KR101225043B1 - Flash point-increased aqueous emulsion composition for surface coating of construction material - Google Patents

Abstract

PURPOSE: An aqueous emulsion composition for coating the surface of a building material is provided to enhance water repellency and penetrability. CONSTITUTION: An aqueous emulsion composition for coating the surface of a building material uses 70-90 wt% of alkyl alkoxy silane mixture, 1-10 wt% of fumed silica, 0.1-3 wt% of emulsifier, and the residual amount of water based on the total weight of the composition. The alkyl alkoxy silane mixture comprises first alkyl alkoxy silane having 8-9 carbons and second alkyl alkoxy silane having 10-14 carbons. The weight ratio of the first to second alkyl alkoxy silane is 9:1-7:3. The first alkyl alkoxy silane is n-octyl trimethoxysilane, and the second alkyl alkoxy silane is decyl triethoxysilane.

Description

Flash Point-Increased Aqueous Emulsion Composition for Surface Coating of Construction Material}

The present invention relates to an aqueous emulsion composition for building surface coatings having a high flash point, and more particularly, by having a composition comprising alkyl alkoxy silane and fumed silica in a creamy stable form, not only having high water repellency and permeability. The present invention relates to an aqueous emulsion composition for building surface coating, which can suppress the neutralization reaction due to carbonation of concrete.

Absorbent materials such as concrete, when water is absorbed, cause damage due to freezing and neutralization by carbon dioxide. Recently, in order to prevent this, an absorption inhibitor is used on the concrete surface to prevent damage caused by absorption. As a causative agent, alkyl alkoxy silane, which is typically used as a monomer, is mainly used. Silane is a material that prevents damage such as freezing and neutralization by converting the capillary of concrete into hydrophobic wells.

However, the absorption inhibitors developed until recently have a disadvantage in that the flash point is lower than 80 ° C. and therefore vulnerable to fire that may occur when used.

For example, Korean Patent Application No. 1996-0017215, "Aqueous Emulsion of Alkoxy Alkoxy Silane, Method for Producing It, and Immersion Absorption Agent Containing the Same" is used as a causative agent of 4 to 8 alkyl in alkyl alkoxy silane. However, in this case, the flash point is about 64 ℃ and not only vulnerable to fire, but also can be very dangerous considering that the surface temperature of the rooftop slab of summer buildings is about 65 ~ 75 ℃.

The patent uses an alkyl alkoxy silane, and the particle size is 0.5 ~ 10㎛ and the concentration of the silane is 5 to 70% by weight of the water-soluble method, but there is a risk. At present, the absorption inhibitor proposed in “Korea Industrial Standard No. KS F 4930, Liquid-type Absorption Agent for Concrete Surface Coating” is applied to inorganic structures such as concrete and penetrates into the water to generate water repellency in the capillary. Using the principle, the flash point specifies that it is 80 ° C.

In order to solve the above problems, it is an object of the present invention to provide an aqueous emulsion composition for building surface coating with improved flash point while maintaining the performance as a liquid absorption inhibitor.

In addition, an object of the present invention is to provide a permeation absorption inhibitor for protecting the concrete surface comprising the aqueous emulsion composition for surface coating of building materials.

The aqueous emulsion composition for building surface coating according to the present invention for achieving the above object is 75 to 90% by weight of the alkyl alkoxy silane mixture, 1 to 10% by weight of fumed silica, 0.1 to 3% by weight of the emulsifier, and the residual amount relative to the weight of the total composition Contains water.

The alkyl alkoxy silane mixture of the present invention is characterized by using a mixture of two kinds of a first alkyl alkoxy silane having 8 to 9 carbon atoms and a second alkyl alkoxy silane having 10 to 14 carbon atoms. By using two kinds of alkyl alkoxy silanes as described above, a flash point of 80 ° C. or more can be ensured while maintaining the performance as an absorption inhibitor.

In a preferred embodiment, the first alkyl alkoxy silane may be n-octyl ethoxy silane and the second alkyl alkoxy silane may be decyl triethoxy silane. Also, preferably, the alkyl alkoxy silane may be an alkyl trialkoxy silane including three functional groups.

The mixing ratio (weight ratio) of the first alkyl alkoxy silane and the second alkyl alkoxy silane is preferably 9: 1 to 7: 3, more preferably 8.5: 1.5 to 7.5: 2.5.

The emulsifier may be selected from nonionic emulsifiers, anionic emulsifiers, cationic emulsifiers and amphoteric emulsifiers, but is not limited thereto.

The present invention also includes the above-described aqueous emulsion composition for building surface coating, and includes a preservative, anti-foaming agent, antibacterial agent, thickening agent, antifoaming agent, and water permeable antipermeable agent for protecting concrete surface containing at least one additive. To provide.

