JP2001062389A - Surface treatment method for civil engineering and construction substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quicken the hardening at a low viscosity and to improve the adhesion to a substrate by forming a coating layer on the surface of a civil engineering and construction substrate by hardening a resin composition containing a radical polymerizable unsaturated group-containing compound, a moisture- curable urethane polymer, and a radical polymerization initiator. SOLUTION: A coating layer is formed on the surface of a civil engineering and construction substrate by hardening a resin composition containing a radical polymerizable unsaturated group-containing compound of an alkyl (meth)acrylate such as methyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, and the like, which is chain polymerizable by a radical species, a moisture- curable urethane polymer, e.g. phenylene diisocyanate, xylene diisocyanate, and the like, and a radical polymerization initiator, e.g. benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for protecting the surface of a substrate for civil engineering and construction such as wood, metal, ceramic, concrete, mortar, asphalt and the like.

[0002]

2. Description of the Related Art Concrete, mortar, asphalt, etc., which serve as base materials for floors, rooftops, walls, sidewalks, etc., are coated with various liquid resins for waterproofing, corrosion protection, dustproofing, aesthetics, and other purposes, and are then cured. In many cases, a treatment for covering the surface of these base materials is performed. For example, urethane prepolymers having an isocyanate group at the terminal are widely used as sealing materials or coating materials for civil engineering and building base materials such as paints, waterproof materials, floor materials, and paving materials. The urethane prepolymer itself has a high viscosity, and usually, from the viewpoint of coating workability, an organic solvent such as xylene is often mixed with the urethane prepolymer to reduce the viscosity. The urethane prepolymer has an isocyanate group at the terminal of the molecule, and this reacts with the moisture in the air, and furthermore, the moisture adsorbed on the base material to increase the molecular weight. Go enough. However, in practice, if the organic solvent mixed for lowering the viscosity does not evaporate into the atmosphere, the curing is insufficient and the surface remains sticky. Therefore, the curing rate of the urethane prepolymer depends on the volatilization rate of the organic solvent, and there is a problem that the curing is particularly slow in winter.

On the other hand, urethane (meth) acrylate is known as a liquid resin having a high curing speed. This is obtained by reacting a urethane prepolymer with a (meth) acrylate having a hydroxy group,
It has a radical polymerizable group at the molecular terminal, and is cured by adding a radical polymerization initiator. By selecting a radical polymerization initiator, for example, curing can be performed even at an ambient temperature of 0 ° C., but when used as a coating material, adhesion to a substrate is inferior to that of a urethane prepolymer.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for coating a base material for civil engineering and construction using a resin composition having a low viscosity, fast curing, and excellent adhesion to a base material. It is assumed that.

[0005]

In order to solve the above-mentioned problems, the present invention provides (a) a radical polymerizable unsaturated group-containing compound and (b) a moisture-curable urethane prepolymer on the surface of a substrate for civil engineering and construction. And (c) forming a coating layer obtained by curing a resin composition containing a radical polymerization initiator,
Provided is a surface treatment method for a substrate for civil engineering and construction.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition used in the present invention will be described. As the compound containing a radically polymerizable unsaturated group as the component (a), any compound can be used without particular limitation as long as it is a compound that undergoes chain polymerization by a radical species. However, when a compound having a hydroxyl group is used as the component (a), by mixing with the moisture-curable urethane prepolymer of the component (b), it reacts with the isocyanate group of the component (b) to obtain a viscosity of the resin composition. May rise. Further, the concentration of an isocyanate group useful for adhesion may decrease, and the adhesion to a substrate may be deteriorated. Therefore, in the present invention, it is preferable to use the component (a) having no hydroxyl group. However, as long as the effects of the present invention such as low viscosity, fast curing, and adhesion are not impaired, the use of the component (a) having a hydroxyl group is preferred. The amount of (a) is equivalent to 1 equivalent of isocyanate group of component (b).
The hydroxyl group of the component is 0.5 equivalent or less, further 0.2
It is preferred that it is not more than the equivalent.

