석조문화재 보수물질로의 적용을 위한 무기질 바인더 안정성 연구

김대식 ( Dae Sik Kim ),도진영 ( Jin Young Do ),조현구 ( Hyen Goo Cho ) 한국광물학회 2014 광물과 암석 (J.Miner.Soc.Korea) Vol.27 No.4

석조문화재 보수물질로서의 적용을 위해 무기질 바인더를 시험하였다. 순수 무기질 바인더와 첨가제를 배합한 3종을 시편으로 제작하였고 거창화강석에 무기질 바인더 시편들을 부착시켜 무기질바인더가 암석에 미치는 영향을 분석하였다. 무기질 바인더와 반응시킬 pH 4.0과 pH 5.6 수용액을 국강우의 산성도와 함유이온을 토대로 제조하였다. pH 8.0 약알칼리수와 pH 6.85 탈이온수를 준비하산성수의 대조군으로 적용하였다. 물반응 후 무기질 바인더 시편의 무게 감소는 시편의 종류에 따라서는 컸지만 물의 산성도와 상관성은 적었다. 순수 무기질 시편의 압축강도가 가장 컸으나 물반응 감소율이 가장 크다. 큰 흡수율은(6.72-12.44 kg/m2·t1/2) 무기질 바인더로부터 용출된 이온 함량과 상관성이 크다. 모든 액성의 수용액이 무기질 바인더와 반응 후 pH 9.0-10.0로 변화하였으며, 수용액에서는 무기질 바인더에서 용해된 Mg2+와 K+이 다량 검출되었다. 용해된 이온들은 수용액 내 음이온들과 결합하여 높은 용해도를 지닌 MgSO4·nH2O 및 KNO3와 같은 백색염을 형성하였다. 암석강화제 발수제를 처리한 무기질 바인더 시편에서는 이온량이 급격하게 감소하였다. Inorganic binders were studied in order to apply a conservation material for stone monument. A pure inorganic binder and 3 species of inorganic binder which contain additives on the basis of a pure inorganic binder were selected as test samples. Through the application of inorganic binders on Geochang granite investigate their influences on stone. pH 4.0 and 5.6 acid solution, respectively were manufactured on the basis of the acidity of domestic rainfall. Alkaline water with pH 8.0 and deionized water with pH 6.85 were prepared as control group. Changes in weights of inorganic binders were not definite according to the acidity of water while weight losses in inorganic binder type were greater after reaction with the water. The compressive strengths of pure inorganic binder was largest before the test but its decrease rate were larger after reaction with the water. Water absorption rate of inorganic binders are 6.72 to 12.44 kg/m2·t1/2 after reaction with the water. Such high absorption was considered that it forced water to move deep into inorganic binder and made the components of inorganic binder dissolve. Acidities of the water of pH 4.0, 5.6, 6.85 and 8.0, respectively were changed to pH 9.0-10.0 after reaction with the inorganic binders. Ion concentrations in the water changed after reaction with the inorganic binders and Mg2+, and K+ significantly increased, dissolved from the binder. The high concentration of ions detected showed that the binder reacted with water and formed white salts with high solubility such as MgSO4 .nH2O, KNO3. Ion concentrations significantly decreased from the binder after treatment with consolidant and water repellent.

바인더 종류에 따른 무기단열재의 열전도 특성에 관한 연구

전찬기,박종필,심재영,정훈,이재성 한국재난정보학회 2016 한국재난정보학회 논문집 Vol.12 No.3

In this study, we conducted about the manufacture of a non-combustible inorganic insulation by replacing the binder type for satisfaction of thermal conductivity for developing a lightweight inorganic insulation. Thermal conductivity was measured using a machine of HFM-436. We made samples are inorganic insulation by using SH-1(liquid) of S company and SH-2(solids). By Mixing Pearlite and SH-4(Liquid) was produced as insulation sample 2. Each was shaped into a binder and pearlite in the frame. After complete drying, thermal conductivity was measured by using HFM-435. The thermal conductivity was determined using two different binder. We analyzed the effect on thermal conductivity in binder. 본 연구에서는 불연성 무기단열재를 제조하기 위해 바인더 종류를 대체하여 열전도율을 충족시키고 경량 무기단열재 개발을 위해 연구하였다. 열전도율 측정은 열전도 측정기인 HFM-436을 이용하여 열전도율을 측정하였다. 무기단열재를 바인더 SH-1(액상), SH-2(고체)와 펄라이트를 배합하여 단열재 샘플1을 만들었고, SH-3(액상)와 펄라이트를 배합하여 단열재 샘플 2를 제조했다. 총 4개의 샘플을 제조했다. 각각 바인더와 펄라이트를 틀에 넣어 성형하였으며 완전건조 후 HFM-435을 이용하여 열전도율을 측정하였다. 두 가지 다른 바인더를 사용하여 열전도율을 측정하였고 바인더에 따른 열전도율의 영향을 분석하였다.