According to the present invention, the alkyl alkoxy silane is present in the mixture of fumed silica and water in a creamy stable form, and can penetrate deeply into building materials such as concrete, and has excellent water repellency effect by the alkyl alkoxy silane, as well as two kinds of different carbon atoms. By using a mixture of alkyl alkoxy silanes, the flash point can be secured above 80 ° C. to reduce the risk of fire that may occur during construction.

All technical terms used in the present invention, unless defined otherwise, have the following definitions and conform to the meanings commonly understood by those skilled in the art in the relevant field of the present invention. Also described herein are preferred methods or samples, but similar or equivalent ones are within the scope of the present invention. The contents of all publications described herein by reference are incorporated into the present invention.

The term “about” means 30, 25, 20, 25, 10, 9, 8, 7, 6, 5, by reference quantity, level, value, number, frequency, percentage, dimension, size, quantity, weight, or length. By amount, level, value, number, frequency, percentage, dimension, size, amount, weight or length, varying by 4, 3, 2 or 1%.

Throughout this specification, the terms “comprises” and “comprising”, unless otherwise indicated in the context, include a given step or component, or group of steps or components, but any other step or component, or It is to be understood that it does not exclude a step or group of components.

The present invention relates to an aqueous emulsion for building surface coating which forms an absorption prevention layer by applying and impregnating a surface layer for the purpose of protecting the surface of building material. The building material to which the present invention is applied is, for example, concrete, cement mortar, ALC panel, asbestos slate, brick, stone, or the like, but is not limited thereto.

Liquid absorbents for coating concrete surfaces using alkyl alkoxy silanes are largely divided into oil and water. In the case of oily oil, it is usually mixed with solvent having boiling point of 110 ~ 140 ℃ and isopropyl alcohol is used as another solvent. However, in such a case, it is difficult to secure even penetration performance because concrete flows down to a wall or the like.

However, when the alkyl alkoxy silane is prepared in a cream form, it is known to react with moisture in the air to be converted into silanol and then polymerized to impart water repellent properties to the interior of concrete to prevent absorption without falling off walls. Can be effectively obtained. In addition, it is effective to increase the strength of concrete after application by having a breathing effect (Breathing Effect) by the impregnation that penetrates deep and polymerized.

The present invention is an aqueous emulsion containing an alkyl alkoxy silane, which is about 70 to 90% by weight of an alkyl alkoxy silane mixture, about 1 to 10% by weight of fumed silica, about 0.1 to 3% by weight of an emulsifier, and a residual amount of water, based on the total weight of the composition. Include.

Hereinafter, each component of the composition according to the present invention will be described in detail.

The present invention is an aqueous emulsion containing alkyl alkoxy silane and fumed silica, as well as excellent water-repellent effect by alkyl alkoxy silane, containing fumed silica, so that the crystals grow by reaction with calcium hydroxide in the concrete capillary By blocking the pores of the water has a waterproof effect. Therefore, neutralization reaction by carbonation of concrete as well as water can be suppressed, and building materials, such as concrete, can be protected from external environments, such as chloride ion and an acid solution.

The fumed silica is reacted with calcium hydroxide in concrete; Ca (OH) ₂ + SiO ₂ → CaO · SiO ₂ · H ₂ O It can polymerize and crystallize through the path to seal the capillary in concrete, preventing water absorption and entering / exiting air, thereby obtaining both water repellency and water resistance. have. This is a well-known reaction or until recently fumed silica is applied to concrete by the high specific surface area, it does not help greatly increase the water-cement ratio, but when used as an impregnating material as in the present invention, the fumed silica is very small It was conceived in the theory that can easily move to concrete capillary.

Preferably, the fumed silica has a particle size of about 5 to 20 μm, and when the particle size is larger than 20 μm, the cream phase cannot be separated into two layers and water resistance is generated when the fumed silica is not used or is less than the appropriate amount. I never do that.

One of the main features of the present invention is the use of a mixture of two alkyl alkoxy silanes having different carbon numbers. In general, the alkyl alkoxy silane used in the aqueous emulsion composition for building surface coating has a disadvantage in that the penetration depth decreases as the number of alkyl carbons increases. However, the present inventors found that the flash point is increased and the penetration depth does not change when the carbon number of the alkyl is limited to 8 to 14, and the result of applying the same confirms excellent absorption prevention and order characteristics. At this time, if the carbon number is less than 8, the flash point is lower than 80 ° C, which does not meet the standard, and it is harmful to the human body when other organic compounds are used. If the carbon number is larger than 14, the penetrability is low and the price is very high. Meanwhile, when the functional group is methoxy, methanol may be generated after the reaction, and thus may be harmful to the human body. Therefore, in the present invention, two kinds of alkyl alkoxy silanes having different carbon numbers are mixed to reduce the risk of fire by appropriately adjusting the flash point while maintaining the action of inhibiting the neutralization reaction by water repellent and carbonation of concrete.

