KR102393955B1 - Eco-friendly Coating Composition for Radon Blocking Based on Aminoclay and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to an environmentally friendly radon blocking coating agent composition including aminoclay particles and a method for preparing the same. A coating agent composition of the present invention has excellent radon blocking capacity by bonding between aminoclay and an aqueous epoxy resin.

Description

Eco-friendly Coating Composition for Radon Blocking Based on Aminoclay and Manufacturing Method Thereof

The present invention relates to an amino clay-based coating composition for environmentally friendly radon shielding and a method for manufacturing the same.

Radon is a substance produced when about 70 natural radioactive substances found on Earth decay. The most common isotopes of radon are Rn-222 (radon gas) and Rn-220 (thoron gas). Radon is a gaseous substance that emits alpha rays that cause genetic polymorphisms related to DNA repair and oxidative stress. There is a bar. In particular, high levels of radon are likely to be present in all underground and above-ground structures and buildings, including basements, apartments, and multi-use facilities, and it is therefore necessary to periodically measure radon concentrations in these types of structures or buildings. In particular, in the current situation where cement concrete house structures are the mainstream, radon is emitted from building aggregates, building materials, or cement concrete, and radon emitted from the ground or building materials increases to a high concentration inside buildings with poor ventilation. . Chen et al. (2015), in a survey of more than 4000 households in 33 Canadian cities, the average radon concentration in all households was 2.59 pCi/L (or 96 Bq/m ³ ), and the highest concentration was 57.21 pCi/L ( or 2117 Bq/m ³ ). Therefore, there is a need for a method capable of reducing indoor radon concentration.

In Korea, too, the concentration of radon in indoor air quality has been set at 4 pCi/L as a management standard based on the "Indoor Air Quality Control Act in Multi-Use Facilities, etc." As a result of measuring the radon gas concentration in the air, 3.4% said that it exceeded the indoor air quality standard of the Ministry of Environment. In addition, as measured by the Air Pollution Lab (Professor Dong-Sul Kim's team) at Kyunghee University, 44 subway platforms and waiting rooms in Seoul were measured, 5 of the platforms and 4 of the waiting rooms exceeded the standard. Therefore, radon reduction construction based on the radon emission rate is required only when the radon concentration is measured high.

As for the method of reducing radon indoors currently used in Korea, in order to prevent radon gas from entering through the gap of a building, a method of blocking the gap as a sealing agent or frequently ventilating it, or radon gas that is inhaled attached to dust is used as a radon progeny. There are ways to reduce it with an air purifier with high removal efficiency. However, the above methods do not have a high radon reduction rate or excessive economic loss is expected.

Accordingly, a method for reducing radon emission by applying a coating agent to building materials has been proposed as a radon reduction method. Conventional epoxy resins used as coatings on the walls of buildings, etc. are preferred coatings due to their characteristics such as corrosion resistance, excellent bonding strength, and resilience at room temperature. It has a limit due to the number of coatings. In order to overcome this limitation, inorganic particles such as SiO ₂ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , CaCO ₃ , and ZnO are added to an epoxy resin, and the stiffness and strength of the coating agent using the interfacial bond between the inorganic particles and the epoxy resin It has been reported that the concentration of radon emitted from building materials such as cement and gypsum board can be decreased through the radon absorption capacity of the zeolite by increasing the zeolite or adding zeolite to the epoxy resin. However, it was found that when the zeolite concentration in the epoxy resin coating agent was very high as 40 wt%, the radon concentration reduction rate was only about 45%.

One technical problem to be achieved by the present invention is to provide an eco-friendly coating composition for radon shielding.

Another technical problem to be achieved by the present invention is to provide a method for manufacturing an environmentally friendly radon shielding coating composition.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

As a technical means for achieving the above-described technical problem, one aspect of the present invention is,

a silane compound in which at least one amine-containing group and at least one hydrolysable group are bonded to a silicon atom; and aminoclay particles derived by dissolving a metal precursor in a solvent; and an aqueous epoxy resin; it provides a coating composition for shielding radon, including.

The amino clay particles may be dispersed in the composition in a delaminated structure when mixed in an aqueous epoxy resin.

The amine-containing group represents -(CH ₂ ) _n NR ¹ R ² , where n is an integer from 0 to 10, and R ¹ and R ² are each independently hydrogen, C _1-10 alkyl, C _2-10 al kenyl, C _2-10 alkynyl, C _6-17 aryl, C _3-17 cycloalkyl, C _1-10 acyl, or R ³ NH ₂ , and R ³ may represent C _1-6 alkylene.

The silane compound is 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyl Dimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (N-[3-(Trimethoxysilyl)propyl]ethylenediamine; DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldime Toxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, Diethylenetriaminopropylmethyldimethoxysilane, diethyleneaminomethylmethyldiethoxysilane, (N-phenylamino)methyltrimethoxysilane, (N-phenylamino)methyltriethoxysilane, (N-phenylamino)methyl Methyldimethoxysilane, (N-phenylamino)methylmethyldiethoxysilane, 3-(N-phenylamino)propyltrimethoxysilane, 3-(N-phenylamino)propyltriethoxysilane, 3-(N- Phenylamino)propylmethyldimethoxysilane, 3-(N-phenylamino)propylmethyldiethoxysilane, and N-(N-butyl)-3-aminopropyltrimethoxysilane, bis[(3-triethoxysilyl) ) may be at least one selected from the group consisting of propyl]amine and bis[(3-trimethoxysilyl)propyl]amine.

The metal precursor is selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Cu ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Al ³⁺ , Fe ³⁺ , and Ce ³⁺ . It may be to provide any one or more metal cations.

The aqueous epoxy resin may be selected from monomeric epoxy resins, polymeric epoxy resins, or mixtures thereof.

The aqueous epoxy resin may be a glycidyl ether of one or more phenols selected from the group consisting of substituted or unsubstituted phenol, bisphenol A, and bisphenol F.

The solvent includes at least one polar solvent, and the polar solvent may be selected from the group consisting of methanol, ethanol, propanol and isopropanol.

The composition may further include a curing agent.

The aminoclay particles include two silicate tetrahedral sheets; and a metal octahedral sheet inserted between the two silicate tetrahedral sheets, wherein an amine-containing group is connected to the silicon of the silicate tetrahedral sheet, and an aqueous epoxy resin is bonded to the nitrogen of the amine-containing group.

The aminoclay particle may be a talc group without a layer charge.

The aminoclay particles may have a unit cell formula of R ₈ Si ₈ M _X O ₁₆ (OH) ₄ , wherein R is an amine-containing group, and x may be 12/(positive charge of M).

The amino clay particles may be characterized in that it is water-soluble.

Another aspect of the present invention is

(a) a metal precursor; is dissolved in a solvent, and (b) a silane compound having at least one amine-containing group and at least one hydrolyzable group bonded to a silicon atom is added to the solution to induce aminoclay particles to do; and (c) adding the amino clay particles to an aqueous epoxy resin.

In the radon shielding coating composition disclosed herein, amino clay particles formed by a silane compound and a metal precursor are exfoliated by an aqueous epoxy resin to form a low volatile organic compound with a size of 200 nm or less. Also, the bonding between the amine-containing group of the amino clay particles and the aqueous epoxy resin increases the crosslinking density of the coating agent, so that even with a low concentration of amino clay particles, more improved radon shielding performance can be obtained.

In addition, since the amino clay particles of the present invention and the water-based epoxy resin form a cross-linkage, they form a denser coating film than conventional coating agents, so it is possible to provide a coating film strong against corrosion or chemical change, as well as high waterproofing ability and thermal stability. can have

In addition, in the aminoclay particles of the present invention, various metal cations can form a metal octahedral layer of aminoclay. Depending on the type of the metal cation, effects such as antibacterial activity, color imparting, and transparency increase can be exhibited.

