JP4795693B2 - Anticorrosion and waterproofing methods for concrete structures - Google Patents

Description

The present invention relates to an anticorrosion / waterproofing method for a concrete structure, and it is not only a flat part such as an upper surface and a wall surface, but also an anticorrosion / waterproofing without a paint film floating, blistering, and pinholes at a protruding corner / entry corner. The present invention relates to a method capable of forming a film simply and with excellent workability.

Conventionally, anticorrosion coatings have been studied for the purpose of preventing corrosion and deterioration of concrete structures. In particular, as a corrosion-resistant coating for the purpose of preventing the occurrence of pinholes, the surface of concrete structures is impregnated with a liquid primer resin in a porous thin film sheet such as a nonwoven fabric or a woven fabric made of synthetic resin fibers, natural fibers, or inorganic fibers. A method for forming a film by forming a sheet layer and then spraying a film-forming resin with a spray is described.
Japanese Patent Laid-Open No. 10-100300

When the method of forming a porous thin film sheet layer with the liquid primer resin as described above is used, it is not sufficient that the porous thin film sheet and the structure are in close contact particularly at the corners of the concrete structure. Macroscopic pinholes cannot be found in anti-corrosion / water-proof coatings, but floating, blisters, and microscopic pinholes have occurred, and sufficient film performance cannot be demonstrated. However, it was not satisfactory.

The present invention has been made in view of the above circumstances, and the purpose thereof is not only macroscopic pinholes that can be visually confirmed even at the protruding and entering corners of a concrete structure, but also floats, blisters, and fineness. An object of the present invention is to provide an anticorrosion / waterproofing method for a concrete structure without a visual pinhole.

In the present invention, as a result of various investigations on the cause of the floating, swelling, and microscopic pinholes of the waterproof / anticorrosive coating of a concrete structure, the following knowledge was obtained.

In other words, it is effective to apply a binder resin composition and then apply a porous thin film sheet to form a waterproof / anticorrosive coating for concrete structures that are free of floats, blisters, and microscopic pinholes. However, in particular, in order to stick a porous thin film sheet even at the corner of the concrete structure, the binder resin composition has a low viscosity such as a primer of less than 1,000 mPa · s. If such a low viscosity resin is applied to the top surface, wall surface, and the corner of the concrete structure, the anti-corrosion / water-proof coating will not be smooth, and the resin will sag. Floating and blistering occurs on the porous thin film sheet. Furthermore, for example, when a porous thin film sheet is pasted with a binder resin composition having a high viscosity exceeding 500,000 mPa · s, no floating or blistering occurs, but the porous thin film sheet is sufficiently impregnated with resin. As a result, not only microscopic pinholes but also macroscopic pinholes are generated. However, surprisingly, when a porous thin film sheet is pasted after applying a binder resin composition having unevenness adjustment performance and impregnation performance to the porous thin film sheet with a trowel, spatula, or roller, a concrete structure It was also found that the resin dripping and the floating and swelling of the porous thin film sheet were prevented even at the protruding and entering corners, and a smooth anticorrosion / waterproof coating could be formed.

The present invention has been completed on the basis of the above knowledge, and the gist thereof is that a porous thin film sheet is pasted after applying a paste-like or putty-like binder resin composition to the surface of a concrete structure. After or after applying the binder resin and pasting the porous thin film sheet, impregnating with a primer as necessary to form a porous thin film sheet layer, on the porous thin film sheet impregnated layer The present invention resides in an anticorrosion / waterproofing method for a concrete structure having a step of coating a film-forming resin material with a brush, a trowel, a spatula, a roller, or a spray to form a film.

Hereinafter, the present invention will be described in detail.

