained by mixing 10 kg of methyl alcohol with the contents.

The weight average molecular weight of the obtained binder resin was 130,000, and the acid value was 117 mgKOH / g. As a result of performing differential scanning calorimetry on the binder resin, the binder resin had a glass transition temperature of -80.
C. to 120.degree.

The methyl alcohol solution of the binder resin was desolvated using a twin-screw extruder, and the diameter was 3 mm and the length was 3 mm.
mm cylindrical pelletization was obtained. 10 g of the pellet
Was added at room temperature to 500 g of a 0.4% by weight aqueous sodium hydroxide solution in a beaker, and was stirred with a magnetic stirrer, and completely dissolved after 4 hours.

The water absorbent resin 50 prepared as described above
Parts by weight and 33% by weight of methyl alcohol
By mixing and dispersing 150 parts by weight of
Dispersion mixture as anti-adhesive material forming paint according to the invention
I got Then, the obtained dispersion mixture is used to construct a retaining wall.
100mm x 100m, which is a construction member such as a sheet pile
m, 1m long H-section steel (steel thickness 10mm)
The coating was evenly applied so as to obtain the adhesion amount shown in Table 1. Self
After 1 hour, the coating film has sufficient strength.
It did not peel off easily even when rubbed hard with a spatula. Also steel
200g / m for material ^TwoTo steel after drying overnight when applied
Has an adhesion strength of 30 kgf / cm^TwoAnd a sufficiently large value
Was. In addition, cold-rolled steel sheets (Japan Test Panel Co., Ltd.)
Water-absorbing resin and binder resin
Of an anti-adhesion material having a mixing ratio of 1: 1 by weight is 100 g /
m^TwoAnd dipped in deionized water
The sex was evaluated. Swells on the water-absorbing resin exposed on the surface
Was observed, but even after 24 hours,
The coating film does not peel off from the steel sheet and has excellent water resistance
I was In addition, the above-mentioned adhesion layer has moderate coating unevenness.
Was.

Then, each of the above-mentioned H-section steel, comparative H-section steel, and blanks (total of 8 pieces) were each 250 mm in inner diameter.
Was inserted into the center of a bottomed paper void tube (manufactured by Showa Marutsu, product name: Sonovoid). The bottom of the void tube was closed with a plastic bag.

On the other hand, as the hydraulic composition, water, ordinary Portland cement, clay, and bentonite were used.
A hydraulic composition (hereinafter, referred to as hydraulic composition A) was prepared in a ratio of 6: 12.2: 34: 1.2 (weight ratio). Then, the hydraulic composition A is mixed with the inserted H
Shaped steel (H-shaped steel ~, H-shaped steel for comparison, blank total 7
This was buried in the above-mentioned void tube so that the book was filled with 900 mm. On the other hand, as a hydraulic composition, a hydraulic composition (hereinafter, hydraulic composition B) comprising water, cement, and Toyoura standard sand in a ratio of 6:10:20 (weight ratio).
) Was prepared. Then, the H-shaped steel (H-shaped steel) into which the hydraulic composition B was inserted was cast into the void tube so that the H-shaped steel was filled with 900 mm. Thereafter, these hydraulic compositions A and B were hydrated.

After a lapse of 7 days, the cured products of the hydraulic compositions A and B were fixed, and the H-section steel was pulled out. Then, the maximum tensile force required for the drawing operation was measured. Table 1 shows the measurement conditions (weight ratio of the water-absorbent resin to the binder resin, the amount of adhesion to the steel material) and the maximum tensile force. The numerical value of the maximum tensile force includes the weight (16.7 kg) of the H-section steel. Also, it was found that even if the coating form is not necessarily uniform, a sufficient anti-adhesion effect can be obtained.

[0061]

[Table 1]

The maximum strength of the H-section steel (blank) not coated with the anti-adhesion material is not less than the measurement limit (300 kg). The maximum strength is reduced, especially the ratio of the water absorbing resin to the binder resin of the H steel is 1: 1 and the coating thickness of the anti-adhesion material is 200 g / m ² . The H-shaped steel was pulled out by a force of 2.3 kg, and it was found that the effect of reducing the force required to slide the mold from the cured product of the hydraulic composition was extremely large.

