KR101153784B1 - Functional paint composition and manufacturing method for the same - Google Patents

Abstract

The present invention provides a water glass coating composition mainly composed of water glass, and a water glass coating composition mainly composed of water glass, wherein the weight ratio of 100 parts by weight of water glass (a), 5-30 parts by weight of silane compound and water is 1: 8 or less, or An aqueous solution (b) and an aqueous silica solution (c) having a weight ratio of silica to water of 1: 1 to 8, and a molar ratio of greater than 1: 4.0 to 6 or less, and a water glass coating composition and a method for producing the coating composition.
The coating composition of the present invention has excellent water resistance, fouling resistance and flame retardancy, and is excellent in solution stability.

Description

Functional coating composition and its manufacturing method {FUNCTIONAL PAINT COMPOSITION AND MANUFACTURING METHOD FOR THE SAME}

The present invention relates to a functional coating composition and a method for producing the same, and more particularly, to a functional coating composition comprising water glass having water resistance, fouling resistance, and flame retardancy, and having a stable solution at room temperature and low viscosity, and having excellent workability. It relates to a manufacturing method.

The technology of applying or coating a paint on the surface of the product has been used as a method for imparting various performances such as water resistance, flame resistance, and stain resistance to the product and protecting the surface of the product from scratches.

Conventionally, as such a coating composition, the organic coating which mainly consists of organic resins, such as an epoxy resin, urethane resin, acrylic resin, etc., has been mainly used. However, these organic paints have advantages in that they are excellent in workability, adhesiveness, flexibility, etc., but organic materials forming the coating film are easily deteriorated by ultraviolet rays, deterioration of the coating film due to moisture absorption, and the durability is low. In the case where an organic substance such as oil adheres to the coating film, it is easily mixed with the coating film, causing contamination of the surface of the coating film. In addition, in the case of organic paints, harmful organic volatiles are generated during paint production or coating film formation, causing pollution of the air as well as causing deterioration of the working environment. Furthermore, once the coating film is formed, it is not environmentally preferable because the coating film does not decompose naturally and generates industrial waste.

Recently, in order to overcome the disadvantages of such organic paints, development of paints using inorganic components such as ceramics, modified silicon, and water glass has been actively attempted. Paints using these inorganic components are more resistant to UV and moisture absorption than organic paints, are more durable, are more resistant to contamination due to poor compatibility with organic materials, and are environmentally friendly because they use little toxic organic materials. There is an advantage.

Among these inorganic components, in particular, water glass is inexpensive, has excellent adhesiveness and flame retardancy, and is widely used as a main component of inorganic paints. However, since water glass is hydrophilic, there is a problem in that the coating film is easily damaged when exposed to water for a long time, and as a result, its use has been limited in fields requiring water resistance. In addition, it is difficult to form a coating film such as high temperature is required for curing, which is a limitation in commercialization.

In particular, in the case of sodium silicate-based water glass, the water glass 3 most commonly used among commercially available water glass is about 3.0 to 3.4, and even in the case of water glass 4 having the highest molar ratio, it is about 3.4. The molar ratio of water glass, for example, can be calculated as (weight ratio of SiO ₂ / Na ₂ O × 1.032) for sodium silicate, and (weight ratio of SiO ₂ / K ₂ O × 1.57) for potassium silicate. The molar ratio of water glass of 1: 3 may be 10 parts by weight of Na ₂ O or K ₂ O and 30 parts by weight of SiO _{2 based} on 100 parts by weight of water glass. When forming a coating film using such commercially available water glass, it does not show sufficient water resistance as mentioned above.

However, when the molar ratio of the water glass exceeds 4.0, excellent water resistance can be obtained when forming the coating film.However, when water glass having such a high molar ratio is used, the viscosity of the solution is very high, and the solution becomes unstable and easily gelled. Very poor workability during use. Thus, conventionally, a coating composition obtained with water glass that satisfies solution stability while ensuring water resistance by increasing the molar ratio of water glass has not been used, and even when water resistance is lowered, there is no example of increasing the concentration of water glass by focusing more on solution stability.

On the other hand, lithium silicate has a property of maintaining a solution stability while having a high molar ratio, but the price is significantly higher than that of sodium silicate, leading to an increase in cost, at least similar or better properties and cheaper water glass coating composition Supply is required.

The present invention is to provide a water glass composition which satisfies the solution stability of the water glass composition while increasing the molar concentration of the water glass to ensure the water resistance of the coating film formed of a coating composition containing water glass as a main component.

Furthermore, it is going to provide the method of manufacturing the coating composition which has such a water glass as a main component.

The present invention relates to a water glass coating composition mainly comprising water glass, wherein a weight ratio of 100 parts by weight of water glass (a), 5-30 parts by weight of silane compound and water is 1: 8 or less, or an aqueous solution thereof (b), and silica and water. A water glass coating composition comprising a silica aqueous solution (c) having a weight ratio of 1: 1 to 8 and having a molar ratio of more than 1: 4.0 and 6 or less is provided.

