Polymers - Vol. 58, No. 4 (April, 2009)

Hot Topics

Vol. 58, No. 4 (April, 2009)

Block Copolymer Lithography and Applications to Electronic Devices
Corporate Research and Development Center, Toshiba Corporation

The performance of electronic devices greatly improves as the feature sizes of their parts become smaller. On the other hand, cost of fabrication is skyrocketing. Block copolymer lithography may become an alternative way of conventional photolithography since it forms nano-scale periodic patterns and can be transferred to substrates. Several kinds of devices were realized. Patterned media for a hard disk drive was demonstrated, while fine aligned nano-scale magnetic particles were fabricated using aligned microdomains of block copolymer as an etch mask. Fabricating a nano-columnar structure on emitting surface of LED doubled the light-extraction efficiency. An ultraviolet wire grid polarizer was realized by nano-scale line and space pattern was obtained for more than cm2-scale by applying the share stress. PMF Preprints, Japan 2008, 17, 138.

Polycarbonate from CO2 : Green & Sustainable Process in Practice
Shinsuke FUKUOKA
Asahi Kasei Corporation
The worldÕs first successful green & sustainable process for producing polycarbonate (PC) from CO2 has been industrialized. Until Asahi KaseiÕs new process, all of PC was derived from CO and most of PC was produced using highly toxic phosgene, very large amount of CH2Cl2 and water. In the new non-phosgene process, three raw materials, CO2, Ethylene Oxide and Bisphenol-A, are transferred to high-quality PC and high-purity monoethylene glycol (MEG) in high yields. As all CO2 used is divided CO and O, and successfully introduced into PC and MEG respectively, 1732 tons of CO2 are utilized, when 10,000 tons of PC are produced. Plant capacity of licensees increases from 340,000 tons/y in 2008 to 600,000 tons/y in the near future. PMF Preprints, Japan 2008, 17, 1.

Sliding Graft Copolymer
Kohzo ITO
Graduate School of Frontier Sciences, The University of Tokyo
Sliding graft copolymer (SGC), molecular necklace having many side chains, was prepared. Side chains in SGC can slide along and rotate around the polymer axis of polyrotaxane. Poly-e-caprolactone side chains are grafted onto cyclodextrin rings of a polyrotaxane by ring-opening polymerization of e-caprolactone initiated by hydroxyl groups of the polyrotaxane. An amorphous, flexible, and sufficiently tough elastomer film was prepared by crosslinking SGC with hexamethylene diisocyanate (HMDI). SGC can be regarded as a new class of supramolecules and graft copolymers, showing intrarmolecular microphase separation due to the sliding motion of side chains. PMF Preprints, Japan 2008, 17, 156.

Biaxially Oriented PET Film with Controlled Amorphous Structure
Masahiro KIMURA*, Isao MANABE, Ryosuke MATSUI, Kozo TAKAHASHI, Tetsuya TSUNEKAWA, and Kouichi ABE
Toray Industries, Inc.
Amorphous structure of PET as semi-crystalline polymer was analyzed by NMR, MDSC and computer chemistry. Precise control of amorphous structure offered a new biaxially oriented film with high YoungÕs modulus or large elongation. Rigid amorphous structure evaluated from MDSC and restricted amorphous structure defined from solid NMR measurement played an important role to improve biaxially stretching ability and mechanical properties. In comparison with a conventional biaxially oriented PET film, about 50 percent increase of YoungÕs modulus and more than 300% elongation were obtained by control of rigid amorphous structure and restricted amorphous structure, respectively. PMF Preprints, Japan 2008, 17, 21.

Recycling Method for Polyester Fiber
Taizo MORI
In most cases, the qualities of recycled fiber products are inferior to the oil based products. In order to solve the problems, we have proposed our chemical recycling method, which achieve the Closed-Loop recycling, for polyester fibers. This recycling process, which is one of the core components of our "ECO- CIRCLE", has been already operated in Japan. This process can reduce the large amount of CO2 exhaust compared to the oil based production process. We are willing to increase ÒECO- CIRCLEÓ members for realizing sustainable society. PMF Preprints, Japan 2008, 17, 7.

Ultra-Sensitive DNA Chip
New Frontiers Research Laboratories, Toray Industries, Inc.
We have developed a new DNA chip whose substrate has a unique minute columnar array structure made of plastic. The DNA chip exhibits ultrahigh sensitivity, up to 100-fold higher than that of reference DNA chips, which makes it possible to monitor gene expression profiles even with very small amounts of RNA (0.1-0.01 mg of total RNA) without amplification. Differential expression ratios obtained with the new DNA chip were validated against those obtained with quantitative real-time PCR assays. This novel microarray technology would be a powerful tool for monitoring gene expression profiles, especially for clinical diagnosis. PMF Preprints, Japan 2008, 17, 9.

