KR100381717B1 - Manufacturing method of ceramic binder - Google Patents

Abstract

The present invention relates to a method for producing a ceramic binder, and more particularly, after modifying the surface of the colloidal cord with a silane compound having a tetra-directional and tri-directional hydrolysable organic functional group, there is a bi-directional silane having a hydrolysable organic functional group. The present invention relates to a process for producing a ceramic binder that can be cured even at low temperatures as well as its beautiful appearance by treating with a compound and then adding a silane-based curing agent.

Description

Manufacturing method of ceramic binder

The present invention relates to a method for preparing a binder, and more particularly, to modify the surface of the colloidal sol with a silane compound having a tetradirectional and tridirectional hydrolysable organic functional group, and then to a bidirectional silane compound having a hydrolyzable organic functional group. After treatment, the present invention relates to a method for producing a ceramic binder which can be cured even at low temperatures as well as a beautiful appearance by adding a silane-based curing agent.

The present invention relates to a method for producing a ceramic binder of ceramic paint, which has excellent physical properties, weather resistance, heat resistance and heat resistance required for interior and exterior materials and thermal materials of modern industrial society, and has a beautiful appearance and ease of use compared to conventional ceramic paints. .

Ceramic paints have characteristic properties that can be compared to general organic paints. For example, ceramic paints tend to be carbonized at high temperatures of 300 ° C or higher. Since deterioration is hardly caused by high temperature and ultraviolet rays, and it has high hardness and glass transition temperature, it is not only hard to attach pollutants due to air pollution and cleaning resilience due to air pollution, and also can easily remove attached pollutants. Have Therefore, the demand for ceramic paints in building and exterior materials and hot materials is expected to increase.

However, despite the excellent characteristics of the ceramic paints as described above, the workability is not improved, such as lowering the baking temperature, curing at room temperature, or a special aging process before using the paint, and thus the ceramic paints are not generalized.

In order to solve this problem, Korean Patent Publication No. 88-529 discloses a two-component inorganic coating composition composed of a main agent containing an organic functional silane compound and a curing agent containing a silica sol. Although there was a problem of curing at a high temperature and preparing a two-component composition for a considerable time before use, there were many limitations in use in spite of excellent corrosion resistance, heat resistance, weather resistance, and contamination resistance. Japanese Patent Laid-Open No. 62-79,274 discloses a coating composition consisting of a silane compound having a tridirectional hydrolyzable organic functional group, a polar organic polar solvent, a silane compound having a tetradirectional hydrolyzable organic functional group, and a water-dispersible acidic silica sol. The composition has a sharp decrease in storage stability over time, poor glossiness due to an increase in the viscosity of the coating when forming the coating, and a significant decrease in the bonding strength of the coating. Therefore, there is a problem to use universally.

Therefore, in the present invention, as a result of research efforts to manufacture a ceramic binder that can overcome the problems of long-term paint aging process, high temperature curing and commercial limitations due to lowering the storage stability of the paint, while maintaining the excellent physical properties of the ceramic paint, The surface of the colloidal sol is modified with a silane compound having a tetradirectional and tridirectional hydrolysable organic functional group, and then treated with a bidirectional silane compound having a hydrolyzable organic functional group to remove hydroxyl groups present at the end of the binder. The present invention has been completed by reducing the degree of crosslinking to solve the problem of storage stability, and forming a high degree of crosslinking to prepare a ceramic binder that can be easily cured even at low temperatures.

Therefore, an object of the present invention is to provide a method for producing a ceramic binder having a beautiful appearance and excellent physical properties.

Hereinafter, the present invention will be described in detail.

In the present invention, (a) colloidal sol is added to the colloidal sol, and the silane compound represented by the following structural formulas (I) and (II) is mixed at a ratio of 10:90 to 30: 70% by weight, followed by stirring. After modifying the above, the organic polar solvent was added thereto, and then a silane compound represented by the following structural formula (III) was added and stirred to prepare a ceramic binder: (b) In a separate container, the following structural formulas (II) and ( III), 100 parts by weight of the silane mixture, 0.1 to 2.0 parts by weight of organic titanate, and 10 to 30 parts by weight of an organic polar solvent, in which the silane compound represented by III) is mixed at a ratio of 10:90 to 20: 80% by weight, are added and stirred Preparing a curing agent; The method of producing a ceramic binder, characterized by mixing the (b) hardening agent with the (a) ceramic binder.

