Tosoh - Company History

Updated: Author:

Financial history 1951–2026 — revenue, cost structure, balance sheet, cash flow and key ratios, year by year →

Founded 1935
Founder Iwase Tokusaburo 岩瀬徳三郎
Founding location 山口県周南市
Core business at founding Caustic soda and soda ash for the rayon and staple-fibre industry
Listed 1949
President Kuwada Mamoru President since 2022 (age 65, as of 2026)
Current priority Capacity investment · Focus and concentration $1.4B (¥220bn) to $1.6B (¥250bn) over three years into the chain business
Founding
In February 1935 Iwase Tokusaburo (岩瀬徳三郎), then a managing director of Tokuyama Soda, founded Toyo Soda Manufacturing at Tonda in Yamaguchi Prefecture — today's Shunan — with capital of ¥3 million, under the banner of an “ideal ammonia-soda works”. The purpose was to supply caustic soda and soda ash to the rayon and staple-fibre makers, and in May of the following year, 1936, it began mass production of ammonia-process soda ash. Because chlor-alkali is a process industry that consumes salt, electricity and limestone in bulk, the plant was gathered onto a single site at Nanyo. In October 1987, alongside a corporate-identity programme, the name was changed to Tosoh.
The Decision
The company kept building, inside the same site, somewhere for the chlorine that electrolysis inevitably produces to go. In October 1953 it put up a cement plant within the Nanyo works in partnership with Onoda Cement, and in May 1966 it began making vinyl chloride monomer by its own oxychlorination process — a design that spared it having to send the by-product chlorine outside. In 1969 it decided on Yokkaichi and in its thirty-sixth year left behind being one company with one plant; the Tekkosha merger of April 1975 took it to seven plants at a stroke, and the merger with Shin Daikyowa Petrochemical in October 1990 completed an integrated structure running from ethylene. The market turned down immediately afterwards, however, and the company withdrew from ten businesses, narrowing to vinyl and reinvesting there. In October 2014 it absorbed Nippon Polyurethane Industry, joining everything from chlorine to MDI inside its own processes.
Today
The division that takes on water-treatment plant and facilities for the electronics industry now earns more than any of the chemical businesses. Consolidated revenue for the year to March 2026 was $6.4B (¥1.02tn) and operating profit $603.8M (¥96bn). Engineering, with sales of $1.2B (¥186bn), is only 18 per cent of the total, yet its segment profit of $255.4M (¥40bn) put it first among the four businesses. Specialty products followed with sales of $1.7B (¥273bn) and profit of $252.3M (¥40bn), while chlor-alkali — the business the company was founded on — was the largest by sales at $2.2B (¥346bn) and yet earned only $12M (¥2bn), down from $62.8M (¥9bn) the year before. The medium-term plan begun in the 2025 financial year does not align its investment with that order: it puts $1.4B (¥220bn) to $1.6B (¥250bn) over three years into the chain business that combines chlor-alkali and petrochemicals.
Competition
The commodity vinyl that other Japanese makers cut back, Tosoh kept as something to renew. It chose a strategy of holding on to commodity vinyl and chlor-alkali and polishing them to the end. Even in the phase when Chinese capacity expansion and a weak market made every rival contract, it went on renewing plant and technology and held the business, and recovered the outlay when the market turned up in the mid-2010s and demand arrived for electrolytic manganese dioxide for electric vehicles. In the same Shunan, Tokuyama — Iwase Tokusaburo's old firm — moved the other way, transferring in March 2026 the domestic cement sales business it had run for eighty-eight years. The economics of what you keep move with the market: chlor-alkali segment profit for the year to March 2026 shrank to a fifth of the previous year's.

Timeline

1935–1968Thirty-four years as a soda maker on a single site at Nanyo

  1. 1935Toyo Soda Manufacturing incorporated at Tonda, Yamaguchi, with ¥3m capital
  2. 1936Soda-ash production begins at the Nanyo works
  3. 1942First bromine plant in Japan working directly from seawater
  4. 1943Caustic soda plant added at Nanyo
  5. 1946Both soda plants designated for reparations; the ammonia process stops for four years
  6. 1949Shares listed on the Tokyo Stock Exchange
  7. 1950Permission granted to restart the ammonia soda process
  8. 1952The reparations designation is lifted
  9. 1953Cement production begins in partnership with Onoda Cement
  10. 1954Ninomiya Yoshimoto becomes president
  11. 1959Nippon Silica Industrial established
  12. 1964Entry into petrochemicals resolved as the Shunan complex is formed
  13. 1965Toyo Stauffer Chemical formed with Stauffer Chemical of the US
  14. 1966Vinyl chloride monomer by in-house oxychlorination; low-density polyethylene follows
  15. 1967Ethyleneamines plant added

