KR102167971B1 - Method for manufacturing inorganic non-flammable ceramic binder capable of long-term storage - Google Patents

Abstract

The present invention is a first step of adding and stirring 25 to 35% by weight of isopropyl alcohol (IPA) to 40 to 45% by weight of a mixture of methoxysilane and alumina sol;
Then, a second step of adding tetraethyl silicate as a binder;
Then, a third step of dropping an acid catalyst to prepare 1-5 solutions;
A fourth step of preparing a second solution by mixing and stirring 8 to 15% by weight of distilled water with 10 to 15% by weight of colloidal silica (silica sol);
A fifth step of gradually dispersing and mixing the 2 liquids with the liquid 1-5 to generate heat of reaction, but mixing again when the initial white color becomes transparent;
A sixth step of aging by stirring for 1-3 hours after the fifth step;
This is a method for manufacturing inorganic non-flammable ceramic binders capable of long-term storage in which the 7th process is sequentially performed in a separate container after the 6th process for an additional day without stirring.
Since each process is sequentially divided and carried out step by step, the reaction time is shortened, the binder performance retention time is extended for more than 6 months, the quality is uniform, and the heat resistance is improved.

Description

Method for manufacturing inorganic non-flammable ceramic binder capable of long-term storage

The present invention relates to a method for manufacturing a ceramic binder, which is mainly applied to fields requiring heat resistance, such as kitchenware, heating supplies, heating plates, and interior and exterior materials for construction, and improves storage of a coating agent by using colloidal silica and silane, and It relates to a method of manufacturing an inorganic non-flammable ceramic binder capable of long-term storage capable of overcoming the limitations of the ceramic binder by sequentially passing through the reaction process.

Binder refers to a material that imparts required properties such as adhesion, film properties, or chemical resistance in the final use by bonding materials of different materials. The binder can be largely divided into an organic binder and an inorganic binder. The organic binder forms a material bond by a carbon bond or an ether bond, and the inorganic binder bonds the material by a Si-O bond or an Al-O bond. The binder can be used for the manufacture of various materials such as paints, waterproofing agents, fibers or rubber. On the other hand, ceramic is an inorganic non-metal made hard by firing and refers to a non-metallic solid mainly bonded with oxygen.

The problem with organic binders widely used in various industrial fields is that they can generate volatile organic compounds (VOC). Volatile organic compounds can have a serious impact on the environment, so regulations are being gradually strengthened. As an alternative to such an organic binder, an aqueous binder or an inorganic binder has been proposed.

As a prior art related to a method of manufacturing an inorganic binder, there is Patent Publication No. 2001-0027894 "Silica-based binder and its manufacturing method". The prior art relates to a silica (SiO2)-based coating material having excellent adhesion that can form a thin film by coating on the surface of glass, single crystal silicon, or metal, and a method of manufacturing the same.Si(OC2H5)4 or ethyl silicate is added to an acid aqueous solution. Si-CH3 group prepared by reacting silica sol made by decomposition with polysiloxane or R2Si(OR')2 (R is CH3 and R'is any one selected from H, CH3 and CH2CH3) Disclosed is a silica sol binder having low viscosity and excellent adhesion. Another prior art related to the method of manufacturing an inorganic binder is Patent Registration No. 0758286 “Method of manufacturing an inorganic polymer binder”. The prior art has 27 to 30 repeating units (n) of monosiloxane based on the bonding unit of -Si-O-, and disiloxane ( disiloxane) is disclosed for inorganic binders having 15 to 18 repeating units.

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In general, in the field of materials that require heat resistance, such as kitchen utensils and pans, a method of preparing a coating agent by reacting silica sol and silane using a sol-gel reaction is widely used.

As such, two methods have been proposed in the prior art.

1). There is a method of forming a coating agent by mixing and stirring silica sol, silane, alcohol, a base catalyst, or an acid catalyst (hereinafter referred to as'conventional method 1').