In the above formula,

R and R ⁴ are each a methoxy group or an ethoxy group;

R ¹ is methyl group, ethyl group, phenyl group, β-3,4-ethoxycyclohexyl group, γ-glycidyloxypropyl group, γ-mercaptoproporyl, γ-methacryloxypropyl or γ-aminopropyl;

R ² is a methoxy group, an ethoxy group or an epoxy group;

R <^3> is a methyl group, an ethyl group, or a phenyl group.

Referring to the present invention in more detail as follows.

The present invention relates to a ceramic binder having excellent storage stability, curing at low temperature, having a strong resistance to moisture, and having a beautiful appearance, and in more detail describing the manufacturing process of the ceramic binder according to the present invention. Same as

First, the surface of the colloidal sol is modified with a silane compound by reacting the colloidal sol with the silane-based mixture represented by the above formulas (I) and (II), and an organic polar solvent is added thereto to prepare the first synthetic reactant. Make. In addition, a bidirectional silane compound having a hydrolyzable organic functional group represented by the above formula (III) is gradually added to the primary synthesis reactant and stirred for a predetermined time to form a ceramic binder. And a ceramic binder is prepared by mixing a ceramic binder with a curing agent, an organic polar solvent and a silane compound having a reactive organic functional group.

As the colloidal sol used in the present invention, either an acidic colloidal sol or an alkali colloidal sol can be used, and the acidic colloidal sol has a pH of 3 to 5 The content of 10 to 30% by weight and the particle size of 5 to 20㎛ is used, and the alkali colloidal sol has a pH of 8.5 to 10.5, the content of the solid content of 20 to 50% by weight and the particle size of 5 to 20㎛. In particular, when an alkali colloidal sol is used, an acid such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, acrylic acid, etc. is added to acidify the alkali to pH 3 to 5, and an alkaline colloidal sol is used. If just used, there is a problem in that the reaction with the silane compound having a hydrolyzable organic functional group is delayed and the alkali roroidal sol is gelled.

In the silane compound used in the present invention, the silane compound having a four-way hydrolyzable organic functional group represented by the above formula (I) is one or more selected from tetramethoxysilane and tetraethoxysilane. Examples of the silane compound having a three-way hydrolyzable organic functional group represented by the above formula (II) include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, and β- (3,4-ethoxy. Cyclohexyl) -triepoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriepoxysilane, and the like. It is one or more selected. The bidirectional silane compound having a hydrolyzable organic functional group represented by the above formula (III) is, for example, one or more selected from dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, and the like.

The silane-based mixtures represented by the formulas (I) and (II) used to modify the colloidal sol surface are slowly added at a molar ratio of 2.5 to 3.0 moles per mole of water contained in the colloidal sol. The reaction was carried out by adding and stirring, wherein the total addition time of the silane compound was 3 to 4 hours, the stirring speed was 100 to 200 rpm, and the reaction temperature was 25 to 30 ° C.

The silane-based mixture represented by the structural formulas (I) and (II) is a silane compound having a four-way hydrolytic organic functional group represented by the structural formula (I) and a tridirectional hydrolyzed organic functional group represented by the structural formula (II). The silane compound has 10:90 to 30: 70% by weight. If less than 10% by weight of the silane compound having a four-way hydrolyzable organic functional group contains a low crosslinking degree, the hardness of the coating film may be lowered when forming the final coating film. If it exceeds 30% by weight, the degree of crosslinking is high and the storage stability of the binder is poor. In addition, the silane-based mixture having the four-way and three-way hydrolyzable organic functional groups represented by the structural formulas (I) and (II) is less than 2.5 molar ratio with respect to 1 mole of water contained in the colloidal sol. If contained, the degree of crosslinking of the binder is lowered, and if it exceeds 3.0 molar ratio, there is a problem of poor storage stability due to an increase in the degree of crosslinking of the binder.

In order to give storage stability to the colloidal sol modified with the silane compound, 15-30 parts by weight of an organic polar solvent is added to 100 parts by weight of the modified colloidal sol to prepare a primary synthetic reactant. As the solvent, methanol, ethanol, isopropanol, normal butanol, butyl cellosolve, matyl ethyne ketone, or the like may be used. If the amount of the added organic polar solvent is less than 15 parts by weight, the effect of storage stability due to the addition of the polar organic solvent cannot be obtained. If it exceeds 30 parts by weight, the storage stability is improved, but the curing reaction of the final coating film is reduced and the coating is carried out. This will reduce the gloss of the coating.

