JPH11197593A - Anticorrosive covering method for concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anticorrosive covering method for a concrete structure by which primer treatment is not required and an anticorrosive covering process can be shortened. SOLUTION: An emulsion of an emulsified copolymer having -35 to +50 deg.C glass transition temp. obtd. by emulsion-polymerizing a monomer mixture consisting of 40-85 wt.% vinyl chloride, 14.5-50 wt.% acrylic ester monomer having <1 g/100 g water solubility at 25 deg.C and 0.5-10 wt.% unsatd. carboxylic acid monomer is blended with cement and inorg. aggregate. The resultant polymer-cement combined compsn. is applied to the surface of a concrete structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a drainage basin, a drainage culvert,
Regarding the anticorrosion coating method for concrete structures used in sewage facilities such as pumping stations and sewage treatment plants, in particular, anticorrosion coating for concrete structures using inexpensive anticorrosion coating materials with excellent corrosion resistance and workability. Concerning the construction method.

[0002]

2. Description of the Related Art Corrosion deterioration of concrete structures used in sewage facilities is caused by the action of microorganisms called sulfur oxidizing bacteria, which converts hydrogen sulfide generated in sewage into sulfuric acid in a water film on the surface of concrete structures. It is known that this occurs when a dilute sulfuric acid aqueous film having a pH of about 1 is formed on the surface of the concrete structure. A sewage terminal treatment plant or a pumping station where sewage stagnation frequency is high has a lot of heavy anticorrosion essential parts where hydrogen sulfide gas easily accumulates and corrosion reaches a reinforcing steel bar of a concrete structure in a few years. Such places include, for example, inflow culverts, sedimentation basins, pump wells, landing ponds, aeration tanks, primary sedimentation basins, sludge storage tanks, sludge concentration tanks, sludge digestion tanks, return waterways, Increasingly, there are manholes in sewers.

In order to prevent corrosion deterioration of concrete structures, epoxy resin, tar epoxy resin, epoxy resin containing ceramic powder, vinyl ester resin, unsaturated polyester resin, vinyl ester resin containing glass flake, modified silicone resin, polyurethane resin The use of an anticorrosion coating method for coating a concrete structure with a liquid resin material such as that described above is being promoted by the Japan Sewage Works Agency and the like. In this anticorrosion coating method, anticorrosion coating is performed after removing the degraded concrete part by dropping, but when corroded to the deep part of the concrete structure, the liquid resin material which is several tens times more expensive than concrete is used. However, if the defective portion of the concrete is thickly applied, the repair cost is increased. Therefore, first, it is necessary to repair the cross section by using an inexpensive non-shrink mortar or the like. In this case, it is necessary to perform a primer treatment on the underlying mortar layer in order to improve the adhesive strength between the underlying mortar layer and the liquid resin material. In addition, when a liquid resin material is applied to a vertical wall portion, a ceiling surface portion, or the like of a concrete structure, the resin dripping occurs due to its own weight before curing, and therefore it is necessary to heat the material to a semi-cured state. Therefore, the conventional anticorrosion coating method using a liquid resin material is performed in the following complicated work steps. In other words, after removing the corroded portion by high-pressure water washing, paint a non-shrink mortar, etc., and repair the cross section of the concrete missing part,
The resulting mortar layer is cured, and the mortar layer surface is
After performing a primer treatment using an epoxy resin primer, a polyurethane primer or the like, and semi-curing or curing the primer, spraying a liquid resin material, painting by a method such as brushing or ironing, and coating the liquid resin material. After semi-curing by heating with an infrared lamp or the like, it is allowed to stand naturally and completely cured.

[0004]

The conventional anticorrosion coating method has the following problems. (1) In order to apply liquid resin material, which is 30 to 80 times as expensive as cement concrete, to a thickness of several mm or more,
The material cost per unit area is very high. Also,
In addition to the anticorrosion coating material, a material cost for a cross-section restoration material, a primer and the like is separately required. (2) Since the process consists of several work steps, labor costs for surface treatment and surface adjustment using a primer are required in addition to the anticorrosion coating, and as a result, the work cost is high. (3) Since it is composed of several work steps, the construction period is long.