1969–1989Yokkaichi and the Shin Daikyowa merger turn a soda maker into a diversified chemical company

  1. 1969Yokkaichi chosen as the first main plant outside Nanyo
  2. 1971Yokkaichi construction begins; vinyl chloride monomer and mercury-process electrolysis plants completed
  3. 1971Entry into scientific instruments via liquid-chromatography columns
  4. 1973Tekkosha Hellas set up in Greece for electrolytic manganese dioxide
  5. 1975Tekkosha absorbed, taking the company to seven plants
  6. 1978Ethyleneamines production starts in the Netherlands
  7. 1979Tosoh USA, Inc. established
  8. 1982Coal-fired boiler added at Nanyo after the oil shocks
  9. 1983Zirconia powder plant added; Sakata and Ishinomaki spun off as Tohoku Tosoh Chemical
  10. 1984Yamaguchi Toshiaki becomes president
  11. 1987Toyo Soda Manufacturing renamed Tosoh
  12. 1988Varian's sputtering-target division bought; Tosoh SMD, Inc. established

1990–2024A million tonnes of vinyl, and the rise of the specialty businesses

  1. 1990Shin Daikyowa Petrochemical and Yokkaichi Polymer merged in
  2. 1991After the bubble: ten businesses exited and selective reinvestment in vinyl
  3. 1994Sputtering targets spun off as Tosoh Specialty Materials
  4. 1995Hyuga plant spun off as Tosoh Hyuga
  5. 1999Caustic soda and vinyl chloride monomer both reach 1m tonnes a year
  6. 2004Tosoh (Guangzhou) Chemical established
  7. 2008Vinyl-isocyanate chain investment completed: 400k t of MDI, 1,000 MW of captive power
  8. 2008Udagawa Kenichi becomes president
  9. 2009First consolidated operating loss and net loss
  10. 2014Nippon Polyurethane Industry absorbed
  11. 2016Yamamoto Hisanobu becomes president
  12. 2017Record profit from the “hold and revive” strategy in vinyl and chlor-alkali
  13. 2022Kuwata Mamoru becomes president
  14. 2024Tosoh Vietnam Polyurethane Co., Ltd established

Founding Story

1935–1968Thirty-four years as a soda maker on a single site at Nanyo

For its first thirty-four years Tosoh was a chlor-alkali company that made everything it made in one place: the Nanyo works on the Seto Inland Sea, chosen because salt, power and limestone could all be landed there in bulk. Sales of $4.7M (¥2bn) in 1951 had reached $61.7M (¥22bn) by 1968, and by then the company had already been forced twice to widen its product line — once by the reparations order that took its flagship plant away for four years, and once by the petrochemical complex that grew up around it.

A Tokuyama Soda executive breaks away to compete with his old firm

Toyo Soda Manufacturing was incorporated in February 1935[1] with capital of ¥3 million[2] at Tonda in Yamaguchi Prefecture — today's Shunan[3] — by Iwase Tokusaburo (岩瀬徳三郎)[4], then a managing director of Tokuyama Soda (today Tokuyama), under the banner of an “ideal ammonia-soda works”. Its stated purpose was to supply caustic soda and soda ash in volume to the rayon and staple-fibre industry, and in May 1936 it began mass production of ammonia-process soda ash[5]. With soda demand climbing steeply, capital was raised from ¥3 million to ¥10 million in April 1937, and soda-ash capacity grew from the 200 tonnes a day of the original plan to 560 tonnes a day by December 1938[6]. Chlor-alkali is a textbook process industry, consuming salt, electricity and limestone in bulk and feeding an enormous body of downstream demand. On the Seto Inland Sea coast the effect was that Iwase, a managing director of the established Tokuyama Soda, was now leading a new company into direct competition with the same trade, and at the outset the whole of production sat on the single site at Nanyo.