The bidirectional silane compound having a hydrolyzable organic functional group is slowly added at a molar ratio of 1.5 to 2 to 1 mole of water contained in the primary synthetic reactant prepared above, and then stirred for 6 to 8 hours to cause a ceramic binder. In this case, the total addition time of the bi-directional silane compound is 3 to 4 hours, the stirring speed is 100 to 200 rpm and the reaction temperature is 25 to 30 ℃. At this time, if the added amount of the bi-directional silane compound having a hydrolyzable organic functional group is less than 1.5 molar ratio, the shelf life of the binder is lowered, and when the amount exceeds 2 molar ratio, the shelf life of the binder is increased but the hardness of the final coating film is decreased.

In addition, by simply mixing a specially prepared curing agent with the ceramic binder prepared above, a ceramic paint having a sufficiently cured and beautiful appearance even at room temperature is obtained, and a ceramic pigment or filler is added to impart various colors and functionality and improve durability of the ceramic coating film. It is also possible to obtain a desired ceramic paint.

The curing agent is a silane system in which a silane compound having a bidirectional organic functional group represented by the structural formula (III) and a silane compound having a tridirectional organic functional group represented by the structural formula (II) are mixed at 10:90 to 20: 80% by weight. 0.1 to 2 parts by weight of the organic titanate and 10 to 30 parts by weight of the organic polar solvent are added to 100 mixtures of the mixture, followed by stirring for 1 to 2 hours at a stirring speed of 50 to 100 rpm.

In the manufacture of a curing agent, the silane compound having a bidirectional organic functional group represented by the above formula (III) and the silane compound having a tridirectional organic functional group represented by the above formula (II) for the optimum curing and beautiful appearance of the coating film is It is desirable to maintain the mixing ratio. Organic titanates include tetraisopropyl titanate, tetrabutyl titanate, tetramethyl titanate, tetraethylhexyl titanate, triethanolamine titanate, titanium acetone titanate, titanium lactate and isopropyl titanium isostyrene When the amount is less than 0.1 parts by weight based on 100 parts by weight of the silane-based mixture, the curing time of the ceramic binder is long, and when it exceeds 2 parts by weight, the curing time of the ceramic binder is shortened, but the storage stability of the mixture is increased. Degrades. In addition, if the amount of the organic polar solvent is less than 10 parts by weight, the storage stability of the mixture is lowered. If it exceeds 30 parts by weight, the storage stability of the mixture is improved, but curing of the binder is poor.

Other binder preparation conditions such as reaction temperature, stirring speed and addition time are optimal conditions in consideration of the stability of the binder, the economics of the reaction, and the film formation of the final binder.

Therefore, the ceramic binder according to the present invention is modified on the surface of the colloidal sol with a silane compound having a tetra-directional and tri-aromatic organofunctional organic functional group, and then treated with a bi-directional silane compound having a hydrolyzable organic functional group. By reducing the degree of crosslinking of the hydroxy group present, it was possible to solve the problem of storage stability, which has been a problem in the conventional binder, and the ceramic binder prepared in the present invention can be cured even at a low temperature because the polymer binder has a high degree of crosslinking. It is resistant to moisture.

Hereinafter, the present invention will be described in more detail with reference to the following Examples, but the present invention is not limited thereto.

Examples 1 and 2:

The ceramic binder was prepared by the composition components and the composition ratio as shown in Table 1 below.

To the colloidal sol, a silane compound having a four-way organic functional group and a silane compound having a three-way hydrolysis organic functional group were slowly added over 3 hours, and stirred at 25 ° C. at a stirring speed of 200 rpm for 1 hour, followed by an organic polar solvent. Add. Then, a bidirectional silane compound having a hydrolyzable organic functional group was slowly added to the reaction over 3 hours, followed by stirring at 25 ° C. for 180 hours at a stirring speed of 180 rpm to form a ceramic binder.

In a separate container, a silane compound having a bidirectional organic functional group, a silane compound having a tridirectional organic functional group, an organic titanate and an organic polar solvent were added thereto, and stirred at 100 rpm for 2 hours to prepare a curing agent. The ceramic binder was cured by mixing with the ceramic binder.

Table 1

(1) An acidic colloidal sol having a pH of 3 to 5, a solid content of 20 to 21% by weight, and an average particle diameter of 10 to 20 µm.

