JP2790929B2 - Repair method of building wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a building wall, and more particularly, to improving the abrasion resistance, weather resistance and aesthetic appearance of a wall surface by applying a coating agent to an exterior wall of the building. The present invention relates to a method for protecting a building wall surface, which can be easily repaired because it can be removed by a cleaning agent.

[0002]

Technical Background of the Invention and Problems There is a problem that the wall surface of a building is deteriorated due to the influence of exhaust gas, acid rain, dust and the like, salt damage, frost damage, etc., and the appearance is deteriorated.
Therefore, various methods for preventing the deterioration of the aesthetic appearance of the building wall surface and for repairing the wall surface having the reduced aesthetic appearance have been studied. As a method of repairing, for example, there is a method of cleaning the surface of a wall surface with a cleaning agent to remove dirt. However, in the method using a cleaning agent, even if dirt adhering to the wall surface can be removed, the surface appearance is not improved again because of the influence of the cleaning agent and the brush. As an aesthetic improver after washing, it has been proposed to apply an aqueous emulsion solution or an organic solvent solution containing a wax component such as a hydrocarbon as a main component. There have been problems such as falling of the coating and peeling. Although a coating agent containing gypsum as a main component has been proposed, there has been a problem in that cracks and warpage of the coating surface occur due to shrinkage during curing.
In addition, a method is known in which a coating agent containing a silane compound or polysiloxane as a main component is applied to a porous inorganic material such as concrete to impart water repellency to prevent deterioration (Japanese Patent Application Laid-Open No. 57-157). 126878, JP-A-62-197369, JP-A-1-292889, JP-A-2-70787, JP-A-2-150
No. 477). However, there is no description on a method for repairing the wall surface with a reduced appearance and a method for repairing the wall surface after applying the coating agent, and further improvement is required.

[0003]

An object of the present invention is to solve the above-mentioned problems and to provide excellent abrasion resistance and weather resistance against the effects of exhaust gas, acid rain, dust and the like, and the deterioration of the building wall surface due to salt damage and frost damage. It is an object of the present invention to provide a method for repairing a building wall surface which can provide an improvement in aesthetic appearance and the like and which can be easily repaired again.

[0004]

The present inventors have conducted various studies in order to achieve the above object, and as a result, by providing a protective coating containing silicone as a main component, which can be removed with a cleaning agent, on the wall of a building, excellent results have been obtained. The present inventors have found that it is possible to provide a method for repairing a building wall surface, which can improve wear resistance, weather resistance, aesthetic appearance, and the like, and that can easily be repaired again, and have accomplished the present invention.
That is, the method for repairing a building wall according to the present invention is characterized in that a coating agent containing silicone as a main component that can be removed with a cleaning agent is applied to the wall of the building.

[0005] In the method of the present invention, the material of the wall surface of the target building is not particularly limited as long as it is a commonly used material. Concrete wall materials
Inorganic materials such as mortar, tile, brick, stone, etc., metal materials such as aluminum, iron, stainless steel, etc., and their surfaces sprayed with synthetic resin spraying material, siliceous spraying material, etc., and further synthetic resin paint And the like. Here, urethane resin type, acrylic resin type, epoxy resin type and the like are exemplified as the synthetic resin spraying material and the synthetic resin paint, and silica sol type, water glass type and silicate material type are exemplified as the siliceous spraying material. . Since the repair method of the present invention is particularly effective in improving aesthetics by imparting gloss, it is particularly preferably used for non-porous wall surfaces having gloss among the above. In addition, it is preferably used for non-porous wall surfaces where the penetration of the coating agent is small because it is easy to remove with a cleaning agent at the time of repair.

The coating agent of the present invention contains silicone as a main component and generally contains a solvent and a curing catalyst. The silicone used in the present invention is obtained by condensing an organosilanetriol represented by R ¹ Si (OH) ₃ or a partial hydrolyzate thereof as a main component. Here, R ¹ represents a monovalent group selected from the group consisting of an alkyl group having 1 to 3 carbon atoms and an aryl group. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group.
Examples of the aryl group include a phenyl group.