[0005]

SUMMARY OF THE INVENTION The present invention provides a polymer-cement composite composition obtained by mixing a cement and an inorganic aggregate with a vinyl chloride-acrylate-unsaturated carboxylic acid emulsion which is resistant to acid corrosion as an anticorrosion coating material. By using the above, the above-mentioned disadvantages are improved, and furthermore, the surface of this anticorrosion coating material is coated with an emulsion copolymer alone or a mixture of an emulsion copolymer and an inorganic aggregate, thereby providing more complete anticorrosion performance. What you get. That is, the present invention relates to a method for anticorrosion coating of a concrete structure, comprising:
85% by weight and (2) solubility in water at 25 ° C. is 1 g / water 100
g of acrylate ester monomer of less than 1 g and less than 0.5 g of (3) unsaturated carboxylic acid monomer of 0.5 to 10% by weight.
A polymer-cement composite composition obtained by blending cement and an inorganic aggregate into an emulsion of an emulsion copolymer having a glass transition temperature of −35 to 50 ° C. obtained by emulsion polymerization of a monomer mixture consisting of An anticorrosion coating method for a concrete structure, characterized by painting on the surface of a structure, and painting the above-mentioned emulsion copolymer or a mixture of the emulsion copolymer and an inorganic aggregate on the painted surface. This is a method for anticorrosion coating of concrete structures.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, in the present invention, a polymer / cement composite composition is coated on the surface of a concrete structure. The polymer-cement composite composition is obtained by mixing cement and an inorganic aggregate into an emulsion of an emulsion copolymer. The emulsion of this emulsion copolymer is
It can be obtained by emulsion polymerization of (1) vinyl chloride, (2) acrylate monomer, and (3) unsaturated carboxylic acid monomer. (1) The vinyl chloride component is used to give the resulting emulsion copolymer mechanical strength, water resistance, acid resistance, alkali resistance, chemical resistance,
It has the effect of imparting aging resistance and the like. 40-85 for vinyl chloride
%, Preferably 50 to 80% by weight. If the amount used exceeds 85% by weight, the obtained emulsion copolymer becomes too hard, resulting in poor film-forming properties, and a dense anticorrosive coating layer is not formed, resulting in a decrease in acid resistance. If it is less than 40% by weight, the resulting anticorrosive coating layer has reduced mechanical properties and acid / alkali resistance.

[0007] The acrylic acid ester monomer of the component (2) is used for the flexibility, film forming property, durability and the like of the obtained emulsion copolymer.
This has the effect of improving the bonding strength, adhesiveness, and the like. Examples of the acrylate-based monomer include acrylates with an alcohol having an alkyl group having 3 to 18 carbon atoms,
Methacrylic acid esters with an alcohol having an alkyl group of from 18 to 18 are exemplified, and these are used alone or in combination of two or more. In an acrylic acid ester with an alcohol having an alkyl group having 19 or more carbon atoms,
Although the solubility in water is satisfactory, the obtained emulsion copolymer becomes too soft, and the mechanical strength of the anticorrosion coating layer decreases. The acrylate monomer must have a solubility in water at 25 ° C. of less than 1 g / 100 g of water. twenty five
The acrylate monomer having a solubility in water at 1 ° C. of 1 g / 100 g or more in water has a small number of carbon atoms in the alkyl group,
The softening effect of the emulsion copolymer (the effect of lowering the glass transition point) is insufficient, the film forming property, the bonding strength, the adhesion are poor, and the water resistance is also reduced.