The water glass may be sodium silicate-based water glass or potassium silicate-based water glass or a mixture thereof. When the water glass is sodium silicate-based water glass, the content of the silica is preferably 10-30 parts by weight, and when the water glass is potassium silicate-based water glass, the content of silica is preferably 4-20 parts by weight.

The water glass coating composition of the present invention may further include a boric acid compound aqueous solution (d) having a boric acid compound of 2-12 parts by weight and a weight ratio of water of 1: 0.5-10. At this time, the boric acid compound is preferably boric acid, borax or a mixture thereof.

In the coating composition of the present invention, it is also preferable that at least one of the silane compound aqueous solution (b), the silica aqueous solution (c) and the boric acid compound aqueous solution (d) is at least one acidic water having a pH of 5 or less.

Furthermore, the coating composition of the present invention may further comprise one or more components of aminomethylpropenyl (AMP), silicone, phosphoric acid compound, aluminum salt, zincated, inorganic pigment and acrylic resin, the coating composition of the present invention is the whole composition It may further comprise a lithium silicate-based water glass in the range of 1 to 50% by weight.

Furthermore, in the present invention, 100 parts by weight of water glass (a), 5-30 parts by weight of silane compound and water are mixed at a weight ratio of 1: 8 or less, or a silane compound or an aqueous solution (b) thereof, and a weight ratio of silica and water is 1: 1. (Iii) preparing an aqueous silica solution (c) of 8 to 8; And (ii) mixing and stirring the above (a) to (c), and provides a method for producing a water glass coating composition having a molar ratio of more than 1: 4.0 and 6 or less.

In the method of preparing a water glass coating composition of the present invention, the water glass may be sodium silicate-based water glass or potassium silicate-based water glass or a mixture thereof. When the water glass is sodium silicate-based water glass, the content of the silica is preferably 10-30 parts by weight, and when the water glass is potassium silicate-based water glass, the content of silica is preferably 4-20 parts by weight.

The method of preparing the water glass coating composition of the present invention may further include adding and stirring the boric acid compound aqueous solution (d) having 2-12 parts by weight of the boric acid compound and water in a weight ratio of 1: 0.5-10. At this time, the boric acid compound is preferably boric acid, borax or a mixture thereof.

In preparing the coating composition of the present invention, it is also preferable that at least one of the silane compound aqueous solution (b), the silica aqueous solution (c) and the boric acid aqueous solution (d) use acidic water having a pH of 5 or less. .

In addition, the coating composition of the present invention may further include one or more components of aminomethylpropenyl (AMP), silicone, phosphoric acid compound, aluminum salt, zincated, inorganic pigment and acrylic resin, the coating composition of the present invention is the whole composition It may further comprise a lithium silicate-based water glass in the range of 1 to 50% by weight.

Furthermore, in the method for preparing the coating composition of the present invention, the method may further include the step of sonicating for 0.3 to 2 hours at a frequency of 28 to 100 kHz.

Unlike conventional paint compositions based on water glass, the functional coating composition of the present invention has a high molar ratio of water glass in the composition, thereby resulting in excellent water resistance of the coating film, which can be used without restriction even in applications where frequent exposure to water is caused. have. Furthermore, despite the high molar ratio of water glass, the solution stability is excellent and workability can be ensured.

In addition, the coating film formed by using the composition of the present invention is flame retardant, has a water resistance and can prolong the life of the coating film even if the coating film is installed in a place with high exposure to water, the coating film by contamination of the coating film surface, in particular organic matter Even if the surface is contaminated, it can be easily removed with water without damaging the surface of the coating film.

The present inventors have steadily researched to develop a water glass coating composition having water resistance and solution stability, and when the silane compound or the silane compound aqueous solution and the silica aqueous solution are mixed in the water glass in a specific content, the molar ratio of the water glass is high and the water resistance is excellent. Nevertheless, it was found out that a coating composition capable of forming a coating film having excellent solution stability was completed, and the present invention was completed.

Hereinafter, the present invention will be described more specifically.

The functional coating composition of the present invention is a water glass coating composition mainly composed of water glass, and includes water glass (a), a silane compound or an aqueous solution thereof (b), and an aqueous silica solution (c), and may optionally include an aqueous solution of a boric acid compound. Can be.

The water glass (a) refers to an aqueous solution of an alkali metal silicate compound in which an alkali metal is bonded to silica (SiO ₂ ) in various molar ratios. The water glass (a) is treated by melting a mixture of silica sand and soda ash at 1,300 to 1,500 ° C. in a low pressure steam cooker. You can get it. Furthermore, you may use commercially available water glass. Suitable water glass for use in the present invention may be sodium silicate-based water glass, potassium silicate-based water glass or mixtures thereof.

Since the water glass component is excellent in flame retardancy, fouling resistance and durability, when forming a coating film using the composition comprising the same, it is possible to obtain a coating film having excellent flame resistance, fouling resistance and durability. However, as described above, since water glass is hydrophilic, there is a problem in that the coating film is easily damaged when it is exposed to water. Therefore, in order to improve the water resistance of the coating film, the present invention increases the molar ratio of the water glass (simply referred to as 'molar ratio') to secure the water resistance of the coating film, and at the same time the coating composition due to the gelation of the solution that appears when the molar ratio is high To prevent the degradation of workability.

