Vol.2 No.2 2009

75/98

Research paper : Study on the PAN carbon-fiber-innovation for modeling a successful R&D management (O. Nakamura et al.)−155−Synthesiology - English edition Vol.2 No.2 (2009) oscillation.” Excited oscillation means “‘cooperation’ where synchronization of the research management and the autonomy was achieved in setting a new research theme that might be useful in society, in the progress of R&D spurred by the researcher’s interest,” and also includes manifest and latent exchanges and “collaborations” with the companies toward industrial use.We present the innovation model based on the process of handing over the PAN carbon fiber to industry as the “exited oscillation model,” and suggest strengthening the management for future innovation production.2 Course of technological invention2.1 Situation of carbon fiber development(1) Summary of invented carbon fiberIn the 1950s, products made from carbon or graphite (highly crystallized carbon) was used only in molded products that took advantage of the heat resistance and conductivity properties, such as electric equipment brush, electrolysis electrode, graphite for nuclear reactors, or in powder products such as carbon black, activated carbon, and colloid graphite. No carbon material in fiber form was known, and graphite fibers were thought to be extremely difficult to manufacture.Since graphite does not melt until it is heated to nearly 4000 ºC under high pressure, carbon could not be melted and spun like glass fiber. Like the manufacture of carbon materials in general, fiber could be obtained only by carbonizing organic material, and investigations were done using various fibrous materials such as cellulose and polyvinylidene chloride fibers. As a result, it was found that acrylonitrile fibers, if carbonized under suitable heating conditions, could be made into graphite by releasing the nitrogen and hydrogen in the molecule mainly as ammonia and hydrocyanic acid, providing carbon that maintained the form of the fiber, and by graphitizing this fibrous carbon by high-temperature treatment. The obtained product had metallic luster, and was observed by x-ray measurement to be profoundly graphitized[4]. The PAN carbon fiber was developed in this manner.(2) Course of developmentOriginally, carbon fiber was developed in the United States in 1956, using rayon as the raw material (Fig. 1)[1]. In the United States, Union Carbide Corporation (UCC) had some success with the rayon carbon fibers.In Japan, Dr. Akio Shindo of GIRIO became aware of the events in the United States, and started studying the carbonization of polyacrylonitrile fiber instead of rayon. In September 1959, a patent was filed[5] for the PAN carbon fiber, and a research entitled “Study of graphite fiber (1st report) – Growth of crystallites in heat treatment” was presented at the Annual Meeting of Chemistry-Related Societies held in October 1959[6]. In November 1959, this research result was also published in the GIRIO News[7] that was circulated widely among the people of companies in the Kansai region. The details of the research are summarized in the GIRIO Report No. 317[8].Through these activities, it could be imagined that the result of PAN carbon fiber research was strategically announced under the judgment that it was highly innovative and had excellent prospects.An advice from a U.S. military personnel in 1965 provided a major turning point for Dr. Shindo’s R&D[2]. Until then, attempts were made to utilize the PAN carbon fiber as a material characterized for its “flexibility” along with its main properties, heat resistance and conductivity. However, the military specialist mentioned that its superiority was “mechanical strength” and “tensile modulus.” The direction of research turned to use as structural material. Since this turning point, the corporate participation in carbon fiber research increased, and the companies’ effort toward industrial use accelerated. For these companies, GIRIO was essential because it was producing outstanding results in the PAN carbon fiber research.In addition to the “collaboration” with industry in research and technical assistance, the research on “standardization,” which is mandatory for the development of new materials, started in 1975. The Japan Industrial Standard (JIS) for carbon fibers was established in 1980. These efforts contributed greatly to the increased competitiveness of the Japanese companies in carbon fiber. It was initially used in leisure products for their light weight and strength. Its use expanded to industrial structural materials for architecture and aircrafts that required reliability, and now the world share of carbon fibers by Japanese companies is about 80 %.2.2 Research environment (research management at GIRIO)At the time carbon fiber development started, GIRIO declared “promotion of industrial technology through research,” and organized the infrastructure and raised people’s enthusiasm.In about 10 years after the World War , there were several products that were put to industrial use from the researches done at GIRIO. The following description is from the GIRIOAnnual Report for 1959[9]. “Part 1 is the research of inorganic chemical engineering. Research on carbon is one of the traditional researches at GIRIO. In addition to the basic research conducted from the past, research of increasing the density of carbon products, electrode for air cell, carbon material for nuclear reactors, and deboronization of caking additive were conducted, but the greatest achievement for this year was ‘the successful manufacturing of graphite fiber

※このページを正しく表示するにはFlashPlayer9以上が必要です