KR19980048678A - Manufacturing method of water repellent glass or water repellent ceramic - Google Patents

Abstract

A method for producing a water-repellent glass or a water-repellent ceramic having durability such as wear resistance, chemical resistance and weather resistance on a solid surface of glass, ceramic, etc., the preparation of a mixed metal oxide sol solution for forming a metal oxide layer having a shape of surface roughness The method is relatively simple, its heat treatment temperature is relatively low, and even though tempered glass and safety glass are used, there is no change in properties such as appearance deformation of the substrate glass or a decrease in strength during the treatment process, and excellent water repellency such as wear resistance Provided are methods for making glass or water repellent ceramic.

Description

Process for producing water repellent glass or water repellent ceramic.

[Industrial use]

The present invention treats the surface of solid substrates such as glass and ceramics with a mixed silica sol solution to form a silica layer having a surface roughness shape, and applies a fluoroalkylsilane (FAS) -based water repellent to provide excellent water repellency. A method of making glass or water repellent ceramics.

[Prior art]

In order to impart water repellency to the glass surface, the surface energy of the glass surface must be made low, and a process of forming a material having a low surface energy, ie, a low surface tension, on the glass surface is required. Compounds having a low surface tension include hydrocarbon compounds, silicone compounds, chlorine compounds, fluorine compounds and the like. In the hydrocarbon compound and the silicon compound, the critical surface tension is around 30 dyn / cm, and the fluorinated alkyl compound (hereinafter referred to as Rf compound) containing CF ₃ and CF ₂ groups in its molecule has a critical surface tension of 20 dyn. It is less than / cm and emits water, polar solvent and oil.

Conventional methods for imparting water repellency to glass surfaces include a method of applying a hydrocarbon compound, and a method using a silicon compound is also disclosed in US Pat. However, the surface treatment of glass using a hydrocarbon compound or a silicon compound has a disadvantage in that water repellency is realized from the definition of critical surface tension but oil repellency and oil repellency are not.

Therefore, in order to simultaneously impart excellent water repellency and oil repellency to the glass surface, it is preferable to form a fluorine compound layer on the glass surface. As a method of forming the fluorine compound layer on the glass surface, firstly, a fluorine polymer such as Teflon is formed on the glass surface. Secondly, a method of forming a fluorine compound layer directly on the glass surface using a fluorocarbon gas, and thirdly, a fluoroalkylsilane, which can form a siloxane bond by reacting with a surface hydroxyl group on the glass surface. Named FAS). The method of directly applying various fluorine-based high molecular compounds such as Teflon has a problem of low scratch resistance and lowering the light transmittance of the glass itself. The method for forming a fluorine compound layer directly on the glass surface using a fluorocarbon gas has been continuously studied by H. Yasuda et al. ( J. Polymer Science; Part A; Polymer Chemistry , Vol., 30, 1731-1739 (1992), Langmuir, 10, 2766-2773 (1994)), but further study is needed for practical use.

Using FAS to impart water repellency on glass surfaces is the most realistic approach and many patents have been filed. For a water repellent agent on the glass surface for this purpose, Japanese Patent Laid-Open No. 58-172242, Japanese Patent Laid-Open No. 58-172243, Japanese Patent Laid-Open No. 58-172245, Japanese Patent Laid-Open No. 58-172246, Japanese Patent Laid-Open 58-190840, Japanese Patent Laid-Open No. 58-223634, and the like. However, when these fluorine-based compounds are applied to general soda-lime glass, there is a problem in that the water repellency deteriorates with time of use due to the elution of alkali components in the glass. In addition, when the water repellent is immediately treated on a flat glass surface, since the adhesion area with the smooth surface shape is relatively small, the water repellent is easily removed from the surface, and thus durability and water repellency are not maintained continuously.

To overcome this, attempts have been made in Japanese Patent Publications No. 4-20781 and US Pat. No. 5,328,768 regarding a method of forming a water repellent film after treating a silica base layer on a glass surface before treating the water repellent agent.

In addition, when forming the silica base layer as disclosed in Japanese Patent Application Laid-Open No. Hei 4-325446 and Japanese Patent Application Laid-open No. Hei 5-24885, polyethylene glycol and triethylene glycol monoylstyrene ether are mixed to form fine pores inside the silica layer. As a result of increasing the durability and as disclosed in Japanese Patent Laid-Open Nos. Hei 4-124047 and Hei 6-116430, at least one transparent metal oxide layer is formed on the glass surface and the surface is etched by wet etching or plasma discharge. A method of forming a water repellent layer thereon after forming fine irregularities by a method has been proposed.

