Through basic studies of various resins, the most suitable resin was selected to improve the reflectivity and productivity in making white opaque polyethylene terephthalate film. Accordingly, oriented films were investigated through conventional blending experiments based on selected resin. First, the results showed that cyclic olefin copolymer (COC) and polyolefin elastomer (POE) were better than other materials (e.g., polymethyl methacrylate (PMMA), polylactic acid (PLA), and polyvinylidene fluoride (PVdF)) in improving properties through optical, thermal, and surface investigations. To observe the compatibilizing effect, high density polyethylene grafted maleic anhydride (HDPE-g-MAH) blended with polyethylene terephthalate (PET) and each selected resin as a compatibilizer. For the compatibilizing effect to reduce the size of the dispersed phase, 5 phr of HDPE-g-MAH was found as the most effective contents through mechanical and morphological studies. COC and POE were blended with PET at a ratio of 70:30, and the process of stretching was performed to identify the shape of the void that contributes to the improvement of the reflectance. Although POE showed better compatibilizing effect than COC through morphological, it was inferior to COC in the reflectance. Because POE was melted at PET film’s stretching temperature, the void contributing reflectance was not formed

폴리에틸렌테레프탈레이트(polyethylene terephthalate, PET) 블렌딩필름에 대해서 반사율과 생산성 향상을 위해 다양한 수지의 블렌딩을 진행하여 각각의 물성 연구를 진행하였다. 사이클릭올레핀 코폴리머(cyclic olefin copolymer, COC)와 폴리올레핀 엘라스토머(polyolefin elastomer, POE), 폴리메틸메타크릴레이트(polymethyl methacrylate, PMMA), 폴리락트산(polylactic acid, PLA) 및 폴리비닐리덴 플루오라이드(polyvinylidne fluroide, PVdF)의 광학적, 열적 및 표면 특성이 가장 우수하고 PET 필름의 생산성에 미치는 영향이 가장 적은 것이 COC와 POE로 판단하여 PET와 70:30으로 각각 블렌드하였다. 선택된 COC와 POE의 상용화 효과를 극대화하기 위해 high density graft maleicanhydride(HDPE-g-MAH)를 함량별로 COC와 POE에 PET와 블렌딩하고, 5 phr의 HDPE-g-MAH가 가장 효과적이며 이를 연신필름으로 제작하여 반사율을 확인하였을 때 COC를 블렌딩한 필름이 POE 블렌딩필름보다 약 30%가량 높은 반사율을 확인하였다. 이는 POE가 PET와 상용화 효과가 우수한 것으로 판단되나 이는 PET 필름의 연신 과정에서 POE가 PET의 연신온도에 녹아 동일 연신온도에서 동시에 연신되어 void(공극)이 형성되지 않아 반사율에 있어서 COC에 비해 열위한 것으로 사료된다

Keywords: polymer blend, biaxially oriented white opaque film, cyclic olefin copolymer, polyolefin elastomer