Mineral filler is used for resin compounds, because it increases the stiffness and thermal stability of a resin compound, and it also cuts down the cost. Calcium carbonate, silica, magnesium oxide, and others are used as filler materials in general, and the type of filler material, the size, and content can affect the physical properties of compounds. Those factors also influence the viscosity of resin mixtures and the workability, and should be adjusted by changing the contents of the filler, which depends on the size. In this study, five kinds of ground calcium carbonate, which were different in size, were used to produce polyester compounds ; the physical properties were compared with the filler size and contents. The mechanical properties were measured by bending strength and tensile strength, and the heat deflection temperature was obtained for thermal stability.

1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
 4. 결 론
 Acknowledgment
 References

• 이윤주(에너지소재본부, 한국세라믹기술원) | Yoonjoo Lee
• 허석(에너지소재본부, 한국세라믹기술원) | Seck Heo
• 김영희(에너지소재본부, 한국세라믹기술원) | Younghee Kim
• 김수룡(에너지소재본부, 한국세라믹기술원) | Soo-Ryong Kim
• 권우택(에너지소재본부, 한국세라믹기술원) | Woo-Teck Kwon Corresponding author