However, the fine pores inside the silica layer formed by the methods disclosed in Japanese Patent Application Laid-Open Nos. 4-325446 and 5-24885 are not stable in the heat treatment process of 400 ° C. or higher, and thus have limitations in the heat treatment process. The methods described in Japanese Patent Laid-Open Nos. 4-124047 and 6-116430 have disadvantages in that an etching process must be included after the silica layer forming process.

On the other hand, Japanese Patent Application Laid-Open No. 5-147976 has prepared two sols having two different molecular weights from metal alkoxides or metalacetylacetonates when forming a metal oxide layer by a sol-gel process, and then mixed them with a number of fine irons. A method of forming a metal oxide layer having a metal oxide layer is disclosed. A method of making glass is disclosed.

EP658525 forms at least three kinds of sol to prepare a primary coating solution, and then heat-treat it at a temperature of 550 ° C or higher to form a water repellent layer on the metal oxide layer having fine roughness. The glass forming method is presented.

However, in the above method, at least three kinds of sol should be formed to prepare a primary coating liquid in order to obtain a metal oxide layer having fine roughness, and its heat treatment temperature is higher than 550 ° C., such as tempered glass or automobile window glass. When safety glass, such as a windshield, is used as a target substrate, there is a disadvantage that a change in properties such as an appearance deformation or a decrease in strength of the substrate glass can be brought about.

The present invention has been made to solve the problems of the prior art as described above, the present invention is a relatively simple method of producing a mixed metal oxide sol solution for forming a metal oxide layer having a shape of surface roughness, the heat treatment temperature is Relatively low, even in the case of tempered glass and safety glass, there is no change in properties such as appearance deformation of the substrate glass or a decrease in strength during processing, and it is possible to manufacture durable water-repellent glass or water-repellent ceramic such as wear resistance. It is to provide a manufacturing method.

In order to achieve the object of the present invention as described above, the present invention, a mixed metal oxide for roughness formation comprising a tetraethoxysilane sol solution having a spherical particle and a tetraethoxysilane sol solution having a particle of a chain form and a solvent Providing a sol solution, the tetraethoxysilane sol solution having the spherical particles, preparing a silica sol solution consisting of tetraethoxysilane, a solvent and a basic catalyst, the step of sealing and stirring and then aged at room temperature, Basic silica sol solution prepared by the method comprising the step of filtration after titrating the pH to 1 to 7 or less with an acid, the tetraethoxysilane sol solution having the particles of the chain form, tetraethoxysilane, solvent and acid Preparing a silica sol solution consisting of a catalyst, sealing, stirring and aging at room temperature The acidic silica sol is a mixed solution of metal oxide sol solution prepared by.

The present invention also includes the step of coating the mixed metal oxide sol solution on a ceramic substrate and heat treatment to form a metal oxide layer having a shape of surface roughness, and applying a fluoroalkylsilane-based water repellent. It provides a method for producing a ceramic, wherein the heat treatment temperature is 100 ℃ to 500 ℃ and the mixed metal oxide sol solution is a mixture ratio of basic silica sol solution: acidic silica sol solution 3 to 7: 7 to 3.

The present invention also provides a method for producing a water-repellent ceramic, wherein the ceramic is glass.

