In order to investigate the effect of the composition of weather-resistant coatings on physical properties, three different weather-resistant coatings were prepared by varying the ratio of a mill-base silicone/acrylic resin and let-down silicone/acrylic resin in weight ratios of 2：8, 3：7, and 4：6. The physical properties and weather-resistance of the prepared coatings were tested. It was found that the thermal stability, salt spray exposure, and weather-resistance were improved with increasing the amount of silicone. The optimum mixing ratio of mill-base silicone/acrylic resin to the let-down silicone/acrylic resin was 2：8. The coating containing silicone component of 30 wt% was found to be suitable as high weather-resistant coatings.

실리콘/아크릴수지를 기반으로 한 내후성 도료의 조성이 물성에 미치는 영향을 연구하기 위하여 안료분산용 및 희석용 실리콘/아크릴수지의 배합비를 중량비율 2：8, 3：7, 4：6의 3종으로 변화시키면서 내후성 도료를 제조하였다. 제조된 도료의 도막물성 및 내후성이 판단할 수 있는 각종 도막실험을 실시한 결과, 실리콘 성분함량이 증가할수록 열적안정성, 염수분무 및 내후성 등이 향상되었으며, 적정배합비는 2：8임을 알 수 있었다. 또한 실리콘 성분을 30 wt% 함유한 도료는 고내후성을 보유함을 확인하였다.

Keywords: -base; let-down; silicone/acrylic resin; weather-resistant coatings