(2) pH 4.0, solid content 20% by weight

Experimental Example

In order to measure the physical properties of the ceramic binders, the following experiments were carried out. Examples 1 and 2 were coated with a thickness of 25 μm on aluminum specimens (7 cm × 15 cm × 3T) subjected to sandblasting and degreasing pretreatment. After standing at room temperature (25 ° C.) for 7 days, the physical properties of the coating film were measured. The results are shown in Table 2 below.

TABLE 2

(1) Gloss: 60 ° mirror reflectance measurement.

(2) Adhesiveness: Measure adhesive tape after 1.5mm cross cut.

(3) Pencil hardness: measured with MIT-UNI pencil.

(4) Solvent resistance: Measured with acetone for 200 round trips.

(5) Boiling water resistance: After immersion in boiling water for 3 hours, the appearance of bubbles and cracks is measured.

(6) Heat resistance: Measured by rapid cooling after 400 ° C / 1 hour.

(7) Hot water resistance: 60 ℃, measured by RH 95 ± 5% / 200 hours method.

(8) Acid resistance: Measured by immersion in 5% H ₂ SO ₄ aqueous solution for 48 hours.

(9) Saline water resistance: Measured by spraying 5% NaCl / 1,000 hours.

(10) Weather resistance: 3,000 hours measured by Weather-O-Mwter.

According to the results of Table 2, the ceramic binder according to the present invention showed excellent results at room temperature curing and coating properties in all items. However, in Comparative Example 1, cracks occurred in the coating film due to the volumetric shrinkage that occurs during coating film formation, which resulted in poor results in all physical properties. In particular, when the pigment is added, it is matte, so the appearance is not beautiful, and the stain resistance is good. Did. In addition, in the case of Comparative Example 2, as shown in the test result requires a two-component aging process, the room temperature curing is not possible, showing poor results in all physical properties.

Claims (8)

(A) To the colloidal sol, a silane mixture in which the silane compounds represented by the following structural formulas (I) and (II) are mixed in a ratio of 10:90 to 30: 70% by weight is added and stirred to modify the colloidal sol. Next, after adding an organic polar solvent, the silane compound represented by following formula (III) is added and stirred to prepare a ceramic binder; (B) 100 parts by weight of the actual limit mixture, in which the silane compounds represented by the following structural formulas (II) and (III) are mixed in a ratio of 10:90 to 20: 80% by weight in a separate container; 0.1 to 2.0 weight of organic titanate Parts and 10 to 30 parts by weight of an organic polar solvent are added and stirred to prepare a curing agent; The method of producing a ceramic binder, characterized by mixing the (b) hardening agent with the (a) ceramic binder. In the above formula, R and R ⁴ are each a methoxy group or an ethoxy group; R ¹ is methyl group, ethyl group, phenyl group, β-3,4-ethoxycyclohexyl group, γ-glycidyloxypropyl group, γ-mercaptopropyl, γ-methacryloxypropyl or γ-aminopropyl; R ² is a methoxy group or an ethoxy group; R <^3> is a methyl group, an ethyl group, or a phenyl group. The method of claim 1. The colloidal sol has an acidic colloidal sol having a pH of 3 to 5, a content of 10 to 30% by weight of solids and a particle size of 5 to 20 μm, or a pH of 8.5 to 10.5, a content of 20 to 50% by weight of solids, and A method for producing a ceramic binder, characterized by using an alkali colloidal sol having a particle size of 5 to 20 μm. The method of claim 2, wherein hydrochloric acid, sulfuric acid, nitric acid, acetic acid, or acrylic acid is added when the alkali colloidal sol is used, and the ceramic binder is used after conversion to pH 3-5. The method for producing a ceramic binder according to claim 1, wherein the silane mixtures represented by the structural formulas (I) and (II) are used in a molar ratio of 2.5 to 3.0 with respect to 1 mole of water contained in the colloidal sol. The method of claim 1, wherein the organic polar solvent is methanol, ethanol, isopropanol, normal butanol, butyl cellosolve or methyl ethyl ketone. The method according to claim 1, wherein the organic polar solvent in (A) is used 15 to 30 parts by weight based on 100 parts by weight of the modified colloidal sol. The method for producing a ceramic binder according to claim 1, wherein the silane compound represented by the structural formula (III) is used in a molar ratio of 1.5 to 2 with respect to 1 mol of water contained in the synthetic reactant. The method of claim 1, wherein the organic titanate is tetraisopropyl titanate, tetrabutyl titanate, tetramethyl titanate, tetraethylhexyl titanate, triethanolamine titanate, titanium acetone titanate, titanium lactate. And at least one selected from isopropyl titanium isostyrene.