Specific examples of the component (a) include methyl (meth) acrylate, butyl (meth) acrylate,
Alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; (meth) acrylates having an aromatic ring such as benzyl (meth) acrylate and phenyl (meth) acrylate Methoxyethoxyethyl (meth) acrylate, (
(Meth) ethoxyethoxyethyl acrylate, alkylene oxide adduct of monoalcohol such as dicyclopentenyloxyethyl (meth) acrylate and esterified product of (meth) acrylic acid; hydroxyethyl (meth) acrylate, hydroxy (meth) acrylate Compounds having a hydroxyl group such as propyl; aromatic vinyl compounds such as styrene, vinyltoluene and divinylbenzene; and vinyl ethers such as butyl vinyl ether and triethylene glycol divinyl ether. Further, compounds having two or more radically polymerizable unsaturated groups in one molecule can also be used. For example, ethylene glycol di (meth) acrylate, 1.4-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) ) Esterified products of polyhydric alkyl alcohols such as acrylates and (meth) acrylic acid; alkylene oxide adducts of polyhydric alkyl alcohols such as diethylene glycol di (meth) acrylate and tetraethylene glycol di (meth) acrylate and (meth) acrylic acid Esterified products of epoxy compounds; epoxy (meth) acrylates which are reactants of epoxy compounds and (meth) acrylic acid; reactants of hydroxyl-terminated polyester polyols which are condensates of polybasic acids and polyhydric alcohols with (meth) acrylic acid Is a polyester poly (meta Acrylate, and the like. As the component (a), one or more of these can be used. In particular, in order to increase the curing speed, it is preferable to include a compound having two or more radically polymerizable unsaturated groups in one molecule.

The moisture-curable urethane prepolymer (b) is obtained by reacting an isocyanate compound with a polyhydric alcohol. As the isocyanate compound, those used in the production of ordinary polyurethane resins can be used. Examples include isocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, and one or more of these can be used.

Examples of the polyhydric alcohol include those used in the production of ordinary polyurethane resins. Examples thereof include alkylene polyols such as ethylene glycol, propylene glycol, 1,6-hexanediol, trimethylolpropane and glycerin; Polyether polyols such as polypropylene glycol;
Examples include hydroxyl group-containing polymers such as polybutadiene having a hydroxyl group and poly (meth) acrylate having a hydroxyl group; ester polyols obtained by condensation of a polybasic acid and a polyhydric alcohol. Further, as the polybasic acid constituting the ester polyol, in addition to a polybasic acid having an unsaturated group described below, for example, succinic acid, adipic acid, phthalic acid, trimellitic acid, polybasic acids such as pyromellitic acid, And their anhydrides. Examples of the polyhydric alcohol constituting the ester polyol include the above-mentioned polyhydric alcohols, and alkylene oxides such as ethylene oxide and propylene oxide can also be used.

[0010] In particular, in order to increase the curing speed, (b)
The moisture-curable urethane prepolymer as a component preferably has an unsaturated bond, and specifically, a polyhydric alcohol having an unsaturated bond is preferably used as the polyhydric alcohol. Examples of the polyhydric alcohol having an unsaturated bond include (1) a polyhydric alcohol having an allyl ether group,
(2) at least one polyhydric alcohol selected from animal or vegetable oils or polyhydric alcohols derived from animal or vegetable oils, and (3) ester polyols obtained by condensation of polybasic acids having unsaturated groups with polyhydric alcohols It is preferable to use

Examples of the polyhydric alcohol having an allyl ether group include ring-opening addition polymers of trimethylolpropane monoallyl ether, pentaerythritol diallyl ether, and allyl glycidyl ether. Animal and vegetable oils or polyhydric alcohols derived from animal and vegetable oils include castor oil and transesterification products of animal and vegetable oils with polyhydric alcohols.

The polybasic acid constituting the ester polyol obtained by condensation of a polybasic acid having an unsaturated group with a polyhydric alcohol is a polybasic acid having an aliphatic carbon double bond. Acid, fumaric acid, itaconic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methyltetrahydrophthalic acid, dimer acid, and anhydrides thereof. Examples of the polyhydric alcohol include the above-mentioned polyhydric alcohols and alkylene oxides. Compounds.

The reaction between the isocyanate compound and the polyhydric alcohol can be carried out in the same manner as in the case of the usual moisture-curable urethane prepolymer, and the molar ratio of the isocyanate group to the hydroxyl group is NCO / OH = 1.2-3. , And heat-mixing at 40 to 100 ° C. is preferable. The end point of the reaction can be determined at a point where almost no increase in viscosity is observed. can do. In the reaction between the isocyanate compound and the polyhydric alcohol, a well-known urethanization catalyst can be used. For example, tin compounds such as dibutyltin dilaurate, dibutyltin dichloride, and dibutyltin oxide; triethylamine, 1,4-diazabicyclo [ Amine compounds such as [2,2,2] octane.

