Tosoh To Acquire Remaining HDI Shares from Asahi Kasei

Tosoh Strengthens HDI Value Chain with Full Acquisition of Nanyo Kasei

Tosoh to Take Full Ownership of HDI Producer Nanyo Kasei

Tosoh Corporation announced plans to acquire the remaining 50% ownership stake in Nanyo Kasei Co., Ltd. from Asahi Kasei Corporation, making the HDI monomer producer a wholly owned Tosoh subsidiary. The transaction is expected to close on March 31, 2027.

Nanyo Kasei, established in 1980 as a joint venture between the two companies, manufactures hexamethylene diisocyanate (HDI) monomer, a key raw material used in high-performance coatings, adhesives, and specialty polyurethane applications.

The acquisition is intended to strengthen Tosoh’s supply security for HDI monomer and support the continued growth of its HDI derivatives business. The move is particularly significant following the September 2026 startup of Tosoh’s new HDI derivatives production facility, which will require a stable and reliable supply of upstream feedstock.

The transaction highlights ongoing efforts by chemical manufacturers to increase vertical integration and secure critical raw material supply chains in specialty chemical markets.

https://www.tosoh.com/news-press/news-releases/2026/tosoh-to-acquire-shares-of-nanyo-kasei-and-make-it-a-wholly-owned-subsidiary