The amount of the acrylate monomer used is as follows:
It is 14.5 to 50% by weight, preferably 20 to 45% by weight. If this amount is less than 14.5% by weight, the resulting emulsion copolymer is too hard, resulting in insufficient film-forming performance, bonding strength, and adhesion.
If the amount is more than 10% by weight, the proportion of vinyl chloride is relatively reduced, and mechanical strength and chemical resistance, particularly acid resistance, are reduced.

[0009] The unsaturated carboxylic acid monomer of the component (3) may be a strong alkali component in concrete, Ca ²⁺ , Al ^3+.
It has the effect of suppressing aggregation / separation of the emulsion due to such cationic components and improving the stability before film formation. Examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid and their acid anhydrides, and these may be used alone or in combination of two or more. Used. The amount of the unsaturated carboxylic acid used is 0.5 to 10% by weight, preferably 1 to 8% by weight. If the amount is less than 0.5% by weight, the dispersion stability of the emulsion will be poor, and if it exceeds 10% by weight, the water resistance will decrease and the resulting emulsion copolymer will be hard.

[0010] In addition to the components (1) to (3), if necessary, an ethylenically unsaturated monomer may be added to the emulsion copolymer to such an extent that the object of the present invention is not impaired. It can be used in amounts up to 10% by weight of the total amount. As the ethylenically unsaturated monomers, styrene, styrene derivatives,
Acrylonitrile, vinyl acetate, vinyl propionate,
Ethylene, methyl acrylate, ethyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, hydroxyl-containing monomers such as 2-hydroxypropyl methacrylate, methacrylamide, N-methylol methacrylamide, N-methoxymethyl methacrylamide, Amide group-containing monomers such as N-butoxymethyl methacrylamide and diacetone methacrylamide; amino group-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; and alkoxyl group-containing monomers such as methoxyethyl methacrylate and butoxyethyl methacrylate. Monomer, glycidyl methacrylate,
Glycidyl group-containing monomers such as glycidyl allyl ether, divinylbenzene, allyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, etc. And the like, and these can be used alone or in combination of two or more.

The emulsion of the emulsion copolymer can be produced by a general emulsion copolymerization method. That is, the above-mentioned monomers are mixed, and an emulsifier, a polymerization initiator and the like may be added thereto, and emulsion polymerization may be performed in an aqueous system, such as a method of batch polymerization and a method of performing polymerization while continuously supplying each component. Various methods can be applied. The concentration of the emulsion copolymer in the emulsion is preferably adjusted to 30 to 70% by weight, particularly preferably 40 to 60% by weight. Examples of the emulsifier for emulsion polymerization include anionic emulsifiers such as alkyl or alkyl allyl sulfate, alkyl or alkyl allyl sulfonate, dialkyl sulfosuccinate, cationic emulsifiers such as alkyltrimethylammonium chloride and alkylbenzylammonium chloride, and polyoxyethylene. Nonionic emulsifiers such as alkyl phenyl ether, polyoxyethylene alkyl ether, and polyoxyethylene carboxylic acid ester are exemplified.

[0012] The above-mentioned emulsion copolymer can be used as the above (1) or (2)
The components, especially component (1), provide excellent water resistance and do not soften by water or acid. However, if the anticorrosion coating film contains a large amount of a low molecular weight surfactant, it is dissolved or absorbed into water. Then, the mechanical strength of the anticorrosion coating film is weakened, and the abrasion resistance is impaired. Therefore, it is preferable to use a reactive surfactant which chemically bonds to the emulsified copolymer instead of using the emulsifier. Examples of the reactive surfactant include those described in JP-A-6-166156, filed by Nissin Chemical Industry Co., Ltd., one of the applicants of the present invention. It is good to use more than weight%.

The amount of the emulsifier used generally varies depending on the properties required for the emulsion copolymer. For example, in order to improve the polymerization stability or to improve the mechanical and chemical stability. On the contrary, it is preferable to increase the amount, and to improve the water resistance of the dried anticorrosion coating film, it is more preferable to decrease the amount. Decide according to each purpose.