2).A part of the catalyst is added to the silica sol to make 1 solution, and the two are first mixed with silane as 2 solution, stirred and reacted, and then aged for a certain period of time, then alcohol is added in 3 solution, stirred again, and then aged. There is a method of making (hereinafter referred to as'conventional method 2').

And, in the case of manufacturing a colored coating agent, the coating agent is manufactured by adding a pigment to the last step.

However, in the case of the conventional method 1, after 48 hours at room temperature, the coating agent becomes a gel due to a condensation reaction, so that the coating agent cannot be worked anymore, so it is difficult to store the coating agent for a long time or transport it over a long distance. .

In addition, in the case of the conventional method 2, since the catalyst is added to the silica sol, long-term storage of one solution is difficult, and there is a problem that the working time, which is the use time after constituting the coating agent, does not exceed 48 hours. Therefore, it has been a major obstacle in overseas exports that require long-term storage and transportation.

On the other hand, the coating agent prepared by the conventional methods 1 and 2, both require preheating of the material before coating the coating agent, and there is a problem that a high temperature drying process of 200°C or higher is required during the coating process.

The present invention is to solve this, and an object of the present invention is to provide a method of manufacturing an inorganic non-flammable ceramic binder capable of long-term storage in which each liquid used when constructing an inorganic composite coating agent can be stored for a long time.

Another object of the present invention is to provide a method of manufacturing an inorganic non-flammable ceramic binder capable of long-term storage, which is a coating composition that has non-flammability by extending the working time of the coating agent and overcoming the limitations of working conditions such as preheating and high-temperature drying.

For this purpose, the method of manufacturing an inorganic non-combustible ceramic binder of the present invention is to add 25 to 35% by weight of isopropyl alcohol (IPA) to 40 to 45% by weight of methoxysilane, and to first stir for 5 to 10 minutes, followed by an acid catalyst. A first step of preparing a liquid by second stirring for 5-10 minutes while dropping;

A second step of preparing a second solution by mixing and stirring 8 to 15% by weight of distilled water with 10 to 15% by weight of colloidal silica (silica sol);

The first and second solutions are mixed and stirred for 10 to 60 minutes to generate heat of reaction, followed by stirring until the temperature reaches room temperature, followed by stirring for 2 hours after the temperature is reached, followed by a third step of aging.

In another example of the present invention, 25 to 35% by weight of isopropyl alcohol (IPA) is added to 35 to 38% by weight of methoxysilane, and 1.5 to 5% by weight of tetraethyl silicate (TEOS) is first stirred for 5 to 10 minutes. Step 1-1 of preparing a 1-1 solution while gradually adding and dispersing;

A 1-2 step of preparing a 1-2 solution by adding 1.5 to 2.5% by weight of an acid catalyst to solution 1-1 and stirring for 20 to 30 minutes;

A second step of preparing a second solution by mixing and stirring 8 to 15% by weight of distilled water with 10 to 15% by weight of colloidal silica (silica sol);

Drop the 2 solution into the 1-2 solution little by little, but when it turns white at the initial drop, stir until it becomes transparent, and when it starts to become transparent, add part of the solution 2 again until it becomes transparent. A third step of reacting for 20 to 30 minutes;

Then, 0.5 to 1.5% by weight of epoxy silane is gradually added to perform a fourth step of improving adhesion.