The organosilanetriols are obtained by hydrolyzing the corresponding hydrolyzable silanes, for example of the formula R ¹ Si (OR ² ) ₃ , wherein R ² represents an alkyl group having 1 to 4 carbon atoms. An organotrialkoxysilane represented by
It can be obtained by hydrolysis in the presence of a catalyst. Here, as R ² , a methyl group, an ethyl group, a propyl group, a butyl group and the like are exemplified. Further, as the hydrolyzable group, a ketoxime group other than the alkoxy group, an acyloxy group, an amino group, an aminoxy group, an alkenyloxy group, a hydrolyzable silane having an amide group, a chlorine atom, and the like can be used, but handling is easy. Therefore, those having an alkoxy group as a hydrolyzable group are preferred. Examples of the hydrolysis catalyst that can be used include organic acids such as acetic anhydride, glacial acetic acid, propionic acid, citric acid, benzoic acid, formic acid, and oxalic acid; aluminum chelate compounds such as aluminum alkyl acetate; tetrachlorosilane and methyltrichlorosilane And chlorosilanes such as dimethyldichlorosilane; inorganic alkaline compounds such as aqueous ammonia; organic alkali compounds such as ethylenediamine; and amino group-containing organosilicon compounds such as γ-aminopropyltrimethoxysilane. Of these, chlorosilane is preferably used because it serves both as a raw material for silicone and a hydrolysis catalyst. Among them, methyltrichlorosilane and dimethyldichlorosilane are preferred. As raw materials for silicone, R ³ ₂ SiX ₂ , R ⁴ ₃ SiX, SiX ₄ (where R ³ and R ⁴ are the same substituents as R ^1, and X is the same or different (Representing a functional group or a hydroxyl group) may be used. Especially of R ³ ₂ SiX ₂ is preferable because of excellent durability of the protective coating. Molar ratio in this case organosilane triol / R ³ ₂ SiX _2, the abrasion resistance of the protective coating, preferably 0.9 / 0.1 or less from the detergency due from preferably 0.2 / 0.8 or higher gloss and cleaning agents of the protective film . Particularly preferably, it is 0.6 / 0.4 to 0.8 / 0.2.

In order to improve the adhesion of the protective film to the wall surface, a silane coupling agent such as an alkoxysilane having an amino group, an acryl group, a methacryl group, a glycidyl group or the like may be blended as a raw material of the silicone. Good. Examples of such alkoxysilanes include amino group-containing alkoxysilanes such as γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ -Alkoxysilanes containing a (meth) acryl group such as methacryloxypropyltrimethoxysilane, and alkoxysilanes containing a glycidyl group such as γ-glycidoxypropyltrimethoxysilane. Among them, amino group-containing alkoxysilanes are preferable because they are easily removed by a detergent. The amount of the silane coupling agent is preferably 0.1 to 5.0 parts by weight based on 100 parts by weight of the silicone.

The condensation reaction is carried out by further heating and stirring after the hydrolysis reaction. Generally, a hydroxyl group or a hydrolyzable group remains in the thus obtained silicone. Although the degree of polymerization of the hydrolyzate silicone is not particularly limited, the viscosity is preferably 10 cP or more because the permeability to the wall surface is small and the protective film can be easily removed at the time of repair. It is preferably 10,000 cP or less because of good coating properties of the agent. Particularly preferred is 20 to 100 cP.

A solvent is generally used for the coating agent of the present invention. The solvent component is not particularly limited as long as it dissolves and disperses the silicone, and includes alcohols such as methanol, ethanol and isopropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, tetrahydrofuran,
Ether alcohols and ethers such as dioxane; ketones such as acetone, methyl ethyl ketone and diethyl ketone; esters such as methyl acetate, ethyl acetate and n-butyl acetate; n-hexane, gasoline, rubber volatile oil, mineral spirits Aliphatic hydrocarbons such as kerosene; aromatic hydrocarbons such as benzene, toluene and xylene; silicone oils such as linear dimethylsiloxane and cyclic dimethylsiloxane; and water. If water is used as the solvent here,
It is preferable to form an emulsion using various emulsifiers. Examples of the silicone oil include low molecular weight polydimethylsiloxanes represented by the general formula (I) or (II) and having volatility at room temperature or at low temperature.