Examples of the polymerization initiator include persulfates such as ammonium persulfate and potassium persulfate, hydrogen peroxide, t-
Water-soluble types such as butyl hydroperoxide, hydrochloride of azobisaminodipropane, etc., benzoyl peroxide, cumene hydroperoxide, dibutyl peroxide, diisopropyl peroxycarbonate, cumyl peroxy neodecanoate, azobisiso Examples thereof include fat-soluble types such as butyronitrile. If necessary, a reducing agent such as sodium acid sulfite, Rongalit, L-ascorbic acid, saccharide, amine or the like can be used in combination. The amount of the polymerization initiator used may be about 0.01 to 3 parts by weight based on 100 parts by weight of the total amount of the monomers.

The emulsion polymerization of the above monomers may be carried out usually at about 35 to 90 ° C., and the reaction time may be usually about 3 to 40 hours. Further, by adding a basic substance at the start or end of polymerization to adjust the pH (preferably pH 5 or more), the resulting emulsion can be left standing, frozen, mechanically and chemically stable. Can be improved. Examples of the basic substance used for adjusting the pH include ammonia, ethylamine, diethylamine, triethylamine, ethanolamine, triethanolamine, dimethylethanolamine, caustic soda, caustic potash and the like.

The emulsion copolymer has a glass transition temperature of -35 to
It needs to be 50 ° C. If the temperature is lower than −35 ° C., the anticorrosion coating film becomes too soft and the mechanical strength decreases.If the temperature is higher than 50 ° C., the continuous anticorrosion coating film is not formed unless heated to 70 to 80 ° C. or higher. And good acid resistance and water resistance cannot be obtained. The glass transition temperature (Tg) of the emulsion copolymer is determined by the following equation. 1 / Tg = Σ (W _i / Tg _i ) Tg; glass transition temperature of emulsion copolymer (unit: K) Tg _i ; glass transition temperature of homopolymer of monomer component (i) (unit: K) W _i;. weight fraction of component (i) in the emulsion copolymer (published 1956 Bull.An.Phys Vol. 1, 123 pp TGF
ox method)

In the present invention, after the corrosion-deteriorated portion of the surface of the concrete structure is suspended and removed by high-pressure water washing or the like, a polymer-cement composite composition obtained by mixing the above emulsion with cement and inorganic aggregate is applied to the surface of the concrete structure. . In this case, since the polymer-cement composite composition adheres to the cement concrete layer by cement-cement bonding, it can strongly adhere to the surface of the concrete structure without performing a primer treatment or the like. Portland cements such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, moderate heat Portland cement, sulfate-resistant Portland cement, etc., blast furnace cement, silica cement, silica Cement, mixed cements such as fly ash cement and the like are exemplified, as inorganic aggregates, mountain sand,
Examples include natural fine aggregates such as river sand, silica sand, and silica stone powder.

The amount of the emulsion constituting the polymer-cement composite composition of the present invention is adjusted so that the solid content of the emulsion is 5 to 45 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the cement. Good to do. If the amount used is less than 5 parts by weight, the anticorrosion coating film cannot sufficiently cover the cement hydrate particles, and is acid resistant, that is,
If the anticorrosion effect becomes insufficient, and if it exceeds 45 parts by weight, the ratio of expensive copolymer becomes large, and the polymer-cement composite composition becomes expensive.

The inorganic aggregate is used for improving mechanical strength such as abrasion resistance of the polymer-cement composite composition, but the amount of the inorganic aggregate is not particularly limited. As it is said, cement
It is advisable to select from 100 to 500 parts by weight, centering on 300 parts by weight for 100 parts by weight.