CNT-Polyimide Nanocomposite Applicable to Nonlinear Optical Devices
National Institute of Advanced Industrial Science and Technology (AIST).
Saturable absorption of single-wall carbon nanotubes (SWNTs) in near-infrared region is a promising nonlinear optical function for optical telecommunication devices. To obtain an optically uniform material that can be formed into a variety of device structures, we developed an SWNT-polyimide nanocomposite in which SWNTs are dispersed in nanometer-scale uniformity. This material was applied to a mode-locked short pulse fiber laser only by attaching a small piece of SWNT-polyimide film onto a fiber connector as shown in the figure. The flexible and robust nature of the polyimide gave a great benefit for such a usage that is hard for conventional semiconductor devices. This material could also be applied to an optical waveguide device promising for future nonlinear optical switching devices. PMF Preprints, Japan 2008, 17, 142.

Fullerene Meets Dendron: Advanced Materials Containing Fullerodendron
Graduate School of Environmental Science, Okayama University
Fullerodendrons, fullerene derivatives having a dendron unit, have attracted considerable attention in the material science because of many potential applications. Introducing dendritic wedge into fullerene is very interesting because self-organized nano-architecture consisting of fullerodendrons can be controlled by the structure, i.e., generation and terminal groups, of the dendron unit. For example, we obtained LB films and liquid crystalline materials having desired molecular arrangement, that could be applied to electronic devices such as field effect transistor (FET). Furthermore, we have found that the formation of supramolecular nanocomposite between fullerodendrons and single-walled carbon nanotubes (SWNTs) using simple sonication method. Interestingly, the fullerodendron/ SWNTs supramolecular nanocomposite was expected to act as the nano solar cell, since we could show the evidence of photoinduced electron transfer between SWNT and fullerene within the composite. PMF Preprints, Japan 2008, 17, 160.

Convenient Preparation of Positive Tone Photo-Sensitive Polyimide by Novel Partially Quantitative Esterified of Poly(amic acid)
Masao TOMIKAWA*, Satoshi YOSHIDA, and Naoyo YOSHIDA
Toray Industries Electronic & Imaging Research Laboratories
We developed novel quantitative esterification of poly(amic acid) by using dimethyl-formamide-dialkylacetal. The esterification ratio was determined by amount of the acetal. The reaction made us to control dissolution rate to alkali-solution conveniently. By using the partial esterified poly(amic acid) and diazide-naphthoquinone compound, we developed novel positive photosensitive polyimide. This method is quite convenient to obtain various types of positive photo-sensitive polyimide precursor. PMF Preprints, Japan 2008, 17, 162.

Multivariate Analysis of 13C NMR Spectra of MMA-HEMA Copolymers
Koichi UTE
Department of Chemical Science and Technology, The University of Tokushima
NMR signals due to each group in copolymers often exhibit overlapped splitting due to comonomer sequences and stereoregularity, and thus assignment of the individual resonance peaks is troublesome. As a new approach to obtain quantitative information from NMR spectra of copolymers without assignment of resonance peaks, methods of multivariate analysis were applied to the analysis of 13C NMR spectra of copolymers of MMA and 2-hydroxyethyl methacrylate (HEMA) prepared by the radical copolymerization under various conditions. The spectral pattern of the copolymers was explained well with the first and the second principal components (PC1 and PC2), and those components showed relationship to chemical composition and syndiotacticity of the copolymers. PMF Preprints, Japan 2008, 17, 23.

Development of High Barrier Films for Flexible Displays
Here I will show functional films developed in Toppan printing, such as optical, barrier and conductive films. Although gas barrier properties for water vapor is not sufficient, transparency and flexibility of plastic substrates are superior to those of the glass substrates. Currently, gas barrier films with water vapour transmittance 10-1~10-2 g/m2/day are used for flexible LCD. For organic electro luminescence (OLED), gas barrier films with 10-2~10-6 g/m2/day is needed. PMF Preprints, Japan 2008, 17, 164.

Synthesis of Mechanically Cross-Linked Polymers
Masataka KUBO
Graduate School of Regional Innovation, Mie University
Copolymerization of a monomer in the presence of a cyclic polymer with polymerizable group (cyclic macromonomer) in high concentration leads mechanically linked three- dimensional network polymer. The network structure is formed by the threading of the cyclic moiety by a segment of another polymer chain. This class of materials has attracted a great deal of interest as new functional materials with unusual chemical, physical and mechanical properties due to the high degrees of freedom in segmental movement since cross-linking points can move in these three-dimensional structures. We have developed various mechanically cross-linked polymers including polystyrene, polyacrylates, poly(dimethylsiloxane), polyelectrolytes, and thermo-sensitive polymers as new class of soft materials. PMF Preprints, Japan 2008, 17, 150.