1. Department of Organic and Polymeric Materials Tokyo Institute of Technology Tokyo 152‐8552 Japan
2. Advanced Material Business Promotion Department Osaka Gas Co., Ltd. Osaka 554‐0051 Japan
3. Department of Chemical Science and Engineering Tokyo Institute of Technology Tokyo 152‐8552 Japan
4. School of Materials and Chemical Technology and Research Institute of Polymer Science and Technology (RIPST) Tokyo Institute of Technology Yokohama 226‐8503 Japan