• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.668-671
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• 2009

Photosensitive polyimide containing methoxy cinnamate derivatives as a photo-alignment layer is investigated. The anisotropy of alignment layer was induced by irradiation linearly polarized UV (LPUV). We studied the effect of the methoxy cinnamate groups on alignment LCs.

• E2M - 전기 전자와 첨단 소재
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• 제9권1호
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• pp.59-66
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• 1996

Polyimides containing cyclobutane ring in main chain is known to be thermally stable and able to be developed in organic solvents after photolysis with 254 nm UV light. This type of polyimides can be used as promising positive photoresist in VLSI fabrication process. In the current VLSI process, photoresist films are formed by spin coating. The film thickness is more than several hundred nano meters. It seems that there is room for improvement of film coating process by introducing Langmuir Blodgett technique. Thereby ultra thin film photoresist can be formed, and higher density of integration in VLSI be achieved. In the present work, depositing procedure of LB films of this polyimide was investigated. LB film thickness was measured by ellipsometry to evaluate deposited film status. Chemical imidization procedure was studied to avoid several problems in thermal imidization. The pattern of submicron dimension has successfully formed on LB film of 8nm thick, which found showing good contrast.

• 한국응용과학기술학회지
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• 제15권4호
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• pp.21-25
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• 1998

Organic-based electroluminescent devices have attracted lots of interests because of their possible application as a large-area flat panel display. Polyimides have been used for photo-alignment in LCD(Liquid Crystal Display). However, the devices used in this study were fabricated with polyimide doped with N,N'-Diphenyl-N,N'-di(m-tolyl)-benzidine(TPD) (3, 10, 30wt%) for electroluminescent hole tranforting layer(EHTL). The photochemical and physical properties of EHTL was studied. The film thicknesses were reduced under illumination with UV light. Polyimide films doped with TPD(3wt%) was irradiated and the electrical properties of the films were studied.

• 폴리머
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• 제28권6호
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• pp.494-501
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• 2004

시클로부탄-1,2,3,4-테트라카복실산 이무수물, 2-(메타크릴로일옥시)에틸-3,5-디아미노벤조에이트 및 1,3-비스(3-아미노프로필)-1,1,3,3-테트라메틸디실록산을 N-메틸-2-피롤리돈 하에서 용액 중합 반응시켜 알칼리 수용액에서 현상이 가능할 뿐만 아니라 가시광선 영역에서 우수한 광투과성을 보이는 신규 감광성 폴리이미드 전구체인 폴리암산 (PAA-0)을 제조하였다. 광개시제의 존재 하에서 노광 후 열경화된 폴리이미드 박막은 2.38 wt%의 테트라메틸암모니움 히드록사이드 수용액에 용해되지 않는 특성을 보였으며, 이를 이용하여 광에 의한 미세 화상 형성 연구를 수행하였다. 폴리이미드 전구체 박막의 광반응에 적합한 광개시제는 2, 2-디메톡시-2-페닐아세토페논임을 알 수 있었고, 최적 광량은 400∼600 mJ/$\textrm{cm}^2$의 범위에 있음이 확인되었다. 감광성 폴리이미드 전구체는 25$0^{\circ}C$의 온도에서 50분간 열경화시킴으로써 투명한 폴리이미드 박막으로 전환이 되었으며, 유기용제를 비롯한 포토레지스트 제거제에 대한 우수한 내용제성 및 가시광선영역에서의 우수한 광투과 특성을 나타내었다.

• 폴리머
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• 제26권6호
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• pp.701-709
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• 2002

새로운 포지티브형 감광성 폴리이미드 전체를 합성하기 위하여, 폴리아믹산의 인부 카르복시산 기를 $K_2$CO$_3$/HMPA 조건 하에서 광분해성 감광성 기인 4,5-dimethoxy-2-nitrobenzyl bromide의 반응시켜 에스테르를 형성하고 나머지 카르복시산기를 화학적 이미드화시켜 poly[imide-co-(amic ester)]를 합성하였다. 합성된 고분자의 구조는 FT-IR, $^1$H-NMR 등으로 확인하였고, DSC와 TGA를 이용하여 열적 특성을 확인하였다. 또한 이 고분자에 자외선을 조사하면 감광성 기인 4,5-dimethoxy-2-nitrobenzyl 기가 분해되어 카르복시산 기를 형성함에 따라 고분자가 알칼리 현상액에 대해 용해하였으며, 이를 이용하여 포지티브 패턴을 형성할 수 있었다. 여러가지 4,5-dimethoxy-2-nitrobenzyl ester 농도를 갖는 poly[imide-co-(amic ester)]의 겔분율 실험을 통하여 감광곡선을 얻었으며, 이를 통해 이 고분자의 감광특성을 조사하였다. 그 결과 감도는 4000~6000 mJ/$\textrm{cm}^2$ 이었으며, 조도는 3.1~4.9 정도인 것으로 확인되었다.

