KR20150142529A - Inorganic particles rising on the surface of water and preparing method the same - Google Patents

Abstract

Provided is a floating inorganic particle which is produced by coating an inorganic particle with a hydrophobizing coating agent, wherein the specific gravity of the inorganic particle is 0.2-3.7 and the average particle diameter of the particle is 0.05-3.5 mm. In addition, provided is a method for producing the floating inorganic particle, which comprises the following steps: providing the hydrophobizing coating agent mixed with a silane compound and water; coating the inorganic particle by adding the hydrophobizing coating agent into the inorganic particle; drying moisture at 60-90°C after the coating is completed; and grinding and distributing the dried and coated inorganic particles. The floating inorganic particle of the present invention floats on a surface of a slurried mixture and offers hydrophobicity at the surface.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an inorganic particle,

FIELD OF THE INVENTION The present invention relates to floating inorganic particles and a method for producing the same.

Conventional inorganic matrix building materials, including artificial stones, concrete blocks and fiber-reinforced concrete boards, can suffer from efflorescence and freezing and thawing, which are generally known to be associated with water absorption through building materials. For example, moisture infiltration into a naturally permeable stone substrate can cause such material to expand, crack, and ultimately degrade the structure of the building material. Moisture also greatly increases microbial penetration and attack, often resulting in unsightly discoloration. Masonry materials based on inorganic binders can cause the same type of degradation due to freezing / thawing conditions, leading to a phenomenon known as spalling and cracking.

Thus, the susceptibility of the material to moisture absorption often results in low resistance to damage by water, high moisture penetration, high moisture transfer, and / or low resistance to freeze thawing. Prevention or reduction of moisture absorption into building materials has been an important aspect of the art.

In the art, it is known to apply a hydrophobic agent to the surface of building materials to impart hydrophobicity, wherein hydrophobic agents are often delivered as a solution, emulsion, or dispersion, and coated or sealed, As shown in Fig. The solvent or liquid phase may be water, an organic liquid, or a mixture thereof. From an environmental point of view, water is preferred as a solvent or a continuous phase to avoid VOC emissions.

In masonry operations such as rocks, concrete blocks, bricks and the like, water travels not only horizontally from the side of the structure but also vertically from adjacent mortars, rocks, bricks, and the like. Thus, hydrophobizing the surface after construction only limits the inflow of water from the outer surface. Water moving in the vertical direction may still enter the masonry and cause damage to wind, freezing, thawing, and the like. However, if all aspects of building materials are hydrophobic prior to construction, hydrophobic coatings can prevent the application of mortar, or subsequent application of plaster, render, stucco, etc.

On the other hand, Patent Document 1 discloses a building material in which an additive such as a silicone resin, an auxiliary hydrophobicizing agent, or wax is added to an artificial stone, artificial sheet or the like and then mixed with the hydrophobic silicone resin through a rolling process. In order to hydrophobize finished articles such as artificial stones, the above-mentioned patent discloses the hydrophobicity of the silane-based hydrophobing agent through physical mixing in powder or fine particulate form by resinizing with an additive such as an auxiliary hydrophobic agent, wax or the like.

However, the above-mentioned patent requires an additive such as an auxiliary hydrophobic agent and wax, and the manufacturing process is complicated by using a silane-based hydrophobic agent as a resin or a powder or a fine particle form, and since the hydrophobic treatment is performed through physical mixing with artificial stone or the like, It tends to fall.

Patent Document 1: Korean Patent Publication No. 2010-0134106

Thus, the present inventors have found that when inorganic particles themselves used for various purposes in various industrial fields are hydrophobized, they float in water, and the present invention has been completed on this basis.

Accordingly, one aspect of the present invention is to provide inorganic particles that float in water.

Another aspect of the present invention is to provide a method for producing the inorganic particles.

[One]. In order to achieve the above-described aspects, the floating inorganic particles according to the present invention can be obtained by coating inorganic particles having a specific gravity of 0.2 to 3.7 and an average particle diameter of 0.05 to 3.5 mm with a hydrophobic coating agent.