In addition, by using a water-based epoxy resin, due to the above-described effect, there is almost no harm to the human body and more environmentally friendly compared to coating agents based on conventional volatile organic compounds (VOCs) and organic solvents. It can provide convenience.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic diagram showing that aminoclay is converted into an intercalated form and an exfoliated form depending on the solvent.
2 is a schematic diagram showing the three-dimensional structure of amino clay.
3 is a schematic diagram showing the bonding reaction between amino clay and an aqueous epoxy resin.
4 is a schematic diagram showing the radon emission pathway of pure epoxy resin and MgAC/aqueous epoxy resin composite.
5 is a cement brick coated with a coating composition for shielding radon according to an embodiment of the present invention.
6 is an image showing the measurement of radon emission of cement bricks on a lab scale according to an embodiment of the present invention.
7 to 10 are results of measuring the radon shielding rate of the radon shielding coating composition according to an embodiment of the present invention.
11 is a result of measuring the radon shielding rate of the coating composition according to Comparative Example 1.
12 is a result of measuring the radon shielding rate of the coating composition according to Comparative Example 2.
13 is a result of measuring the radon shielding rate of the coating composition according to Comparative Example 3.
14 and 15 are results of measuring the radon shielding rate of the coating composition according to Comparative Examples 4 and 5.
16 to 20 are results of measuring the radon shielding rate of the coating composition according to Comparative Examples 6 to 10.
21 is an image showing measuring the radon shielding rate in a sheet according to an embodiment of the present invention.
22 is a result of measuring the amount of radon emission of a sheet coated according to an embodiment and a comparative example of the present invention.
23 shows the process of measuring the radon emission amount of the cement floor of the real scale (real field scale) coated according to an embodiment of the present invention.
24 is a microscopic view of the surface of a coating agent according to an embodiment and a comparative example of the present invention.
25 is a result of measuring the surface of a coating agent according to a comparative example and an embodiment of the present invention with a scanning electron microscope (SEM).
26 is a result of measuring a cross section of a coating agent according to a comparative example and an embodiment of the present invention with a scanning electron microscope (SEM).
27 is a result of measuring the surface of a coating agent according to a comparative example and an embodiment of the present invention with an integrated ion beam scanning electron microscope (FIB-SEM).
28 is a result of measuring energy dispersive X-ray spectroscopy (EDAX) of the surface of a coating agent according to a comparative example and an embodiment of the present invention.
29 is an X-ray powder diffraction (XRD) analysis result of a coating agent and MgAC according to an embodiment and a comparative example of the present invention.
30 is a low-angle X-ray powder diffraction (XRD) analysis result of a coating agent according to a comparative example and an embodiment of the present invention.
31 is a Fourier transform infrared (FTIR) spectroscopic analysis result before drying of the coating agent and MgAC according to an embodiment and a comparative example of the present invention.
32 is a Fourier transform infrared (FTIR) spectroscopic analysis result after drying of the coating agent according to a comparative example and an embodiment of the present invention.
33 is an X-ray photoelectron spectroscopy (XPS) analysis result of a coating agent according to a comparative example and an embodiment of the present invention.
34 is a thermal mass analysis (TGA) and derivative thermogravimetric analysis (DTG) results of a coating agent according to a comparative example and an embodiment of the present invention.
35 is a result of measuring the thermal decomposition activation energy (E _a ) of a coating agent according to a comparative example and an embodiment of the present invention.
36 is a result of measuring the contact angle (contact angle) of a coating agent according to a comparative example and an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be “connected (connected, contacted, coupled)” with another part, it is not only “directly connected” but also “indirectly connected” with another member interposed therebetween. "Including cases where In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless the context clearly indicates otherwise in this specification, "shielding rate" may mean 'radon shielding rate', and the term "reduction rate" refers to 'radon concentration reduction rate' unless the context clearly indicates otherwise. can be understood including

One aspect of the present invention is

a silane compound in which at least one amine-containing group and at least one hydrolysable group are bonded to a silicon atom; and aminoclay particles derived by dissolving a metal precursor in a solvent; and an aqueous epoxy resin; it provides a coating composition for shielding radon, including.

The silane compound may react with a metal cation provided by the metal precursor to form a silicate tetrahedron to form a nanoclay structure. The amine-containing group of the silane compound is present on the surface of the amino clay, and an oxirane group of the aqueous epoxy resin reacts thereto to be bonded thereto.

According to the exemplary embodiment of the present application, the amine-containing group may be represented by -(CH ₂ ) _n NR ¹ R ² . wherein n is an integer from 0 to 10, R ¹ and R ² are each independently hydrogen, C _1-10 alkyl, C _2-10 alkenyl, C _2-10 alkynyl, C _6-17 aryl, C ₃ It may represent _-17 cycloalkyl, C _1-10 acyl, or R ³ NH ₂ , and R ³ may represent C _1-6 alkylene.

According to one embodiment of the present application, the silane compound may be one in which two or more silicon atoms having at least one hydrolyzable group are bonded to one amine-containing group. In this case, the silane compound is (X ¹ ) _m (Y ¹ ) _3-m Si - Z ¹ -N - Z ² - Si (X ² ) _q (Y ² ) _3-q (wherein X ¹ and X ² is an alkoxy group containing 1 to 6 carbons, Y ¹ and Y ² are alkyl groups containing 1 to 8 carbons, Z ¹ and Z ² are alkylene groups having 1 to 12 carbons, m and q is independently 1, 2 or 3).

The said hydrolysable group means the group which gives a hydroxyl group (silanol group) by hydrolysis. The hydrolyzable group of the present invention includes, for example, an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group; hydroxyl group; acetoxy group; chlorine atom; isocyanate group; etc. are mentioned preferably. Among them, a C _1-4 alkoxy group is preferable, and a C _1-2 alkoxy group may be more preferable.

According to one embodiment of the present application, in the silane compound, the number of hydrolyzable groups bonded to the central silicon atom is usually 1 or more, preferably 2 or more, and usually 3 or less.

According to one embodiment of the present application, the silane compound is 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), 3-aminopropylmethyldie Toxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (N-[3-(Trimethoxysilyl)propyl]ethylenediamine; DAS), aminoethylaminopropyltriethoxy Silane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylene Triaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethyleneaminomethylmethyldiethoxysilane, (N-phenylamino)methyltrimethoxysilane, (N-phenylamino)methyltriethoxysilane , (N-phenylamino)methylmethyldimethoxysilane, (N-phenylamino)methylmethyldiethoxysilane, 3-(N-phenylamino)propyltrimethoxysilane, 3-(N-phenylamino)propyltrie Toxysilane, 3-(N-phenylamino)propylmethyldimethoxysilane, 3-(N-phenylamino)propylmethyldiethoxysilane, and N-(N-butyl)-3-aminopropyltrimethoxysilane, bis It may be at least one selected from the group consisting of [(3-triethoxysilyl)propyl]amine and bis[(3-trimethoxysilyl)propyl]amine.

The metal precursor refers to a material providing a metal cation constituting the amino clay of the present invention. The metal cation of the present invention is the central metal of a metal octahedral sheet, such as Mg ²⁺ , Ca ²⁺ , Cu ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Al ³⁺ , Fe ³⁺ , and Ce ³ . It may be any one or more selected from the group consisting of ⁺ . preferably Mg ²⁺ or It may be Cu ²⁺ , more preferably Mg ²⁺ .

The metal precursor of the present invention may also be a salt in which a counter ion to the metal cation is an anion. The anion may be, for example, Cl ⁻ or NO ₃ ⁻ .

According to a non-limiting embodiment of the present invention, the metal precursor is MgCl ₂ , AlCl ₃ , FeCl ₃ , CuCl ₂ , ZnCl ₂ , or Zn(NO ₃ ) ₂ It may be. Preferably, the metal precursor may be MgCl ₂ or CuCl ₂ . According to another embodiment of the present application, one or more metal precursors may be used in the coating composition of the present invention.

According to one embodiment of the present application, the solvent includes at least one polar solvent, and the polar solvent may be selected from the group consisting of methanol, ethanol, propanol and isopropanol. Preferably, it may be any one or more selected from ethanol and isopropanol.