The reaction can be carried out in the presence of a solvent. A solvent inert to isocyanate and hydroxyl groups is used, and examples thereof include toluene, xylene and butyl acetate. Further, the component (a) of the present invention can be used as a solvent. As the radical polymerization initiator of the component (c), a polymerization initiator used for curing a radical polymerizable resin such as an unsaturated polyester resin or an epoxy acrylate is used. For example, benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide Oxides,
t-butyl perbenzoate, azobisisobutyronitrile, and the like. Further, when curing by irradiation with light such as ultraviolet light, benzophenone, benzoin isobutyl ether, benzoin isopropyl ether, benzyldimethyl ketal, 2,2-diethoxyacetophenone , 1
-Hydroxycyclohexylphenyl ketone, ethylphenylglyoxylate, 2-chlorothioxanthone,
Examples thereof include 2,4-diisopropylthioxane and 2,4,6-trimethylbenzoyldiphenoylphosphine oxide, and one or more of these can be used.

In the above resin composition, (a),
The mixing ratio of each of the components (b) and (c) can be appropriately selected depending on the setting of the viscosity of the obtained resin composition and the pot life until gelation, and is based on 100 parts by weight of the component (a). ,
Component (b) is 50 to 400 parts by weight, component (c) is 0.1
It is preferable to mix in a range of from 10 to 10 parts by weight, and (a)
More preferably, the component (b) is mixed in the range of 80 to 250 parts by weight and the component (c) in the range of 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the component. Insufficient component (a) results in slow curing and high viscosity. If the component (b) is insufficient, the adhesion to the substrate is poor. Insufficient component (c) results in slow curing and poor workability.

In the above resin composition, (a)
The proportion occupied by the total of the components (b) and (c) is 10 to 100.
% By weight, more preferably 20 to 100% by weight.
And more preferably 30 to 100% by weight.
The resin composition may further include a curing accelerator, a filler, a thixotropic agent, a drying improver, a colorant, and the like.

In order to increase the curing speed, it is preferable to use a curing accelerator comprising a metal salt of an organic carboxylic acid as the component (d). As metal salts of organic carboxylic acids, for example, cobalt, manganese, lead, nickel,
Examples include metal salts of metals such as magnesium, zinc, tin, copper, iron and zirconium with organic carboxylic acids such as octylic acid, naphthenic acid and acetic acid.

Further, tertiary amines can be used as a curing accelerator other than the metal salts of the organic carboxylic acid as the component (d). For example, fragrances such as dimethylaniline, dimethyltoluidine and N, N-dihydroxyethyltoluidine can be used. Aliphatic tertiary amines such as triethylamine, N-methylmorpholine, triethylenediamine, dimethylethanolamine, methyldiethanolamine, and triethanolamine; Furthermore, the above-mentioned urethanization catalyst can be used as a curing accelerator.

The metal salt of the organic carboxylic acid of the component (d) is expressed in terms of the weight of the metal with respect to 100 parts by weight of the component (a).
It is preferable to mix in a range of 0.001 part by weight to 1.0 part by weight. In the case of mixing a tertiary amine or a urethanization catalyst, 100 parts by weight of the component (a) is used.
It is preferable to mix in a range of 0.05 parts by weight to 10 parts by weight.

As the filler, aluminum hydroxide, talc,
Examples include silica sand, crushed stone, calcium carbonate, antimony oxide, and glass flake. Examples of the thixotropic agent include fine anhydrous silica, asbestos, clay, and fatty acid amide compound. Examples of the drying improver include paraffin, wax, drying oil and the like.

Examples of the coloring agent include organic pigments, inorganic pigments, dyes and the like. To form a coating layer formed by curing the resin composition on the surface of a substrate for civil engineering and building, carbon fiber,
Glass fiber, a reinforcing material such as polyamide fiber or the like is impregnated with the resin composition as a coating material, and may be cured by being in close contact with a base material, or may be cured after applying the resin composition to the base material. Is also good. In the treatment method of the present invention, a preferable mode for forming the coating layer is, as described above, impregnation, application, and coating of the resin composition, followed by curing to form a coating layer. Such treatment improves the adhesion between the substrate and the coating layer.

The base material for civil engineering and construction is not particularly limited, and includes base materials such as floors, rooftops, wall surfaces, sidewalks and the like. The material is not particularly limited, and includes wood, metal, ceramic, concrete, mortar, asphalt, and the like.However, the resin composition used in the present invention has a low viscosity, so that it can be easily impregnated into a base material, and This is particularly effective when treating the surface of a substrate for civil engineering and construction having a porous surface such as concrete, mortar, asphalt, etc.

