플렉서블 디스플레이 기판용 투광성 섬유 복합체 필름의 제조 및 연구

Abstract

차세대 디스플레이는 높은 투광도와 낮은 열 팽창 계수를 갖는 플렉서블한 기판을 포함한 디스플레이 이다. 현재 플렉서블한 고분자 필름에 대한 연구가 활발히 진행 중이다. 투광성 고분자 필름은 디스플레이로 구동되기 위해 낮은 열팽창 계수를 요구한다. 하지만 무정형 고분자 필름의 열 팽창 계수는 55~80ppm/℃로 높은 값을 보인다. 따라서 이 연구에서는, 직조된 유리 섬유를 사용하여 유리 섬유 복합체를 제조 함으로써 낮은 열 팽창 계수를 갖는 고분자 필름을 제조 하였다. 더불어 고분자 수지와 유리 섬유와의 굴절률을 매칭 시키고, 유리 섬유에 아크릴레이트로 표면 처리를 함으로써 아크릴레이트계 고분자 수지와의 인력을 강화함으로써 80% 이상의 높은 투광도를 갖는 유리 섬유 복합체 필름을 제조하였다. 또한, 180도의 공정 온도를 거친 섬유 복합체 필름의 표면 모폴로지 문제를 해결하기 위하여 다 관능기를 가진 물질을 첨가하였다. 8개와 10개의 아크릴레이트 작용기를 갖는 물질을 첨가해 줌으로써 유리 전이 온도 이상의 공정온도에서 황변이 되거나 유리 섬유와 바인더 사이에 갈라짐이 생기는 것을 방지하였다. |It is an important issue to develop the flexible polymer substrate with the high transmission and low thermal expansion coefficient for the realization of the next generation flexible display. Chemists have made many different attempts to prepare the fiber composite which possesses the high optical transparency. The transparent polymer film with the low thermal expansion coefficient (<20 ppm/℃) is required for the development of the flexible display. However, the most of transparent amorphous polymer film show the high CTE values in the range of 55~80 ppm/℃. In this study, the acrylic binders with the controlled refractive index were prepared in order to improve the transparency of the fiber composite. The transmittance could be observed above 80%. Also, in order to improve the interaction of interface between glass fiber and binder, the glass fiber was treated with an acrylate silane coupling agent(3-(Trimethoxysilyl)propyl methacrylate). So, the chemical linkage between glass fiber and binder was induced. The transmittance was increased by 4% after glass fiber was acrylated. Also, the poor thermal stability of glass fiber composite was solved by incorporating the multi-functional groups along the network. When the POSS with 8 functional groups and 10 functional acrylate were added into the binder, the composite showed the Tg-less transition, which results in the much improved thermal stability. Finally, the application of composite film on flexible LCD was also demonstrated.; It is an important issue to develop the flexible polymer substrate with the high transmission and low thermal expansion coefficient for the realization of the next generation flexible display. Chemists have made many different attempts to prepare the fiber composite which possesses the high optical transparency. The transparent polymer film with the low thermal expansion coefficient (<20 ppm/℃) is required for the development of the flexible display. However, the most of transparent amorphous polymer film show the high CTE values in the range of 55~80 ppm/℃. In this study, the acrylic binders with the controlled refractive index were prepared in order to improve the transparency of the fiber composite. The transmittance could be observed above 80%. Also, in order to improve the interaction of interface between glass fiber and binder, the glass fiber was treated with an acrylate silane coupling agent(3-(Trimethoxysilyl)propyl methacrylate). So, the chemical linkage between glass fiber and binder was induced. The transmittance was increased by 4% after glass fiber was acrylated. Also, the poor thermal stability of glass fiber composite was solved by incorporating the multi-functional groups along the network. When the POSS with 8 functional groups and 10 functional acrylate were added into the binder, the composite showed the Tg-less transition, which results in the much improved thermal stability. Finally, the application of composite film on flexible LCD was also demonstrated.