Representative Example

After preparing a silica sol solution to form spherical silica particles, a basic silica sol solution subjected to basic treatment (pH7 or more but less than 14) and a silica sol solution for forming a polysiloxane in a chain form, followed by acid treatment (pH7 or less) Each acidic silica sol solution of 1 or more) is prepared. The two kinds of silica sol solutions thus prepared are aged for a certain period of time. The basic silica sol solution is treated with acid to be in the range of pH 1 to 5, and then the solution is filtered using a ceramic filter having a size of 1 to 150 µm. The mixed silica sol solution is prepared by mixing the filtered silica sol solution in an appropriate ratio with the acidic silica sol solution aged for a certain period of time. The mixed silica sol solution is aged for a certain period of time to induce the growth of silica sol particles. The solution thus prepared is a mixture of different types of particles of spherical and chain structure. Due to the properties of different types of particles, the solution is easily attached to the glass surface and has very fine irregularities and good surface roughness. By having the surface roughness of this characteristic it is possible to form a silica layer having a higher durability than the existing EP658525A2, and abrasion resistance is improved due to the maximization of the water-repellent layer by increasing the surface area. Soda-lime glass was applied to the mixed silica sol solution on the surface of the glass by an impression method and then placed in a drier and dried at 100 ° C. to 150 ° C. for 30 minutes, and then sintered at 200 ° C. to 500 ° C. using an electric furnace. Soda-lime glass coated with silica is applied with a water-repellent agent through the pulling method, put into an electric furnace of 150 ℃ to 300 ℃ and maintained for 20 minutes to 1 hour and then allowed to cool. The water repellent is prepared by hydrolysis and polycondensation reaction of the fluoroalkylsilane solution to maximize the siloxane reaction with the glass surface. The water repellent is, for example, a fluoroalkylsilane compound, ie CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCH ₃ (Cl) ₂ , CF _{It is prepared using 3} CH ₂ CH ₂ SiCl ₃ and CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ and the like and water for hydrolysis, and catalysts such as hydrochloric acid, nitric acid, acetic acid and the like. If the heat treatment temperature after the water repellent treatment is 350 ℃ or more because the decomposition of the fluoro compound is lost water repellency, the surface of the glass becomes turbid.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only preferred embodiments of the present invention showing the constitution and effects of the present invention, and the present invention is not limited to the following examples.

Example 1

Preparation of Basic Silica Sol Solution

A basic silica sol solution was prepared using 10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as a metal alkoxide, 86.5% by weight of ethyl alcohol as a solvent, and 3.1% by weight of ammonia water (NH ₄ OH) as a basic catalyst. After sealing, the mixture was stirred for 2 hours and then aged in a 25 ° C. incubator for 2 days. The basic silica sol solution aged for a certain period of time was titrated to pH 4 with hydrochloric acid, and then filtered using a ceramic filter having a size of 1 to 150 µm.

Preparation of Acidic Silica Sol Solution

10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide, 85.98% by weight of ethyl alcohol as solvent, 0.02% by weight of hydrochloric acid (35%) as acidic catalyst, 3.6% by weight of distilled water After the solution was prepared, it was sealed, stirred for 2 hours, and then aged in a 25 ° C. incubator for 2 days.

Mixing and Aging of Solutions

The mixed silica sol solution was prepared by mixing the basic silica sol solution and the acid silica sol solution prepared above in a ratio of 7: 3. The solution was again put into a 25 ° C. incubator and aged for 6 days.

Cleaning of glass

Soda-lime glass of 3cm x 8cm x 0.5cm was first washed with a surfactant, and then immersed in distilled water and washed secondly with an ultrasonic cleaner for 15 minutes. After the third washing with acetone was put in a dryer of 120 ℃ dried and stored in a desiccator.

Silica layer formation

The glass which was pre-washed in the mixed silica sol solution mixed at a constant ratio was applied at a pulling speed of 30 cm / min using a DIP COATER. After coating, the coating film was dried in a drier at 100 ° C to 150 ° C for 30 minutes, and then fired at 400 ° C for 30 minutes using an electric furnace (raising rate of 7 ° C / min).

Water repellent treatment

Heptadecadecylfluorotrimethoxysilane CF as water repellent₃(CF₂)₇CH₂CH₂Si (OCH₃)₃ 2 g, 0.15 g of distilled water, 85 g of isopropyl alcohol, 15 g of ethyl alcohol, and 0.82 g of hydrochloric acid (35%) were mixed in a beaker, stirred for 30 minutes, and then stirred at 10 ° C. at 75 ° C. to obtain a sufficiently hydrolyzed and polycondensed water repellent agent. It was heated to reflux for a time. After apply | coating this water repellent to the glass in which the silica layer was formed at the pulling speed of 15 cm / min, it heat-processed at 150 degreeC for 30 minutes, and produced the water repellent glass.

evaluation

The contact angle to water was measured using a CA-X measuring instrument (manufactured by Cooperative Interface Science), and the wear resistance was measured by using a wiper blade for automobiles while dropping water at a load of 200,000 times (1 round trip), 550g. The contact angle was measured after 34,000 wear tests with a load of / cm. Light resistance test (Orlel) measured the contact angle after 100 hours irradiation with a 1000W Xe Lamp. The alkali resistance test was immersed in 1N-NaOH for 6 hours, then taken out, washed with distilled water, dried and the contact angle was measured. The moisture resistance test measured contact angle after 336 hours, RH 98% at 45 degreeC. The accelerated weather test measured the contact angle after 2000 degreeC and 2000 hours.