Through the war years demand for soda expanded with the growth of the rayon and staple-fibre industry, and in 1942 the company answered a request from the Navy[7] by building at Nanyo the first bromine plant in Japan to work directly from seawater[8]. It was a business created to meet a wartime demand for domestic supply — bromine being the feedstock for anti-knock compounds — and it widened the product portfolio to soda ash, caustic soda and bromine. Capital spending nonetheless stayed concentrated on the single Nanyo works, and the picture of Toyo Soda from the war years to the eve of the surrender is one of chlor-alkali and inorganic chemicals piled up on the ground at Nanyo, exploiting a site that combined the Inland Sea, the salt fields and coal-fired power. The controlled wartime economy left no room to open new sites in other regions, and concentration on a single location was, in its way, what allowed the business to expand as fast as it did.

Four years without its flagship plant, and the move into cement and instruments

With defeat came the reparations order of August 1946, which designated both the ammonia-process and the electrolytic soda plants, so that the restart of the ammonia process — the company's flagship — had to wait four years, until 1950. Around the electrolytic soda plant, which the authorities permitted to keep running[9], the gap was filled by in-house production of electrolytic caustic soda and of organic chemicals, work whose character was largely that of finding substitute products to keep confiscated capacity from standing idle. From 1947, beginning with chlorosulphonic acid, the company moved into chlorine- and bromine-based chemicals[10]; permission to restart the ammonia soda process came in January 1950, and the reparations designation itself was lifted in April 1952[11]. Along the same line of makeshift, in October 1953 Toyo Soda completed a cement plant inside the Nanyo site in partnership with Onoda Cement[12], riding on that new plant the wave of postwar reconstruction demand known as the “three whites” boom. It was the first step away from being a soda specialist.

In 1954, following the sudden death of the third president, Sadanaga Keiho (貞永敬甫), Ninomiya Yoshimoto (二宮善基) took the presidency[13]. Ninomiya led head-office-driven rationalisation and sustained capital investment from the front: sales of about $15.8M (¥6bn) in fiscal 1954 had more than doubled in nine years, to about $37.8M (¥14bn) in fiscal 1963[14]. Alongside expanded capacity in the core caustic soda and soda ash, a phosphoric-acid plant was added in 1962[15], a joint venture with Stauffer Chemical of the United States was formed in 1965[16], and in April 1971 the company entered scientific instruments, using its own development of columns for liquid chromatography as the way in[17]. Under Ninomiya the business spread in concentric circles around the inorganic soda core. The accumulation of capital spending and of small tie-ups outside its own industry sowed the distant seed of the functional-products group later called “the third pillar”.

Petrochemicals hemmed in by the geographical ceiling of a single site

When the Shunan petrochemical complex was established in 1964, Toyo Soda resolved on a full entry into petrochemicals[18]. In a joint venture with the local Tokuyama Soda it set up Shunan Petrochemical and built an EDC (ethylene dichloride) plant[19]; in May 1966 it began making vinyl chloride monomer by its own oxychlorination process[20], followed in September of the same year by low-density polyethylene[21] and in October 1967 by ethyleneamines[22] — a rapid succession of olefin- and vinyl-based intermediates, all downstream of caustic soda, lined up inside the Nanyo site. The groundwork for the integrated “soda and vinyl” production method, meshing an electrolysis plant and petrochemical units on one piece of land, was laid here. Feeding the chlorine that comes out of caustic soda production straight into vinyl chloride monomer inside the company was also the rational way to avoid having to sell that by-product chlorine to outsiders.

The petrochemical business nonetheless remained concentrated at Nanyo alone, and the preconditions for operating at complex scale — land, process water and a supply of ethylene — met an obvious geographical ceiling there. Starting vinyl chloride monomer production had formally graduated the company from soda specialisation, but reaching the scale of a “diversified chemical company” ranked with Sumitomo Chemical, Mitsubishi Chemical Industries and Mitsui Toatsu Chemicals would require a second manufacturing base outside Nanyo and an ethylene centre of its own. What came out of that was the wager on Yokkaichi — the first full-scale plant Toyo Soda would build anywhere other than Nanyo since its founding.

1969–1989Yokkaichi and the Shin Daikyowa merger turn a soda maker into a diversified chemical company

The second era is the one in which Toyo Soda stopped being a company with one factory. Yokkaichi gave it a second base and an entry into the Ise Bay complex, the Tekkosha merger gave it five more plants in a single transaction, and the 1987 change of name to Tosoh declared that the soda specialist was gone — with sales rising from $75M (¥27bn) in 1969 to $1.3B (¥218bn) in 1986 as it went.