In the present invention, the water glass coating composition contains silica. The silica is to increase the molar ratio of the water glass, it is possible to adjust the molar ratio of the water glass according to the content of the silica. The water resistance of the coating film obtained can be improved by raising the molar ratio of water glass, Furthermore, the density of a coating film can be improved by increasing the content of solid content in a composition. Suitable silica in the present invention includes, for example, colloidal silica or micro silica.

As such, the water glass coating composition of the present invention can obtain water glass having a high molar ratio by including silica, and preferably, the molar ratio of the water glass is more than 4.0 and 6.0 or less. In this way, by increasing the molar ratio of the water glass, not only has excellent water resistance, but also excellent solution stability during use or storage, and furthermore, excellent flame retardancy and contamination resistance, that is, it is easy to remove contaminants attached to the coating film with water. It is possible to form a coating film having excellent properties.

For this purpose, when the water glass uses sodium silicate-based water glass, the silica is preferably added in an amount of 10-30 parts by weight with respect to 100 parts by weight of water glass, and in the range of 4-20 parts by weight when the water glass is potassium silicate. It is preferred to add in the content of.

When the content of silica is less than each of the above ranges, the molar ratio of the water glass cannot be sufficiently increased, and thus the effect of improving the water resistance to be obtained in the present invention cannot be sufficiently obtained. The upper limit of the silica is not particularly limited, and the content of silica can be appropriately adjusted according to the molar ratio of the water glass used. For example, according to the present invention, in the resultant composition, the molar ratio of water glass is preferably 1: 6 or less, so that the content of silica can be adjusted therefrom. However, since the molar ratio of commonly used water glass No. 3 is about 3-3.4, it is preferable to contain about 30 parts by weight in the case of sodium silicate-based water glass, and about 20 parts by weight in the case of potassium silicate.

However, even when the water-soluble powder silicate is simply mixed with the water glass, the molar ratio of the water glass can be increased. However, the coating composition obtained therefrom has a high viscosity and cannot obtain solution stability as a paint due to rapid gelation. Therefore, in this invention, it is preferable to contain the said silica in aqueous solution state. It is preferable that the aqueous silica solution (c) of the present invention has a weight ratio of water 1-8 to silica weight 1. If the weight ratio of silica to water is less than 1: 1, the solid content is high, which may lead to an increase in the viscosity of the solution, and it is not easy to bond with water glass by the silane compound, which is another component of the composition, and the weight ratio is greater than 1: 8. In the case where the water content is too high, the paint viscosity is low and the paint adhesiveness is lowered. Thus, there is a problem in workability, which is preferably used within the above range.

The coating composition of the present invention contains a silane compound. The silane compound serves to increase the molar ratio of the water glass by inducing bonding of the water glass in the coating composition with inorganic materials such as silica or boric acid compound added thereto. Furthermore, coating film adhesiveness can be improved by including a silane compound.

The silane compound preferably has a content of 5-30 parts by weight based on 100 parts by weight of water glass. If the silane compound is less than 5 parts by weight, water glass and silica cannot be sufficiently bonded, and thus, entanglement of water glass in the composition cannot be sufficiently prevented, and a dense coating film cannot be obtained. On the other hand, if it exceeds 30 parts by weight can not be expected to further increase the effect obtained by the addition of the silane compound, it is economically undesirable.

The silane compound of the present invention may be mixed with water and used in the form of an aqueous solution. Therefore, the silane compound is preferably used so that the weight ratio of the silane compound and water is in the range of 1: 8 or less. When the weight ratio of the silane compound and water is 1: 5 or less, binding of the water glass and silica can be induced, thereby achieving solution stability of the water glass. However, when it exceeds 1: 8, there is a concern that the paint composition is too thin because the moisture content is high and workability is lowered.

Silane compounds that can be used in the coating composition of the present invention are not limited thereto, but include, but are not limited to, silicic acid, siloxane, tetramethoxysilane (TMOS), and tetraethoxysilane (TEOS). , Methyltrimethoxy silane, methyltriethoxy silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, γ-glycid Oxypropyltrimethoxysilane, γ-glycidoxyoxymethylmethylethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxy Silane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, methyltrimethoxysilane and tris- [3- (trimethoxysilyl ) Propyl] isocyanate or its hydrolyzate Can use water, and may be used by mixing them alone, or two or more.

In addition, the coating composition of the present invention may include a boric acid compound. The boric acid compound further improves the water resistance of the coating film, and serves to improve the flame retardancy, and further, may prevent the surface of the coating film from easily collapsing when an external impact such as a scratch is applied to the coating film.