According to one embodiment of the present application, the metal cation forms a metal octahedral sheet in the aminoclay structure. A metal octahedral sheet can be formed irrespective of the type of metal cation, but the finally formed coating film may exhibit an incidental effect depending on the type of metal cation. For example, when Cu ²⁺ is used, the antibacterial activity of the coating film can be further increased, and when Al ³⁺ is used, amino clay having a high density can be produced, thereby exhibiting the shielding effect of the high-density coating. In addition, non-toxicity can be expected when Mg ²⁺ and Ca ²⁺ are used. On the other hand, when Al ³⁺ , Mg ²⁺ , and Ca ²⁺ are used, a transparent coating may be formed, and when Cu ²⁺ is used, a transparent coating may also be formed, but when the concentration is deep, a light green color is obtained. It may be In addition, it is another advantage of the present invention that the coating film can exhibit the intrinsic properties of cations. In addition, when two or more metal cations are included, a combined effect may be exhibited.

In the radon shielding coating agent according to an embodiment of the present application, the amino clay particles formed by the silane compound and the metal precursor can be completely exfoliated in the aqueous epoxy resin, so that low volatile organic compounds (low volatile organic compounds; low -VOCs) and bonding between the amine-containing group of the aminoclay particles and the aqueous epoxy resin removes structural defects and improves crosslinking density, so that even with a low concentration of aminoclay particles, the radon shielding performance can be further improved. 1, the amino clay of the present invention is characterized in that it is easily converted into an intercalated form in a low-polarity solvent such as ethanol and an exfoliated form in an aqueous solution containing water. . Conventional nanoclays such as Cloisite Na ⁺ and nanomaterials such as ZnO and CaCO ₃ may have structural defects and changes in properties due to incompatibility with a matrix made of organic compounds without additional surface treatment, and the nanoclay and When a filler such as a nanomaterial is not completely delaminated in the substrate, the intercalation and agglomeration of the filler may limit the properties and properties of blocking gas molecules. However, the amino clay particles according to the present invention can be completely delaminated in the aqueous epoxy resin, so that even if they are contained in a low concentration due to the above-described effect, they can have high radon shielding rate characteristics. The radon shielding coating agent according to an embodiment of the present invention exhibits a radon shielding rate of 80% or more when coated once on a coating member, and exhibits a radon shielding rate of 99% or more when applied twice or more repeatedly. The upper limit of the radon shielding rate is not particularly limited, but may be 100% or less. Through this, it can be seen that when zeolite is included in a high concentration (40 wt%) as a nanomaterial filler in the conventional epoxy resin coating agent, it has a much higher radon shielding rate than that showing a radon shielding rate of 45% or less.

Aminoclay according to an embodiment of the present invention has a characteristic of a large aspect ratio like conventional 2D nanomaterials such as graphene oxide and zeolite, and has the effect of maximizing the movement distance of molecules during diffusion of gas molecules to prevent diffusion and permeation. It is shown in the schematic diagram of FIG. As a result, it has radon shielding performance by suppressing diffusion and permeation of radon gas molecules. In addition, since an amine-containing group is already present in the particles in the step of inducing the above-mentioned amino clay particles, unlike conventional nanomaterials, it does not require a separate surface treatment step to increase the interfacial bonding with the epoxy material. The reaction with the resin may have an effect of increasing the crosslinking density.

According to an embodiment of the present application, the content of amino clay may be included in an amount of 0.5 to 1.0% by weight based on the aqueous epoxy resin. When the content of amino clay exceeds 1.0 wt %, amino clay remaining without reflection with the epoxy resin may occur, resulting in excessive viscosity increase and fast curing speed. In addition, when the content of amino clay is less than 0.5% by weight, the radon shielding rate may be reduced.

According to one embodiment of the present application, the content of the aqueous epoxy resin may be all except for the content of the amino clay particles based on the entire coating composition. Also, in another example, water may be further included in the mixing process of the amino clay particles and the aqueous epoxy resin, which is not limited as long as it is a user-friendly ratio known in the art.

The aqueous epoxy resin includes both a monomer epoxy resin and a polymer epoxy resin as a material having an oxirane group and polymerizable by ring opening. Epoxy resins are excellent in heat resistance, electrical insulation, adhesiveness, and the like. In particular, the oxirane group of the epoxy resin may be connected by reaction with the amine-containing group present on the surface of the aminoclay particle formed by the silane compound and the metal precursor. Accordingly, not only the strength of the amino clay-based coating film is increased, but also the adhesiveness is improved. In addition, the coating film may have a property of shielding the emission of radon.

The aqueous epoxy resin is not limited as long as it is a component commonly used to improve heat resistance and electrical insulation in the art, and may be used in the coating composition of the present invention. The aqueous epoxy resin of the present invention may be a monomeric epoxy resin, a polymeric epoxy resin, or a mixture thereof. Specifically, epoxy resins of types such as bisphenol A type, bisphenol F type, tetrabromo DPP type, novolak resin type, diamine type, diacid type, and diol type can be used. Specifically, the epoxy resin may be a glycidyl ether of one or more phenols selected from the group consisting of substituted or unsubstituted phenol, bisphenol A, and bisphenol F. Representative examples of the permissible substituent herein include a halogen, an ester group, an ether group, a sulfonate group, a siloxane group, a nitro group and a phosphate group. Preferred aqueous epoxy resins may be prepared according to the composition as exemplified in an embodiment of the present invention to be described later, and a commercially available aqueous epoxy resin may be used. As preferred examples, commercially available aqueous epoxy resins include p-tert-butylphenyl glycidyl ether; 2,2-bis[4-(2,3-epoxypropoxy)-phenyl)propane (diglycidyl ether of bisphenol A)] and Shell Chemical Co, Houston, TX. (Shell Chemical Co.) "EPON 828 (EPON 828)", "EPON 1004 (EPON 1004)" and "EPON 1001F (EPON 1001F)", and Dow Chemical Co., Midland, Michigan. (Dow Chemical Co.) under the trade names "DER-331", "DER-332" and "DER-334". Other suitable epoxy resins include the glycidyl ethers of phenol formaldehyde novolac, such as those available under the trade names "DEN-431" and "DEN-428" from Dow Chemicalco. According to one embodiment of the present application without limitation, the aqueous epoxy resin may be p-tert-butylphenyl glycidyl ether, and may be Araldite-M manufactured by career henan chemical co. In addition, the aqueous epoxy resin is 4,4'-(1-methylethylidene)bisphenol polymer and 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxymethylene)]bis It may be [oxirane], and it may be Epocoat Aqua of Samhwa Paint Industry Co., Ltd. or FREE ZON 200 of Donghae Chemical Industry Co., Ltd., but is not limited thereto.

In one embodiment of the present application, the coating composition may further include a curing agent. The curing agent added to the coating composition may be included in an amount of 40 to 100% by volume based on the content of the aqueous epoxy resin in the coating composition. The content of the curing agent in the coating composition may be adjusted according to the user's convenience, but it may be preferable to be included within the above content range in consideration of the viscosity, spreadability, curing rate, etc. of the coating composition.

The curing agent may be mixed with the coating composition comprising the amino clay particles and the aqueous epoxy resin to be used as a two-component coating composition, wherein the curing agent is preferably mixed 10 to 60 minutes before coating the coating composition. . The curing agent may be included without limitation as long as it is known in the art for curing aqueous epoxy resins, but preferably, the curing agent composition may include various modifications of a polyamine compound, specifically, a phenol-based compound, It may be a modified product modified by reaction with a bornyl compound, an epoxy compound, or an acrylic compound. Preferred examples include a composition containing a polyamine compound containing a primary to tertiary amine group in the molecule, a composition containing the polyamine compound and an epoxy compound, or an epoxy amine adduct modified by reacting the polyamine compound with an epoxy compound. It may be a composition comprising an amine adduct). More preferably, the polyamine compound may be a polyamine compound having two primary amine groups in the molecule. For example, the coating speed of the coating composition, the hardness and strength of the coating film, etc. can be controlled by a reaction in which the amine group included in the curing agent composition is condensed with the oxirane group included in the aqueous epoxy resin composition.

In another embodiment of the present application, the coating composition is a plasticizer, a defoamer, a matting agent, a preservative, an anti-corrosion agent, an adhesion promoter, a thickener, Any additive known in the art to improve the physical properties of the coating composition, such as a flame retardant, or to provide additional physical properties according to the user's convenience is not limited and may further include.