Detailed examples according to the conditions were performed according to the following Table 1, the evaluation results are shown in Table 2.

Example 2

Preparation of Basic Silica Sol Solution

A basic silica sol solution was prepared using 10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as a metal alkoxide, 86.5% by weight of ethyl alcohol as a solvent, and 3.1% by weight of ammonia water (NH ₄ OH) as a basic catalyst. After sealing, the mixture was stirred for 2 hours and then aged in a 25 ° C. incubator for 4 days. The basic silica sol solution aged for a certain period of time was titrated to pH 3 with hydrochloric acid, and then filtered using a ceramic filter having a size of 1 to 150 µm.

Preparation of Acidic Silica Sol Solution

10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide, 86.5% by weight of ethyl alcohol as solvent, 0.02% by weight of hydrochloric acid (35%) as acidic catalyst, 3.6% by weight of distilled water After the solution was prepared, it was sealed, stirred for 2 hours, and then aged in a 25 ° C. incubator for 4 days.

Mixing and Aging of Solutions

The mixed silica sol solution was prepared by mixing the basic silica sol solution prepared above and the acidic silica sol solution in a ratio of 5: 5. The solution was again put into a 25 ° C. incubator and aged for 4 days.

Cleaning of glass

It carried out similarly to Example 1.

Silica layer formation

The glass which was pre-washed in the mixed silica sol solution mixed at a constant ratio was applied at a pulling speed of 30 cm / min using a DIP COATER. After coating, the coating film was dried in a drier at 100 ° C to 150 ° C for 30 minutes, and then fired at 400 ° C for 30 minutes using an electric furnace (raising rate of 7 ° C / min).

Water repellent treatment and evaluation

It carried out similarly to Example 1.

Example 3

Preparation of Basic Silica Sol Solution

A basic silica sol solution was prepared using 10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as a metal alkoxide, 86.5% by weight of ethyl alcohol as a solvent, and 3.1% by weight of ammonia water (NH ₄ OH) as a basic catalyst. After sealing, the mixture was stirred for 2 hours and then aged in a 25 ° C. incubator for 4 days. The basic silica sol solution aged for a certain period of time was titrated to pH 2 with hydrochloric acid, and then filtered using a ceramic filter having a size of 1 to 150 µm.

Preparation of Acidic Silica Sol Solution

10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide, 86.5% by weight of ethyl alcohol as solvent, 0.02% by weight of hydrochloric acid (35%) as acidic catalyst, 3.6% by weight of distilled water After the solution was prepared, it was sealed, stirred for 2 hours, and then aged in a 25 ° C. incubator for 4 days.

Mixing and Aging of Solutions

The mixed silica sol solution was prepared by mixing the basic silica sol solution and the acid silica sol solution prepared above in a ratio of 3: 7. The solution was again put into a 25 ° C. incubator and aged for 2 days.

Cleaning of glass

It carried out similarly to Example 1.

Silica layer formation

The glass which was pre-washed in the mixed silica sol solution mixed at a constant ratio was applied at a pulling speed of 30 cm / min using a DIP COATER. After coating, the coating film was dried in a drier at 100 ° C to 150 ° C for 30 minutes, and then fired at 400 ° C for 30 minutes using an electric furnace (raising rate of 7 ° C / min).

Water repellent treatment and evaluation

It carried out similarly to Example 1.

Example 4

Preparation of Basic Silica Sol Solution

A basic silica sol solution was prepared using 10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as a metal alkoxide, 86.5% by weight of ethyl alcohol as a solvent, and 3.1% by weight of ammonia water (NH ₄ OH) as a basic catalyst. After sealing, the mixture was stirred for 2 hours and then aged in a 25 ° C. incubator for 2 days. The basic silica sol solution aged for a certain period of time was titrated to pH 2 with hydrochloric acid, and then filtered using a ceramic filter having a size of 1 to 150 µm.