Example 2 A binder resin was prepared by the following method. That is, 0.525 kg of acrylic acid was added to a 50 L capacity tank reactor equipped with a thermometer and a dropping device.
1.725 kg of methyl acrylate, 2.4 kg of ethyl acrylate, 2.85 kg of methyl methacrylate, 30 g of 2,2′-azobis- (2,4-dimethylvaleronitrile) as a polymerization initiator, and methyl as a solvent 15 kg of alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring in a nitrogen gas atmosphere, and reacted for 5 hours. As a result, a 33% by weight methyl alcohol solution of the acid-containing resin was obtained. The weight average molecular weight of the obtained binder resin was 110,000, and the acid value was 51 mgKOH / g.

The water absorbent resin 50 prepared in Example 1
By mixing and dispersing parts by weight and 150 parts by weight of a 33% by weight methyl alcohol solution of the binder resin of Example 2, a dispersion mixture as a coating for forming an anti-adhesion material according to the present invention was obtained.

Using the obtained dispersion mixture, a width of 200 m
mx 200 mm, length 500 mm H-section steel (steel thickness
10 g) with a uniform thickness of 200 g of anti-adhesive film on the surface
/ M ^TwoWas applied. The coating has sufficient adhesion to H-section steel
Yes, does not peel off easily even with strong scraping with an iron spatula
Was.

On the other hand, a hydraulic composition was prepared by mixing 135 parts by weight of river sand and 100 parts by weight of water with 55 parts by weight of ordinary Portland cement, and the hydraulic composition was mixed with 400 parts by weight.
It was poured into a borehole excavated to a depth of at least mm. Next, the above-mentioned H-shaped steel was vertically embedded in the backfilled material by a length of 400 mm.

After 7 days, the H-section steel was extracted from the solidified hydraulic composition. The H-section steel could be easily pulled out of the backfill material. H calculated from the pulling force required for extraction
The maximum bond strength between the section steel and the hydraulic composition is 0.01 kg /
cm ² .

Example 3 A binder resin was prepared by the following method. That is, 0.525 kg of acrylic acid was added to a 50 L capacity tank reactor equipped with a thermometer and a dropping device.
1.725 kg of methyl acrylate, 2.4 kg of ethyl acrylate, 2.85 kg of methyl methacrylate, 30 g of 2,2′-azobis- (2,4-dimethylvaleronitrile) as a polymerization initiator, and methyl as a solvent 15 kg of alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring in a nitrogen gas atmosphere and reacted for 5 hours. As a result, a 33% by weight methyl alcohol solution of the acid-containing resin was obtained. The weight average molecular weight of the obtained binder resin was 110,000, and the acid value was 51 mgKOH / g.

The water absorbent resin 50 prepared in Example 1
By mixing and dispersing parts by weight and 150 parts by weight of a 33% by weight methyl alcohol solution of the binder resin of Example 2, a dispersion mixture as a coating for forming an anti-adhesion material according to the present invention was obtained.

The obtained dispersion mixture was applied to a predetermined portion of a movable mold as shown in FIGS. 1 and 2. The same Portland cement as used in Example 2 was used for casting. Four days later, it was confirmed that the concrete had hardened to some extent, and the movable mold was slid on the surface of the hardened concrete to a portion where the next concrete was poured. I could slide without problems. A portion of the concrete contact surface of the movable formwork had peeled off the anti-adhesive material, and was reapplied to the portion by brush or spray.

The above concrete was poured into a newly created new space. Similarly, after 4 days, the slide was performed again, but the slide was possible without any problem. The cured surface after sliding also had a good shape.

Example 4 and Comparative Example The anti-adhesion material used in Example 1 was applied to a movable mold similar to Example 3 as an anti-adhesion material, and a casting test was performed. All of the movable molds using the anti-adhesion material of the present invention exhibited a good sliding effect.However, when only the binder resin was used, or when the movable mold was used as it was, after the cement was hardened, it was easy. Could not move. Example 5 A binder resin was prepared by the following method. That is, a tank reactor having a capacity of 50 L equipped with a thermometer and a dropping device,
Acrylic acid 0.45kg, ethyl acrylate 2.4k
g, 0.15 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, 2.1 kg of methyl acrylate, 3.85 kg of methyl methacrylate, 28 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 contents were aged at 65 ° C. for further 3 hours to obtain a 50% by weight methyl alcohol solution of a binder resin.