The aminoclay particles include two silicate tetrahedral sheets; and a metal octahedral sheet inserted between the two silicate tetrahedral sheets, wherein an amine-containing group is connected to the silicon of the silicate tetrahedral sheet, and an aqueous epoxy resin is bonded to the nitrogen of the amine-containing group.

The amino clay particles may refer to nano-sized clay in which organic ions are introduced into the clay layer. In addition, the amino clay particle may refer to one unit particle in which a metal octahedral sheet and a silicate tetrahedral sheet are connected.

According to one embodiment of the present application, the aminoclay particles include two silicate tetrahedral sheets; and a metal octahedral sheet interposed between the two silicate tetrahedral sheets, wherein an amine-containing group is bonded to the silicon of the silicate tetrahedral sheet. The amino clay particles may have a silicate tetrahedral sheet and a metal octahedral sheet in a ratio of 2:1. The description of the amine-containing group is the same as described above.

The silicate tetrahedral sheet is a structure in which silicon is coordinated by four Os, and three corners existing on one side of the tetrahedron form a two-dimensionally connected hexagonal ring and are combined in a plane to form a tetrahedral plate. In these hexagonal annular tetrahedral plates, the anions forming the three corners shared with other tetrahedra are called basal oxygen, and this plane is called the basal oxygen plane. However, in the present application, the above-described amine-containing group may be substituted for one of the three bottom oxygens of the tetrahedron. The other edge, which is not shared with the other tetrahedra, is called apical oxygen, and they are usually aligned in the same direction. The tetrahedral sheet is combined with the octahedral sheet, and the negative ion plane shared with the octahedral plate becomes the vertex oxygen side. The silicate clay of the laminate structure shown in FIG. 2 can improve the thermal properties, mechanical properties, barrier properties, flame retardancy and antibacterial properties of the epoxy material when added to the epoxy material.

The metal octahedral sheet is selected from the group consisting of one or more metal cations, such as Mg ²⁺ , Ca ²⁺ , Cu ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Al ³⁺ , Fe ³⁺ and Ce ³⁺ . Any one or more metal cations to be formed is a form in which 6 O or OH groups are octahedral. The octahedral plate can be thought of as two planes of closely packed oxygen ions, with positive ions occupying octahedral sites between the two planes.

On the other hand, clay minerals can be classified according to the size of the layer charge, and those without a layer charge per unit cell are classified as talc. According to one embodiment of the present application, the amino clay particles may be talc group-like clay particles having no layer charge. Specifically, the three-dimensional structure of the amino clay particles in FIG. 2 can be referred to, and the inside of the coating agent of the present invention is composed of clay particles to form a stable coating layer, and as shown in FIG. 3, the surface of the clay particles is The amine group forms a cross-link with the aqueous epoxy resin to form a dense layer, thereby shielding radon and having a waterproof ability. The aqueous aminoclay particles of the present invention may have a unit cell formula of R ₈ Si ₈ M _X O ₁₆ (OH) ₄ , R is an amine-containing group, and x is 12/(positive charge of M). Here, M means the aforementioned metal cation.

According to one embodiment of the present invention, the amino clay particles may be characterized in that it is water-soluble. According to the results of previous studies, it can be seen that aminoclay particles are more hydrophilic than PVP, and in particular, the surface made of MgAC/PVP composite shows super-hydrophilic properties. Due to the higher hydrophilicity of the surface of the amino clay particles, the reactivity between the amino clay particles and the aqueous epoxy resin may increase. As the mechanical properties of the coating film are improved due to cross-linking between the amino clay particles and the epoxy resin, moisture penetration becomes difficult. Therefore, it can have the same level or improved waterproofing ability as that of the conventional epoxy resin.

According to another embodiment of the present invention, the amine group remaining in the coating composition comprising the amino clay particles and the aqueous epoxy resin destabilizes the cell membrane of the microorganism, so that the composition may have antibacterial activity. In addition, the coating composition may further have an additional antibacterial activity due to the metal cation contained in the amino clay particles. Based on the results of previous studies known to exhibit antimicrobial activity through the mechanism in which metal ions penetrate bacteria or bacteria to destroy cell membranes and introduce active oxygen, it can be easily predicted that the coating composition containing the amino clay particles will also have high antibacterial activity. there is.

Another aspect of the present invention is

(a) a metal precursor; is dissolved in a solvent, and (b) a silane compound having at least one amine-containing group and at least one hydrolyzable group bonded to a silicon atom is added to the solution to induce aminoclay particles to do; and (c) adding the amino clay particles to an aqueous epoxy resin.

The radon shielding coating agent of the present invention prepared by the above manufacturing method has amino clay particles to which silicon, oxygen, and metal atoms are connected, and the coating film formed by coating the coating agent on the coating member can be used for radon shielding. The aqueous epoxy resin is cross-linked to the amine group present on the surface of the amino clay particle, thereby enhancing the strength of the coating film and exhibiting an excellent radon shielding effect.

Hereinafter, the manufacturing method will be described in detail.

(a) a silane compound, (b) a metal precursor, and (c) an aqueous epoxy resin of the present application may be dissolved in a solvent and mixed. In this case, the solvent may preferably be water. (a) silane compound, (b) metal precursor, and (c) aqueous epoxy resin may be simultaneously dissolved in one solvent, but after dissolving (a) silane compound and (b) precursor in a first solvent, amino clay ( For example, it may be MgAC) to induce a structure and (c) to dissolve by mixing an aqueous epoxy resin. The first solvent includes at least one polar solvent, and the polar solvent may be selected from methanol, ethanol, propanol and isopropanol. In the case of dissolving through the two processes as described above, after sufficiently forming the amino clay structure, it is possible to control the formation of an aqueous epoxy resin on the surface of the amino clay particles. In addition, aminoclay particles derived by dissolving and mixing (a) a silane compound and (b) a metal precursor in a solvent may be mixed with (c) an aqueous epoxy resin in the form of a dried powder. The coating composition prepared by the above three processes may exhibit an equivalent radon shielding effect. When a polar solvent with high water and hydrophilicity is used as described above, it may have characteristics that are harmless to the human body and environment-friendly due to low volatility, and may increase convenience during on-site construction.

The process of mixing aminoclay particles derived by dissolving and mixing (a) a silane compound and (b) a metal precursor in a solvent to (c) an aqueous epoxy resin in the form of a dried powder, more specifically, (a) Dissolving a metal precursor in a solvent, (b) adding at least one amine-containing group and at least one hydrolyzable group to a silicon atom of a silane compound to the solution to induce aminoclay particles; and (c) adding the aminoclay particles to the aqueous epoxy resin. In this case, the step of dissolving the metal precursor and the silane compound may be achieved by mixing the solvent and the solute followed by stirring, and the stirring is preferably performed for 6 hours or more. In this case, the solvent includes at least one polar solvent, and the polar solvent may be selected from the group consisting of methanol, ethanol, propanol and isopropanol. The induced amino clay particles may be obtained in the form of a powder by drying at 30 to 50° C., and a process of pulverizing the powder may be further included. In addition, the amino clay particles may be added to the aqueous epoxy resin and then stirred, and the stirring may be performed for 1 to 10 minutes.

According to an embodiment of the present application, the coating composition may further include a curing agent, wherein the curing agent may refer to the curing agent composition described above. After adding the curing agent, it may be stirred, and in this case, the stirring may be performed for 1 to 10 minutes. The coating composition of the present invention may be used as a two-component composition further comprising a curing agent, wherein the coating composition in which the curing agent is mixed is preferably coated within 10 to 60 minutes.

The coating composition of the present disclosure may be applied to a coating member and dried to be coated. The amino clay particles fill the fine space on the surface of the coating member, and as it dries, moisture evaporates and curing proceeds. In this case, the coating composition of the present invention may exhibit waterproofing ability by forming a dense coating film by crosslinking between the amino clay particles and the aqueous epoxy resin. In another example of the present invention, the coating composition of the present invention may exhibit antibacterial activity by metal cations contained in aminoclay particles.