Another example of the present invention is to add 25 to 35% by weight of isopropyl alcohol to 40 to 45% by weight of alumina sol mixed in a ratio of 5 to 7 parts by weight and 35 to 38 parts by weight of methoxysilane, followed by stirring in a stirring tank. -The first step of preparing the third liquid;

A second step of preparing a solution 1-4 by stirring for 20 to 30 minutes while dropping 0.5 to 3.5% by weight of tetraethyl silicate (TEOS) to the solution 1-3;

A third step of preparing a solution 1-5 by dropwise adding 1-2% by weight of acetic acid or formic acid to the solution 1-4;

A fourth step of preparing a second solution by mixing 10 to 15% by weight of colloidal silica with 8 to 15% by weight of distilled water;

Add part 2 to solution 1-5 and react with exothermic reaction, and add 2 solution to 1st addition and stirring at the beginning of white color but 3~4 minutes to become transparent, add 2nd solution to add 2nd solution and stir for 3~4 minutes A fifth step of repeatedly adding and stirring in such a manner that the second liquid is added again when it becomes transparent;

A sixth step of aging by stirring for an additional 1 to 3 hours after completion of the addition of the second liquid in the fifth step; And

After the 6th process, the 7th process of further aging without stirring for a day in a separate container is sequentially performed.

As described above, the present invention promotes the reaction by dropping an acid catalyst by first stirring methoxysilane and alcohol, and diluting the silica sol in distilled water to promote an exothermic reaction during the second stirring to increase adhesion and increase adhesion. As the condition maintenance time can be maintained for more than 6 months, storage performance is improved.

In the present invention, methoxysilane and tetraethyl silicate are stirred in alcohol to gradually add and disperse tetraethyl silicate, and an acid catalyst is added dropwise to increase the binding strength, and the silica sol is diluted in distilled water and further mixed to generate heat by self-heating. By doing this, it increases the caking property and increases storage.

In the present invention, methoxysilane and alumina sol are simultaneously mixed with alcohol, and a silica diluent is added to the mixture of tetraethyl silicate and acetic acid in sequence, followed by self-heating and aging to increase caking and non-flammability to around 1000°C. By providing a non-combustible binder.

The first aspect of the present invention is aimed at securing storage stability when two liquids (silicasol) are added through the improvement of the conventional method 1 and the conventional method 2 described above.

To this end, a mixture of methoxysilane and alumina sol with alcohol gave viscous properties by adding tetraethyl silicate, followed by mixing and stirring with an acid catalyst, followed by adding a silica sol (collidal silica) diluent in sequence, and adding alcohol A coating agent is prepared so that silane and alumina sol are well dissolved, and caking properties are imparted by addition of tetraethyl silicate.

Silane in the present invention (Silane) is also referred to as silane, a generic term for silicon hydride Si _n H _2n . When simply referring to silane, it refers to the compound SiH ₄ of n = 1. Compounds such as n = 2, 3 are referred to as disilane and trisilane. The name silane is also used when referring to an organic compound in which a hydrogen atom of SiH ₄ is substituted with a hydrocarbon group or the like. Anything spontaneously ignites in the air, but is stable even at room temperature if the air is blocked and stored. Compared to the corresponding paraffinic hydrocarbon, it is clearly unstable, and it is easy to react with a water hydroxide alkali solution or the like or to undergo thermal decomposition. Usually, when a mixture of magnesium powder and fine silica powder is ignited, magnesium silicide, Mg ₂ Si, is decomposed into acid to form a mixture with hydrogen. It makes a derivative in which hydrogen is substituted with an alkyl group, a halogen hydroxyl group, etc., and is very important as a parent of an organosilicon compound. Extremely toxic. SiH ₄ is a colorless gas with a peculiar odor and has a melting point of 184.7 and a boiling point of 112. It ignites spontaneously in the air. It reacts with an alkali hydroxide solution to generate hydrogen and becomes an alkali silicate. When heated, it decomposes to form hydrogen and silicon. It is stable at room temperature. In the present invention, the use of methoxysilane (OFS-6060; manufactured by Dow Corning) is exemplified, but is not limited thereto.

The silica sol in the present invention is a colloid in which fine particles of silicic acid (SiO ₂ nH ₂ O) are dispersed in a dispersion medium such as water. Used as a binder such as paint.

Isopropyl alcohol in the present invention is isopropyl alcohol or propan-2-ol, 2-propanol is the chemical formula of C ₃ H ₈ O It is a chemical, colorless, and flammable solvent.