The anticorrosion / waterproofing method of the present invention comprises applying a binder resin composition to the surface of a concrete structure, and then sticking a porous thin film sheet to form a porous thin film sheet layer, and then over the porous thin film sheet layer. And forming a film-forming resin material. And, in the present invention, in order to prevent the floating, swelling, and pinholes of the coating film at the corners and corners of the concrete structure which is also a problem, the binder resin composition has a non-land surface adjustment performance, and porosity. A porous thin film sheet layer is formed using a binder resin composition having impregnation performance to a thin film sheet. After attaching the porous thin film sheet, the binder resin composition is applied to the porous thin film sheet. In the case where an object is not sufficiently impregnated, a porous thin film sheet layer is formed by impregnating with a primer as necessary. The primer may be applied to the flat portion as necessary.

The binder resin composition used in the present invention includes a binder resin, a curing agent, a diluent and a filler. Furthermore, auxiliary agents such as additives, anti-sagging agents, coloring agents and extender pigments are included as necessary.

Examples of the binder resin include epoxy resins, vinyl ester resins, non-styrene type vinyl ester resins, urethane resins, unsaturated polyester resins, and acrylic resins. Moreover, as a hardening | curing agent, if a binder resin is hardened, there will be no restriction | limiting in particular, A well-known thing will be used. Any known diluent can be used without particular limitation as long as it dissolves the binder resin. The filler is not particularly limited as long as it is dispersed in the binder resin, and a known material is used.

The viscosity of the binder resin composition is 3,000 mPa · s (25 ° C .: BM type rotational viscometer, No. 4, rotor, 60 min ⁻¹ ) or more, preferably 5,000 mPa · s or more, in order to have unevenness adjusting performance. It is desirable to be. In the case of a binder resin composition having a viscosity of less than 3,000 mPa · s, the anticorrosion / waterproof coating of the concrete structure is not smooth, and the binder resin composition is liable to sag, especially when applied to the protruding corner / entry corner. Floating and blistering easily occur on the porous thin film sheet. Moreover, in order to have the impregnation performance into the porous thin film sheet, 250,000 mPa · s (25 ° C .: B8U type rotational viscometer, No. 6 rotor, 20 min ⁻¹ ) or less, preferably 200,000 mPa · s or less is desirable. . In the case of a binder resin composition having a viscosity exceeding 250,000 mPa · s, the porous thin film sheet is not sufficiently impregnated with the resin, and as a result, not only microscopic pinholes but also macroscopic pinholes are generated. It becomes easy to do.

Among the binder resins, an epoxy resin is preferable in consideration of adhesiveness with concrete, chemical resistance, shrinkage resistance, and handleability. Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, hydrogenated epoxy resins thereof, novolac type epoxy resin, glycidyl ester type epoxy resin, urethane modified epoxy resin, Nitrogen-containing epoxy resins, epoxy resins derived from alcohols, polybutadiene, natural rubber, rubber-modified epoxy resins derived from natural rubber having terminal carboxyl groups, flame retardant epoxy resins containing bromine, alicyclic epoxy resins Etc.

In view of high curing reactivity or easy formation of a three-dimensional network structure in the cured product, an epoxy resin containing at least two epoxy groups in the molecule is preferable. More preferred are novolak type epoxy resins such as epichlorohydrin-bisphenol A type epoxy resin and epichlorohydrin-bisphenol F type epoxy resin.

The epoxy resins can be used alone or as a mixture. Moreover, it can also be used as a mixture with the monoepoxy compound etc. which reduce the viscosity of an epoxy resin.

As curing agents for epoxy resins, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, m-xylylenediamine, m-phenylenediamine, 2,4,6-tris (dimethylaminomethyl) Amines such as phenol, tertiary amine salts, polyamide resins, imidazoles, dicyandiamides, ketimines, boron trifluoride complex compounds, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, endomethylenetetrahydroanhydride Examples thereof include carboxylic anhydrides such as phthalic acid, dodecinyl succinic anhydride, pyromellitic anhydride and chlorenic anhydride, phenols and carboxylic acids.

Examples of the epoxy resin diluent include butyl glycidyl ether, phenyl glycidyl ether, alkyl glycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether. Examples of the non-reactive diluent include phthalate plasticizers such as benzyl alcohol, dioctyl phthalate, and butyl benzyl phthalate.