According to one embodiment of the present application, an additional coating agent, flame retardant, water-based paint, etc. may be applied on the film to which the coating composition of the present invention is applied. That is, the coating agent of the present invention may be applied as an undercoat layer, and an additional topcoat layer coating may be applied. The additional coating agent may be used without limitation as long as it is commonly applied to wallpaper or interior articles for the purpose of waterproofing, corrosion prevention, coating strengthening, flame retardancy, antibacterial, deodorizing, gloss, and the like.

By coating the coating composition for radon shielding of the present invention on a substrate, a coating film can be formed, and the shape of the substrate may be flat or curved, and may have a three-dimensional structure in which a plurality of surfaces are combined. . In addition, the substrate may be a cellulosic surface such as wood, textile, fiber, paper, and cardboard; masonry surfaces such as porous inorganic substrates including concrete, mortar, brick, stone, gypsum, stucco, terra cotta, dried brick, plaster, limestone, marble, porcelain and tiles; and concrete building structures.

By using the radon shielding coating composition of the present invention, it is possible to provide a coating film exhibiting excellent radon shielding. It can be mainly applied to the inner wall of a building, a structure using cement, and the surface of a building. In addition, it is suitably used for articles, such as body, window glass (front glass, side glass, rear glass), mirror, bumper, etc. in transport apparatuses, such as a train, a car, a ship, and an aircraft. In addition, it can be used for outdoor applications such as exterior walls of buildings, tents, photovoltaic modules, sound insulation boards, and concrete. Moreover, it can be used also for various indoor facilities, such as a kitchen, a bathroom, a wash basin, a mirror, each member article around a toilet, a chandelier, porcelain, such as a tile, artificial marble, and an air conditioner. Moreover, it can be used for a jig, an inner wall, piping, etc. in a factory.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

manufacturing example. Preparation of metal-silane compound mixture and aminoclay particles

After dissolving 1.68 g of MgCl _{2 ·} 6H ₂ O in 16 mL of ethanol contained in a flask, 2 mL of APTES was added to the solution and stirring at room temperature and pressure for 6 hours to induce magnesium amino clay (MgAC) particles, the As a result, a white suspension was obtained. The suspension was dried in an oven at 40° C. to obtain pulverized magnesium aminoclay (MgAC) particle powder.

The APTES (3-aminopropyltriethoxylsilane >98%) is from Sigma-Aldrich (St. Louis, MO, USA), MgCl _{2 ·} 6H ₂ O (Magnesium chloride hexahydrade >98%) from Junsei Chemical (Tokyo, Japan), ethanol (EtOH, >94.5%) was obtained from Daejung Chemical & Metals (Siheung, Korea).

Example 1. Preparation of coating composition for radon shielding

After adding the MgAC particle powder obtained in Preparation Example to 0.5 wt % to 50 mL of an aqueous epoxy resin, stirring for 5 minutes to obtain a MgAC/water-based epoxy resin coating composition.

30 minutes before applying and coating the coating composition, 40 mL of a curing agent is added to the composition and further stirred for 5 minutes to prepare a two-component coating composition. The composition of the aqueous epoxy resin and curing agent is shown in Table 1 below.

water-based epoxy resin composition Volume ratio (%) Titanium dioxide (TiO ₂ ) 10 Phenol, 4,4'-(1-methylethylidene)bis-, polymer with (chloromethyl)oxirane, 3-phenyl-2-propenoate 60 Calcium Carbonate (CaCO ₃ ) 10 Water 20 hardener poly(oxypropylene)diamine 3 Water 87 Phenol, 4,4'-(1-methylethylidene)bis-, polymer with (chloromethyl)oxirane, 3-phenyl-2-propenoate 10

As a result, a coating composition for shielding glossy radon was prepared.

Example 2. Preparation of coating composition for radon shielding

The MgAC particle powder obtained in Preparation Example is added to 50 mL of a commercially available matt aqueous epoxy resin so as to be 0.5 wt %, and then stirred for 5 minutes to obtain a matte MgAC/water-based epoxy resin coating composition. The matte water-based epoxy resin further includes a matting agent in the existing water-based epoxy resin, so that the gloss of the coating composition is further reduced.

The following steps are performed in the same manner as in Example 1.

As a result, a coating composition for matte radon shielding was prepared.

Example 3. Preparation of coating composition for radon shielding

The MgAC particle powder obtained in Preparation Example was added to 50 mL of an aqueous epoxy resin obtained by mixing the aqueous epoxy resin of Table 1 and the matte aqueous epoxy resin of Example 2 in a 1:1 volume ratio so as to be 0.5 wt %, followed by stirring for 5 minutes. A MgAC/aqueous epoxy resin coating composition is obtained.

The following steps are performed in the same manner as in Example 1.

As a result, a coating composition for semi-gloss radon shielding was prepared.

Comparative Example 1. Pure Epoxy Resin Coating Composition

A pure epoxy resin coating composition was prepared by mixing 50 mL of an aqueous epoxy resin composition and 40 mL of a curing agent composition having the configuration described in Table 1 above.

Comparative Example 2. A coating composition in which a primer and charcoal (carbon material) are mixed

A coating composition was prepared by adding charcoal to a commercially available primer of Company A.

Comparative Example 3. Acrylic resin coating composition

A commercially available acrylic resin coating composition from Company B was used.

Comparative Example 4. Coating composition for conventional radon shielding

A commercially available liquid charcoal water-based paint from Company C was used. The water-based paint is characterized in that it further includes additives such as activated carbon, calcium, carbon, anion stone, and mosquito repellent to oil extracted from natural products.

Comparative Example 5. Coating composition for conventional radon shielding

A commercially available coating agent for blocking radon and asbestos from Company D was used.

Comparative Example 6. Water-based urethane resin coating composition

Among the commercially available coating agents containing an aqueous urethane resin of E's company, a coating agent characterized by high elasticity was used.

Comparative Example 7. Water-based urethane resin coating composition

Among the commercially available coating agents containing an aqueous urethane resin of Company E, a coating agent characterized by high adhesion was used.

Comparative Example 8. Water-based urethane resin coating composition

The coating agent according to Comparative Example 6 and the coating agent according to Comparative Example 7 were mixed in a 1:1 volume ratio and used.

Comparative Example 9. Water-based urethane resin coating composition

The aqueous urethane resin coating composition of Comparative Example 9 was prepared by adding MgAC according to Preparation Example of the present invention to the coating agent according to Comparative Example 6 so as to be 0.5% by weight of the total coating composition.

Comparative Example 10. Water-based urethane resin coating composition

APTES 2mL was further mixed with the coating agent according to Comparative Example 8 to prepare an aqueous urethane resin coating composition of Comparative Example 10.

Evaluation Example 1. Radon shielding rate measurement at lab scale

As shown in FIG. 5 , it can be seen that the composition is uniformly applied when the composition according to the embodiment and the comparative example of the present invention is sprayed on the cement bricks, respectively, and then dried and coated at room temperature for 24 hours.

Referring to FIG. 6 , the composition according to an embodiment and a comparative example of the present invention was coated on cement bricks having a width of 3 cm × height 10 cm × length 20 cm. Before coating with the composition, a putty was first coated as a primer to fill defects such as surface cracks of the brick and to adhere the coating composition, and the putty was calcium carbonate (65-75%) And Handy Coat Eco Life Putty (Terraco Ltd) containing acrylic acid-2ethylhexyl acrylate-styrene polymer (1-5%) as a main component was used.

Each cement brick coated as above was placed in a shielded chamber with a width of 30 cm × height 30 cm × length 30 cm, and the total concentration of radon released from the cement bricks for 48 hours using Radon Eye RD200 (Radon FTLab) ( Measurement units: pCi/L, picocuries per liter) were measured. At this time, the radon concentration of the surrounding environment was used as the reference concentration, and as a result, the radon shielding rate was calculated and expressed as the reduction rate compared to the radon concentration reference concentration of Equation 1 below.

[Equation 1]

Wherein C _o is the average radon concentration of the cement bricks, C _i is the average radon concentration of the cement bricks after coating the coating composition according to Examples and Comparative Examples of the present invention, C _w is the radon concentration of the surrounding environment (reference concentration )am.