[2]. In the above-mentioned [1], the floating inorganic particles may be coated with 75 to 95% by weight of the inorganic particles with 5 to 25% by weight of the hydrophobic coating agent.

[3]. In the above-mentioned [1], the inorganic particles may be selected from the group consisting of an oxide mineral, a hydroxide mineral, and a silicate mineral.

[4]. In the above-mentioned [1], the hydrophobic coating agent may be a mixed solution of a silane compound and water.

[5]. Wherein the silane compound is at least one selected from the group consisting of hexamethyldisilane, ethyltriethoxysilane, triethylethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methoxytrimethylsilane, trimethylchlorosilane, and Triethylchlorosilane, and triethylchlorosilane.

[6]. Another aspect of the present invention is to provide a hydrophobic coating agent obtained by mixing a silane compound and water, adding the hydrophobic coating agent to inorganic particles and coating the same, Drying the water at a temperature of 90 DEG C, and crushing and classifying the dried and coated inorganic particles.

[7]. In the above step [6], the coating step is a step of coating 5 to 25% by weight of the hydrophobic coating agent on 75 to 95% by weight of the inorganic particles.

[8]. In the above-mentioned [6], the inorganic particles may be selected from the group consisting of an oxide mineral, a hydroxide mineral, and a silicate mineral.

[9]. In the above-mentioned [6], the hydrophobic coating agent may be a mixed solution obtained by mixing a silane compound and water in a ratio of 1: 1 to 1: 3 in the presence of an acid catalyst.

[10]. In the above-mentioned [9], the silane compound may be at least one selected from the group consisting of hexamethyldisilane, ethyltriethoxysilane, triethylethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methoxytrimethylsilane, And triethylchlorosilane.

[11]. In the above-mentioned [6], the inorganic particles may have a specific gravity of 0.2 to 3.7 and an average particle diameter of 0.05 to 3.5 mm.

The floating inorganic particles of the present invention float from the mixture in the slurry state to the surface and have the effect of imparting hydrophobicity to the surface. In addition, when the floating inorganic particles are used as building materials, it is possible to protect against damage due to weathering, freezing and thawing which are known to be related to water absorption.

In particular, when mixed with a curing type building material, the watertightness of the material itself is increased through the floating inorganic particles, thereby effectively preventing water absorption from the outside, thereby preventing moisture absorption. As a result, damage to durability, freezing / thawing, neutralization and the like associated with moisture absorption can be effectively suppressed.

FIGS. 1A and 1B are photographs showing the presence of two floating silica sand particles prepared according to Example 1 of the present invention in water, and confirming whether or not they are floating. FIG.
FIG. 2 is a photograph showing the appearance of the floating loess soil prepared in Example 2 by adding it to water; FIG.
FIG. 3 is a photograph showing flotation of flotation aluminum oxide (Al ₂ O ₃ ) prepared according to Example 3 of the present invention by adding it to water;
FIG. 4 is a photograph of floating calcium carbonate (CaCO ₃ ) prepared according to Example 4 of the present invention by adding it to water to check whether it is floated;
FIG. 5 is a photograph showing the floating state of magnesium oxide (MgO) prepared according to Example 5 of the present invention by adding it to water; FIG.
6A and 6B are photographs showing that the inorganic particles prepared according to Comparative Example 1 were added to water and their injuries were confirmed
7 is a schematic view showing a process for producing the floating inorganic particles of the present invention.

Before describing the invention in more detail, it is to be understood that the words or words used in the specification and claims are not to be construed in a conventional or dictionary sense, It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the constitution of the embodiments described in the present specification is merely a preferred example of the present invention, and does not represent all the technical ideas of the present invention, so that various equivalents and variations And the like.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The present invention provides an inorganic particle floating in water by hydrophobic coating an inorganic component (inorganic particle) constituting the inorganic mineral and the inorganic mineral, and a method of producing the inorganic particle. The mineral may be at least one selected from an oxide mineral, a hydroxide mineral, and / or a silicate mineral, and may include all the minerals contained in each mineral and inorganic components constituting each mineral. Further, the inorganic particles have an average particle diameter of 0.05 to 3.5 mm, and particles having a specific gravity of 0.2 to 3.7 can float. The inorganic particles may be coated with 5 to 25% by weight of a hydrophobic coating solution prepared from a silane compound on the basis of 100% by weight of the inorganic particles to prepare inorganic particles floating in water after the heat treatment. As far as the Applicant knows to date, there is no example in which the inorganic particles themselves are hydrophobized for the purpose of floating in water.