Clearing the one-company, one-plant barrier in the thirty-sixth year

In 1969, riding on a capacity-expansion plan centred on Daikyowa Petrochemical, by then one of the core firms of the Yokkaichi complex in Mie Prefecture, Toyo Soda decided on Yokkaichi as the site of the first main plant it would own anywhere but Nanyo. A vinyl chloride monomer plant and a mercury-process electrolytic soda plant were completed in 1971, a high-pressure polyethylene plant in 1972 and a vinyl polymer plant in 1973, establishing the base of the Yokkaichi works, which in a little over three years of construction became a second main plant on a par with Nanyo. It was the moment a company that had run for thirty-six years as one company with one plant at Nanyo[23] turned into a chemical maker with a genuinely multi-site geography.

In parallel with Yokkaichi, from the early 1970s Toyo Soda also ran an overseas production programme. It began in 1973 with the establishment of Tekkosha Hellas in Greece to make electrolytic manganese dioxide[24], followed by vinyl polymer in Indonesia in 1975[25] and ethyleneamines in the Netherlands in 1978[26] — overseas plants raised for three separate markets, the Mediterranean rim, South East Asia and north-west Europe. The prototype of the chemicals portfolio with a high overseas sales ratio that still characterises Tosoh today was born alongside the construction work at Yokkaichi. Flexible response to changes in the business environment underpinned the company's competitiveness.

The Tekkosha merger and a jump to seven plants at a stroke

In April 1975 the company absorbed Tekkosha, a ferroalloy maker in the Tohoku region that had been diversifying into electrolytic manganese dioxide and vinyl polymer[27]. The merger added five plants — Yamagata, Toyama, Hyuga, Sakata and Ishinomaki — which together with the directly held Nanyo and Yokkaichi made seven plants at a stroke[28]. In the same April the Tokyo Research Centre was completed at Ayase in Kanagawa Prefecture, concentrating the R&D function in parallel[29], so that the outline of a nationwide diversified chemical company took shape organisationally as well. The Tekkosha merger achieved in one transaction both a geographical extension into Tohoku, Kyushu and Hokuriku and an expansion of the special-steel and ferroalloy product range — the largest M&A in Tosoh's history.

Hit by the two oil shocks that struck the Japanese chemical industry in the second half of the 1970s, Toyo Soda hurried a fuel switch from heavy oil to coal, adding a coal-fired boiler at the Nanyo works in June 1982[30] and otherwise restructuring its process businesses by recomposing their energy base. In 1984, after the sudden death of the sixth president, Morishima Tozo (森嶋東三), Yamaguchi Toshiaki (山口敏明) became president[31] and set out a programme of management tasks — taking the domestic lead in chlor-alkali, nurturing new businesses, strengthening R&D, and preparing for internationalisation through a corporate-identity programme and new head-office functions — that moved the centre of gravity from efficiency improvement in process industry towards “shedding the skin of a soda maker”.

The renaming to Tosoh, and the Shin Daikyowa merger that marked the arrival

Under Yamaguchi's direction, in October 1987 the company carried out a change of name accompanied by a corporate-identity programme and a new statement of corporate philosophy. Toyo Soda Manufacturing became Tosoh[32] — a switch from a name that still carried the strong colouring of soda specialisation to a new brand as a diversified chemical company that took in specialty businesses as well. In parallel the Yamaguchi regime built up the base of what it called the “third pillar”, the specialty businesses of scientific instruments, functional materials and electronics; in 1988 it bought the sputtering-target division of Varian of North America and established Tosoh SMD, Inc., a full-scale entry into semiconductor materials[33]. It was a landmark year that embodied the change of name, as a materials company built around electrolysis plants broadened its face into a supplier of electronic materials.