The boric acid compound may include 2-12 parts by weight based on 100 parts by weight of water glass. If the content of the boric acid compound is less than 2 parts by weight, the effect obtained by the addition of the boric acid compound is insignificant, and if it exceeds 12 parts by weight, there is a risk of hardening the water glass in the coating composition to inhibit solution stability. Preference is given to using boric acid compounds.

The boric acid compound of the present invention is preferably dissolved in water and used in an aqueous solution state. In general, the boric acid compound has a low solubility in water, making it difficult to mix with water glass, and hardens the water glass to lower solution stability. Therefore, it is preferable to mix a boric acid compound in aqueous solution state. The boric acid compound aqueous solution (d) of the present invention preferably has a weight ratio of boric acid compound and water in the range of 1: 0.5-10. When the weight ratio is less than 1: 0.5, the boric acid compound may not be sufficiently dissolved, and may exist in a solid state, thereby deteriorating the solution stability of the composition. When the weight ratio is greater than 1:10, the water content is excessively high. Since the viscosity may lower the viscosity of the coating film adhesion force, it is preferable to satisfy the above range.

The boric acid compound may be boric acid, borax or a mixture thereof. Examples of the boric acid include orthoboric acid, metaboric acid, tetraboric acid, methyl borate, ethyl borate, and boric acid esters, and these may be used alone or in combination. When a boric acid and borax mixture is used, a larger amount of boric acid compound can be dissolved in water, and the mixing ratio of boric acid and borax preferably has a mixing ratio of 1-4: 1-4.

At least one of the water forming the aqueous silane compound solution, the aqueous silica solution, and the boric acid compound solution is more preferably used from an acidic water having a pH of 5 or less from the viewpoint of improving the water resistance of the coating composition and improving the solution stability.

Such a coating composition of the present invention has a molar ratio of water glass of more than 4.0 to 6.0 or less. The water glass coating composition having such a high molar ratio not only has excellent water resistance, but also has excellent solution stability during use or storage, and furthermore, has excellent flame retardancy, and easily removes contaminants attached to the coating film with water. A coating film having excellent properties can be formed.

The water glass coating composition of the present invention may further include one or more components of aminomethylpropenyl (AMP), silicone, phosphoric acid compound, aluminum salt, zincated, inorganic pigment and acrylic resin, if necessary, in order to improve coating properties. .

The amino metal propphenol is to improve the crack preventing effect of the coating film by improving the dispersibility of each component of the coating composition. Aminometal propphenol is preferably added in an amount of 1-10 parts by weight, and is added in an aqueous solution. At this time, it is preferable that aminometal propphenol and water are the aqueous solution mixed with the weight ratio of 1: 0.5-3.

The silicone is to increase the solid component in the composition, it is preferably added in an amount of 0.3 to 15 parts by weight based on 100 parts by weight of water glass. If the content of silica is less than 0.3 parts by weight, the effect of the addition of silicon is insignificant, and if it exceeds 15 parts by weight, the stability of the composition solution is lowered.

The aluminum salt improves water resistance and adhesion, but is not limited thereto. For example, aluminum silicate, aluminum phosphate, or the like may be used alone or in combination. On the other hand, the content of the aluminum salt is preferably about 30 to 150 parts by weight based on 100 parts by weight of water glass. This is because when the content of the aluminum salt is less than 30 parts by weight, the effect of improving water resistance and adhesion is insignificant, and when it exceeds 150 parts by weight, the stability of the composition solution is lowered.

The zincation is for imparting hardening and anti-corrosion performance, but is not limited thereto. For example, zinc oxide may be used alone or in combination. On the other hand, the zinc content is suitably about 0.5 to 50 parts by weight in 100 parts by weight of water glass. If the zinc content is less than 0.5 parts by weight, the corrosion resistance is inferior, and if it exceeds 50 parts by weight, the adhesion decreases due to the rapid reaction of the coating film, cracking occurs.

The inorganic pigment is intended to impart color to the coating film and to improve aesthetics, without being limited thereto. For example, titanium dioxide, carbon black, iron oxide, iron oxide, iron oxide black, iron oxide, molybdate orange, anatase, or the like may be used alone or in combination, and in particular, in the case of white, titanium dioxide is preferably used. Do. It is preferable that the said inorganic pigment is 3 to 60 weight part with respect to 100 weight part of water glass. This is because when the content of the inorganic pigment is less than 3 parts by weight, the color is hardly expressed, and when it exceeds 60 parts by weight, the solution stability is lowered.

The acrylic resin is for crack prevention and adhesion, but is not limited thereto, for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, styrene Acrylic monomers and the like can be used alone or in combination. On the other hand, the content of the acrylic is preferably about 0.5 to 100 parts by weight based on 100 parts by weight of water glass. This is because when the content of acryl is less than 0.5 part by weight, the effect of improving cracking and adhesion is insignificant, and when it exceeds 100 parts by weight, fouling resistance is inferior.