Preparation of Acidic Silica Sol Solution

10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide, 86.5% by weight of ethyl alcohol as solvent, 0.02% by weight of hydrochloric acid (35%) as acidic catalyst, 3.6% by weight of distilled water After the solution was prepared, it was sealed, stirred for 2 hours, and then aged in a 25 ° C. incubator for 2 days.

Mixing and Aging of Solutions

The mixed silica sol solution was prepared by mixing the basic silica sol solution prepared above and the acidic silica sol solution in a ratio of 5: 5. The solution was again put into a 25 ° C. incubator and aged for 4 days.

Cleaning of glass

It carried out similarly to Example 1.

Silica layer formation

The glass which was pre-washed in the mixed silica sol solution mixed at a constant ratio was applied at a pulling speed of 30 cm / min using a DIP COATER. After coating, the coating film was dried in a drier at 100 ° C to 150 ° C for 30 minutes, and then fired at 400 ° C for 30 minutes using an electric furnace (raising rate of 7 ° C / min).

Water repellent treatment and evaluation

It carried out similarly to Example 1.

Example 5

Preparation of Basic Silica Sol Solution

A basic silica sol solution was prepared using 10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as a metal alkoxide, 86.5% by weight of ethyl alcohol as a solvent, and 3.1% by weight of ammonia water (NH ₄ OH) as a basic catalyst. After sealing, the mixture was stirred for 2 hours and then aged in a 25 ° C. incubator for 4 days. The basic silica sol solution aged for a certain period of time was titrated to pH 3 with hydrochloric acid, and then filtered using a ceramic filter having a size of 1 to 150 µm.

Preparation of Acidic Silica Sol Solution

10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide, 86.5% by weight of ethyl alcohol as solvent, 0.02% by weight of hydrochloric acid (35%) as acidic catalyst, 3.6% by weight of distilled water After the solution was prepared, it was sealed, stirred for 2 hours, and then aged in a 25 ° C. incubator for 4 days.

Mixing and Aging of Solutions

The mixed silica sol solution was prepared by mixing the basic silica sol solution and the acid silica sol solution prepared above in a ratio of 3: 7. The solution was again put into a 25 ° C. incubator and aged for 6 days.

Cleaning of glass

It carried out similarly to Example 1.

Silica layer formation

The glass which was pre-washed in the mixed silica sol solution mixed at a constant ratio was applied at a pulling speed of 30 cm / min using a DIP COATER. After coating, the coating film was dried in a drier at 100 ° C to 150 ° C for 30 minutes, and then fired at 200 ° C for 30 minutes using an electric furnace (raising rate of 7 ° C / min).

Water repellent treatment and evaluation

It carried out similarly to Example 1.

Example 6

Preparation of Basic Silica Sol Solution

A basic silica sol solution was prepared using 10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as a metal alkoxide, 86.5% by weight of ethyl alcohol as a solvent, and 3.1% by weight of ammonia water (NH ₄ OH) as a basic catalyst. After sealing, the mixture was stirred for 2 hours and then aged in a 25 ° C. incubator for 4 days. The basic silica sol solution aged for a certain period of time was titrated to pH 3 with hydrochloric acid, and then filtered using a ceramic filter having a size of 1 to 150 µm.

Preparation of Acidic Silica Sol Solution

10.4% by weight of tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide, 86.5% by weight of ethyl alcohol as solvent, 0.02% by weight of hydrochloric acid (35%) as acidic catalyst, 3.6% by weight of distilled water After the solution was prepared, it was sealed, stirred for 2 hours, and then aged in a 25 ° C. incubator for 4 days.

Mixing and Aging of Solutions

The mixed silica sol solution was prepared by mixing the basic silica sol solution and the acid silica sol solution prepared above in a ratio of 7: 3. The solution was again put into a 25 ° C. incubator and aged for 4 days.

Cleaning of glass

It carried out similarly to Example 1.

Silica layer formation

The glass which was pre-washed in the mixed silica sol solution mixed at a constant ratio was applied at a pulling speed of 30 cm / min using a DIP COATER. After coating, the coating film was dried in a drier at 100 ° C to 150 ° C for 30 minutes, and then fired at 400 ° C for 30 minutes using an electric furnace (raising rate of 7 ° C / min).

Water repellent treatment and evaluation

It carried out similarly to Example 1.

