By Liz White, UT stafTokyo-Asahi Kasei Fibers Corp. said 30 Nov that it has initiated legal action in Seoul District Central Court in South Korea to prevent Hyosung Corp. infringing a patent Asahi Kasei Fibres holds for chlorine-resistant elastic polyurethane (spandex) filament. Japanese fibre maker AKF owns Korean Patent 131106 on polyurethane material for making spandex fibres with greatly improved chlorine resistance: the main use for such fibres is in swimwear. The Japanese fibre maker, which has recently signed a deal with Lanxess GmbH to buy the German group's Dorlastan spandex business, said it purchased some of Hyosung's type H250" chlorine-resistant grade spandex via normal commercial routes. Examination of this product indicated that "its composition was consistent with that protected by the patent," said AKF, resulting in its decision to take legal action. AKF stressed that it also holds patents protecting this technology in Japan, the US, Germany, the UK, Italy, the Netherlands, Canada, and Singapore, and will take action if its rights are infringed in these territories. "