When the coating film is formed by using the coating composition of the present invention, unlike coating compositions mainly containing water glass, a coating film which does not dissolve in water can be formed, without being restricted even in an application where the exposure to water is frequent. It can be used, it is possible to form a coating film having excellent properties such as flame retardancy, fouling resistance, adhesion. Therefore, the coating composition of the present invention can be applied to a variety of products, such as interior walls, exterior walls, building materials, wood, tiles, concrete surfaces of buildings can be used as a flame retardant or anti-scribing agent for preventing graffiti.

In addition, natrazol, CMC, and the like may be further added to improve the storage stability of the solution, coating workability, leveling of the final coating, and the like, and a thickener may also be used.

Thus, the water glass coating composition obtained by this invention can be mixed with a lithium silicate type water glass, and can be used. As described above, lithium silicate-based water glass is expensive, but has a high molar ratio to be obtained in the present invention, and also has excellent solution stability. Thus, even when mixed with the water glass coating composition obtained according to the present invention, a high molar ratio can be maintained. Bars can be mixed and used in appropriate proportions. Furthermore, when mixing lithium silicate type water glass, it is also preferable at the point which can prevent the whitening phenomenon of a water glass coating composition further. However, when the mixing ratio of lithium silicate is too high, there is a fear of causing excessive price increase of the water glass coating composition. Therefore, the lithium silicate-based water glass may comprise 1-50%, preferably 3-30%, more preferably 5-25% of the weight of the water glass coating composition of the present invention.

Hereinafter, the method of manufacturing the coating composition of this invention is demonstrated. In the method for producing the coating composition of the present invention, the description of the composition is omitted.

The paint composition mainly comprising the water glass of the present invention includes water glass (a), a silane compound or an aqueous solution thereof (b), and an aqueous silica solution (c), and optionally includes an aqueous solution of boric acid compound (d). .

In preparing the coating composition of the present invention, each component is preferably added to the water glass in the form of an aqueous solution. For example, when silica is added to the water glass in a solid state, it causes entanglement of the water glass and solution stability cannot be obtained. This is not much different from the result obtained even after adding water or adding silica to the water glass mixed with water. In addition, there is a concern that the problem of solution stability due to the increase in the molar ratio due to the mixing of silica. Further, even when the boric acid compound as an optional component is added in a solid content state, it causes solidification of the water glass, which is not preferable. Therefore, it is preferable that the composition component used by this invention uses what was made into aqueous solution.

However, since the silane compound is itself in a solution state, it may be added in the form of a stock solution, and further, the silane compound may be added in an aqueous solution state.

Therefore, in order to manufacture the coating composition of this invention, the aqueous solution of a silica and a boric acid compound is prepared.

On the other hand, the silane compound can be used as it is, as described above, and can be selectively used in aqueous solution. When the silane compound is to be used as an aqueous solution, 5-30 parts by weight of the silane compound and water may be mixed and used in a weight ratio of 1: 8 or less. At this time, it is preferable to stir for 30 minutes to 1 hour in the temperature range of 35-50 ℃, the stirring speed is not particularly limited, but the range of 300-500rpm is preferred. The water may be used general water, acidic water of pH 5 or less may be used.

The aqueous silica solution (c) may be obtained by mixing and mixing 10-30 parts by weight of silica with water at a weight ratio of 1: 1-8. At this time, although not particularly limited, the mixture is stirred at room temperature for 10 minutes to 1 hour, and the stirring speed may be performed in the range of 300-500 rpm.

Furthermore, the boric acid compound aqueous solution (d) may be obtained by mixing 2-12 parts by weight of a boric acid compound of boric acid, borax or a mixture thereof with water at a weight ratio of 1: 0.5-10. At this time, it is preferable to stir for 30 minutes to 1 hour in the temperature range of 35 to 50 ℃, the stirring speed is not particularly limited, but the range of 300-500rpm is preferred. In addition, the agitation may be performed by ultrasonic waves, and specifically, may be obtained by stirring by sonicating for 15 minutes to 2 hours at a frequency of 28 to 100 kHz.

The coating composition of the present invention can be obtained by mixing the prepared aqueous solutions in the following manner. The order in which these composition components are mixed is not specifically limited, The water glass coating composition in which the molar ratio rose by obtaining aqueous solution of each component can be obtained.

On the other hand, it is preferable to mix at least any one of these with the silane compound or its aqueous solution before mixing the water glass and the aqueous silica solution, and then mix the remaining components. For example, the silane compound or its aqueous solution (b) is mixed with water glass (a) and stirred, followed by stirring and mixing the aqueous silica solution (c) with the resulting mixture of (a) and (b). A paint composition can be obtained. As another example, the coating composition of this invention can be obtained by mixing and stirring a silane compound or its aqueous solution (b) with aqueous silica solution (c), and then mixing and stirring water glass (a). As another example, a silane compound or a part of its aqueous solution (b) is mixed with water glass (a) and stirred, a silane compound or a part of its aqueous solution (b) is mixed with an aqueous silica solution (c), and then the respective results are mixed. The coating composition of this invention can be obtained by stirring. It will be understood by those skilled in the art that the coating composition can be obtained by various other procedures besides this method.