In one preferred embodiment, in the present invention, concrete is prepared by mixing two kinds of the first alkyl alkoxy silane having 8 to 9 carbon atoms and the second alkyl alkoxy silane having 10 to 14 carbon atoms among the alkyl alkoxy silanes having excellent anti-absorption properties. By reducing the surface tension of the capillary tube, the absorption function is ensured and the flash point is increased.

Examples of the first alkyl alkoxy silane include n-octyl triethoxy silane, I-butyl triethoxy silane, I-butyl trimethoxy silane, n-octyl trimethoxy silane, and the like. Preference is given to using n-octyl triethoxy silane.

Examples of the second alkyl alkoxy silane include decyl triethoxy silane, decyl trimethoxy silane, and the like, preferably decyl triethoxy silane.

In one embodiment of the present invention, n-octyl ethoxy silane and decyl triethoxy silane composed of trifunctional groups were used.

The mixing ratio of the second alkyl alkoxy silane in the alkyl alkoxy silane mixture has the advantage that the flash point is higher, but the penetrability is lowered when the content is more than a certain amount, so the mixing ratio of the first alkyl alkoxy silane and the second alkyl alkoxy silane The weight ratio is preferably about 9: 1 to 7: 3, more preferably about 8.5: 1.5 to 7.5: 2.5.

The emulsifier is not particularly limited, but anionic emulsifiers such as fatty acid salts, alkyl sulfate ether salts, alkylallyl sulfonates and alkyl phosphate ether salts, and nonionics made of polyoxyethylene compounds, sorbitol compounds, sorbitan compounds and silicone compounds Emulsifiers. In addition, cationic emulsifiers include quaternary ammonium salt compounds and lecithin compounds as amphoteric emulsifiers. These emulsifiers can be used individually or in mixture.

If the amount of the emulsifier is large, the water absorption capacity is drastically reduced, so that the effect as an anti-absorption agent is lost. In addition, the higher the content of the alkyl alkoxy silane has a better effect, and if made of less than 70% may be ineffective in the formation of a water-repellent layer in concrete.

The aqueous emulsion composition of the present invention may be prepared using an emulsifier and a disperser under conditions sufficient to form an emulsion having an alkyl alkoxy silane drop of 2-10 μm in diameter in water to form an alkyl alkoxy silane, water, emulsifier and any other additives. It can be obtained by emulsifying. The diameter of the drop can be adjusted by selecting the emulsification and disperser and by adjusting the emulsification conditions such as stirring speed, discharge pressure from the nozzle, emulsification time and the like.

In one embodiment of the present invention, about 70 to 90% by weight of the alkyl alkoxy silane mixture, about 1 to 10% by weight of the fumed silica, about 0.1 to 3% by weight of the emulsifier, and the residual amount of water are mixed in a high speed stirrer of 3,000 rpm or more. To form a creamy form.

When the prepared alkyl alkoxy silane cream is applied to a structure made of inorganic absorbent material such as concrete, the alkyl alkoxy silane absorbs and penetrates into the capillary of concrete while being transparently changed by agglomeration, and then the alkyl alkoxy silane undergoes dehydration reaction. It converts into a polymer and becomes water repellent and modifies the surface of concrete capillary to a hydrophobic layer. When the stirring speed is low during manufacture, the viscosity of the cream is low, an emulsion phase is obtained. In this case, a layer separation occurs within several hours or several tens of days, resulting in deterioration of performance or polymerization, thereby not exhibiting performance.

The present invention also contains an aqueous emulsion composition for surface coating of building materials, and includes a preservative, anti-foaming agent, antibacterial agent, thickening agent, antifoaming agent, and water permeation inhibitor for concrete surface protection containing at least one additive selected from the group consisting of water-based colorants. To provide.

The preservatives prevent the emulsion from degrading, and the antimicrobial and antimicrobial agents prevent mold and bacteria from propagating on the substrate to which the emulsion is applied. Such auxiliaries can be used without particular limitations as long as they do not impair the stability of the emulsion. Examples of such adjuvants include haloallylsulfone-containing, iodine propargyl-containing, N-haloalkylthio-containing, benzoimidazole-containing, nitrile-containing, pyridine-containing, 8-oxyquinoline-containing, benzothia Sol-containing, isothiazoline-containing, organotin-containing, phenol-containing, quaternary ammonium-containing, triazine-containing, thiadiazine-containing, anilide-containing, admantan-containing, dithio Carbamate-containing, inorganic salt-containing and brominated indanone-containing compounds. Among the compounds, a compound that is easily dissolved in water may be used as a preservative, and a compound that is not easily dissolved in water may be used as a preservative or an antibacterial agent.