The radon shielding rate measurement results for Examples 1 to 3 and Comparative Examples 1 to 10 of the present invention are shown in Table 2 and FIGS. 7 and 9 to 20 below. Hereinafter, “reduction rate” means a value obtained by obtaining the C _i /C _O value and subtracting it from 1, that is, the reference concentration is not considered. In addition, the “reduction rate compared to the reference concentration” is a value obtained using Equation 1 above.

reference concentration
(pCi/L) Average concentration before coating
(pCi/L) Maximum concentration before coating
(pCi/L) Average concentration after coating
(pCi/L) Maximum concentration after coating
(pCi/L) decrease rate
(%) Decrease rate compared to the reference concentration
(%) Example 1
1 coat 0.48 2.67 3.85 0.72 1.21 73.03 89.04 Example 1
2 coats 0.48 2.67 3.85 0.47 1.00 82.39 100 Example 2
2 coats 0.48 3.39 5.39 1.70 3.07 49.85 58.07 Example 2
2 coats + matte resin
1 coat 0.48 3.39 5.39 0.36 0.68 89.38 100 Example 3
2 coats 0.48 2.88 4.63 0.48 0.83 83.33 100 Comparative Example 1
1 coat 0.48 3.21 3.64 2.33 3.4 27.41 32.33 Comparative Example 2
1 coat 0.48 1.88 2.85 1.16 1.92 38.29 51.42 Comparative Example 3
2 coats 0.48 1.62 2.65 1.23 2.06 24.07 34.21 Comparative Example 4 0.48 1.94 3.32 1.18 1.89 39.17 52.05 Comparative Example 5 0.48 2.07 3.28 1.48 2.23 28.50 37.10 Comparative Example 6
2 coats 0.48 2.69 4.74 1.95 2.85 27.50 33.48 Comparative Example 7
2 coats 0.48 3.38 6.13 2.07 3.81 38.75 45.17 Comparative Example 8
2 coats 0.48 3.47 6.10 2.49 4.72 28.24 33.00 Comparative Example 9
2 coats 0.48 3.33 5.56 1.80 3.05 45.94 53.68 Comparative Example 10
2 coats 0.48 2.96 5.24 1.85 3.58 37.50 44.75

Referring to Table 2, FIGS. 7 and 9 to 20, Comparative Examples 1 to 10 used as a conventional coating agent did not exceed a maximum of 60% in shielding rate when coated once, whereas according to an embodiment of the present invention, It can be seen that the radon shielding coating composition shows a radon shielding rate of 89% or more with only one coating, and shows a radon shielding rate of 100% compared to the reference concentration when coated twice. This is a significantly higher radon shielding rate than Comparative Examples 4 and 5, which are conventionally used as a coating agent for blocking radon. It was confirmed that even in the case of having a shielding performance, 100% radon shielding rate can be exhibited with one matte aqueous epoxy resin coating after two coatings. In another embodiment, when a semi-glossy composition is prepared by mixing the coating composition for glossy radon shielding and the coating composition for matte radon shielding in another embodiment, the result shows a radon shielding rate of 83% or more when coated once and 100% when coated twice. Through, it suggests that the coating composition for radon shielding can be implemented in various examples according to the convenience of the user.

After a predetermined time elapses after coating the coating composition according to an embodiment of the present invention, the measurement results of the radon shielding rate of the cement bricks are shown in Table 3 and FIG. 8 below.

Example 1 After coating
elapsed time Average concentration (pCi/L) Maximum concentration (pCi/L) before coating 2.67 3.85 7 days 0.75 1.38 30 days 0.75 1.47

Referring to Table 3 and FIG. 8, when the radon concentration emitted from the cement bricks before coating is on average 2.67 pCi/L and up to 3.85 pCi/L, the coating composition according to an embodiment of the present invention is coated on the cement bricks coated with It can be seen that the radon concentration emitted when 7 days have elapsed and the radon concentration released when 30 days have elapsed significantly decreased to an average of 0.75 pCi/L, and after coating with a maximum of 1.38 pCi/L and 1.47 pCi/L, respectively. It can be seen that there is little change in the radon shielding performance even over time.

Evaluation Example 2. Measuring the radon shielding rate when coating the floor board

As shown in Figure 21, Specimen 1 coated twice with the coating composition for radon shielding according to an embodiment of the present invention on a conventional sheet plate, Specimen 2 additionally subjected to edge binding after coating twice, the composition For the uncoated specimen 3 and the specimen 4 subjected to edge binding without coating the composition, radon emission was measured as in the evaluation example 1.

As a result, the radon shielding rate of each specimen is shown in FIG. 22 and Table 4 below.

reference concentration
(pCi/L) Average concentration before coating
(pCi/L) Maximum concentration before coating
(pCi/L) Average concentration after coating
(pCi/L) Maximum concentration after coating
(pCi/L) decrease rate
(%) Decrease rate (%) compared to the reference concentration Psalm 1 0.48 4.87 7.71 3.37 5.15 30.80 34.16 Psalm 2 0.48 4.87 7.71 0.97 1.94 79.89 88.83 Psalm 3 0.48 4.87 7.71 2.74 4.54 43.73 48.51 Psalm 4 0.48 4.87 7.71 2.22 3.9 54.41 60.36

Referring to Table 4 and Figure 22, it can be seen that the radon shielding rate of Specimen 2 coated with the coating composition according to an embodiment of the present invention and subjected to edge binding was the highest. The reason why the radon shielding rate of Specimen 3 is higher than that of Specimen 1 is that the radon emission from the edge of Specimen 1 is more severe as the surface radon emission rate of Specimen 1 coated with the coating composition is very low. can

Evaluation Example 3. Measurement of radon shielding rate on real field scale

23, in order to test the radon shielding rate of the radon shielding coating composition according to an embodiment of the present invention on a real field scale, three-dimensional 6 including the floor and wall of a suburban house in Seocheon-si, Chungcheongnam-do, Korea After applying the coating composition according to the present invention to a surface, coating it once, and drying it overnight, the amount of radon emission was measured from six three-dimensional surfaces including the cement floor and wall surfaces before and after coating the composition.

As a result, the radon shielding rate is shown in Table 5 below.

reference concentration
(pCi/L) Average radon concentration before coating
(pCi/L) Maximum radon concentration before coating
(pCi/L) Average radon concentration after coating
(pCi/L) Maximum radon concentration after coating
(pCi/L) decrease rate
(%) Decrease rate (%) compared to the reference concentration Evaluation Example 3 0.48 4.01 4.90 0.39 0.69 62.5 85.91

Referring to Table 5, it can be seen that the coating composition according to an embodiment of the present invention exhibits a radon shielding rate of 85% or more compared to the reference concentration when the coating composition is coated on a real-scale building.

Evaluation Example 4. Surface test of coatings

Hereinafter, a sample obtained by coating a pure epoxy resin and a coating composition for radon shielding according to an embodiment of the present invention on a cement specimen having a length of 1 cm and a width of 1 cm, and then drying in a Teflon mold, “Sample 1” and “Sample 2”, respectively ” is said. The surfaces of Sample 1 and Sample 2 were measured with a microscope (Eclipse LV150N, Nikon, Tokyo, Japan) and a scanning electron microscope (SEM, SEM-4700, Japan), and are shown in FIGS. 24 and 25 , respectively. At this time, when measuring with a scanning electron microscope, each sample was coated with gold (Au) to increase the conductivity of the sample surface and to prevent surface charging.

24 and 25, the surface of Sample 2 (image b in FIG. 24, image b1 in FIG. 25) is denser than the surface of Sample 1 (image a in FIG. 24, image a1 in FIG. 25) and has fewer defects. can be checked This is because the coating composition is coated in a denser form due to cross-linking between MgAC and the aqueous epoxy resin in the radon shielding coating composition according to an embodiment of the present invention, and the MgAC particles are It can be suggested that it is uniformly dispersed. As a result, it can be inferred that the low concentration of MgAC is uniformly dispersed, thereby reducing the free volume in the aqueous epoxy resin and acting as a barrier, thereby suppressing the permeation rate of radon gas molecules.