According to the present invention, the inorganic particles can be hydrophobicized by physical and chemical methods. That is, the physical method is simple mixing of the inorganic particles in the process of drying the hydrolyzed silane compound or as a single body among the particles. The chemical reaction forms a hydrophobic terminal through a chemical reaction between the OH functional group on the particle surface and the hydrolyzed silane compound. These physicochemical reactions occur at the same time and exhibit the property of floating in water with excellent hydrophobicity.

Inorganic minerals used as main materials in the present invention include oxide minerals composed of compounds in which various kinds of metal elements are bonded to oxygen, hydroxide minerals which are partially or totally substituted with hydroxyl groups (OH-) instead of oxygen, (Si ₂ O ₃ ) bonded with Si-O tetrahedra (SiO ₂ ), which make up more than 90% of the crust and upper mantle, and can contain many silicate minerals in abundance and abundance. It covers all the minerals included in each range of minerals and the inorganic components that make up each mineral. The inorganic particles preferably have a specific gravity of 0.2 to 3.7 and an average particle diameter of 0.05 to 3.5 mm. If the specific gravity is less than 0.2, the yield may be reduced during crushing and sieving (classifying). If the specific gravity is more than 3.7, the particles have hydrophobicity on the surface of the particles, but they tend to sink into water due to high specific gravity. When the average particle diameter of the inorganic particles is less than 0.05 mm, the yield of the fracture after the hydrophobic coating decreases, resulting in a time-consuming and economical consumption. On the other hand, when the average particle diameter exceeds 3.5 mm, That is, the area of the surface of the uncoated particles increases, and the hydrophobicity may be deteriorated.

According to the present invention, the hydrophobic coating agent to be mixed together with the inorganic particles may be coated with from 5 to 25% by weight to 75 to 95% by weight of the inorganic particles. If the amount of the hydrophobic coating agent is less than 5% by weight, uniform mixing with the target inorganic particles is difficult, and the hydrophobic coating as a whole may not be achieved. In addition, only a partial coating may be formed, resulting in no floating in the water. On the other hand, when the amount exceeds 25% by weight, a large amount of coating liquid is lost due to the mixing of a large amount of coating liquid, and a lot of coating liquids are mixed with each other during drying after mixing to cause hardening like stones.

The hydrophobic coating agent may be a mixed solution obtained by mixing a silane compound and water in a weight ratio of 1: 1 to 1: 3 in the presence of an acid catalyst such as hydrochloric acid, sulfuric acid or nitric acid. If the mixing ratio of water is less than 1, the hydrolysis of the silane does not proceed smoothly, so that it is difficult to impart hydrophobic properties to the inorganic particles due to difficulty in forming OH functional groups and hydrophobic terminals on the surface of the particles. When the mixing ratio exceeds 3, It is necessary to use a hydrophobic coating agent in an amount more than the required amount to use, which may cause economic loss.

On the other hand, the silane compound can be represented, for example, by the formula R ¹ _{4 -n} -SiXn wherein n is 1 to 3, R is alkyl or aromatic, heteroaromatic, or hydrogen, X is a halogen element Or an alkoxy group (OR, R may be alkyl or aromatic, heteroaromatic). Specific examples of such silane compounds include hexamethyldisilane, ethyltriethoxysilane, triethylethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methoxytrimethylsilane, trimethylchlorosilane, and triethylchlorosilane , But is not limited thereto.

As the silane compound, a disiloxane may also be used, and its formula is R ₃ Si-O-SiR ₃ . Here, the group R may be the same or different, alkyl, aromatic, heteroaromatic, or hydrogen.

On the other hand, Fig. 7 is a process drawing showing the method for producing the floating inorganic particles of the present invention.

