Our History

Yoneyama’s Milestones

Founder: Kojiro Mizuki

Left his birthplace of Higashiishikuro village (in present-day Nanto, Toyama prefecture) for Osaka in the spring of 1910 at the age of 17 or 18. Apprenticed at the Ueda Seiyaku pharmaceutical company (in Nakatsu). Transferred to the Matsuno Seiyakusho pharmacy (in Toyosaki), producing sulfuric and nitric acid. Established Yoneyama Yakukagaku Kojo, the forerunner of the present-day company.

Corporate emblemYakkōjirushi

The origin of this emblem is unknown, but it is thought to have been inspired by a stamp of a similar design on a papier maché tiger attached to bamboo grass provided as a charm against illness during a festival at the Sukunahikona Shrine in the Doshomachi area of Osaka (known as a center of pharmaceutical products).

1918: Yoneyama Yakukagaku Kojo is established as partnership with Choji Yoneyama in former county of Nishinari, Osaka prefecture. Is later moved to Fukushima-ku (present-day Ohiraki) in city of Osaka.
Starts refining sulfuric acid, nitric acid and hydrochloric acid, and manufacturing and selling ammonia water, washing soda, caustic soda and other products.

1929: Partner Choji Yoneyama dies and the company comes under sole control of Kojiro Mizuki.

1932

Company is established and incorporated as Yoneyama Yakukagaku Kojo G.K.

(The Yoneyama name is perpetuated as a way to pay homage to the late partner and preserve the company’s founding spirit.)

1946: Kojiro Mizuki establishes Mizuki Seiyaku Kaisha, Ltd. to sell pharmaceutical products.
Kojiro Mizuki is appointed President & Director.

1948: Company changes name from Mizuki Seiyaku Kaisha, Ltd. to YONEYAMA KAGAKU KOGYO KAISHA, LTD.
Kojiro Mizuki is appointed President & Representative Director.

1949: Yoneyama Yakukagaku Kojo G.K. and YONEYAMA KAGAKU KOGYO KAISHA, LTD. merge under the latter name.

Kojiro Mizuki is appointed President & Representative Director.

1952: Yoshiji Mizuki is appointed President & Representative Director.

1954: Nagoya Branch Office opens, expanding sales in Tokai, Chubu and Hokuriku markets.

1956: Tokyo Branch Office (present-day Tokyo Sales Office) opens, expanding sales in Kanto market.

1958: Company receives JIS display plant permit for organic/inorganic reagents from the Japanese Industrial Standards Committee, creating benefits for industry with its test reagents for use in analysis.

1962: Ashikaga Plant is created in the city of Ashikaga (Tochigi prefecture), expanding sales in Kanto market.
Starts producing sodium phosphate and ammonium phosphate.

1963: Kitahama Sales Office (present-day Osaka Sales Office) opens, augmenting Kansai area and expanding sales in Chugoku, Shikoku and Kyushu markets.
Ashikaga Plant starts producing ABC dry chemical fire-extinguishing agent.

1966: Ashikaga Plant starts producing ammonium acetate.

1967: Suita Kasei Kogyo KK is established.

1973: Headquarters and Osaka Sales Office are moved to Nishitenma in city of Osaka, while Osaka Plant is moved to city of Katano in Osaka prefecture.

1974: Koichi Mizuki is appointed President & Representative Director.

1979: Osaka Plant expands production equipment for food additives and high-purity reagents.

1987: Ashikaga Sales Office opens, expanding sales in northern Kanto and Shinetsu markets.

1988: Ashikaga Plant starts large automatic continuous crystallization facility operation.

Initial company establishment

YONEYAMA KAGAKU KOGYO in the late 1950s
(Fukushima-ku in city of Osaka)

1982
Phosphate facility at Osaka Plant

1988
Large automatic continuous crystallization facility at Ashikaga Plant

1994: Ashikaga Plant expands production equipment for organic acid ammonium.
Osaka Plant starts producing organic acid salts.

1997: Yoshiaki Mizuki is appointed President & Representative Director.

1998: Ashikaga Plant completes crystallization facility, expands production of organic acid ammonium salts.

1999: New product release: Melroad deicer

2001: Company acquires ISO 9001 certification (all business units).

2001: Naohide Mizuki is appointed President & Representative Director.

2003: New product release: Losspee bottom material refining agent

2006: Changshu Yoneyama Chemical Industry Co., Ltd. is established in Changshu, Jiangsu province, China.

2010: Ashikaga Plant adds wastewater treatment facility storage tank in compliance with Water Pollution Prevention Act.
Environmental measures are later augmented at Osaka Plant and other sites.

2015: Osaka Plant completes new power kneader high-purity forced crystallization equipment.

2016: Osaka Plant starts high-mix, low-volume production.
Completes connectable/selectable CSCC crystallization equipment.

2018: Company marks its centennial.

2018: Nagoya Sales Office/Business Development Office is created.

Ammonia storage tank at Ashikaga Plant

2016
CSCC high-mix, low-volume production equipment at Osaka Plant

2019: Nagoya sales office opened in Naka-ku, Nagoya.

2021: Corporate Planning Department is created.

2021: Kohei Mizuki is appointed President & Representative Director.

2022: Organization of Sales Department is changed to 1st Group, 2nd Group, and Business Development Office.