Colloidal silica (Cathonic silica sol) in the present invention refers to silicon dioxide present in water as a hydrate, and may be in a gas or a non-acceptor, and is prepared by adding silicon tetrahalide in water or gradually adding concentrated hydrochloric acid to an aqueous alkali silicate solution. And also referred to as "silicasol".

The solubility of silicic acid in water is small, but the silicic acid made as above does not precipitate well at room temperature in a sol or jelly state. When heated, silicon dioxide with a small degree of hydration gradually precipitates. Alcohol, acetone, sugar, etc. do not have a condensing action, but most of the organic acids such as alkali salts, activated carbon, and hydroxides of aluminum or iron have a condensing action, and sodium acetate is particularly effective. Acid and alkali act as dehydration. It adsorbs organic dyes, alcohol, acetone, etc. It reacts immediately with hydrofluoric acid and dissolves.

It dissolves non-polar substances and evaporates easily without leaving magnetic stains, so it is widely used as a cleaning solution for IT parts such as semiconductors and LCDs, and is a colorless organic solvent with strong alcohol scent used as a binder for paints and inks.

Alumina sol in the present invention is a colloidal liquid of alumina hydrate using water as a dispersion medium. Commercialized products are alumina-100, -200, -520, and the viscosity is due to the amount of Al ₂ O ₃ .

TEOS (TetraEthylOrthoSilicate) in the present invention is tetraethylordosilicate, and is referred to as tetraethyl silicate [Si(OC ₂ H ₅ )]-[Dow Corning's model name 6697, 6040 product] _, ethyl silicate, alkoxide, and the like.

In the case of the conventional method 1, the method is mainly carried out when coating is applied by receiving an order from a factory, and is not suitable for long-distance transportation or long time, such as overseas export. Therefore, in the present invention, a catalyst is added to the silica sol containing moisture to partially hydrolyze the silane, and alcohol is added to ensure stability of the binder.

An example of the present invention is to make 1 solution including methoxysilane, acid catalyst, and alcohol, and mix 2 solutions obtained by diluting silica sol in distilled water into 1 solution as a separate coagulant to form a coating composition, which has excellent hardness. It is possible to make a coating that has the properties of the coating film that is condensed. At this time, since hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, formic acid, propionic acid, acetic acid, and the like can be used as the catalyst, it is referred to as an acid catalyst, and acetic acid is particularly preferred.

As a preferred example, 40 to 45% by weight of methoxysilane, 1.5 to 2.5% by weight of an acid catalyst, and 25 to 35% by weight of isopropyl alcohol are mixed to make 1 solution, and 10 to 15% by weight of silica sol is added to 8 to 15% by weight of distilled water. A coating composition is prepared by mixing 2 solutions diluted in% with 1 solution to function as a separate coagulant.

Another example of the present invention is to make 1-1 solution including methoxysilane, tetraethyl silicate (TEOS), and alcohol, to make 1-2 solution by dropping an acid catalyst in solution 1-1, and dilute silica sol in distilled water. When one 2 liquids are mixed with 1-2 liquids to function as a separate coagulant to form a coating composition, a coating agent having excellent hardness can be prepared with coating properties.

Another preferred example is methoxysilane 35 to 38% by weight, tetraethyl silicate (TEOS) 1.5 to 5% by weight, and isopropyl alcohol 25 to 35% by weight to make a 1-1 solution, and acid catalyst to solution 1-1 1.5~2.5% by weight is added dropwise to make 1-2 solution, and the 2 solution obtained by diluting 10 to 15% by weight of silica sol in 8 to 15% by weight of distilled water is started as a coagulant. To manufacture.