The method for preparing floating inorganic particles according to the present invention comprises the steps of providing a hydrophobic coating agent obtained by mixing a silane compound and water, and adding the hydrophobic coating agent to inorganic particles and coating the coating. Drying and pulverizing and classifying the dried and coated inorganic particles.

According to the present invention, the hydrophobic coating agent prepared by the above-mentioned method can be coated with 5 to 25% by weight of the selected inorganic particles and stirred to achieve uniform mixing. When uniform mixing is achieved, the mixture is dried at a temperature of 60 to 90 ° C, preferably 70 to 85 ° C to remove all of the water, and crushed and classified by a well-known method known to those skilled in the art, Can be produced. If the temperature is less than 60 ° C, the time required for drying increases and the moisture of the coating liquid may remain, which may lower the hydrophobicity of the inorganic particles. If the temperature exceeds 90 ° C, There is a high possibility that the terminal is broken, so that it may tend to sink or hydrophobicity when put into water after crushing.

As described above, in the present invention, the inorganic particles are hydrophobized through the hydrophobic coating liquid, so that the hydrophobic material in the particulate or powder form can penetrate all the corners of the inorganic particles, which can not be hydrophobicized, to impart the hydrophobicity as much as possible. In addition, from the viewpoint of uniform dispersion, the solution has advantages that are convenient to use, unlike particles and powders.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the scope of the present invention is not limited to the following examples.

Production Example 1

Manufacture of hydrophobic coating agent

1 to 2 drops of hydrochloric acid (35%) were added to the mixed solution at a ratio of 1: 1 of MTMS (methyltrimethoxysilane), which is not mixed with each other, at pH 2 to 4 to prepare a transparent one-component solution . During mixing, the exothermic reaction causes the mixed solution to generate heat and produce methanol (CH ₃ OH). Then, it was allowed to cool to complete the hydrophobic coating agent. Hydrophobic MTMS, methanol, and unreacted water are present in the hydrophobic coating thus prepared. The mixing reaction of MTMS and water is shown in the following reaction formula (1).

[Reaction Scheme 1]

Production Example 2

Manufacture of hydrophobic coating agent

Add 1 to 2 drops of hydrochloric acid (35%) to the mixed solution at a ratio of 1: 3 of MTMS (methyltrimethoxysilane) and water at a ratio of 1: 3 to prepare a transparent one-component solution Respectively. Upon mixing, the exothermic reaction causes the mixed solution to generate heat and produce methanol (CH ₃ OH). Then, it was allowed to cool to complete the hydrophobic coating agent. Hydrophobic MTMS, methanol, and unreacted water are present in the hydrophobic coating thus prepared.

Example 1

(Silica sand No. 6) having an average specific gravity of about 2.5 to 2.8 and an average particle diameter of about 0.35 to 0.7 mm and quartz stone (silica sand SP) having a particle diameter of 0.05 mm were subjected to the hydrophobic treatment And about 15% by weight of a coating agent were added, and the mixture was homogeneously mixed, followed by drying in a dryer at about 85 캜 for 2 hours. The dried silica sand was crushed and sieved to obtain silica sand.

The injured silica prepared according to Example 1 of the present invention was added to water to confirm whether or not it was floated. The results are shown in Figs. 1A and 1B. It was confirmed that all the floating inorganic particles manufactured using the silica sand No. 6 and silica sand SP were floated in water.

Example 2

20% by weight of the hydrophobic coating material prepared in Preparation Example 2 was added to the red loess particles having an average specific gravity of about 2.7 to 2.8 and an average particle diameter of about 0.074 mm and uniformly mixed. Lt; / RTI > The dried loess was crushed and sieved to obtain floating loess. The results are shown in Fig. 2, and it was confirmed that the floating yellow loess also floated in water.

Example 3

Aluminum oxide (Al ₂ O ₃ ) having an average specific gravity of about 3.7 and an average particle diameter of about 0.6 mm was added to 10% by weight of the hydrophobic coating agent prepared in Preparation Example 1 and uniformly mixed. Lt; / RTI > for 2 hours. The dried aluminum oxide was crushed and sieved to obtain floating aluminum oxide. The results are shown in Fig. 3, and it was confirmed that the floating aluminum oxide floats on the water.