Examples of the filler include heavy calcium carbonate, light calcium carbonate, kaolin, talc, silica, titanium oxide, aluminum silicate, magnesium oxide, zinc oxide, carbon black, and silica sand. Examples of the additive include silane coupling agents such as aminosilane and epoxysilane.

The porous thin film sheet used in the present invention is not particularly limited as long as it retains the impregnated binder resin and primer, and has adhesiveness with the binder resin and primer, glass fiber, carbon fiber, Nonwoven fabrics or woven fabrics made of rock wool fibers, rayon fibers, polyester fibers, nylon fibers, vinylon fibers, etc., mineral paper, and the like can be mentioned. The porous thin film sheet may be a nonwoven fabric or a woven fabric formed by combining two or more selected from these fibers. Mineral paper is a paper made of highly functional powder such as calcium carbonate, calcium hydroxide, talc, activated carbon powder, calcium silicate, magnesium carbonate and the like.

Among these, short glass fibers having a diameter of 6 to 20 microns: glass fiber paper in which chop strands are uniformly dispersed in water and made into paper by a wet papermaking method is preferred, and the thickness is 0.02 to 0.5 mm. A quantity of 15-80 g / m ² is suitable.

The primer used in the present invention is not particularly limited as long as it has adhesiveness with the binder resin impregnated in the porous thin film sheet, the porous thin film sheet, and the film-forming resin material. For example, the epoxy resin composition Solvent-free, solvent-type, and water-based primers made of products and polyurethane resin compositions can be used.

As a film-forming resin material used in the present invention, it has adhesion with a binder resin or primer impregnated into a porous thin film sheet, and has anticorrosion and waterproof performance, and is applied with a brush, a trowel, a spatula, a roller, or a spray. Thus, any film may be used as long as it forms a film.

As the film-forming resin material, an epoxy resin, a vinyl ester resin, an acrylic resin, or the like is used, but a polyurea resin is preferable in consideration of shortening the work period and elongation following a crack. The polyurea resin is generally composed of a main agent and a curing agent, and polyisocyanate is used as the main agent, and polyetheramine and aromatic polyamine are used as the curing agent. Examples of commercially available products include “trade name: POLYSHIELD AIN-20” manufactured by SPI. Urea / urethane resin can also be used. In that case, polyisocyanate is used as the main agent, and polyether polyol, modified amine, and curing catalyst (amine-based or metal-based) are used as the curing agent.

The present invention relates to a method for preventing corrosion and waterproofing of concrete structures, and there is no coating float, blistering, and pinholes not only in flat portions such as the upper surface and wall surface, but also in the protruding corners and inward corners. A smooth anti-corrosion / water-proof coating can be formed in a short construction period. In general, when a large-scale concrete structure is a concrete molded on-site, voids such as air holes and burrows that are likely to occur on the concrete surface in contact with the formwork are replaced with cement or polymer. It takes a lot of time to adjust the surface of the cement-based or binder resin, such as epoxy resin, vinyl ester resin, non-styrene vinyl ester resin, urethane resin, unsaturated polyester resin, acrylic resin, etc. And costly. On the other hand, in the present invention, since the corrosion of the concrete structure can be completely suppressed in a short construction period by simple and excellent workability, the industrial value of the present invention is remarkable.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded. The viscosity is 25 ° C., and the viscosity is less than 8,000 mPa · s in accordance with the viscosity of the binder resin composition. BM type rotational viscometer, No. 4 rotor, 60 min ⁻¹ , 8,000 to 160,000 mPa · s For those less than BH type rotational viscometer, No. 6 rotor or No. 7 rotor, 20 min ⁻¹ , 160,000 mPa · s or more, B8U type rotational viscometer, No. 6 rotor, measured with 20 min ⁻¹ did. The microscopic pinhole test was performed using a “TO-250C pinhole detector” (for concrete substrate) manufactured by Sanko Electronic Laboratory Co., Ltd., with a voltage of 7 kV, and a specimen (JIS concrete plate, 360 × 600 × 50 mm) was inspected for the presence of pinholes. The evaluation was performed with ○: no pinholes, Δ: pinholes (5 locations or less / test version), and X: multiple pinholes (6 locations or more / test plate). The unevenness adjustment performance of the binder resin composition was evaluated by visual observation of a state where a 0.5 mm step was provided on the test plate and the binder resin was applied 1.0 kg / m ² upward. The evaluation was made with O: smooth finish, x: resin dripping, etc. without smooth finish. In addition, the confirmation of floating and swelling of the porous thin film sheet layer at the protruding corner and the entering corner was visually inspected. Evaluation was performed with ◯: no floating and no swelling, and ×: with floating and / or swelling. The impregnation performance of the binder resin composition into the porous thin film sheet was evaluated by an adhesion test using a Kenken-type tensile test (based on JIS A 6909). Evaluation was performed by ○: base material destruction, ×: destruction in the sheet layer.

