1936 April : Started as TOKYO OHKA RESEARCH LABORATORY.
1940 October : Reorganized as a joint-stock company, TOKYO OHKA KOGYO CO., LTD.
1967 January : SAGAMI PLANT (present SAGAMI OPERATION CENTER) began operations.
1980-1989
1980 November : Held the 1st TOKYO OHKA SEMINAR (semiconductor technology seminar).
1981 June : UTSUNOMIYA PLANT (our first full-scale mass production plant for photoresists used in semiconductor manufacturing) began operations.
1983 February : SAGAMI SECOND PLANT (present SHONAN TECHNICAL CENTER) began operations.
December : KUMAGAYA PLANT (plant for manufacturing industrial chemicals) began operations.
1984 January : YAMANASHI PLANT (exclusive plant for manufacturing photopolymer printing plates) began operations.
October : PROCESS EQUIPMENT PLANT (within SAGAMI SECOND PLANT / present SHONAN TECHNICAL CENTER) began operations.
December : ASO PLANT began operations.
1986 July : Listed in the Second Section of Tokyo Stock Exchange.
1987 March : Established OHKA AMERICA, INC. in California, U.S.
June : GOTEMBA PLANT began operations.
September : Established OHKA (UK) LTD. (present OHKA EUROPE LTD.).
1989 April : Established T.O.K. INTERNATIONAL, INC. in Oregon, U.S.
October : IKUNO PLANT began operations.
November : Held the 10th TOKYO OHKA SEMINAR.
1990-1995
1990 September : Listed in the First Section of Tokyo Stock Exchange.
November : Held the 1st TOKYO OHKA SEMINAR in Korea.
1992 October : Established TOK ENGINEERING CO., LTD.
December : Merged OHKA AMERICA, INC. and T.O.K. INTERNATIONAL, INC. (OHKA AMERICA, INC. / present TOKYO OHKA KOGYO AMERICA, INC.).
1993 May : OREGON PLANT of OHKA AMERICA, INC. (present TOKYO OHKA KOGYO AMERICA, INC.) began operations.
1994 February : KORIYAMA PLANT began operations.
May : Held the 1st TOKYO OHKA SEMINAR in Taiwan.
1995 May : Established TOK ITALIA S.p.A.
1996-1999
1996 July : Acquired ISO 9002 registration for GOTEMBA PLANT and SAGAMI OPERATION CENTER.
October : Dry Film Resist plant of TOK ITALIA S.p.A. began operations.
1997 February : Completed construction of new research building in SAGAMI OPERATION CENTER.
March : Established TOK TECHNO SERVICE CO., LTD.
May : Completed construction of our first oversea photoresist manufacturing plant for semiconductor fabrication at OREGON PLANT of OHKA AMERICA, INC.
December : Completed the third phase construction (manufacturing plant of photoresists for deep-UV) of KORIYAMA PLANT, and started the manufacture.
1998 January : Established TOK TAIWAN CO., LTD.
April : Completed construction of new research building in SHONAN PLANT (present SHONAN TECHNICAL CENTER).
1999 May : Acquired ISO 9002 registration for all the plants of Manufacturing Department.
November : Held the 20th TOKYO OHKA SEMINAR.
: Stripper / thinner manufacturing plant of TOK TAIWAN CO., LTD. began operations.
: Acquired ISO 14001 registration for KORIYAMA, UTSUNOMIYA and GOTEMBA PLANT.
2000-
2000 August : Completed construction (July) of the new headquarters building at the site that its Kawasaki Plant had used to stand, and has moved to the new headquarters.
2001 February : Developed TARF-P series (High-resolution, positive type photoresist for ArF excimer lasers).
March : Developed DELS series (Dielectric Layer sheet for PDP).
October : Completed construction of ELASLON manufacturing line in YAMANASHI PLANT.
December : Developed TELR-P series (Positive type photoresist for Organic EL Display).
2002 March : Developed TR63000 (Large square substrate coater / Developer system).
: Developed OEBR-CAN021 (Negative type photoresist for electron beams).
August : Established SINGAPORE REPRESENTATIVE OFFICE.
: Completed construction of PDP manufacturing material production plant in KORIYAMA PLANT.
October : Established SHANGHAI REPRESENTATIVE OFFICE.
2003 February : Completed construction of new research building in SAGAMI OPERATION CENTER.
October : SEOUL MARKETING OFFICE began operations.
November : DISTRIBUTION CONTROL CENTER began operations.
December : Developed TMMR (Permanent photoresist for MEMS).
2004 September : Established TOK KOREA CO., LTD.
October : Established CHANG CHUN TOK (CHANGSHU) CO., LTD.
2005 December : Established TOKYO OHKA KOGYO EUROPE B.V.
2006 January : OHKA AMERICA, INC. has changed its name to TOKYO OHKA KOGYO AMERICA, INC.
February : OHKA EUROPE LTD. has transferred all its business to TOKYO OHKA KOGYO EUROPE B.V.
: Completed construction of new research building in SAGAMI OPERATION CENTER.
2007 April : Completed construction of new research building in SAGAMI OPERATION CENTER.
2008 March : Completed construction of office building in Aso Pant.
2008 November : Developed TWM/TWR series ?wafer handling system for processing through-silicon vias?.
2008 December : Developed TR165000FC series?float coating system?.
2009 April : Completed construction of stripping solution manufacturing plant in TOKYO OHKA KOGYO AMERICA, INC.?Oregon Plant?.
June : Developed EPLUS?diffusion source for photovoltaic?.
2011 January : Newly organized Marketing Division, Marketing Department.
June : Newly organized New Business Development Division, New Business Development Department.
November : Built a new production line of semiconductor photoresist in Koriyama plant.
2012 August : Established TOK ADVANCED MATERIALS CO., LTD.