戦時期日本の代用繊維開発と戦後への継承 : 鐘淵紡績のカネビヤンの挫折

During World War II, Japanese companies pursued the development of synthetic fibers as substitutes for such natural fibers as cotton and wool. A well-known case is polyvinyl alcohol (PVA) fiber, industrialized after the war under the brand name Vinylon by Jurashiki Rayon (Kuraray) and Dai-Nippon Cotton Spinning. This paper considers the case of Kanebian, another variety of PVA fiberm produced by Kanegafuchi Cotton Spinning (Kanebo). Kanebian's development was advanced almost concurrently with that of Vinylon but ultimately was suspended, though its realization was close at hand. The reasons why Kuraray succeeded in industrializing Vinylon and establishing its own market lie in its shift from "negative substitution" - the goal of compensating for a shortage of natural fibers -- to "positive substitution," which brought out and commercialized the peculiar attributes and attractions of synthetic fibers as substitutes for natural fibers. This process was the necessary condition for the survival of wartime substitute fibers in the postwar environment. After the war Kanebo made the reconstruction of natural fibers its highest priority, thereby delaying the development of synthetic fibers and widening the gap with Kuraray's progress. The two fibers had reached similar levels of development by the end of the war. But Kanebo's management was negative about Kanebian's prospects because of its defects in quality and cost and therefore was cool toward its further development. Kanebo's engineers worked to address these weaknesses as they emerged in the postwar years, and sought out optimum markets while watching Vinylon's progress closely. Their unrelernting effort and confidence in Kanebian's potential did not sway management's assessment of the product, however, and ultimately Kanebo discontinued the development of Kanebian. The decision to suspend development seems at first glance to have been mistaken given Kuraray's success. It has its own validity and rationality, however, when we take into consideration Kanebo's founding and principal business which was cotton spinning, the postwar recovery of the cotton spinning industry, Kanebian's technical properties and its potential, and the limited support from industrial policy at the time. This article explains this assertion in detail by studying the process from development to suspension, and considers it as an aspect of the shift from "negative" to "positive substitution."