1969 September	Established Seikoh Chemicals Co.,Ltd. with the capital of 2 million yen. Kojiro Seiki became the president. Started manufacturing and selling surface coating agent for PVC leather.
1971 December	HQ and factory were moved to current location
1974 May	Established Sheng Kuang Chemical Co.,Ltd. in Taiwan as a joint venture between Seikoh and local company.
1975 October	Started manufacturing and selling polyurethane resin for synthetic leather.
1982 September	The capital was increased to 10 million yen.
1982 November	Second factory was built.
1983 October	R&D center was built.
1985 March	The capital was increased to 30 million yen.
1987 March	Third factory was built.
1988 June	New HQ building was built.
1989 March	Second production facility was built in main factory. Increased production capacity of polyurethane resin.
1994 January	The capital was increased to 60 million yen.
1995 October	Established Nantong Shengguang Chemical Industry Co.,Ltd. in China as a joint venture between Seikoh and local company.
2001 July	Acquired ISO 9001 certification
2003 April	Started manufacturing and selling water-borne polyurethane resin.
2004 December	Kojiro Seiki became the chairman of board. Toshiyuki Seiki became the president.
2007 September	Established A.F.Seikoh Co.,Ltd in Thailand as a joint venture between Seikoh and local company.
2013 January	Expanded HQ and main factory area.
2014 December	New R&D center was built.
2018 October	Third production facility was built in main factory. Increased production capacity of water-borne surface coating agent.