[0011]

Embedded image

Of these, low molecular weight polydimethylsiloxanes are preferred because they provide good shielding of abrasions on building walls and the protective coating formed is easy to remove during repair. preferable. When an early drying property is required, it is preferable to contain an alcohol such as methanol, ethanol or propanol, and particularly preferable is ethanol. These solvents may be used as a mixture of two or more kinds. In this case, the low molecular weight polydimethylsiloxane is preferably used in an amount of 100 to 500 parts by weight based on 100 parts by weight of the silicone.
The compounding amount of the solvent is preferably 100 to 2,000 parts by weight based on 100 parts by weight of the silicone from the viewpoint of workability of applying the coating agent.

[0013] A curing catalyst is generally used in the coating agent of the present invention. As such a catalyst, a general curing catalyst used for a condensation-curable silicone composition can be used, and an organic amine such as triethanolamine; a metal carboxylate such as tin octylate and zinc octylate; dibutyltin dilaurate; Organotin compounds such as dibutyltin octoate; titanates such as tetrabutyltitanate and tetrapropyltitanate; quaternary ammonium compounds such as quaternary ammonium carboxylate; γ-aminopropyltriethoxysilane;
Examples include amine silane coupling agents such as (β-aminoethyl) -γ-aminopropyltrimethoxysilane, and dibutyltin dilaurate or tetrabutyl titanate is preferred from the viewpoint of safety and health. Two or more of these catalysts may be used in combination, and the amine-based silane coupling agent is also effective in improving the adhesion to the wall surface of the protective coating. The amount of the catalyst is preferably from 0.01 to 10 parts by weight, particularly preferably from 0.05 to 2.0 parts by weight, based on 100 parts by weight of the silicone, in view of the curing speed of the coating agent and the pot life.

The coating agent of the present invention may contain, if necessary, an ultraviolet absorber, a leveling agent, a thickener, a pigment, a dye,
Antioxidants can be included. As a coating method on the building wall, a method such as brush coating, spray coating, roller coating and the like can be used. The thickness of the coating has the effect of shielding the deteriorated part and has the appropriate coating strength.
The range is preferably from 0.5 to 50 μm, and more preferably from 15 to 20 μm. If necessary, only the deteriorated portion may be formed into a film with the coating agent of the present invention to the above-mentioned thickness. After coating, the coating agent of the present invention is cured by air drying for several hours to several days to form a good protective film.

Examples of the cleaning agent used in the method of the present invention include an alkaline cleaning agent and an acidic cleaning agent, and an alkali cleaning agent is preferable because of its good detergency. Examples of the alkaline cleaning agent include caustic alkali, alkali silicate, alkali phosphate, alkali carbonate, alkali borate, alkali aluminate, and inorganic alkali compounds such as ammonia water, monoethanolamine, diethanolamine, triethanolamine, and monoethanolamine. Aqueous solutions of organic alkaline compounds such as alkanolamines such as isopropanolamine, diisopropanolamine and triisopropanolamine, morpholines, pyrrolidones and pyridines. The protective film made of the coating agent of the present invention can be easily removed by rubbing with a brush using the above-mentioned cleaning agent.

[0016]

According to the method of the present invention, excellent abrasion resistance, weather resistance and aesthetic appearance are imparted to a building wall against the effects of exhaust gas, acid rain, dust, salt damage and frost damage. The practical value is extremely high from the viewpoint of environmental issues. Furthermore, when the coating itself is deteriorated with the passage of time, the protective coating provided on the building wall by the method of the present invention can be easily peeled and washed with a cleaning agent, and the coating agent is applied to the portion again. By doing so, it is possible to impart excellent wear resistance, weather resistance, and improvement in aesthetic appearance, and it is easy to repair the building wall surface.

