Journal of the Korean Wood Science and Technology

The Korean Society of Wood Science & Technology (한국목재공학회)
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Thermal Stability and Surface Hardnes of UV-curable Epoxy Acrylate Coatings for Wooden Flooring

마루바닥재용 자외선 경화형 에폭시 아크릴레이트 도료의 열안정성과 표면경도

  • 황현득 (서울대학교 산림과학부 환경재료과학 전공 바이오복합재료 및 접착과학 연구실) ;
  • 최재훈 (서울대학교 산림과학부 환경재료과학 전공 바이오복합재료 및 접착과학 연구실) ;
  • 문제익 (서울대학교 산림과학부 환경재료과학 전공 바이오복합재료 및 접착과학 연구실) ;
  • 김현중 (서울대학교 산림과학부 환경재료과학 전공 바이오복합재료 및 접착과학 연구실)
  • Received : 2008.07.19
  • Accepted : 2008.09.10
  • Published : 2008.11.25
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Abstract

Environmental friendly UV-curable coatings, having excellent hardness, gloss, mar and chemical resistance, are commonly used for the wooden flooring coatings. Especially epoxy acrylate oligomers are chosen for the wooden flooring coatings, due to their thermal stability and fast curing. In this study, we investigated the effect of the acrylate functionality on the thermal stability and surface hardness. The thermal degradations of monomers, oligomer, photoinitiator and formulated coatings with different acrylate functionality were measured using a thermogravimetric analysis (TGA). And the surface hardness was also measured with a pendulum hardness tester to compare relationship between the thermal stability and the physical property. The cured coatings became thermally stable by crosslinking during UV-curing. Both the thermal stability and surface hardness of cured coatings were improved with increasing acrylate functionality.

고경도, 고광택, 고내마모성 및 고내산성 등의 물성이 요구되는 마루바닥재의 상도용 도료로는 물성이 우수하면서도 환경친화적인 자외선경화형 도료가 많이 사용되고 있다. 그 중에서도 특히 에폭시 아크릴레이트계의 올리고머는 높은 열안정성과 속경화 특성으로 인하여 목재내장재의 도료로써 많이 사용되고 있다. 본 연구에서는 아크릴레이트 관능기 수가 자외선 경화형 에폭시 아크릴레이트 도료의 열안정성 및 표면경도에 미치는 영향을 분석하고자 하였다. 조성분을 이루는 모노머, 올리고머, 광개시제 각각의 열분해 거동 및 아크릴레이트 관능기수가 달리 배합된 에폭시 아크릴레이트 도료의 열안정성을 열중량분석기(TGA)를 사용하여 평가하였으며, 열안정성과 물리적 물성과의 관계를 확인하기 위하여 진자경도계를 이용하여 표면경도를 측정하였다. 경화 전 후의 열분해 거동 및 표면경도를 비교한 결과, 자외선 경화 중에 발생하는 가교에 의해 도막의 열안정성이 부여되며, 관능기의 수가 많아짐에 따라 열안정성뿐만 아니라 표면경도도 향상됨을 확인하였다.

Keywords

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