Another example of the present invention is to add 25 to 35% by weight of isopropyl alcohol to 40 to 45% by weight of a mixture mixed in a ratio of 35 to 38 parts by weight of methoxysilane to 5 to 7 parts by weight of alumina sol, followed by stirring in a stirring tank. To prepare 1-3 solutions;

Dropping (Dripping) 0.5 to 3.5% by weight of tetraethyl silicate (TEOS) to the solution 1-3 and stirring for 20 to 30 minutes to prepare a solution 1-4;

1-5 solution is prepared by dropwise adding 1-2% by weight of acetic acid or formic acid to solution 1-4;

10-15% by weight of colloidal silica is mixed with 8-15% by weight of distilled water to prepare 2 liquids as a coagulant;

Add part 2 to solution 1-5 and react with exothermic reaction. Add 2 solution is white at the beginning of the first addition, but becomes transparent by stirring for 3 to 4 minutes. When the mixture became transparent by stirring for 4 minutes, the mixture was repeatedly added and stirred in such a manner as to further add 2 liquids; A sixth step of further aging by stirring for an additional 1 to 3 hours after the completion of the addition of the second liquid; And

After additional aging, the 7th step of further aging without stirring for a day in a separate container is sequentially performed.

<Comparative Example 1>

First, in Comparative Example 1, a coating agent was prepared according to the conventional method 1, coated on a sand blast-treated aluminum base without preheating, and then dried at a temperature between 60 and 100°C.

As a result, the dried coating film was not good in appearance and had a poor gloss of 19.1. In addition, the adhesiveness did not peel off from the base, and the pencil hardness was good at 8H. Flexibility was moderate, and the port life of the coating was 48 hours. Heat resistance temperature was 700 degreeC

<Comparative Example 2>

In Comparative Example 2, a coating agent was prepared according to the conventional method 2, and the coating was applied to a sand blast-treated aluminum base without preheating, and then dried at a temperature between 130 and 150°C.

As a result, the dried coating had a poor appearance and had a poor gloss of 7.7. And the adhesion did not peel off from the aluminum base, and the pencil hardness was good at 8H. The flexibility was moderate, the storage stability was 6 months, and the port life of the coating agent was 48 hours. The heat resistance temperature was 750°C.

<Example 1>

One solution is made by mixing 420 grams of Dow Corning's brand name OFS-6060, an acid catalyst, and 300 grams of isopropyl alcohol, and 120 grams of distilled water (140 grams of Dow Corning's brand name OFS-6697, which is a silica sol). The coating composition is prepared by mixing and stirring the 2 solutions diluted in 1 solution to function as a separate coagulant.

On the other hand, Example 1 was coated on a sand blast-treated aluminum base without preheating, and then dried at a temperature between 130 and 150°C.

As a result, the dried coating was excellent in appearance and had a good gloss of 65. In addition, the adhesiveness was not peeled off from the aluminum substrate, and the pencil hardness was also good at 8H. The flexibility was moderate, the storage stability was 1 year, and the port life of the coating agent was excellent at 168 hours. The heat resistance temperature was 800°C.

<Example 2>

In Example 2, 300 grams of isopropyl alcohol (IPA) was added to 380 grams of Dow Corning's brand name OFS-6060, which is a methoxysilane, and stirred at a primary 300 rpm for 7 minutes, while tetraethoxysilane (TEOS), a product of Dow Corning Co., Ltd. Step 1-1 of preparing a 1-1 solution while gradually adding and dispersing 20 grams of -6697;

A 1-2 step of preparing a 1-2 solution by dropping 20 grams of acetic acid, which is an acid catalyst, to the solution 1-1, and stirring at 300 rpm for 20 to 30 minutes;

A second step of preparing a second solution by mixing and stirring 120 g of distilled water at 300 rpm with 140 g of colloidal silica (silica sol);

Drop the 2 liquid into the 1-2 solution little by little, but when it turns white at the initial drop, stir at 300 rpm until it becomes transparent, and when it becomes transparent, drop part of the 2 solution again until it becomes transparent at 300 rpm. A third step of reacting for a total of 30 minutes by stirring in a manner;

Subsequently, 10 grams of Dow Corning's OFS-6040, which is an ethoxysilane, is slowly added to perform the fourth step of improving adhesion to prepare an inorganic non-flammable ceramic binder.