In the present invention, these civil engineering and construction base materials may be directly coated, or they may be already coated with a resin or the like, or may be overlaid and coated thereon. Good. After coating with the resin composition, a thermosetting resin such as an unsaturated polyester resin, an epoxy resin, an epoxy acrylate, a urethane acrylate, or an acrylic syrup, or a resin such as a solvent-type resin paint or an emulsion resin paint is laminated thereon. By applying the coating, a tough coating layer having a multilayer structure can be formed.

Of course, as the form of the above-mentioned coating layer,
The form is not particularly limited as long as it is a layer formed on the surface of the substrate for civil engineering construction. For example, it is a primer layer, an intermediate layer, a top coat layer, or the like. The curing of the resin composition may be performed in an ambient temperature atmosphere, or may be performed under heating or by irradiation with light such as ultraviolet rays.

The surface treatment method of the present invention is effective for waterproofing, anticorrosion, dustproofing, aesthetics, and other purposes of a substrate for civil engineering and construction, but is particularly effective for waterproofing. Further, the resin composition can be used not only for coating a substrate for civil engineering and construction, but also for coating another substrate.

[0026]

EXAMPLES (Production Example 1) A flask equipped with a cooling pipe, a stirrer, a thermometer, a gas introduction pipe, and a dropping funnel was charged with 264 g of toluene diisocyanate, 546 g of diethylene glycol dimethacrylate, and 0.12 g of benzoquinone, and nitrogen gas was added. And 555 g of castor oil having a hydroxyl equivalent of 347 was added dropwise at 60 ° C. over 2 hours. After completion of the dropwise addition, 0.24 g of dibutyltin dilaurate was added, and the mixture was further heated at 60 ° C. for 4 hours to obtain a resin (1) having a viscosity of 5 Stokes at 25 ° C. (Production Example 2) A flask equipped with a cooling pipe, a stirrer, a thermometer, a gas introduction pipe, and a dropping funnel was charged with 556 g of toluene diisocyanate and 207 g of xylene, heated while blowing nitrogen gas, and heated at 60 ° C with 54 g of trimethylolpropane. Polypropylene glycol (molecular weight 400) 4
80 g of the mixture were added dropwise over 2 hours. After dropping,
0.33 g of dibutyltin dilaurate was added and a further 6
After heating at 0 ° C. for 4 hours and cooling, 520 g of diethylene glycol dimethacrylate and 0.12 g of benzoquinone were added to obtain a resin (2) having a viscosity of 7 Stokes at 25 ° C. (Production Example 3) In a flask equipped with a cooling pipe, a stirrer, a thermometer, a gas introduction pipe, and a dropping funnel, 340 g of toluene diisocyanate and diethylene glycol dimethacrylate 6 were added.
Then, 100 g of benzoquinone and 0.15 g of benzoquinone were charged and heated while blowing nitrogen gas, and 660 g of a dimer acid ethylene oxide adduct having a hydroxyl equivalent of 333 was added dropwise at 60 ° C. over 2 hours. After completion of the dropwise addition, 0.30 g of dibutyltin dilaurate was added, and the mixture was further heated at 60 ° C. for 4 hours. After cooling, trimethylolpropane trimethacrylate 70 was added.
g was added to obtain a resin (3) having a viscosity of 8 Stokes at 25 ° C. (Production Example 4) In a flask equipped with a cooling pipe, a stirrer, a thermometer, a gas introduction pipe, and a dropping funnel, 348 g of toluene diisocyanate and diethylene glycol dimethacrylate 4 were added.
And 213 g of methyl methacrylate, and 0.15 g of benzoquinone. The mixture was heated while blowing nitrogen gas, and 172 g of trimethylolpropane monoallyl ether and polypropylene glycol (molecular weight: 40
0) 400 g of the mixture was added dropwise over 2 hours. After completion of the dropwise addition, 0.28 g of dibutyltin dilaurate was added, and the mixture was further heated at 60 ° C for 4 hours to obtain a resin (4) having a viscosity of 6 Stokes at 25 ° C. (Production Example 5) A flask equipped with a cooling pipe, a stirrer, a thermometer, a gas introduction pipe, and a dropping funnel was charged with 556 g of toluene diisocyanate and 500 g of xylene, heated while blowing nitrogen gas, and heated at 60 ° C with 54 g of trimethylolpropane. Polypropylene glycol (molecular weight 400) 4
80 g of the mixture were added dropwise over 2 hours. After dropping,
0.33 g of dibutyltin dilaurate was added and a further 6
The mixture was heated at 0 ° C. for 4 hours to obtain a urethane prepolymer (5) having a viscosity of 7 Stokes at 25 ° C. (Production Example 6) In a flask equipped with a cooling pipe, a stirrer, a thermometer, a gas introduction pipe, and a dropping funnel, 487 g of toluene diisocyanate, 626 g of styrene, and 0.14 of benzoquinone were added.
g, and heated while blowing in nitrogen gas.
Then, 87 g of diethylene glycol was added dropwise over 30 minutes.
After the completion of the dropwise addition, the mixture was further heated for 1 hour, and then 364 g of hydroxyethyl methacrylate was added dropwise for 1 hour. After completion of the dropwise addition, 0.28 g of dibutyltin dilaurate was added, and the mixture was further heated for 2 hours to obtain a urethane methacrylate (6) having a viscosity of 5 Stokes at 25 ° C. (Examples 1 to 4, Comparative Examples 1 and 2) To each resin obtained in Production Examples 1 to 6, a radical polymerization initiator and a curing accelerator shown in Table 1 were mixed to obtain a resin composition.