Evaluation Example 5. Cross-sectional testing of coatings

The scanning electron microscope (SEM, SEM-4700, Japan) measurement results of the cross sections of the samples 1 and 2 are shown in FIG. 26, and the integrated ion beam scanning electron microscope (FIB-SEM) measurement results of the samples 1 and 2 are shown. is shown in FIG. 27 .

Referring to FIGS. 26 and 27 , numerous defects of about 1 to 3 μm appear in the SEM image of the cross section of Sample 1 (a of FIG. 26 and a2 of FIG. 27 ), and in particular, the structural defects increase near the edge. , which is due to the weak interfacial bond between the epoxy and nanoparticles (CaCO ₃ and TiO ₂ ) contained in the epoxy resin. It can be inferred that radon is more readily released into the environment through the above defects. On the other hand, in the cross section of Sample 2 (Fig. 26 b, Fig. 27 b2) in which the radon shielding coating composition of the present invention was dried, structural defects existing in conventional pure epoxy resins due to cross-linking between the amino clay particles and the aqueous epoxy resin were observed. It can be seen that the edge is denser and smoother than the edge of the cross-section of Sample 1. The coating composition for radon shielding according to an embodiment of the present invention has almost no structural defects on the surface and inside in the dried thin film state as described above, which can effectively act to prevent radon emission.

Evaluation Example 6. Energy dispersive X-ray spectroscopy (EDAX) measurement

The results of energy dispersive X-ray spectroscopy (EDAX) analysis on the cross sections of Sample 1 and Sample 2 are shown in FIG. 28 . The EDAX analysis is a result of the measurement for the voids (in the area indicated by the red solid line) shown in FIG. 27, and Mg and Si elements, which are not included in the pure epoxy resin coating composition of Sample 1, are in the voids in the cross section of Sample 2 It can be confirmed that it is contained in 0.69 wt%. In addition, it can be seen that the N content is increased due to the presence of amino clay particles in Sample 2 according to an embodiment of the present invention.

Evaluation Example 7. X-ray diffraction (XRD) and low angle XRD measurements

X-ray diffraction (XRD) and low angle of samples 1, 2 and MgAC powder samples above by integrating a θ/θ goniometer with 40 kV, 30 mA CuKα radiation emission via a Rigaku D/max-2500 (18 kW, Japan). An X-ray diffraction (low angle XRD) pattern was measured, and the results are shown in FIGS. 29 and 30 .

29 and 30, through the very widely distributed bands of Sample 1 and Sample 2 and the stretch peak around 20°, it can be seen that the pattern is caused by the amorphous structure of the dried aqueous epoxy resin. there is. The peaks of CaCO ₃ and TiO ₂ in the aqueous epoxy resin are not observed, and the peaks observed at 6.13°, 22.27°, and 59.25° of the MgAC powder sample are (001), (020, 110), and (060) of amorphous MgAC. , 320), but the absence of MgAC-specific peak on the (001) plane in Sample 2 indicates that MgAC is completely delaminated in the aqueous epoxy resin.

Referring to the prior literature, when MgAC is intercalated in an aqueous epoxy resin, it can be referred to that the peak of the (001) plane appears at 1 to 10°. The fact that the aminoclay particles MgAC are not embedded in the polymer matrix indicates that they are completely dispersed in the matrix in the form of delamination. The permeation rate of gas molecules depends on the ratio of the length (L) to the width (W) of the nanosheet, and the larger the ratio of L to W, the lower the permeation rate. The ratio may mean that the nanosheets in the polymer matrix are completely delaminated. Therefore, it can be inferred that the complete delamination form of MgAC in the coating composition according to an embodiment of the present invention can be applied to gas barrier.

Evaluation Example 8. Fourier Transform Infrared (FTIR) Measurements

31 shows Fourier transform infrared (FTIR, FTIR-4100, Japan) spectra of Samples 1 and 2 before drying. At this time, the FTIR spectrum of the MgAC sample was referred to.

According to Figure 31, in the MgAC sample 3420cm ^-1 (-OH), 3033/2937cm ^-1 (-CH ₂ ), 2008cm ^-1 (-NH ₃ ⁺ ), 1622cm ^-1 (-NH ₂ ), 1487cm ^-1 ( -CH ₂ ), 1127 cm ^-1 (-Si-C-), 1035 cm ^-1 (-Si-O-Si-), 934 cm ^-1 (-CN-), 703 cm ^-1 (-Mg-O-Si-) ) and 558 cm ^-1 (-Mg-O-) are shown. These results are similar to those of the prior literature, and are 1502 cm ^-1 (aromatic stretching CC), 1040 cm ^-1 (ether stretching COC), and 915 cm ^-1 (oxirane stretching COC) of undried Samples 1 and 2 ), and 831 cm ⁻¹ (stretching COC of oxirane groups) indicate the inclusion of an aqueous epoxy resin in the sample. The 558 cm ^-1 band of the epoxy resin sample shows -Ti-O- and -Ca-O-, which results from the content of TiO ₂ and CaCO ₃ in the aqueous epoxy resin of Samples 1 and 2 before drying (see above). Table 1). When MgAC was contained at a low concentration in Sample 2 before drying, there was no change in the spectrum of the aqueous epoxy resin, but MgAC in Sample 2 before drying through -Mg-O-Si- stretching vibration (703 cm ^-1 ) It can be seen that including In addition, the 915 cm ^-1 peak appeared to be slightly decreased in Sample 2 compared to Sample 1, which can be presumed to be due to the reaction between the aqueous epoxy resin in Sample 2 and the amine-containing group of MgAC.

In addition, referring to FIG. 32 showing the FTIR spectra of Sample 1 and Sample 2 after drying, in Sample 2, the FTIR spectrum shows a defect of 915 cm ⁻¹ and 831 cm ⁻¹ peaks, which are water-based epoxy resin and MgAC upon drying. It is presumed to occur due to the formation of epoxy-amine cross-links in the liver. In addition, it appears that the overall structure of the epoxy is not significantly affected by the amount of MgAC in Sample 2.

Evaluation Example 9. X-ray photoelectron spectroscopy (XPS) analysis

As a result of X-ray photoelectron spectroscopy (XPS) (Kratos Analytical, AXIS Nova, Manchester, UK) measurement using AI Kα X-ray monochromatic radiation at 120 W for Sample 1 and Sample 2, N 1s, O 1s and C A detailed spectrum of 1s is shown in FIG. 33 .

First, for the N 1s spectrum of Sample 1 (FIG. 33 a), (c) a 399.74 eV peak originating from ₃ -N ⁴² appeared, indicating that a complete reaction occurred between the epoxy and amine-containing groups in Sample 2 during the drying process. Able to know. In contrast, sample 2 (Fig. 33b) has an additional peak of 401.23 eV originating from NH ⁴⁰ , presumably because MgAC reacts with epoxy before drying to form NH groups due to cross-link formation between MgAC and epoxy. do. In addition, the presence of MgAC in Sample 2 can be confirmed through the shift of the O 1s peak to 532.82 eV (-Si-O-Si-) in Sample 2 when compared to Sample 1. In addition, C=O is a specific functional group in the polymer resin containing chloromethyl oxirane and is not measured in MgAC. Therefore, the presence of MgAC in Sample 2 can be further confirmed through the increase of the peak ratio between CC (285.35 eV) and C=O (286.84 eV) and the presence of the CN (289.76 eV) peak.

Evaluation Example 10. Thermal stability measurement

In order to measure the thermal stability of Samples 1 and 2, TGA and DTG measurements were performed through SDT Q600 (TA Instruments Inc., USA) under a nitrogen atmosphere at 30 to 600° C., where the heating rate and nitrogen flow rate were 10° C./min. and 0.1 dm ³ /min. Fig. 34 shows the results of thermal mass analysis (TGA) (Fig. 34 a) and derivative thermogravimetric analysis (DTG) (Fig. 34 b) of samples 1 and 2; The TGA result was shown as a plot in FIG. 35 by measuring the thermal decomposition activation energy (E _a ) through the following Equations 2 to 4 using the integration of Horowitz and Metzger.

[Equation 2]

[Equation 3]

[Equation 4]

α is the decomposition rate, E _a is the thermal decomposition activation energy, R is the gas constant, T _max is the temperature at the maximum weight-loss rate, W _o , W _t , and W _∞ are the initial, actual, represents the final mass. The results are shown in Table 6 below.