물유리계 바인더의 첨가제가 Al-Si7Mg 합금 주조 시 소착에 미치는 영향

배민아,김명환,박정욱,이만식 대한금속·재료학회 2018 대한금속·재료학회지 Vol.56 No.4

Traditional organic binders used by the foundry industry produce problems such as generation of volatile organic compounds(VOCs), smoke and etc. A water glass binder system has been developed to improve the casting strength and to solve the environmental problems. However the water glass binder has a serious problem of sand burning. In this study, a commercial water glass binder was modified to reduce sand burning during aluminium casting by the addition of Calcium carbonate, activated carbon, and monosaccharide. The modified water glass binder was characterized by XRF, viscometer and TGA-DTA. We then evaluated the water glass binder core strength. Casting tests were conducted using Al-Si7Mg alloy to compare the ability to prevent sand burning in a sand mold. The XRF results of the prepared modified water glass binder showed a similar molar ratio of SiO2/Na2O to the commercial one. From the TGA-DTA analysis and gas emission calculation, it was considered that gas generation and corresponding inhibition of sand burning would be maximized with the monosaccharide-added water glass binder. Casting evaluation showed reduced sand burning for the water glass binder with mono saccharide. Also, core strength was found to be similar to the commercial water glass binder. These results prove that the monosaccharide-added water glass binder could replace the traditional organic binder.

무기바인더의 내수강도 발현에 미치는 식물성 왁스의 영향

배민아,김경호,이만식,백재호 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.10

An inorganic binder is eco-friendly because it can be cured at low temperatures and does not emit harmful gases. In addition, related research is progressing rapidly owing to the small defects in the core. On the other hand, inorganic binders based on silicates (SiO2-Na2O) have unique absorbent properties. This results in the absorption of moisture from the air and the weakening of the bonding force. In particular, the castings used in cast steel require high-strength properties because of the higher temperatures than aluminum castings. In this study, waxes containing ester groups were selected to improve the absorption of moisture of inorganic binders. The inorganic binder was characterized by X-ray fluorescence and thermogravimetric analysis-differential thermal analysis. The inorganic binder core strength was then evaluated. In the case of an inorganic binder containing wax, the water resistance increased to 216 N/cm2, confirming the up to 55% improvement in strength. Excellent casting characteristics were confirmed through steel castings. 무기바인더는 저온에서 경화가 가능하며, 유해가스를 배출하지 않는 친환경성과 중자 조형 시 성형된 제품의 결함이 작다는 장점으로 인해 주조 산업에 적용하고자 관련 연구가 급속도로 진행되고 있다. 그러나 실리케이트(SiO2-Na2O)를 주성분으로 하는 무기바인더는 실리케이트 특유의 흡습성으로 인해 공기 중 수분을 흡습하여 결합력이 약해져 주형의 강도가 급격히 감소하는 문제가 있다. 특히 주강 주조에 사용되는 사형 주형의 경우 알루미늄 주조보다 높은 주입 온도로 인해 고강도의 주물 특성을 요구한다. 이에 본 연구에서는 무기바인더의 강도와 흡습성을 개선하기 위해 에스테르기를 함유하는 왁스를 이용하여 이를 효율적으로 합성하는 방법을 연구하였다. 또한 합성된 무기바인더의 특성을 XRF와 TGA를 통해 확인하고, 일반강도와 내수강도 평가를 진행하여 주형의 강도 개선 여부를 확인하였다. 그 결과 에스테르기를 함유하는 왁스를 포함한 무기바인더의 경우 일반 강도가 증가하였으며, 특히 내수강도가 118 N/cm2에서 216 N/cm2까지 증가하여 약 55 %의 내수강도 개선 효과를 확인하였다. 또한 실제 주강 제품을 제작한 뒤 주조를 통해 우수한 주조 특성을 확인하였다.