The mixing and stirring of the silane compound with water glass or silica is not particularly limited, but the components are preferably mixed and heated to 65 to 100 ° C, followed by stirring for 30 minutes to 2 hours. Thereafter, stirring with the addition of the remaining components can be carried out by mixing while maintaining the temperature of the resultant obtained in the above range after stirring for 1 to 4 hours.

The water glass coating composition thus obtained has a high molar ratio of water glass in the composition, thereby improving the water resistance of the formed coating film, and of course, suppressing gelation during use and storage of the coating composition, thereby obtaining excellent solution stability. Thereby, the molar ratio of the water glass coating composition can be formed in more than 4.0 range.

Optionally, the method may include mixing and stirring the boric acid compound aqueous solution (d) in the water glass coating composition obtained by each of the above methods. The stirring is not particularly limited, but may be performed at 300-500 rpm for 1-4 hours. On the other hand, the aqueous solution of boric acid compound may be added to the resultant obtained by mixing and stirring the silane compound or its aqueous solution (b) in step iii) of each method.

On the other hand, the coating composition obtained by the method of the present invention may be further subjected to ultrasonic treatment in order to obtain a more homogeneous composition. The sonication is performed by applying a frequency of 28 to 100 kHz. In the case of performing the ultrasonic treatment, a more homogeneous mixture can be formed, whereby a homogeneous coating film can be formed and solution stability can be achieved.

The water glass coating composition of the present invention may further include at least one additional component of aminomethylpropenol, silicone, phosphate compound, aluminum salt, zincated, inorganic pigment and acrylic resin, if necessary, in order to improve coating properties. Furthermore, in addition to these, natrazol, CMC, and the like may be further added to improve storage stability of the solution, paintability, leveling of the final coating, and the like, and a thickener may also be used.

As such, the water glass coating composition obtained by the present invention may further include mixing with the lithium silicate-based water glass. The lithium silicate-based water glass has a high molar ratio and has excellent solution stability, and even if mixed with the water glass coating composition obtained according to the present invention, it can maintain a high molar ratio, and can be used by mixing in an appropriate ratio, water glass coating composition It is possible to further prevent the whitening phenomenon. At this time, the lithium silicate-based water glass is preferably mixed in the range of 1% to 50% of the weight of the water glass coating composition.

Hereinafter, the present invention will be described in more detail with reference to specific examples. In the following examples, only the example using sodium silicate-based water glass as water glass will be described. However, a person skilled in the art will obtain a water glass coating composition to be obtained in the present invention by using potassium silicate-based water glass from the disclosure of the present invention. Will be readily appreciated.

Example

Example  One

A water glass 3 of sodium silicate (molar ratio 1: 3, 100 parts by weight of Na ₂ O: SiO ₂ ) was prepared in Reaction Vessel 1.

In the reaction vessel 2, 20 parts by weight of γ-glycidoxy propyltrimethoxysilane and 50 parts by weight of water were added, and the temperature was raised to 45 ° C., followed by stirring at a speed of 400 rpm for 45 minutes to prepare a silane compound aqueous solution.

20 parts by weight of silica and 80 parts by weight of water were mixed in the reaction vessel 3, and stirred at a speed of 400 rpm for 10 minutes to form an aqueous silica solution.

The obtained silane compound aqueous solution was mixed with the reaction vessel 1 including the water glass, and the reaction vessel 1 was heated to 95 ° C. and stirred at a speed of 400 rpm for about 1 hour.

The resulting aqueous silica solution was slowly added to the reaction vessel 1 with stirring, followed by stirring for 3 hours to prepare a coating composition.

Example  2

A water glass 3 of sodium silicate (molar ratio 1: 3, 100 parts by weight of Na ₂ O: SiO ₂ ) was prepared in Reaction Vessel 1.

In the reaction vessel 2, 20 parts by weight of γ-glycidoxy propyltrimethoxysilane and 50 parts by weight of water were added, and the temperature was raised to 45 ° C., followed by stirring at a speed of 400 rpm for 45 minutes to prepare a silane compound aqueous solution.

20 parts by weight of silica and 80 parts by weight of water were mixed in the reaction vessel 3, and stirred at a speed of 400 rpm for 10 minutes to form an aqueous silica solution.

4 parts by weight of ortho boric acid and 12 parts by weight of water were mixed in the reaction vessel 4, and an ultrasonic wave of 40 kHz was added at room temperature for 1 hour to form an aqueous boric acid compound solution.

After mixing the silane compound aqueous solution of the reaction vessel 2 to the reaction vessel 1 containing the water glass, the reaction vessel 1 was heated to 95 ℃ and stirred at a speed of 400rpm for about 1 hour.

The silica aqueous solution of the reaction vessel 3 was mixed in the reaction vessel 1, and then heated to 90 ° C. and stirred at a speed of 400 rpm for about 1 hour.

In addition, the boric acid compound aqueous solution of the reaction vessel 4 was slowly added to the reaction vessel 1 with stirring, and then stirred for 3 hours to prepare a coating composition.