In October 1990 the company committed to a reorganisation that merged, at the same moment, Shin Daikyowa Petrochemical — which ran the ethylene centre of the Yokkaichi complex — and its downstream affiliate Yokkaichi Polymer[34]. This completed an integrated petrochemical structure in which Tosoh itself held the olefins that start from ethylene and their derivative range, and consolidated sales immediately after the merger jumped to about $2.3B (¥330bn)[35]. Twenty-one years after the 1969 decision to go to Yokkaichi, and fifty-five years after its founding, Tosoh had reached a position spoken of alongside Sumitomo Chemical, Mitsubishi Chemical Industries and Mitsui Toatsu Chemicals as one of Japan's representative diversified chemical companies[36]. Running ethylene, vinyl and caustic soda on two poles, the Inland Sea and Ise Bay, made for an unusually balanced two-site structure among Japan's process-industry chemical makers.

1990–2024A million tonnes of vinyl, and the rise of the specialty businesses

The last era runs the integrated vinyl-and-soda structure to its limit and then discovers what that costs: capacity of a million tonnes a year, a first operating loss in 2009, the Nippon Polyurethane merger that closed the chain from salt to MDI, and — by the year ended March 2025, with group sales above $7.1B (¥1.06tn) — a profit order in which the soda business that gave the company its name ranks last.

A million tonnes a year of caustic soda and vinyl monomer, and the commodity exposure it revealed

To use to the full the integrated vinyl-and-soda structure won in the Shin Daikyowa merger, Tosoh concentrated expansion investment on the vinyl chain through the second half of the 1990s, and in June 1999 both caustic soda and vinyl chloride monomer reached a production capacity of one million tonnes a year across Nanyo and Yokkaichi combined. Tosoh's standing as one of the largest domestic players in vinyl and soda was settled by that million-tonne structure. In April 2008 the completion of the vinyl-isocyanate chain investment programme added MDI capacity of 400,000 tonnes a year and 1,000 MW of captive power generation, framing a process-industry core business in which everything from upstream electricity and caustic soda to downstream vinyl and urethane was operated as one.

Immediately after that vinyl-isocyanate plant investment was completed, the Lehman shock of September 2008 struck world demand for exactly this process industry. In the year ended March 2009 consolidated operating profit fell into deficit for the first time, at a loss of $217M (¥20bn), and the net loss of $270.5M (¥25bn) was among the worst results the company had recorded this century. The operating loss in the basic-materials segment alone reached $187.1M (¥18bn), and the integrated vinyl-and-soda structure built through merger and million-tonne investment had, ironically, been shown up by those figures for its dependence on the commodity cycle. The fate of a process business — add capacity to match the peak of demand and be crushed by fixed costs in the trough — was something Tosoh now experienced at first hand. Barely six months separated the decision to expand capacity from the fall into loss, a case study in the cruelty of the investment cycle.

The Nippon Polyurethane merger completes the vinyl-isocyanate chain

As an extension of the restructuring that followed the Lehman shock, in October 2014 Tosoh absorbed Nippon Polyurethane Industry, bringing the integrated structure of chlorine-based products (vinyl) and isocyanate-based products (MDI) inside the Tosoh group. The merger established as the standard form of the company's core business a distinctive structure — the “vinyl-isocyanate chain” — in which everything from the caustic soda and chlorine produced by the electrolysis of salt to the final derivative, MDI, is joined in a single in-house process. The design principle of absorbing the swings of the commodity cycle, the affliction of any process industry, with the steadier demand for high-value urethane products downstream came close to its finished form here. The aim was to shrink dependence on outside sales of intermediates such as chlorine gas and hydrogen chloride to near zero and close the loop inside the company's own lines.

From FY15 (the year ended March 2016), the first full year after the merger, operating profit in the chlor-alkali business turned upward, reaching $603.3M (¥67bn) in FY17 (year ended March 2018) and $529M (¥70bn) in FY21 (year ended March 2022), at the top of its historical range. The integrated structure binding vinyl and MDI together produced, even as it took the waves of overseas markets, a stable level of profit as Tosoh's central earnings pillar, and reinforced to a degree — by capturing urethane demand downstream — the exposure to the commodity cycle that the Lehman shock had laid bare. These were the years in which a restructuring several years in the making, including the Nippon Polyurethane merger that rebound the core businesses, finally began to be repaid in the accounts as well. Six years after falling into loss, Tosoh in this recovery phase was for the first time in a long while stacking up profit growth in both its process and its functional businesses.