[0017]

The present invention will be described below with reference to examples. In addition, the part in an Example represents a weight part,% represents weight%, and the viscosity shows the value of 25 degreeC.

Synthesis Example 1 Methyltrimethoxysilane 1360 was placed in a flask equipped with a stirrer, heating jacket, reflux condenser and dropping funnel.
g (10 mol), 200 g of methanol and methyltrichlorosilane were charged so that the hydrochloric acid content was 50 ppm, and 171 g (9.5 mol) of water was gradually added dropwise using a dropping funnel while stirring. The mixture was kept at a reflux temperature (about 68 to 72 ° C.) for 4 hours to carry out hydrolysis and condensation reactions. After distilling off volatile components under the conditions of normal pressure and 100 ° C, the pressure was gradually reduced to 40 mmHg, 150
The volatile components were further distilled off under reduced pressure under the condition of
630 g (A-1) of silicone was obtained. Synthesis Example 2 The amounts of alkoxysilane and acetic acid shown in Table 1 were charged into a flask equipped with a stirrer, a heating jacket, a reflux condenser, a moisture meter, and a dropping funnel, and gradually heated while stirring. When the liquid temperature reached 80 ° C., the amount of water shown in Table 1 was gradually added dropwise. The hydrolysis and condensation reaction were carried out while maintaining the temperature at which the alcohol generated by the reaction was refluxed (about 78 to 83 ° C) for 4 hours. Next, heating and stirring were continued while removing the alcohol distilled off by the water quantifier. When the distillation of the alcohol was stopped and the temperature of the reaction solution was increased, the heating was stopped, the temperature was returned to room temperature, and the silicone having the viscosity shown in Table 1 was returned. (A-2, A-3 and A-4) were obtained. Synthesis Example 3 A flask equipped with a stirrer, a heating jacket, a reflux condenser and a dropping funnel was charged with methyltrimethoxysilane 95.
2 g (7 mol), 198 g of phenyltrimethoxysilane (1 mol
l), 516 g (4 mol) of dimethyldichlorosilane and 1500 ml of toluene were charged, and 234 g (13 mol) of water was gradually added dropwise with stirring. After completion of the dropwise addition, the mixture was refluxed at a temperature of about 110 ° C. for 1 hour.
Heating and stirring were performed for hours. The reaction solution was gradually cooled to room temperature, transferred to a separating funnel, allowed to stand and separated into an organic layer and an aqueous layer, and the lower aqueous layer was removed to obtain a silicone solution. A saturated saline solution was added to the organic layer and the mixture was stirred well, and then allowed to stand to separate an aqueous layer. After repeating this salting-out operation twice,
Water was added and the organic layer was washed twice with the same operation. This organic layer was placed in a flask equipped with a stirrer, a heating jacket and a water content meter, and volatile components were distilled off under reduced pressure at 30 mmHg and 80 ° C. for 3 hours.
5) was obtained. Reference Example 1 In a container, 50 parts of carnauba wax, 25 parts of liquid paraffin, 9 parts of polyoxyethylene (10) stearate, 9 parts of polyoxyethylene (40) stearate, and polyoxyethylene (1 part)
0) Take 12 parts of octyl phenyl ether, gradually heat and dissolve, stir while heating at 90 ° C, stir for 1 hour while gradually adding 380 parts of water heated to 90 ° C, then cool and stir And cooled to 25 ° C. to obtain an emulsion composition (B
-1) was obtained. Reference Example 2 In the same manner as in Reference Example 1, an aqueous dispersion (B-2) containing 33% of liquid paraffin and 12% of propylene glycol monostearate was prepared. Reference Example 3 As in Reference Example 1, carnauba wax 20%, glycerin monolaurate 5% and polyethylene glycol 10
% Of an aqueous dispersion (B-3).