As Examples 1 to 4, after applying a binder resin composition (adhesion amount: 1.0 kg / m ² ) having the viscosity shown in Table 1 with a roller or a trowel, glass fiber paper (thickness: 0.23 mm, basis weight: 31 g / m ² ) was pasted and cured at 23 ° C. for 1 day. Further, if necessary, 100 parts by weight of bisphenol F type epoxy resin (epoxy equivalent: 168 g / eq, manufactured by Japan Epoxy Resin) as a primer, 1,6-hexanediol diglycidyl ether (manufactured by Sakamoto Pharmaceutical Co., Ltd.) An epoxy resin composition containing 37.6 parts by weight and 67.6 parts by weight of a curing agent (manufactured by Dainippon Color Material Co., Ltd .: “Epoxy-modified MXDA”) was applied with a roller at an adhesion amount of 0.3 kg / m ^2. After a time, a polyurea resin (manufactured by SPI: trade name “POLYSHIELD AIN-20”, adhesion amount: 3.0 kg / m ² ) was applied with a special coating machine and cured at 23 ° C. for 7 days to prepare an anticorrosion / waterproof coating. .

For the application of the polyurea resin, a special coating machine with power: 45 A, 200 V, 50 Hz, supply pressure: 400 Psi, discharge amount: 13 kg / min (Max), primary heater: 4500 W × 2 (9000 W) was used. The compressor used at that time was a power of 20 A, 200 V, 50 Hz, a discharge pressure of 0.64 to 0.83 MPa, and a discharge air amount of 0.44 m ³ / min.

In Table 1, in Example 1, as a binder resin composition having a viscosity of 5,000 mPa · s, 100 parts by weight of a bisphenol A type epoxy resin (epoxy equivalent: 189 g / eq, manufactured by Japan Epoxy Resin), 1,6-hexanediol Epoxy resin composition containing 26.2 parts by weight of diglycidyl ether (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), 10.9 parts by weight of talc and 40.2 parts by weight of a curing agent (manufactured by Dainippon Color Material Co., Ltd .: “Epoxy Modified MXDA”) In Example 2, as a binder resin composition having a viscosity of 10,000 mPa · s, 100 parts by weight of a bisphenol A type epoxy resin (epoxy equivalent: 189 g / eq, manufactured by Japan Epoxy Resin), 1,6-hexanediol diglycidyl Ether (manufactured by Sakamoto Pharmaceutical Co., Ltd.) 26.2 parts by weight, talc 23.1 parts by weight An epoxy resin composition containing 34.5 parts by weight of “Epoxy-modified MXDA” manufactured by Color Materials Co., Ltd. was used as a binder resin composition having a viscosity of 50,000 mPa · s in Example 3, and a bisphenol A type epoxy resin (epoxy) Equivalent: 189 g / eq, manufactured by Japan Epoxy Resin) 100 parts by weight, 1,6-hexanediol diglycidyl ether (produced by Sakamoto Yakuhin Kogyo), 13.3 parts by weight, talc 42.2 parts by weight, and curing agent (Dainippon Coloring Materials) An epoxy resin composition containing 28.7 parts by weight of “Epoxy-modified MXDA” manufactured by Kogyo Co., Ltd. was used as a binder resin composition having a viscosity of 200,000 mPa · s in Example 4, and a bisphenol A type epoxy resin (epoxy equivalent: 189 g / eq, manufactured by Japan Epoxy Resin) 100 parts by weight, 1,6-hexanediol diglycidyl An epoxy resin composition containing 12.6 parts by weight of Teru (Sakamoto Yakuhin Kogyo Co., Ltd.), 82.4 parts by weight of talc and 25.3 parts by weight of a curing agent (manufactured by Dainippon Color Materials Co., Ltd .: “Epoxy Modified MXDA”) did.