Specialty products and engineering begin to overtake the base businesses

Alongside the traditional mainstays of petrochemicals and chlor-alkali, the specialty group of the functional-products business — high-silica zeolites, zirconia, fused silica, instrument-related products and bioscience — raised its share of the company's segment mix through the 2010s. In FY16 (year ended March 2017), functional products earned an operating profit of $315.6M (¥35bn) against $427.1M (¥48bn) for chlor-alkali, a gap narrowed to near parity, and in FY21–FY22 functional-product operating profit of $331.1M (¥44bn) to $372.2M (¥52bn) made it a continuing earnings pillar for the whole of Tosoh. Some thirty years after being named “the third pillar” at the 1987 corporate-identity programme, the specialty businesses had drawn level with the core businesses in profit as well. Improved profitability in semiconductor process chemicals and in instrument-related products in particular lifted the whole functional-products segment.

The engineering business — water-treatment plants and facilities for the electronics industry — also began to grow from the late 2010s, and in FY24 (year ended March 2025) it recorded sales of $1.1B (¥169bn) and operating profit of $224.5M (¥34bn), making it the highest-margin segment in the company. Segment operating profit that year ran functional products $257.9M (¥39bn), engineering $224.5M (¥34bn) and chlor-alkali $63.5M (¥10bn): Tosoh, long known as “the soda company”, had converted into a structure in which the soda business is no longer the breadwinner. In 2019 president Yamamoto Hisanobu (山本寿宣) declared a policy of securing stable earnings from the base businesses of vinyl and chlor-alkali while raising the proportion of specialty products, signalling that the company's position was moving from process-industry materials maker to functional-materials company. A profit order in which the founding mainstay falls to the bottom and the later functional businesses take the top is unusual for a process-industry chemical maker.

Read the full history in Japanese →

Notes

  1. Tosoh, securities report (corporate-history section: February 1935, Toyo Soda Manufacturing Co., Ltd. established)↩
  2. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  3. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  4. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  5. Tosoh, securities report (corporate-history section)↩
  6. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  7. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  8. Tosoh, securities report (corporate-history section)↩
  9. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  10. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  11. 企業の歴史 : 明治百年 (Corporate Histories: A Century of Meiji, Keizai Shunju-sha, 1968)↩
  12. Tosoh, securities report (corporate-history section)↩
  13. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  14. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  15. Tosoh, securities report (corporate-history section)↩
  16. Tosoh, securities report (corporate-history section)↩
  17. Tosoh, securities report (corporate-history section)↩
  18. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  19. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  20. Tosoh, securities report (corporate-history section)↩
  21. Tosoh, securities report (corporate-history section)↩
  22. Tosoh, securities report (corporate-history section)↩
  23. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  24. Tosoh, securities report (corporate-history section)↩
  25. Tosoh, securities report (corporate-history section)↩
  26. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  27. Tosoh, securities report (corporate-history section)↩
  28. Tosoh, securities report (corporate-history section)↩
  29. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  30. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  31. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  32. Tosoh, securities report (corporate-history section)↩
  33. Tosoh, securities report (corporate-history section)↩
  34. Tosoh, securities report (corporate-history section)↩
  35. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩
  36. 日本会社史総覧 (Compendium of Japanese Corporate Histories, Toyo Keizai Inc., 1995)↩

References & sources

  1. Corporate Histories: A Century of Meiji, Keizai Shunju-sha (1968), the Toyo Soda Manufacturing entry.
  2. Compendium of Japanese Corporate Histories, Toyo Keizai Inc. (1995), the Tosoh entry — sales and management figures for the Ninomiya and Yamaguchi years.
  3. Tosoh Corporation (annual securities reports), including the corporate-history section and the segment disclosures used for the FY16–FY24 profit figures.

Yen amounts are converted at the average rate of each figure’s own year — not today’s rate; revenue charts are shown in yen. Exchange rates & sources — the full ¥/US$ table →

Data API

Tosoh’s history, presidents and financials are published as static JSON — no key, plain GET. One API per public page, and one per section where a page carries several tables. Full specification →

/api/4042/company.json ·/api/4042/history.json ·/api/4042/ceo.json ·/api/4042/financials.json ·/api/4042/financials/segment.json ·/api/4042/financials/pl.json ·/api/4042/financials/cf.json ·/api/4042/financials/bs.json ·/api/4042/financials/employee.json ·/api/4042/financials/stock.json ·/api/4042/financials.csv ·/api/4042/financials_history.csv

/api/companies.json ·/api/decisions.json ·/api/api-manifest.json