The thickener is to improve the stability of the emulsion against phase separation. The thickener is not particularly limited as long as there is no side effect on the stability of the silane and the substrate surface to which the emulsion is applied. Examples of the thickener include modified polyacrylic acid, modified polyacrylic acid, polyacrylic acid, alkali salts of polyacrylic acid, alginate, alginic acid ester, polyvinyl alcohol, polyether, casein, mannan, starch, chitosan, carboxymethyl cellulose And methoxymethyl cellulose. The polymers can be used alone or together.

However, in the case of the water-based colorant, it is also possible to use an ink, a dye, or a color indicator such as phenolphthalein, but if it lasts for a long time, it may cause problems such as discoloration.

Hereinafter will be described in detail the operation of the composition and the preferred embodiment of the present invention configured as described above. The embodiments are provided to more easily explain the present invention, and thus the technical scope of the present invention is not limited thereto.

[ Example  One]

The alkyl alkoxy silane emulsion cream was prepared by rapidly stirring the alkyl alkoxy silane mixture 1 solution at a weight as shown in Table 1 to 3,000 rpm or more while slowly falling into the water and the surfactant 2 solution. At this time, the alkyl alkoxy silane mixture was a mixture of n-octyl ethoxy silane: decyl triethoxy silane = 8: 2 (weight ratio), and sorbitol fatty acid ether was used as an emulsifier of two solutions. The performance of the prepared emulsion cream in concrete is shown in Table 2.

1 solution 2 solution Alkyl Alkoxy Silane Mixture
(weight%) Fumed silica
(weight%) water
(weight%) Emulsifier
(weight%) Defoamer
(weight%) 80 2 16.4 1.35 0.25

Item result Penetration depth (mm) 9mm Permeability ratio (%) 0.02 Flash point (℃) 87

[ Test Example  One]

Table 3 shows the performance of penetration depth, flash point, and absorption ratio when the weight ratio of decyl triethoxy silane in the alkyl alkoxy silane of Table 1 was changed to “Korean Industrial Standard No. KS F 4930, Liquid Absorption Agent for Concrete Surface Coating”. On the basis of the decyl triethoxy silane is used.

The flash point was measured at 81 ° C. when 15% by weight of decyl triethoxy silane was used, and 87 ° C. when 20% by weight was used. In addition, both penetration depth and absorption ratio did not deteriorate as compared with those without decyl triethoxy silane. The decyl triethoxy silane used is therefore at least 15% by weight and preferably 15-25% by weight in the alkyl alkoxy silane.

% By weight of decyl triethoxy silane in the alkyl alcohol silane Penetration depth
(mm) flash point
(%) Absorption coefficient ratio
(%) Comparative example 0 8 64 0.09 Example 1 15 9 81 0.09 Example 2 20 8 87 0.08 Example 3 30 7 94 0.08

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (5)

70 to 90% by weight of the alkyl alkoxy silane mixture, 1 to 10% by weight of fumed silica, 0.1 to 3% by weight of the emulsifier, and the rest using water,
The alkyl alkoxy silane mixture is a mixture of two kinds of the first alkyl alkoxy silane having 8 to 9 carbon atoms and the second alkyl alkoxy silane having 10 to 14 carbon atoms at 9: 1 to 7: 3 (weight ratio),
The first alkyl alkoxy silane is n-octyl triethoxy silane, the second alkyl alkoxy silane is decyl triethoxy silane, and
An aqueous emulsion composition for building surface coating, wherein the flash point is 80 ° C. or higher. The method of claim 1,
Mixing ratio (weight ratio) of said 1st alkyl alkoxy silane and 2nd alkyl alkoxy silane is 8.5: 1.5-7.5: 2.5, The aqueous emulsion composition for building surface coatings. The method of claim 1,
The emulsifier is selected from nonionic emulsifiers, anionic emulsifiers, cationic emulsifiers and amphoteric emulsifiers, the aqueous emulsion composition for building material surface coating. Containing an aqueous emulsion composition for building surface coatings according to any one of claims 1 to 3,
A preservative, an anti-corrosion agent, an antibacterial agent, a thickening agent, an antifoaming agent, and an aqueous coloring agent, characterized in that it contains at least one additive selected from the group consisting of. delete