The weight average molecular weight of the obtained binder resin was 130,000, and the acid value was 119 mgKOH / g. Further, as a result of performing differential scanning calorimetry of the binder resin, the binder resin has a glass transition temperature of -80 ° C or more.
It had two in the range of 120 ° C.

By mixing and dispersing 50 parts by weight of the water-absorbent resin prepared in Example 1 and 100 parts by weight of a 50% by weight methyl alcohol solution of the binder resin of Example 3, the anti-adhesive material according to the present invention was obtained. A dispersion mixture as a coating composition was obtained.

The above-mentioned dispersion mixture is applied on a polyester cloth and dried to form an anti-adhesion layer made of a mixture of a water-absorbent resin and a binder resin on the cloth.
g / m ² was obtained, and grease was applied to the back surface to form an adhesive layer. This anti-adhesion material sheet was attached to a movable formwork similar to that of Example 3,
Concrete was poured under the same conditions as in Example 3. After the curing, the mold was moved in the same manner as in the casting test of the movable mold in the application form such as Example 3. The slide was possible without any problem. In the movable mold, it was found that the slide could be performed satisfactorily both in the form of application as in Example 3 and in the form of attaching a sheet applied on a base material such as polyester as in this example. .

[0079]

According to the method for releasing a mold according to the first aspect of the present invention, concrete is cast using a movable mold as described above, and after the concrete has hardened to some extent, the movable mold is released. Sliding the frame on the surface of the hardened concrete to the place where the next concrete is to be poured, releasing the mold, casting new concrete in the new space created, and then continuing the concrete to build a concrete structure A method for constructing a concrete structure to be carried out, characterized in that a mixture of a water-absorbing resin and a binder resin is present between the mold and the hydraulic composition.

Thus, when the form is slid along the surface of the hardened concrete, the swollen water-absorbing resin prevents the form from adhering to the concrete and exerts a lubricating effect. Becomes slippery, and the form is easily moved. Therefore, the labor (frictional force) required for the work of moving the form can be greatly reduced, and the workability can be greatly improved.

As the binder resin, an alkali water-soluble resin or an acid value of 40 mgKOH / g to 500 mg
By using a resin of mgKOH / g, the binder dissolves in alkaline water, so that swelling of the water-absorbing resin is not hindered. Therefore, the effect of preventing the adhesion between the mold and the concrete and the lubricating effect by forming the swelling gel layer between the water-absorbent resin and the concrete can be maximized. In addition, since the anti-adhesion material made of the mixture of the binder resin has water resistance to neutral water such as rainwater, the anti-adhesion material is not peeled off or damaged by water before application. Further, the strength of the anti-adhesion material itself is high, and the adhesion to various substrates such as a mold, cloth, paper, and plastic film is also high. For this reason, the anti-adhesion layer is hardly peeled and damaged even during impact, rubbing, etc. during construction, and the effect of reducing the adhesive force and frictional force between the mold and the cured product of the hydraulic composition is stably obtained. Can do things.

[0082]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a mold release method according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the surface of the mold in the mold releasing method according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Water-absorbing resin and alkali water soluble resin, or resin mixture whose acid value is 40 mgKOH / g-500 mgKOH / g 2 Moving mold 3 Newly cast hydraulic composition 4 Existing hydraulic composition (cured product) 5) Water-absorbing resin particles 6 Alkaline water-soluble resin or acid value of 40 mg
KOH / g to 500 mg KOH / g Resin 71 used in processing sheet 1 into a sheet, base material such as paper, film, cloth, etc. 8 Adhesion used to fix sheet-formed anti-adhesion material 2 Material or adhesive layer

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Hattori 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (56) References JP-A-2-112561 (JP, A) JP-A Sho 64-58715 (JP, A) JP-A-1-146606 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E04G 11/22

Claims (1)

(57) [Claims] 1. A hydraulic composition is cast using a movable mold.
After the hardening of the hydraulic composition, the movable mold is
Slide along the surface of the cured product
This is a method for releasing the movable formwork used for
The method of releasing the movable mold includes a movable mold and a hydraulic set.
A mixture of a water-absorbent resin and a binder resin between the product
The acid value of the binder resin is 40 mg
KOH / g to 500 mgKOH / g
Release method of movable formwork.