Comparative Example 1

A mixed silica sol solution was prepared by mixing a basic silica sol solution and an acidic silica sol solution at a ratio of 10: 0, and the mixed solution was put into a 25 ° C. incubator and aged for one day, in the same manner as in Example 2. Was carried out.

Comparative Example 2

The mixed silica sol solution was put into a 25 ° C. incubator and subjected to the same procedure as in Comparative Example 1 except that the mixture was aged for 8 days.

Comparative Example 3

A mixed silica sol solution was prepared by mixing a basic silica sol solution and an acidic silica sol solution at a ratio of 0:10, and the mixed solution was put into a 25 ° C. incubator and aged for 8 days, in the same manner as in Example 2. Was carried out.

[Comparative Example 4]

The mixed silica sol solution was put into a 25 ° C. incubator and subjected to the same procedure as in Comparative Example 3 except that the mixture was aged for 8 days.

TABLE 1

Conditions according to the examples.

Silica Sol Maturation Period: (day) Mixed non-basic silica sol: acid silica sol Mixed silica sol maturation period: (day) Silica Layer Forming Temperature (℃) Example 1 2 7: 3 6 400 Example 2 4 5: 5 4 300 Example 3 4 3: 7 2 400 Example 4 2 5: 5 4 400 Example 5 4 3: 7 6 200 Example 6 4 7: 3 4 400 Comparative Example 1 4 10: 0 One 300 Comparative Example 2 4 10: 0 8 300 Comparative Example 3 4 0: 10 One 300 Comparative Example 4 4 0: 10 8 300

TABLE 2

Example and Comparative Example Results.

Initial contact angle / water (°) Wiper Blade Wear Resistance (15g / cm, 200,000times) Wiper blade 550g / cm, 36000 times Xe Lamp irradiation (1000W, 100 hours) Alkali test Moisture resistance Weather resistance 2000 hours Contact angle scratch Example 1 112.1 107.1 radish 107.5 110.1 109.5 111.8 110.8 Example 2 128.2 107.5 radish 111.4 127.5 110.4 120.5 118.5 Example 3 116.7 108.3 radish 108.2 115.9 112.7 112.3 114.2 Example 4 127.1 108.5 radish 94.2 125.8 108.9 109.4 112.9 Example 5 115.5 108.4 radish 100.2 114.7 113.2 108.9 109.8 Example 6 117.8 108.7 radish 112.4 117.1 116.1 112.4 116.8 Comparative Example 1 107.6 - - 76.6 - - - - Comparative Example 2 101.8 - - 42.5 - - - - Comparative Example 3 109.0 - - 70.5 - - - - Comparative Example 4 111.5 - - 86.7 - - - -

The method for preparing a mixed metal oxide sol composition solution for forming a metal oxide layer having a shape of surface roughness is relatively simple, its heat treatment temperature is lower than the softening point of ordinary soda lime glass, and durability such as wear resistance as shown in the results of Table 2 It is possible to manufacture this excellent water-repellent glass.

Claims (6)

Tetraethoxysilane sol solution having spherical particles; Tetraethoxysilane sol solution having chain-shaped particles; Solvents; Mixed metal oxide sol solution for forming roughness. The tetraethoxysilane sol solution having the spherical particles according to claim 1, Preparing a silica sol solution consisting of tetraethoxysilane, a solvent and a basic catalyst; Sealing and agitating at room temperature after stirring; Filtering the pH with an acid below 1 to 7 and then filtering; Is a basic silica sol solution prepared by the method comprising, Tetraethoxysilane sol solution having the particles of the chain form, Preparing a silica sol solution consisting of tetraethoxysilane, a solvent and an acidic catalyst; Sealing and agitating at room temperature after stirring; Mixed metal oxide sol solution is an acid silica sol solution prepared by the method comprising a. Forming a metal oxide layer having a shape of surface roughness by applying the mixed metal oxide sol solution of claim 1 on a ceramic substrate and performing heat treatment; Applying a fluoroalkylsilane-based water repellent; Method for producing a water-repellent ceramic containing. The method of claim 3, wherein the heat treatment temperature is 100 ℃ to 500 ℃. The method of claim 3, wherein the mixed metal oxide sol solution is a mixture of a basic silica sol solution and an acidic silica sol solution in a range of 3-7: 7-3. The method of claim 3, wherein the ceramic is glass.