Examples 1 to 9 and Comparative Examples 1 to 3 Coating agents were prepared according to the composition shown in Table 2, and the shielding properties, weather resistance, water resistance, detergency, and appearance were evaluated by the following methods. Table 2 shows the results. [Preparation of test piece] A white tile board of 15 × 15 cm in size,
Scratched lightly with sandpaper. This was sprayed with a coating agent using an air gun and air-dried for one day to form a protective film, thereby preparing a test piece. [Shielding Property] The appearance of the test piece was visually observed and evaluated according to the following four grades. ：: The abrasion portion is well shielded, and the transparency of the coating is good. ：: A part of the scratch portion is exposed, but the transparency of the coating is good. Δ: A part of the abrasion part was exposed, and the transparency of the coating was slightly poor. ×: Insufficient shielding effect and no transparency of the film. [Water resistance] After running tap water for 14 hours on the test piece, the appearance was visually observed and evaluated according to the following four grades. ：: The abrasion portion is well shielded, and the transparency of the coating is good. ：: A part of the scratch portion is exposed, but the transparency of the coating is good. Δ: A part of the abrasion part was exposed, and the transparency of the coating was slightly poor. ×: Insufficient shielding effect and no transparency of the film. [Weather resistance] 500 using sunshine weather meter
After exposure for a period of time, the appearance was visually observed and evaluated according to the following four grades. ：: The abrasion portion is well shielded, and the transparency of the coating is good. ：: A part of the scratch portion is exposed, but the transparency of the coating is good. Δ: A part of the abrasion part was exposed, and the transparency of the coating was slightly poor. ×: Insufficient shielding effect and no transparency of the film. [Aesthetics] After the test piece was allowed to stand for 2 months at 25 ° C. and a relative humidity of 60%, the appearance was visually observed and evaluated according to the following four grades. A: The transparency of the film is good and there is no adhesion of dust. ：: The transparency of the coating is good, but some dust adhesion is observed. Δ: Transparency of the coating film was slightly poor, and some dust adhered. ×: The transparency of the coating film was poor, and adhesion of dust was observed. [Washability] A test piece was placed in a 2% aqueous sodium hydroxide solution for 30 minutes.
After immersion for 5 minutes, it was washed with water and the remaining state of the protective film was evaluated according to the following four grades. A: The coating is completely removed. ：: The coating remains on a very small portion, but is completely removed by further immersion for 10 minutes. Δ: The coating remains partially, but is completely removed by further immersion for 20 minutes. ×: Most of the coating remained, and the remaining coating was observed even after immersion for 20 minutes.

[0020]

[Table 1]

[0021]

[Table 2]

As shown in Table 2, each of the coating agents used in the method of the present invention showed good results with respect to each property such as improvement of water resistance and aesthetic appearance. On the other hand, since the coating agent of the comparative example has water solubility, it was inferior in water resistance and could not obtain a sufficiently satisfactory result on weather resistance.

Example 10 Instead of a white tile plate, a stainless steel plate, polished granite, and an acrylic lysine sprayed PC panel were used.
The same evaluation was performed using the coating agent of Example 6.
Good results were obtained in all of the shielding properties, water resistance, weather resistance, aesthetic appearance and detergency.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E04G 23/02 C09K 3/18 104

Claims (8)

(57) [Claims] 1. A wall of a building that can be removed with a cleaning agent.
A method for repairing a building wall, comprising applying a coating agent containing silicone as a main component. 2. The cleaning agent according to claim 1, wherein the cleaning agent is an alkaline cleaning agent.
Repair method described. 3. The repair method according to claim 1, wherein the silicone is a silane or siloxane condensate containing organosilanetriol or a partial condensate thereof as a main component. 4. The repair method according to claim 3, wherein the coating agent comprises (A) 100 parts by weight of silicone (B) 0.01 to 10 parts by weight of a curing catalyst (C) 100 to 2000 parts by weight of a solvent. 5. The repair method according to claim 4, wherein the solvent is a volatile polysiloxane. 6. The repair method according to claim 4, wherein the curing catalyst is an amino group-containing alkoxysilane. 7. The repair method according to claim 4, wherein the silicone has a viscosity of 10 to 10,000 cP. 8. The repair method according to claim 1, wherein the wall of the building is made of a non-porous material.