Immediately after mixing, 6.4 g of the resin composition was used.
Is impregnated into a single 450 cm glass fiber mat of 5 cm square,
The concrete was covered by being in intimate contact with a concrete plate. The surface hardening time was evaluated by leaving the film in an atmosphere at 25 ° C. and taking the time from the adhesion to the time when the surface was hardened and the stickiness by finger touch disappeared as the surface hardening time. Further, after the test specimen was left for one day, a 4 cm square iron jig was adhered to the cured surface with an epoxy-based adhesive, and the adhesion between the coating layer and the concrete layer was measured with a Kenken-type adhesion tester.

Table 1 shows the results. (Examples 5 and 6, Comparative Example 3) A radical polymerization initiator and a curing accelerator shown in Table 2 were mixed with each of the resins obtained in Production Examples 1, 4, and 5, to obtain a resin composition. Immediately after mixing, a concrete plate was applied in an amount of 300 g / m ² . 5. After standing for 1 day in an atmosphere of 30 ° C., an unsaturated polyester resin mixed with 100 parts by weight of Epolac N-423PW (manufactured by Nippon Shokubai) and 1 part by weight of 55% methyl ethyl ketone peroxide on the surface. 4 g was impregnated into 5 cm × 5 cm of No. 380 glass fiber mat and lined. After further leaving at 30 ° C. for one day, a 4 cm square iron jig was adhered to the lining surface with an epoxy adhesive, and the adhesive strength between the coating layer and the concrete layer was measured with a Kenken-type adhesive strength tester.

Table 2 shows the results. Example 7 200 g of a water-based epoxy primer, JC primer (manufactured by Nippon Shokubai Co., Ltd.), was added to a concrete plate.
/ M ² was applied. Production Example 4 after leaving at 25 ° C. for 1 day
100 parts by weight of the resin obtained in step 5, titanium oxide 5 parts by weight,
% Metal content cobalt octylate 1.0 part by weight, hardener 32
A resin composition mixed with 1.0 part by weight of 8E (manufactured by Kayaku Akzo Co., Ltd.) was applied to the primer-treated surface in an amount of 300 g / m ² . After 2 hours, the coated surface had dried and cured and had a uniform and glossy appearance.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

According to the present invention, curing is fast with low viscosity,
The substrate for civil engineering and construction can be coated using a resin composition having excellent adhesion to the substrate.

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Claims (3)

[Claims] 1. A resin composition comprising (a) a radically polymerizable unsaturated group-containing compound, (b) a moisture-curable urethane prepolymer, and (c) a radical polymerization initiator on the surface of a substrate for civil engineering and construction. A method for treating a surface of a substrate for civil engineering and construction, which forms a coating layer obtained by curing the above. 2. The base for civil engineering and construction according to claim 1, wherein after forming a coating layer formed by curing the resin composition on the surface of the substrate for civil engineering and building, a resin layer is further provided on the coating layer. Surface treatment method for materials. 3. The civil engineering structure according to claim 1, wherein a coating layer formed by curing the resin composition is formed on the resin layer of the substrate for civil engineering and construction having a resin layer provided on a surface thereof. Surface treatment method for architectural base materials.