Example 4

Calcium carbonate (CaCO ₃ ) having an average specific gravity of about 2.93 and an average particle diameter of about 0.074 mm was added to 20 wt% of the hydrophobic coating agent prepared in Preparation Example 2 and uniformly mixed. Lt; / RTI > for 2 hours. The dried calcium carbonate was crushed and sieved to obtain floating calcium carbonate. The results are shown in Fig. 4, and it was confirmed that the calcium carbonate also floated in water.

Example 5

20% by weight of the hydrophobic coating agent prepared in Preparation Example 2 was added to magnesium oxide (MgO) having an average specific gravity of about 3.2 to 3.7 and an average particle diameter of about 0.05 mm and uniformly mixed. And dried in a dryer for 2 hours. The dried magnesium oxide was crushed and sieved to obtain a floating magnesium oxide. The results are shown in Fig. 5, and it was confirmed that the floating magnesium oxide also floated in water.

Comparative Example 1

Aluminum oxide having a specific gravity of about 3.9 and sand having an average particle diameter of about 4 mm were added to 20% by weight of the hydrophobic coating agent prepared in Preparation Example 2 and uniformly mixed. Lt; / RTI > The dried aluminum oxide and sand were crushed and sieved. The results are shown in Figs. 6A (aluminum oxide) and 6b (sand). The aluminum oxide and the sand were hydrophobic, but the specific gravity was high and the particle diameter was large.

As has been confirmed in the above-mentioned Examples, the present invention produced floating inorganic particles by using constituent components constituting inorganic and inorganic minerals as a main material. As a result, it can be seen that water repellency and waterproofing are imparted by imparting hydrophobicity to inorganic particles and using them as additives.

While the present invention has been described in detail with reference to the preferred embodiments thereof, it should be understood that the present invention is not limited thereto. It will be apparent that modifications and improvements can be made by those skilled in the art.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (11)

Wherein the inorganic particles having a specific gravity of 0.2 to 3.7 and an average particle diameter of 0.05 to 3.5 mm are coated with a hydrophobic coating agent. The method according to claim 1,
Wherein the floating inorganic particles are coated with 75 to 95% by weight of inorganic particles and 5 to 25% by weight of a hydrophobic coating agent. The method according to claim 1,
Wherein the inorganic particles are at least one selected from the group consisting of oxide minerals, hydroxide minerals and silicate minerals. The method according to claim 1,
Wherein the hydrophobic coating agent is a mixed solution of a silane compound and water. The method of claim 4,
The silane compound may be at least one selected from the group consisting of hexamethyldisilane, ethyltriethoxysilane, triethylethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methoxytrimethylsilane, trimethylchlorosilane, and triethylchlorosilane At least one selected from the group consisting of inorganic particles. Providing a hydrophobic coating agent obtained by mixing a silane compound and water;
Adding and coating the hydrophobic coating agent to the inorganic particles;
Drying the water at a temperature of 60 to 90 DEG C when the coating is performed; And
And crushing and classifying the dried and egg-coated inorganic particles. The method of claim 6,
Wherein the coating step comprises coating 5 to 25% by weight of the hydrophobic coating agent on 75 to 95% by weight of the inorganic particles. The method of claim 6,
Wherein the inorganic particles are at least one selected from the group consisting of an oxide mineral, a hydroxide mineral, and a silicate mineral. The method of claim 6,
Wherein the hydrophobic coating agent is a mixed solution of a silane compound and water in a ratio of 1: 1 to 1: 3 in the presence of an acid catalyst. The method of claim 9,
The silane compound may be at least one selected from the group consisting of hexamethyldisilane, ethyltriethoxysilane, triethylethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, methoxytrimethylsilane, trimethylchlorosilane, and triethylchlorosilane ≪ / RTI > The method of claim 6,
Wherein the inorganic particles have a specific gravity of 0.2 to 3.7 and an average particle diameter of 0.05 to 3.5 mm.

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