초록
벤조산 폴리에스테르/락톤 폴리올의 합성은 디올로서 폴리카프로락톤 0201, 트리올로서 트리메틸올프로판, 2염기산으로서 아디프산 및 1염기산으로 벤조산을 사용하였다. 폴리이소시아네이트 프리폴리머는 HDI-biuret형인 Desmodur N-100을 사용하였다. 벤조산 폴리에스테르/락톤 폴리올, 폴리이소시아네이트, 안료, 습윤분산제 및 플로우개량제 등을 블렌드하여 2성분계 폴리우레탄 도료를 제조하였다. 제조된 폴리우레탄 도료로서 도막시편을 제작하여 각종 도막 물성시험을 행한 결과 KS 규격에서 제시한 기준치와 비교하여 내마모성, 촉진내후성, 황변도는 우수하게, 굴곡성, 내충격성, 60$^{\circ}$ 경민광택도, 접착력, 내유성, 명도지수차는 양호하게, 경도는 다소 나쁘게 나타났다. 따라서 디올로서 폴리카프로락톤 0201을 도입한 후 내유성, 굴곡성, 내충격성의 장점이 나타남을 확인하였다. 또한 벤조산 함량변화에 따른 고화 및 경화거동을 살펴 본 결과, 고화에 따른 건조시간은 2~4시간으로, 경화에 따른 가사시간은 20~37시간으로 각각 나타나, 도막표면의 고화 및 경화상태가 양호함을 보여주었다.
Benzoic acid polyester/lactone polyol were synthesized by polycaprolactone 0201 as diol, trimethylolpropane as triol, adipic acid as dibasic acid, and benzoic acid as monobasic acid. Polyisocyanate prepolymer Desmodur N-100 of HDI-biuret type was used in this study. Two-component polyurethane coatings were prepared by blending benzoic acid polyester/polycaprolactone, polyisocyanate, wetting/dispersing agent, white pigment, and flowing agent. Various properties were examined on the film coated with the prepared polyurethane. They showed excellent physical properties such as abrasion resistance, accelerated weathering resistance, and yellowness index. They also showed good physical properties such as flexibility, impact resistance, 60$^{\circ}$ specular gloss, cross hatch adhesion, hydrocarbon resistance, and lightness index difference. Hardness of coating showed a little poor character. The introduction of polycaprolactone 0201 as diol in the polyurethane coatings improved the hydrocarbon resistance, impact resistance, and flexibility of coatings. According to the drying and curing behavior with the contents of benzoic acid, they seem to have reasonable coating properties such as drying time of 2 to 4 hours and pot-life time of 20 to 37 hours.