T _s (℃) T _max (℃) E _a (°C) carbonization residue
(weight%) sample 1 331 365 100 11.32 sample 2 313 343 121 13.79

Referring to FIGS. 34 to 35 and Table 6, it can be seen that the thermal stability of the aqueous epoxy resin is increased compared to Sample 1, which is a pure epoxy resin, due to the MgAC content in Sample 2. In Sample 1 and Sample 2, a stepwise thermal decomposition process due to polymer chain decomposition occurs, in which case T _s and T _max can be seen to decrease due to the MgAC content in Sample 2. The decrease in T _s and T _max in Sample 2 can be explained by the initial thermal decomposition of MgAC. The organic chain of APTES begins to decompose around 260° C., and the carbonized residue of Sample 1 indicates that some decomposition products are not volatilized. Comparing the higher carbonization residue (13.79%) of Sample 2 at 600°C with that of Sample 1 (11.32%), this can be attributed to the MgAC content in Sample 2, and the carbonization residue transfers mass and heat. It provides a protective film and slows the rate of heat dissipation, thereby increasing the thermal resistance of Sample 2. In addition, the derivative thermogravimetric (DTG) profile (Fig. 34b) shows that the maximum loss rate of sample 2 is lower than that of sample 1, which is a pure epoxy resin, indicating that MgAC is an insulating barrier that prevents mass loss during thermal decomposition. suggests that it can act as Furthermore, E _a (121 kJ/mol) of Sample 2 is higher than that of Sample 1 (100 kJ/mol). This means that Sample 2 according to the embodiment of the present invention has higher thermal stability, and thus thermal decomposition of Sample 2 requires more energy. The improvement in thermal stability of Sample 2 can be explained in the form of delamination of MgAC, and it can be interpreted that the individual aminoclay (MgAC) layer in the structure exhibits a blocking effect from volatile decomposition products.

Evaluation Example 11. Contact angle measurement

Phoenix 10 (Surface Electro Optics) was used to measure the contact angles of Sample 1 and Sample 2, and analysis was performed through SEO Surfaceware (Surface Electro Optics). The volume of the solution in contact with the surface was constant at approximately 5 μL. The contact angle measurement result is shown in FIG. 36 .

Referring to FIG. 36, it can be seen that the contact angle (a in FIG. 36) of Sample 1, which is a pure epoxy resin, is 62.51° ± 2.96, and the contact angle of Sample 2 (b in FIG. 36) in which MgAC is added to Sample 1 is 54.10. It can be seen that it decreases to ° ± 2.96, which can be explained by the hydrophilicity of MgAC.

Evaluation Example 12. Antimicrobial ability measurement

Escherichia coli 3.6 x 10 ⁵ CFU/mL, Staphylococcus aureus 3.7 x 10 ⁵ CFU/mL, and Candida 1.3 x 10 ⁵ CFU/mL on a specimen coated with the coating composition according to an embodiment of the present invention on 5cm x 5cm marble After inoculation, the concentration of each strain was measured 24 hours after the inoculation, and the reduction rate of the strain concentration was measured and shown in Table 7 below. In this case, as a control piece, uncoated marble was used.

Test Items Test result initial concentration
(CFU/mL) concentration after 24 hours
(CFU/mL) decrease rate
(%) coli contrast 3.6 X 10 ⁵ 9.0 X 10 ⁶ - test piece 3.6 X 10 ⁵ < 10 99.9 Staphylococcus aureus contrast 3.7 X 10 ⁵ 2.6 X 10 ⁶ - test piece 3.7 X 10 ⁵ < 10 99.9 candida contrast 1.3 X 10 ⁵ 2.3 X 10 ⁶ - test piece 1.3 X 10 ⁵ < 10 99.9

Referring to Table 7, it can be seen that the test piece coated with the coating composition according to the embodiment of the present invention exhibits an excellent level of antibacterial activity.

The description of the present invention described above is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

Claims (14)

A coating composition for shielding radon, comprising:
a silane compound in which at least one amine-containing group and at least one hydrolysable group are bonded to a silicon atom; and aminoclay particles derived by dissolving a metal precursor in a solvent; and
water-based epoxy resins;
including,
When the amino clay particles are mixed in an aqueous epoxy resin, they are dispersed in the composition in a delaminated structure,
The amino clay is a coating composition for shielding radon, characterized in that it is included in an amount of 0.5 to 1.0% by weight based on the aqueous epoxy resin.
delete According to claim 1,
The amine-containing group represents -(CH ₂ ) _n NR ¹ R ² , where n is an integer from 0 to 10, and R ¹ and R ² are each independently hydrogen, C _1-10 alkyl, C _2-10 al kenyl, C _2-10 alkynyl, C _6-17 aryl, C _3-17 cycloalkyl, C _1-10 acyl, or R ³ NH ₂ , and R ³ represents C _1-6 alkylene, A coating composition for radon shielding.
According to claim 1,
The silane compound is 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyl Dimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (N-[3-(Trimethoxysilyl)propyl]ethylenediamine; DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldime Toxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, Diethylenetriaminopropylmethyldimethoxysilane, diethyleneaminomethylmethyldiethoxysilane, (N-phenylamino)methyltrimethoxysilane, (N-phenylamino)methyltriethoxysilane, (N-phenylamino)methyl Methyldimethoxysilane, (N-phenylamino)methylmethyldiethoxysilane, 3-(N-phenylamino)propyltrimethoxysilane, 3-(N-phenylamino)propyltriethoxysilane, 3-(N- Phenylamino)propylmethyldimethoxysilane, 3-(N-phenylamino)propylmethyldiethoxysilane, and N-(N-butyl)-3-aminopropyltrimethoxysilane, bis[(3-triethoxysilyl) ) Propyl] amine and bis [(3-trimethoxysilyl) propyl] amine will at least one selected from the group consisting of, radon shielding coating composition.
According to claim 1,
The metal precursor is selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Cu ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Al ³⁺ , Fe ³⁺ , and Ce ³⁺ . A coating composition for radon shielding, which provides any one or more metal cations.
2. The method of claim 1
Wherein the aqueous epoxy resin is selected from a monomeric epoxy resin, a polymeric epoxy resin, or a mixture thereof, a coating composition for radon shielding.
7. The method of claim 6,
The aqueous epoxy resin is a glycidyl ether of one or more phenols selected from the group consisting of substituted or unsubstituted phenol, bisphenol A, and bisphenol F, radon shielding coating composition.
The method of claim 1,
The solvent includes at least one polar solvent, and the polar solvent is selected from the group consisting of methanol, ethanol, propanol and isopropanol.
The method of claim 1,
The composition may further include a curing agent, a coating composition for shielding radon.
The method of claim 1,
The amino clay particles are
two silicate tetrahedral sheets; and
A structure consisting of a metal octahedral sheet inserted between the two silicate tetrahedral sheets,
An amine-containing group is connected to the silicon of the silicate tetrahedral sheet, and an aqueous epoxy resin is bonded to the nitrogen of the amine-containing group, the radon shielding coating composition.
The coating composition for radon shielding according to claim 10, wherein the aminoclay particle is a talc group without a layer charge.
11. The method of claim 10, wherein the aminoclay particles have a unit cell formula of R ₈ Si ₈ M _X O ₁₆ (OH) ₄ , wherein R is an amine-containing group, and x is 12/(positive charge of M). The coating composition for shielding radon.
The coating composition for radon shielding according to claim 10, wherein the aminoclay particles are water-soluble.
It relates to a method for preparing a coating composition for shielding radon, comprising:
(a) a metal precursor; is dissolved in a solvent, and (b) a silane compound having at least one amine-containing group and at least one hydrolyzable group bonded to a silicon atom is added to the solution to induce aminoclay particles to do; and
(c) adding said aminoclay particles to an aqueous epoxy resin;
When the amino clay particles are mixed in an aqueous epoxy resin, they are dispersed in the composition in a delaminated structure,
The amino clay is a method for producing a coating composition for shielding radon, characterized in that contained in 0.5 to 1.0% by weight based on the aqueous epoxy resin.

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