In the polymer-cement composite composition, water alone is not sufficient to obtain appropriate fluidity for construction work only with water contained in the emulsion. The amount of water added is the total amount of the water in the emulsion and the water
It is good to be in the range of 40 parts by weight to 70 parts by weight with respect to 100 parts by weight, but since the fluidity of the polymer-cement composite composition varies depending on the kneading method, JIS R 5201
(Physical test method of cement) 11. It is necessary to measure and determine the flow value by the flow test. According to tests by the present inventors, the flow value should be in the range of 180 to 270.
Further, in order to increase the fluidity without increasing the water content, a fluidizing agent such as a naphthalene sulfonic acid formalin condensate salt, a melamine resin sulfonic acid formalin condensate salt, an olefin / maleic acid copolymer salt, or a lignin sulfonate is used. May be added. The method of mixing the emulsion, cement and inorganic aggregate is not particularly limited, but first, using a mortar mixer, knead the cement and the inorganic aggregate (dry blending), add water to the mixture, and knead the mixture. It is good to knead with adding.

The obtained polymer-cement composite composition is applied to the surface of the concrete structure having been subjected to the hanging treatment without spraying a primer, in the same manner as a usual cement mortar application method, such as a spraying method, an iron coating method or the like. After coating, the coating is cured by natural curing for 4 to 7 days or more to form an anticorrosive coating.

Another aspect of the present invention is that, after the application of the above-mentioned polymer / cement composite composition, the above-mentioned emulsion copolymer alone or the above-mentioned emulsion copolymer and an inorganic skeleton are further coated on the anticorrosion coating layer. Is applied to form an anticorrosion coating.
The acid resistance of the anticorrosion coating layer can be further increased by coating the emulsion copolymer, and the mechanical strength such as the wear resistance of the anticorrosion coating layer can be improved by coating the inorganic aggregate. . The amount of the inorganic aggregate used is optional, but if it is too large, the anticorrosion coating film becomes brittle and easily cracks.
It is preferred that the amount be not more than part by weight. When these are applied, the already formed anticorrosion coating film may be in a cured or uncured state. The anticorrosion coating composed of the emulsion copolymer alone or a mixture of the emulsion copolymer and the inorganic aggregate has a low adhesive strength to the cement concrete layer, but a polymer containing 5% or more of the emulsion copolymer. -Since the polymers are bonded to each other and strongly adhere to the anticorrosion coating layer made of the cement composite composition, it is not necessary to apply a primer treatment to the surface of the anticorrosion coating layer.

[0023]

EXAMPLES (Example 1) After sufficiently replacing the inside of a polymerization vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet with nitrogen, 1150 parts by weight of deionized water, 2-ethylhexyl acrylate (vs. Water solubility 0.01 gf / water 100 gf) 370 parts by weight, maleic anhydride 30 parts by weight, emal O (sodium laurin sulfate, manufactured by Kao Corporation, trade name) 10 parts by weight, Neugen EA
30 parts by weight of -170 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name) were charged, and the pressure in the polymerization vessel was reduced, and 600 parts by weight of vinyl chloride was charged. After the inside of the polymerization vessel was heated to about 60 ° C, 100 parts by weight of a 1% aqueous solution of ammonium persulfate was injected to start emulsion polymerization, and the emulsion polymerization was completed by maintaining the internal temperature at 60 ° C for 16 hours. did.

Next, the inside of the polymerization vessel was cooled to 30 ° C., and 40 parts by weight of Nonion HS-240 (polyoxyethylene phenyl ether, manufactured by NOF Corporation) was added to KM-681F.
A (Silicone defoamer, Shin-Etsu Chemical Co., Ltd., trade name)
10 parts by weight were added, the pH was adjusted to 8.5 with sodium hydroxide, and the mixture was aged at room temperature for 24 hours to obtain an emulsion. The resulting emulsion has a solid content of 45%, a viscosity of 500 cP and a Tg of -6.
° C.

