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Studies on Photoprotection of Walnut Veneer Exposed to UV Light

자외선 노출에 의한 Walnut 베니어의 광 변색 방지 연구

  • Park, Se-Yeong (Department. of Forest Sciences, College of Agriculture & Life Sciences, Seoul National University) ;
  • Hong, Chang-Young (Department of Forest Biomaterials, North Carolina State University) ;
  • Kim, Seon-Hong (Advanced Industrial Material Team/Research & Technology Division, Ingredient Business Unit) ;
  • Choi, June-Ho (Department. of Forest Sciences, College of Agriculture & Life Sciences, Seoul National University) ;
  • Lee, Hyo-Jin (Surface-Finishing & Fastening Technology Team, Hyundai Motor Company) ;
  • Choi, In-Gyu (Department. of Forest Sciences, College of Agriculture & Life Sciences, Seoul National University)
  • 박세영 (서울대학교 농업생명과학대학 산림과학부) ;
  • 홍창영 ;
  • 김선홍 (대상(주) 소재BU 연구기술본부 소재1연구실 산업신소재팀) ;
  • 최준호 (서울대학교 농업생명과학대학 산림과학부) ;
  • 이효진 (현대자동차 표면처리체결기술개발팀) ;
  • 최인규 (서울대학교 농업생명과학대학 산림과학부)
  • Received : 2017.12.19
  • Accepted : 2018.04.04
  • Published : 2018.05.25

Abstract

The purpose of this study was to evaluate the effect of several chemical treatments to prevent photodegradation of wood veneer by external UV (Ultraviolet) light. Of woods, walnut veneer is selected as a raw material for this study since it is known as a luxurious wood with dark color giving an esthetic effect. Alcohol-benzene, hydrogen peroxide ($H_2O_2$) and sodium hypochlorite (NaClO) solution were used for investigate the effect on color stabilization. Despite the removal of the extractive compounds, which is known as a discoloration component, a significant color change of walnut wood veneer was observed. Meanwhile, the veneers treated by 20 and 30% $H_2O_2$ solution at $75^{\circ}C$ for 1 h also showed the no positive effect of color stability exposed to UV light although they have a bleaching effect on wood veneer. Besides, it was difficult to maintain the original color of walnut veneer due to the elution of the extractive compounds. On the other hands, the veneer treated by NaClO solution indicated the good performance on color stability despite of the intensive UV light test. However, when the concentration exceeds 3%, surface roughness and fiber damage occurred simultaneously. Therefore, the walnut species should be treated with proper concentration when sodium hypochlorite is applied to the veneer.

본 연구에서는 자외선 노출에 의한 목재베니어의 광 열화를 방지하기 위하여 변색 요인을 제거하여 그 효과를 평가하고자 하였다. 목재 중 추출물함량이 높고 어두운 색상을 나타내며 고급용재로 사용되고 있는 대표 활엽수종인 walnut을 공시재료로 선택하여 광 열화 분석 및 방지법에 관한 연구에 사용하였다. 베니어 내 발색단을 함유하는 물질을 탈리하기 위해 실시한 알코올-벤젠, 과산화수소 및 차아염소산나트륨 수용액 처리 후 광 안정성 평가를 실시하였다. 광 변색인자로 알려진 추출물 성분의 제거 후에는 색 안정화 효과를 보이지 않았다. 한편, 리그닌 성분을 제거하기 위하여 과산화수소를 20, 30% 농도로 하여 $75^{\circ}C$에서 1시간 처리하였으며, 그 결과 표면색상에 대한 표백효과는 나타내었으나 추출물 용출에 따른 재색 유지가 어려우며 광 노출에 대한 안정화 효과를 나타내지 않았다. 반면, 차아염소산나트륨 수용액을 1, 2 및 3% 농도로 하여 동일 온도 및 시간 조건에서 처리 한 베니어의 광 노출 평가결과, 추출물 용출에 의한 재색변화는 나타났지만, 광 노출에 의한 색상 변화는 관찰되지 않았으므로 우수한 안정화 효과를 나타낼 수 있었다. 하지만, 3% 이상 농도에서는 베니어 표면의 거칠기와 손상이 발생되므로, walnut 베니어의 경우 적정 농도조건에서의 처리가 필요한 것으로 사료된다.

Keywords

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