Example  3

8 parts by weight of γ-glycidoxy propyltrimethoxysilane is used to prepare an aqueous silica solution using 10 parts by weight of silica and 10 parts by weight of water, and an aqueous solution of boric acid compound is prepared by using 2 parts by weight of orthoboric acid and 4 parts by weight of water. Except that was prepared in the same manner as in Example 2.

Example  4

30 parts by weight of γ-glycidoxy propyltrimethoxysilane and 150 parts by weight of water are used to prepare an aqueous silane compound solution, and 30 parts by weight of silica and 125 parts by weight of water to prepare an aqueous silica solution, and 10 parts by weight of borax. And 50 parts by weight of water was used in the same manner as in Example 2 except that an aqueous boric acid compound solution was prepared.

Example  5

Water glass, silane compound aqueous solution, silica aqueous solution and boric acid aqueous solution were prepared in the same manner as in Example 2.

After mixing the silane compound aqueous solution of the reaction vessel 2 to the reaction vessel 3 including the aqueous silica solution, the reaction vessel 3 was heated to 95 ℃ and stirred for about 1 hour at a speed of 400rpm.

The resulting product of the reaction vessel 3 was slowly added to the reaction vessel 1 containing water glass while stirring, and then stirred for 1 hour to prepare a coating composition.

In addition, the boric acid compound aqueous solution of the reaction vessel 4 was slowly added to the reaction vessel 1 with stirring, and then stirred for 3 hours to prepare a coating composition.

Example  6

Water glass, silane compound aqueous solution, silica aqueous solution and boric acid aqueous solution were prepared in the same manner as in Example 2.

After mixing 35 parts by weight of the silane compound aqueous solution of the reaction vessel 2 into each of the reaction vessel 1 containing water glass and the reaction vessel 3 including the aqueous silica solution, the reaction vessels 1 and 3 were heated to 95 ° C., respectively, to about 1 Stir at a rate of 400 rpm for hours.

The resulting product of the reaction vessel 3 was slowly added to the reaction vessel 1 with stirring, and then stirred for 1 hour to prepare a coating composition.

In addition, the boric acid compound aqueous solution of the reaction vessel 4 was slowly added to the reaction vessel 1 with stirring, and then stirred for 3 hours to prepare a coating composition.

Comparative example  One

A water glass 3 of sodium silicate (molar ratio 1: 3, 100 parts by weight of Na ₂ O: SiO ₂ ) was prepared in Reaction Vessel 1. 20 parts by weight of methyltrimethoxysilane, 20 parts by weight of silica and 4 parts by weight of orthoboric acid were added to the reaction vessel 1, 50 parts by weight of water were mixed, and the reaction vessel 1 was heated to 85 ° C. and 400 rpm for 3 hours. Stirring at a speed to prepare a water glass coating composition.

Comparative example  2

A water glass coating composition was prepared in the same manner as in Example 2, except that an aqueous silica solution was prepared using 8 parts by weight of silica and 15 parts by weight of water.

Comparative example  3

A water glass coating composition was prepared in the same manner as in Example 2, except that an aqueous silica solution was prepared using 32 parts by weight of silica and 80 parts by weight of water.

Comparative example  4

A water glass coating composition was prepared in the same manner as in Example 2, except that an aqueous silane compound solution was prepared using 4 parts by weight of methyltrimethoxysilane and 20 parts by weight of water.

Comparative example  5

A water glass coating composition was prepared in the same manner as in Example 2, except that an aqueous silane compound solution was prepared using 32 parts by weight of methyltrimethoxysilane and 100 parts by weight of water.

As a property of the water glass coating compositions according to the above Examples 1 to 6 and Comparative Examples 1 to 6, the stability of the solution and the physical properties of the coating film formed of the coating composition, the film stability, water resistance and In terms of flame retardancy, each of the following evaluations, and the results are shown in Table 1.

Solution stability evaluation

It was visually observed whether the coating composition prepared by the above Examples and Comparative Examples was left at room temperature to cause gelation in solution. As a result, when the coating film gels within 1 hour, the gelation occurs after 1 to 3 hours, and the gelation occurs after 3 hours to 5 hours. The case where it occurs is represented by ◎.

Coating property evaluation

In order to judge the physical properties at the time of coating film formation of the coating composition obtained by the said Example and the comparative example, each coating composition obtained by each said Example and the comparative example was apply | coated on a white tile, and it hardened for 3 days, and the coating film was formed.

< crack  Assessment of occurrence

By observing the surface of the coating film formed on the surface of the tile, it was visually confirmed whether cracks occurred on the surface. As a result of the observation, cracks are formed on the entire surface of the coating film, and the cracks are severe and are easily observed by the naked eye. The cracks are partially observed on the surface of the coating film. △ when the surface is observed, no crack is observed with the naked eye.However, when the surface of the coating film is enlarged, it is possible to confirm that the minute crack is present. Indicated.

<Film water resistance evaluation>

After immersing the tile on which the coating film is formed in water for 24 hours, it is possible to visually confirm that the coating film on the surface is peeled off when the coating film is taken out, or the case that the coating film is peeled off when the surface is rubbed by hand × As shown.