• 폴리머
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• 제30권2호
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• pp.97-107
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• 2006

방향족 강직사슬 폴리이미드는 높은 주사슬 간의 인력으로 인해 유기용제에 용해되지 않고 상전이온도가 분해 온도보다 높아 응용분야에 많은 제한이 되고 있다. 방향족 폴리이미드의 가공성을 향상시키기 위해서 긴 곁사슬을 도입하면 가공성 향상뿐만 아니라 곁사슬과 주사슬 사이에 독특한 구조를 가지게 됨으로써 새로운 응용분야를 개척할 수가 있다. 본 논문에서는 여러 가지 형태의 곁사슬을 가지는 방향족 폴리이미드의 합성과 화학구조에 따른 물성변화에 대해 논의하고 또한 폴리이미드의 액정배향막, 감광재료, 교대 다층박막, 발광재료 등으로의 응용특성에 관해서도 조감한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1625-1628
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• 2006

Two different negative-type photosensitive polyimides were synthesized and characterized for an application as an interdielectric layer in TFTLCD array. In the case of photocurable polyimides, the photosensitive moiety, 2-HHSP, was synthesized through 3 step reaction, and then was incorporated into side chains of polyimide precursor by post reaction. Optimum compositions of negative-type photocurable polyimde were also formulated. For photopolymerizable polyimides, two novel UV monomers containing imide linkages were prepared. An aqueous alkaline developable polymer matrix was synthesized by free radical copolymerization. A negative photoresist formulation was developed utilizing synthesized UV monomers containing imide linkage, photoinitiator, UV oligomer, and alkali developable polymer matrix. It was found that viaholes with good resolution, high transmittance and thermal resistance could be obtained by photolithographic process utilizing the negative-type photoresist formulations.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.480-483
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• 2005

We report on studies of photoalignment of cholesteric liquid crystals on photosensitive phenylon-based polymer. We found that reflective and electro-optical characteristics of cholesteric cells strongly depend on UV exposure doze. The optimized UV treatment of the polymer allowed us to obtain the same quality of alignment on standard rubbed polyimide orientants. At the same time, the photosensitive orientant possesses evident advantage of the effective control of cholesteric textures

• Macromolecular Research
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• 제8권4호
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• pp.172-178
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• 2000

We synthesized polymethacrylate and polyurethane bearing a photosensitive azobenzene chromophore. Photo-induced birefringence of the thin film was observed under a linearly polarized light(λ = 532 nm). Dynamic behaviors of birefringence in two polymers were investigated in terms of the rate constants of growth and decay. An induced dichroism was observed from polarized UV-VIS absorption spectroscopy. Layers of two photosensitive polymers were used for aligning liquid crystal (LC) molecules instead of one of the rubbed polyimide layers in the conventional twisted nematic cell. For producing homogeneous alignment of a nematic LC molecule, a linearly polarized light was exposed to the films of two polymers. The stability of the LC alignment upon the linearly polarized light exposure was also studied.

• Macromolecular Research
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• 제9권5호
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• pp.247-252
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• 2001

Tricyclic aliphatic dianhydride monomer, tricycle[4.2.2.0]dec-9-ene exo, endo-3,4: 7,8-tetra-carboxylicdianhydride (TCDDA), was synthesized by photochemical reaction and poly(amic acid)s from TCDDA and diamines such as 1,4-bis-(4-aminophenoxy)benzene (BAB), 2,2-bis(4-(4-aminophenoxy) phenyl) propane (BAPP), 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane (BAPHF), bis(4-(4-ami-nophenoxy) phenyl)sulfone (BAPS), and 1,4-bis-(4-aminophenoxy)biphenyl (BABP) were prepared. The inherent viscosities of the poly(amic acid)s were between 0.39 and 0.50 dL/g. The poly(amic acid)s were converted to polyimide films by thermal imidization. The glass transition temperatures (T$\_$g/) of the polyimides were in the range of 201-263$\^{C}$. The thermogravimetric analysis (TGA) thermogram of these polyimides showed the temperatures of 5% weight losses between 375 and 393$\^{C}$ in nitrogen atmosphere. To show their utility for image generation, degradations of these polyimides in UV exposure were investigated by UV spectroscopy.