As Comparative Examples 1 to 5, as shown in Table 2, an anticorrosion coating was prepared in the same manner as in Examples except that the viscosity of the binder resin composition, the presence or absence of the porous thin film sheet, and the presence or absence of the primer were changed. .

In Table 2, as a binder resin composition having a viscosity of 2,000 mPa · s in Comparative Example 3, bisphenol A type epoxy resin (epoxy equivalent: 189 g / eq, manufactured by Japan Epoxy Resin Co., Ltd.) 100 parts by weight, 1,6-hexane An epoxy resin composition containing 13.3 parts by weight of diol diglycidyl ether (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) and 40 parts by weight of a curing agent (manufactured by Dainippon Color Materials Co., Ltd .: “Epoxy-modified MXDA”), and Comparative Example 4 and 5 as a binder resin composition having a viscosity of 300,000 mPa · s, 100 parts by weight of a bisphenol A type epoxy resin (epoxy equivalent: 189 g / eq, manufactured by Japan Epoxy Resin Co., Ltd.), 1,6-hexanediol diglycidyl ether ( (Sakamoto Yakuhin Kogyo Co., Ltd.) 26.2 parts by weight, talc 46.9 parts by weight and curing agent (Dainippon Color Material Company Ltd. was used to "epoxy-modified MXDA") epoxy resin composition comprising 30.8 parts by weight.

As is clear from the above results, the float and swelling of the porous thin film sheet impregnated layer at the protruding corner and the entering corner are not confirmed in the case of the example, and further, microscopic pinholes are also confirmed. There wasn't. On the other hand, when the unevenness adjustment performance of the binder resin composition as in Comparative Example 3 is insufficient, the resin dripping occurs when applied upward, and the sheet impregnated layer floats and bulges in the protruding corner / entry corner portions. confirmed. Further, when the impregnation performance into the porous thin film sheet of the binder resin composition as in Comparative Example 4 and Comparative Example 5 is insufficient, the unevenness adjustment performance and the sheet impregnation layer in the exit corner / entrance corner portion Although there was no float or swelling, the porous thin film sheet was not sufficiently impregnated with the binder resin, microscopic pinholes were confirmed, and as a result of the Kenken-type tensile test, destruction within the sheet layer was confirmed. . Moreover, in the case of the comparative example 1, the comparative example 2, and the comparative example 5 which did not use a porous thin film sheet, the micro pinhole was confirmed in all.

Claims (3)

After applying a paste-like or putty-like binder resin composition , which is an epoxy resin composition , to the surface of a concrete structure, a porous thin film sheet is pasted thereon, and then a coating is formed on the porous thin film sheet-impregnated layer An anticorrosion / waterproofing method for a concrete structure comprising a step of applying a forming resin material with a brush, a trowel, a spatula, a roller, or a spray to form a film.   The method for preventing corrosion / waterproofing a concrete structure according to claim 1, wherein the binder resin composition has a viscosity of 3,000 to 250,000 mPa · s.   The anticorrosion / waterproofing method for a concrete structure according to any one of claims 1 and 2, wherein the film-forming resin material is a polyurea resin.