On the other hand, 450 gf of ordinary Portland cement (trade name, made by Chichibu Onoda Co.) and standard sand for cement strength test according to ISO679 (trade name, made by Japan Cement Association)
After kneading 1350 gf with a mortar mixer, tap water 225
gf was added and kneaded. When the flow value of the obtained cement mortar was measured according to JIS R 5201, it was 160. Then, apply this cement mortar to the bottom 200mm × 20
0mm, 50mm side wall height, cast at 20 ℃, 90% R
After being left in a humidity box of H for 24 hours, the mold was removed, and immersed in water at 20 ° C. for 27 days for curing. The bottom (200m) of the obtained cement mortar specimen (about 19mm x 200mm x 200mm)
m × 200mm) One side and four sides (19mm × 200mm) are covered with paraffin, and then put in 1N (about 5% by weight) sulfuric acid aqueous solution.
After immersion for 14 days, the surface (200 mm x 200 mm) not coated with paraffin was subjected to acid corrosion. When tap water was applied to the surface, the thickness of the cement mortar specimen was It was 16mm.

On the other hand, 450 gf of the above Portland cement and 1350 gf of the standard sand were kneaded with a mortar mixer, mixed with 160 gf of tap water and kneaded, and then added with 200 gf of the emulsion prepared above (solid content 90 gf + water 110 gf). And kneaded to obtain a polymer-cement composite composition. The obtained polymer / cement composite composition had a water cement ratio of 60% and a polymer cement ratio of 20%, and the flow value measured in accordance with JIS R 5201 was 210. Next, except for the paraffin on the side of the cement mortar specimen whose surface was corroded, the cement mortar was placed in the mold, and the prepared polymer-cement composite composition was cast on the corroded surface, and the temperature was lowered to 20 ° C. and 90 ° C. After leaving in a humidity box of 48% RH for 48 hours, the mold is removed, and the temperature is reduced to 20 ° C and 60% RH.
Cured in the room for 26 days. The cement mortar layer of the obtained two-layer specimen had a thickness of 16 mm, and the polymer-cement composite composition layer had a thickness of 19 mm.

The side surface of this two-layer specimen was coated with paraffin in the same manner as described above, and only the surface (200 × 200 mm) of the anticorrosion coating layer made of the polymer / cement composite composition was opened, and sulfur oxidation was actually performed. PH 1.0, which is a corrosive environment where bacteria inhabit, ie 0.1 normal (about 0.5% by weight concentration)
When immersed in a sulfuric acid aqueous solution for 96 days and the change in weight was measured, the rate of change in weight of the two-layer specimen was zero. On the other hand, in order to check the adhesive strength between the corroded surface of the cement mortar and the anticorrosive coating layer composed of the polymer-cement composite composition, a flat-bladed punch with a sharpened tip was used at the interface between the two. And hit it with a mallet, but it was in the same destruction condition as the concrete part, and the boundary surface did not peel and break.

(Example 2) In the same manner as in Example 1, the polymer-cement composite composition of Example 1 was cast on the corroded surface of a corroded and deteriorated cement mortar specimen, and the mixture was heated at 20 ° C and 60% RH.
Was left in the room for 3 hours. And the film thickness after drying is
The emulsion used in Example 1 was brush-coated on the surface of the uncured anticorrosion coating layer composed of the polymer-cement composite composition so as to have a thickness of 0.15 mm, and dried and cured to obtain an anticorrosion film. This specimen is designated as 2A.

On the other hand, in the same manner as in Example 1, the polymer / cement composite composition of Example 1 was cast on the corroded surface of the corroded and deteriorated cement mortar specimen, and placed in a room at 20 ° C. and 60% RH for 24 hours. I left it. And the film thickness after drying is 0.15mm
Then, the emulsion of Example 1 was brush-coated on the surface of the anticorrosion coating layer made of the cured polymer-cement composite composition, and dried and cured to obtain an anticorrosion film. This specimen is designated as 2B.

