高分子 Vol.64 No.7
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特集 ガラスに挑む高分子材料
展望 COVER STORY: Highlight Reviews
高分子材料の高透明化技術
Highly Transparent Technologies for Polymer Materials
金井 俊孝
Toshitaka KANAI
<要旨> 高透明材料のIT分野や包装フィルム・容器分野への適用事例を紹介する。さらに、高透明化技術として、PPシート成形技術を取り上げ、押出成形では結晶生成に影響する冷却条件に着目し、冷却固化前の溶融樹脂膜の剪断応力の制御と、ダイを出た後の急冷・熱処理による透明性制御、樹脂性状の制御によって透明性を向上させる技術を紹介する。
Keywords: Polypropylene / Transparency / Spherulite / Crystallization / Heat Treatment / Multilayer
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トピックス COVER STORY: Topics and Products
結晶性シクロオレフィンポリマーの開発
Development of Crystalline Cycloolefin Polymer
早野 重孝
Shigetaka HAYANO
<要旨> Crystalline Cycloolefin Polymer was developed for the first time as a means to enhance thermal properties of conventional Cycloolefin Polymer. Stereocontrol of ROMP of norbornene(NB), dicyclopentadiene(DCP) and tetracyclododecene(TCD) was achieved by Mo- and W-based binary catalysts. Hydrogenated poly(NB)s were crystalline polymers irrespective of their tacticities, but melting of isotactic polymer was much higher than atactic and syndiotactic ones. Isotactic and Syndiotactic hydrogenated poly(DCP)s were clarified to be crystalline polymers of which meltings were extremely high. Syndiotactic hydrogenated poly(TCD) was entirely amorphous. On the other hand, atactic and isotactic polymers were revealed to be crystalline.
Keywords: Cycloolefin / Metathesis / Stereoselective / Dicyclopentadiene / Norbornene / Crystalline Polymer / Polyolefin
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耐熱透明ポリマー基板材料の開発経緯と現在
Development of Thermally Stable and Colorless Polymer Substrate Materials, Past and Present
安藤 慎治
Shinji ANDO
<要旨> Recently, colorless and transparent polymer films exhibiting high thermal stability and good mechanical properties attract much of interests as substrate materials for flexible organic light-emitting diode (OLED) displays. A colorless fluorinated polyimide was firstly invented by DuPont in 1965, and it has been tried out for aerospace and optical communication applications. In the last decade, Japanese chemical companies have developed various kinds of colorless polyimides (PIs) for flexible display applications using fluorinated and/or alicyclic source materials, of which the coefficients of thermal expansion (CTE), refractive indices, birefringence, glass transition temperatures, electric resistance and film thickness are precisely controlled. In particular, control of CTE for reducing residual stress at the surface between PI substrate and inorganic layers of ITO and/or IGZO is of special importance, and it was achieved by judicious choice of molecular structure and processing conditions. However, the high moisture uptake and significant transmission of oxygen and moisture compared with inorganic glass are still the challenging task.
Keywords: Flexible Display / Film Substrate / Colorless Polyimide / Thermal Stability / Thermal Expansion
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粘土を用いたガラス代替材料の開発
Development of Glass Alternative Material Using Clay
蛯名 武雄
Takeo EBINA
<要旨> A smectite-based gas barrier coating film was developed. In the coating layer, thin smectite crystals are orderly and densely stacked and an added organic polymer acts as a binder. Purified bentonite and synthetic smectite were used because of their good film formability. The film is prepared by a solution-casting method. The film has superior heat-resistance and gas barrier performance. Transparent films were also successfully made from synthetic smectite and transparent organic polymer. Such a gas barrier film is prepared using a water-soluble polymer and a synthetic smectite clay. The film also has high visible light transparency and it is stable up to 350 degree Celsius. This film is expected to be applied for glass-alternative flexible films.
Keywords: Clay / Nanocomposite / Gas Barrier / Visible Light Transparency
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有機-無機ハイブリッドハードコート
Organic-Inorganic Hybrid Hardcoat
蔵岡 孝治
Koji KURAOKA
<要旨> Organic-inorganic hybrid flexible hardcoat layers on poly(ethylene terephtalate) (PET) and polycarbonate (PC) were prepared by sol-gel method. The prepared hardcoats were homogenous and transparent, and light transmittance of the hardcoats was high. This transparency is important for applications, such as touch panel and packaging materials. Pencil hardness of the prepared hardcoats were 3H on PET and B on PC, respectively. The prepared hardcoats indicated a high degree of flexibility (Diameter of Mandrel was 10 mm on flexibility test). This flexibility combined with hardness is a novel property of the organic-inorganic hybrid hardcoat film due to dispersion of inorganic segments and organic segments at the molecular level and the effect of phenyl groups.
Keywords: Organic-Inorganic Hybrid / Hardcoat / Silica
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セルロースナノ材料
Cellulose Nanoaterials
能木 雅也
Masaya NOGI
<要旨> This topics presented optically transparent nanopaper using cellulose nanofibers only without any polymers. The nanopaper have high optical transparency and low coefficient of thermal expansions like glass, higher thermal resistance than plastics, and high foldability like traditonal paper. This topics have also brief introductions about electronic device applications such as transparent electrodes, transistor arrays, ultra flexible nonvolatile memory, foldable antenna. Thus, the nanopaper is one of the best candidate for future flexible electronic device materials.
Keywords: Cellulose Nanofiber / Paper Electronics
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イソシアヌル酸を母核とする高耐久・高透明材料
The High Reliability Optical Material Based on the Isocyanuric Acid
大森 健太郎
Kentaro OHMORI
<要旨> The curable resin for advanced electronic materials is required to excellent workability and heat resistance and transparency. For such application field, we have developed a novel epoxy resin having high thermal stability and low absorption to visible light. The material is designed to UV and/or Thermal curable resin, and soluble to popular organic solvents. From these properties, the developed epoxy resin is expected to be beneficial for the transparent sealing material for optical semiconductor such as LED and the clear film substrate.
Keywords: Multifunctional Epoxy Monomer / Isocyanuric Acid / Optical Materials
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グローイングポリマー Polymer Science and I: A Personal Account
分子の気持ちを考える
Let’s Think about the Feelings of Molecules
逢坂 直樹
Naoki OUSAKA
<要旨> When I was a graduate student, I have read a wide variety of scientific papers that helped me to enhance not only my knowledge but also the ability of logical thinking.
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高分子科学最近の進歩 Front-Line Polymer Science
分子の自己組織化とフォトン・アップコンバージョン
Molecular Self-Assembly and Photon Upconversion
楊井 伸浩・君塚 信夫
Nobuhiro YANAI, Nobuo KIMIZUKA
<要旨> Photon upconversion (UC) is the key technology to overcome the thermodynamic efficiency limits in solar energy conversion devices. Triplet-triplet annihilation (TTA)-based UC has drawn increasing attention in recent years, primarily because of its occurrence with low-intensity, noncoherent light as the excitation source. To date, efficient TTA-UC has been achieved in solution because diffusion of triplet molecules is essential for energy transfer processes. However, the use of volatile organic solvents and deactivation of triplet states by molecular oxygen significantly disturb their practical applications. Although recently the TTA-based UC has been investigated in solid polymer films, the slow molecular diffusion limits the efficiency of TTA-UC. To solve these problems, we are proposing a paradigm shift from molecular diffusion to energy migration. Assemblies of donor and acceptor display a sequence of efficient donor-to-acceptor triplet-triplet energy transfer (TTET), triplet energy migration, and TTA in the self-assembled state.
Keywords: Photon Upconversion / Self-Assembly / Energy Migration
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