A coating agent was prepared by different manufacturing steps compared to Example 1, coated on a sand blast-treated aluminum substrate, and then dried at a temperature between 60 and 100.

As a result, the dried coating was excellent in appearance and had a good gloss of 57. In addition, the adhesion was good because it did not peel off, and the pencil hardness was also good at 8H. Flexibility was moderate. The storage stability was 1 year, and the port life of the coating was excellent at 168 hours. The heat resistance temperature was 850°C.

<Example 3>

In Example 3, 290 grams (ml) of isopropyl alcohol was added to 400 grams of a mixture of 70 grams of alumina sol, manufactured by Nissan Chemical Co., Ltd. product name Alumina Sol 520 and 330 grams of Dow Corning Co., brand name OFS-6060, which are methoxysilanes. A first step of preparing a 1-3 solution by stirring at 300 rpm;

The second step of preparing 1-4 solution by dropping 20 grams of TEOS, the brand name OFS-6697 manufactured by Dow Corning, to the solution 1-3 and stirring for 20 to 30 minutes;

A third step of preparing liquid 1-5 by dropping 20 grams of acetic acid into liquid 1-4;

A fourth step of preparing a second solution by mixing 140 grams of colloidal silica with 130 grams of distilled water;

Add 50 grams of part 2 to solution 1-5 and react with exothermic reaction. Addition 2 solution is white at the beginning of agitation but becomes transparent by stirring for 3 to 4 minutes. A fifth step of repeatedly adding and stirring in a manner of adding 2 liquids again when the mixture becomes transparent by stirring for 3 to 4 minutes;

A sixth step of aging by stirring for an additional 1 to 3 hours after completion of the addition of the second liquid in the fifth step; And

After the 6th process, an inorganic non-flammable ceramic binder is prepared in which the 7th process is sequentially performed in a separate container for an additional day without stirring.

Compared with Examples 1 and 2, a coating agent was prepared by slightly different from the process sequence, and after coating on a sand blast-treated aluminum substrate, it was dried at a temperature between 60 and 100.

As a result, the dried coating film was excellent in appearance and had a good gloss of 59. And the adhesion did not peel off, and the pencil hardness was also good at 8H. Flexibility was moderate. The storage stability was 1 year, and the port life of the coating was excellent at 168 hours. Moreover, the heat resistance temperature was 900 degreeC.

Claims (3)

delete delete Agent for preparing solution 1-3 by adding 25 to 35% by weight of isopropyl alcohol to 40 to 45% by weight of alumina sol 5 to 7 parts by weight and 35 to 38 parts by weight of methoxysilane Step 1;
A second step of preparing a solution 1-4 by stirring for 20 to 30 minutes while dropping 0.5 to 3.5% by weight of tetraethyl silicate (TEOS) to the solution 1-3;
A third step of preparing a solution 1-5 by dropwise adding 1-2% by weight of acetic acid or formic acid to the solution 1-4;
A fourth step of preparing a second solution by mixing 10 to 15% by weight of colloidal silica with 8 to 15% by weight of distilled water;
Add part 2 to solution 1-5 and react with exothermic reaction. Add 2 solution is white at the initial stage of stirring, but when it becomes transparent by stirring for 3 to 4 minutes, add additional solution 2 for 3 to 4 minutes A fifth step of repeatedly adding and stirring in such a manner as to further add 2 liquids when the mixture becomes transparent by stirring;
A sixth step of aging by stirring for an additional 1 to 3 hours after completion of the addition of the second liquid in the fifth step; And
A method of manufacturing an inorganic non-flammable ceramic binder capable of long-term preservation in which the seventh step of further aging for a day without stirring in a separate container after the sixth step is sequentially performed.