<Flame retardancy evaluation>

Wood chopsticks were immersed for half a second for 10 seconds in the water glass coating compositions obtained in Examples 1 to 8 and Comparative Examples 1 to 4, and then completely dried for 2 hours. The torch was burned for 10 seconds to form a coating film of wooden chopsticks.

The case where the wood chopsticks were on fire was × and the fire was not on, but the case where black charcoal was formed on the surface of the wooden chopsticks was indicated by △, and the degree of slight sooting on the surface was not indicated by ○.

Solution stability Crack occurrence Water resistance Flammability Example 1 ○ ○ ◎ ◎ Example 2 ◎ ◎ ◎ ◎ Example 3 ◎ ○ ○ ◎ Example 4 ○ ◎ ◎ ◎ Example 5 ◎ ◎ ◎ ◎ Example 6 ◎ ◎ ◎ ◎ Comparative Example 1 × × × × Comparative Example 2 ○ ○ × ○ Comparative Example 3 △ △ ○ ○ Comparative Example 4 × △ × △ Comparative Example 5 △ ○ × △

In the above embodiment, but not described with respect to the embodiment including the other additives described in the present invention, these examples are examples of the present invention, those skilled in the art to which the present invention belongs From the description of the invention, additives may be appropriately selected and used as necessary.

Claims (21)

A water glass coating composition mainly composed of water glass,
Water glass (a) 100 parts by weight,
Silane compound or its aqueous solution (b) whose weight ratio of 5-30 weight part of silane compounds and water is 1: 8 or less, and
A silica aqueous solution (c) having a weight ratio of silica to water of 1: 1 to 8,
A water glass coating composition having a molar ratio of at least one selected from Na ₂ O and K ₂ O in the composition and SiO ₂ greater than 1: 4.0 and not more than 6. The water glass coating composition of claim 1, wherein the water glass is sodium silicate-based water glass. The water glass coating composition according to claim 2, wherein the silica content is 10-30 parts by weight. The water glass coating composition of claim 1, wherein the water glass is potassium silicate-based water glass. The water glass coating composition according to claim 4, wherein the silica content is 4-20 parts by weight. The water glass coating composition of claim 1, wherein the water glass coating composition further comprises an aqueous solution of boric acid compound (d) having a weight ratio of 2-12 parts by weight of a boric acid compound and water of 1: 0.5-10. The water glass coating composition of claim 1 or 6, wherein at least one of the silane compound aqueous solution (b), the silica aqueous solution (c) and the boric acid aqueous solution (d) is at least one acidic water having a pH of 5 or less. . The water glass coating composition according to claim 6, wherein the boric acid compound is boric acid, borax or a mixture thereof. The water glass coating composition according to claim 1 or 6, further comprising at least one component of aminomethylpropenyl (AMP), silicone, phosphoric acid compound, aluminum salt, zincation, inorganic pigment and acrylic resin. The water glass coating composition of claim 1, further comprising lithium silicate-based water glass in the water glass coating composition in a range of 1 to 50% of the weight of the composition. Water glass (a) 100 parts by weight,
Silane compound or its aqueous solution (b) which mixed 5-30 weight part of silane compounds and water in the weight ratio of 1: 8 or less, and
Preparing an aqueous silica solution (c) having a weight ratio of silica and water of 1: 1 to 8, respectively; And
Mixing and stirring the (a) to (c),
The method of producing a water glass coating composition having a molar ratio of SiO ₂ and at least one selected from Na ₂ O and K ₂ O present in the composition comprising the above (a) to (c) and greater than 1: 4.0. 12. The method of claim 11, wherein the water glass is sodium silicate-based water glass. The method of claim 12, wherein the silica content is 10-30 parts by weight. 12. The method of claim 11, wherein the water glass is potassium silicate-based water glass. The method of claim 14, wherein the silica content is 4-20 parts by weight. The method for preparing a water glass coating composition according to claim 11, further comprising a step of adding 2-12 parts by weight of a boric acid compound and an aqueous boric acid compound solution (d) having a water ratio of 1: 0.5-10. . The water glass coating composition of claim 11 or 16, wherein at least one of the silane compound aqueous solution (b), the silica aqueous solution (c) and the boric acid aqueous solution (d) is at least one acidic water having a pH of 5 or less. Way. The method of claim 16, wherein the boric acid compound is boric acid, borax, or a mixture thereof. 17. The water glass paint of claim 11 or 16, comprising the step of adding at least one component of aminomethylpropenol (AMP), silicone, phosphoric acid compound, aluminum salt, zincation, inorganic pigment and acrylic resin. Method for preparing the composition. The method of claim 11 or 16, further comprising the step of mixing with the water glass coating composition and lithium silicate-based water glass in the range of 1 to 50% of the weight of the composition. The method of claim 11 or 16, further comprising the step of sonicating for 0.3 to 2 hours at a frequency of 28 to 100 kHz.