Al과 Si의 몰비에 따른 알루미노 실리케이트계 무기 바인더의 경화 특성 분석

양완희(Yang Wan-Hee),이세현(Lee Sea-Hyun),송태협(Song Ttae-Hyeob) 대한건축학회 2007 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.27 No.1

More recently, interest in Aluminosilicate inorganic binder gained a new momentum due to the materials inherent fire resistance and chemical resistance. Aluminosilicate inorganic binders are new building materials synthesized by reacting aluminium and silicon containing materials with alkaline silicate solution. As reported earlier, there are some obvious differences between conventional portland cement chemistry and inorganic binder's polymerisation. While it is known that the binding property of cement is due to the presence of calcium through formation of calcium silicate hydrate in a semi-crystalline phase, inorganic binder utilize the polycondensation of silica and alumina at a high alkali concentration. And aluminosilicate inorganic binders have emerged as novel building materials with its chemical and physical properties and reductions in CO2 emissions, compared with ordinary portland cement. Therefore, in this paper will attempt to analyze the microscopic characteristics(SEM, XRD and TGA) of aluminosilicate inorganic binder according to the mole ratio of aluminium and silicon, and to verify the difference between aluminosilicate inorganic binder and ordinary portland cement.

고기능성 세라믹 주형 및 중자 제작을 위한 3원계 무기 바인더 시스템 개발

박혜영,조근호,최현희,김봉구,김은희,양승철,정연길 한국재료학회 2022 한국재료학회지 Vol.32 No.12

In existing ceramic mold manufacturing processes, inorganic binder systems (Si-Na, two-component system) are applied to ensure the effective firing strength of the ceramic mold and core. These inorganic binder systems makes it possible to manufacture a ceramic mold and core with high dimensional stability and effective strength. However, as in general sand casting processes, when molten metal is injected at room temperature, there is a limit to the production of thin or complex castings due to reduced fluidity caused by the rapid cooling of the molten metal. In addition, because sodium silicate generated through the vitrification reaction of the inorganic binder is converted into a liquid phase at a temperature of 1,000 °C. or higher, it is somewhat difficult to manufacture parts through high-temperature casting. Therefore, in this study, a high-strength ceramic mold and core test piece with effective strength at high temperature was produced by applying a Si-Na-Ti three-component inorganic binder. The starting particles were coated with binary and ternary inorganic binders and mixed with an organic binder to prepare a molded body, and then heat-treated at 1,000/1,350/1,500 °C to prepare a fired body. In the sample where the two-component inorganic binder was applied, the glass was liquefied at a temperature of 1,000 °C or higher, and the strength decreased. However, the firing strength of the ceramic mold sample containing the three-component inorganic binder was improved, and it was confirmed that it was possible to manufacture a ceramic mold and core via high temperature casting.

1P-714 Strength change of inorganic binder according to ceramic additives and its application

박동국,이만식 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

The use of inorganic binders, which generate little harmful substances compared to organic binders, has been increasing worldwide. Although inorganic binders are known to be excellent in heat resistance and durability, they are very vulnerable to moisture resistance and cannot be used in high temperature and high humidity environment such as summer in Korea. Ceramics have excellent abrasion resistance and corrosion resistance at high temperatures. Particularly, it has higher strength at high temperature, low thermal conductivity and thermal expansion coefficient, but has no adhesion. Therefore, many studies have been carried out to increase the adhesive strength through the addition of a binder or surface modification. This study discusses the variation of strength of a mixture of typical ceramics such as alumina, silica, and aluminosilica with an inorganic binder. In addition, the thermal stability of the mixture was confirmed by casting into cast steel.

물유리계 바인더로 제조한 천연주물사와 인공주물사 중자의 강도 특성

배민아,김판성,김경호,이만식,백재호 대한금속·재료학회 2021 대한금속·재료학회지 Vol.59 No.4

Natural sand and organic binders are commonly used in casting processes, but these ingredients produce environmental problems with dust and harmful TVOC(Total Volatile Organic Carbon) gases. Research on the introduction of artificial sand and inorganic binders to solve these environmental problems is being actively conducted mainly in the casting industry. Artificial sand has superior durability and a spherical shape compared to natural sand, and above all, it does not generate dust. In addition, inorganic binders have the advantage that no harmful gas is generated during casting and the used sand can be recycled. This study confirmed whether inorganic binders can be applied when replacing natural sand with artificial sand. First, eco-friendly inorganic binders that do not produce harmful gas were synthesized. Then characteristic analyses were carried out with artificial sand and natural sand. Physical and chemical properties were compared using X-Ray Fluorescence (XRF), Powder Flow Test (PFT) and particle size distribution analyses. The general strength and absorption (absolute humidity 29.9 g/cm3) strength of the sample core was measured using each sand (artificial sand, natural sand) and inorganic binder. Also, X-ray Photoelectron Spectroscope (XPS) analysis confirmed the combination structure. As a result, it was confirmed that artificial sand exhibited mold characteristics with similar strength even with lower inorganic binder content than natural sand.