Next, 100 parts by weight of the emulsion of Example 1 was mixed with 95 parts by weight of 4500 to 5100 branes (trade name, manufactured by Tokai Kogyo Co., Ltd.) with silica powder and Izu special powder to prepare an emulsion containing silica powder. did. Then, in the same manner as in Example 1, the polymer-cement composite composition of Example 1 was poured onto the corroded surface of the corroded and deteriorated cement mortar specimen.
After standing in a room at 60 ° C. and 60% RH for 3 hours, the above-mentioned emulsion containing silica powder was subjected to anticorrosion of the uncured polymer-cement composite composition so that the film thickness after drying was 0.3 mm. The surface of the coating layer was brush-coated and dried and cured to obtain an anticorrosion film. This specimen is designated as 2C.

On the other hand, in the same manner as in Example 1, the polymer / cement composite composition of Example 1 was cast on the corroded surface of the corroded and deteriorated cement mortar specimen, and was placed in a room at 20 ° C. and 60% RH for 24 hours. After standing, the above silica emulsion-containing copolymer emulsion is brush-coated on the surface of the cured anticorrosive coating layer made of the polymer-cement composite composition so that the film thickness after drying becomes 0.3 mm in thickness, and then dried. After curing, an anticorrosion film was obtained. This specimen is referred to as 2D.

The specimens 2A to 2D prepared above were coated with paraffin on the sides in the same manner as in Example 1, and only the anticorrosion film was left open to prepare a 1N (about 5% by weight) aqueous sulfuric acid solution. After immersion for 96 days, the weight before and after the test was measured, and there was no change in weight. On the other hand, in order to examine the adhesive strength of the anticorrosion coating composed of the emulsion alone or a mixture of the emulsion and the inorganic aggregate, both sides of the SUS304 foil having a thickness of 0.1 mm × 10 mm and a SUS304 foil were coated with a silicone primer “ Primer U ”(Shin-Etsu Chemical Co., Ltd., trade name) and silicone rubber adhesive“ KE4
5RTV "(brand name, manufactured by Shin-Etsu Chemical Co., Ltd.)
When a 90 peel test was performed under the conditions of 00 mm / min, the peel adhesion strength of the anticorrosion coating to the anticorrosion coating layer was 2A, 2B,
Both 2C and 2D exhibited strong adhesion of 2 kgf / cm or more.

[0033]

According to the present invention, an inexpensive emulsion obtained by mixing an emulsion of an emulsion copolymer composed of vinyl chloride, an acrylate monomer and an unsaturated carboxylic acid monomer having excellent acid resistance. Since the anticorrosion coating of the concrete structure is performed using the polymer-cement composite composition, the restoration of the corrosion-degraded concrete layer to its original state (cross-section restoration) can be performed in one step without the need for cross-section restoration materials and primers. ,
Moreover, excellent anticorrosion properties can be obtained. Further, in the case of anticorrosion coating, a primer treatment step is not required, so that it is possible to significantly reduce the construction period and labor costs as compared with the conventional anticorrosion coating method represented by epoxy resin mortar coating.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16L 58/10 F16L 58/10 // (C04B 28/02 24:26) (72) Inventor Ichiro Shimizu 2 Kitafu, Takefu-shi, Fukui 17-17 Nishin Chemical Industry Co., Ltd.

Claims (2)

[Claims] 1. An anticorrosion coating method for a concrete structure, comprising: (1) 40 to 85% by weight of vinyl chloride; and (2) an acrylate monomer having a solubility in water at 25 ° C. of less than 1 g / water of less than 100 g. Emulsion having a glass transition temperature of -35 to 50 ° C obtained by emulsion polymerization of a monomer mixture consisting of 14.5 to 50% by weight of a polymer and (3) 0.5 to 10% by weight of an unsaturated carboxylic acid monomer. A method for anticorrosion coating of a concrete structure, characterized by coating a polymer / cement composite composition obtained by mixing a copolymer emulsion with a cement and an inorganic aggregate on the surface of the concrete structure. 2. A method for anticorrosion coating of a concrete structure, characterized by coating the coating surface of claim 1 with the emulsion copolymer of claim 1 or a mixture of the emulsion copolymer and an inorganic aggregate.