바인더 종류에 따른 무기단열재의 열전도 특성에 관한 연구

Chanki Jeon,Jaeseong Lee,Hoon Chung,Jongpil Park,Jaeyeong Shim 한국재난정보학회 2016 한국재난정보학회 논문집 Vol.12 No.3

본 연구에서는 불연성 무기단열재를 제조하기 위해 바인더 종류를 대체하여 열전도율을 충족시키고 경량 무기단열재 개발을 위해 연구하였다. 열전도율 측정은 열전도 측정기인 HFM-436을 이용하여 열전도율을 측정하였다. 무기단열재를 바인더 SH-1(액체), SH-2(고 체)와 펄라이트를 배합하여 단열재 샘플1을 만들었고, SH-3(액체)와 펄라이트를 배합하여 단열재 샘플 2를 제조했다. 총 4개의 샘플을 제조했다. 각각 바인더와 펄라이트를 틀에 넣 어 성형하였으며 완전건조 후 HFM-435을 이용하여 열전도율을 측정하였다. 두 가지 다른 바인더를 사용하여 열전도율을 측정하였고 바인더에 따른 열전도율의 영향을 분석하였다. In this study, we conducted about the manufacture of a non-combustible inorganic insulation by replacing the binder type for satisfaction of thermal conductivity for developing a lightweight inorganic insulation. Thermal conductivity was measured using a machine of HFM-436. We made samples are inorganic insulation by using SH-1(liquid) of S company and SH-2(solids). By Mixing Pearlite and SH-4(Liquid) was produced as insulation sample 2. Each was shaped into a binder and pearlite in the frame. After complete drying, thermal conductivity was measured by using HFM-435. The thermal conductivity was determined using two different binder. We analyzed the effect on thermal conductivity in binder.

Improvement in the hygroscopicity of inorganic binder through a dual coating process

Choi, Hyun-Hee,Kim, Eun-Hee,Lee, Hye-Ju,Kim, Bong-Gu,Jung, Yeon-Gil,Zhang, Jing Elsevier Sequoia 2019 Progress in organic coatings Vol.135 No.-

<P><B>Abstract</B></P> <P>The use of an anti-absorbent is proposed in this work to reduce the hygroscopicity of the inorganic binder in the casting mold, in which the anti-absorbent is coated on the mold prepared with an inorganic binder. Three types of polymers were used to select material with optimal water resistance. Polystyrene (PS) and polyvinyl alcohol (PVA) were used as a water-insoluble polymer and water-soluble polymer, respectively. In addition, polyurethane (PU) prepolymer has intermediate properties between PS and PVA. PVA and PU prepolymer were used for comparative testing with PS. For this testing process, the prepared green body was dipped into a solution of inorganic binder precursor mixed with tetraethyl orthosilicate (TEOS, SiO<SUB>2</SUB> precursor) and sodium methoxide (NaOMe, Na<SUB>2</SUB>O precursor), and then dipped into a solution of coating reagent after a drying process. Thus, these series of coating processes in a green body is called a dual coating process. Finally the sample was heat-treated at 1000 °C to generate a glass phase by an organic–inorganic conversion process. In the sample prepared with PS, the highest contact angle and a high firing strength were exhibited, independent of polymer concentration, while the sample coated with PVA showed lower green and firing strengths. When prepolymer, PU, was applied, the green strength was remarkably improved, showing lower firing strength compared with that of PS. The green and firing strengths were optimized through the dual coating process with PS. Moreover, the moisture-proof effect of the dual coating process was verified through the moisture steam test.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Development of a <I>new</I> coating process reduced the hygroscopicity of inorganic binder. </LI> <LI> The highest firing strength was <I>obtained</I> in a mold coated with polystyrene (PS). </LI> <LI> The desirable strength was shown in a mixture of PS and polyurethane (PU) prepolymer. </LI> <LI> The contact angle increased in the order of polyvinyl alcohol (PVA), PU, and PS. </LI> <LI> PS and the PU prepolymer were preferable to increase the moisture absorption effect. </LI> </UL> </P>