Can a single laboratory breakthrough reshape an entire industry for generations? In 1959, Dr. Akio Shindo — a researcher at Japan's Government Industrial Research Institute in Osaka (GIRIO) — filed a patent for a new way to make carbon fiber from polyacrylonitrile (PAN), a synthetic polymer most researchers had given up on. Today, PAN-based carbon fibers are found in Boeing 787 fuselages, Formula 1 chassis, hydrogen tanks, wind turbine blades, tennis rackets and bicycle frames. More than six decades on, the industry is thriving — and its original commercial champion, Toray Industries, is celebrating its 100th anniversary.
Agency of Industrial Science and Technology, Japan
GIRIO was established in 1920 as a public research institution to support industries in the Kansai region — particularly small and medium-sized enterprises — with a long-standing focus on textiles and carbon materials. It was renamed AIST Kansai in 2001 and remains Japan's second largest research base.
All of GIRIO's research has been guided by a consistent mission: developing products that improve quality of life and support public safety and security. In the decades following World War II, its carbon R&D focused on challenges such as increasing the density of carbon products and producing carbon materials for nuclear reactors — the scientific ground on which Dr. Shindo's 1959 breakthrough would eventually be built.
The carbon fiber problem before 1959
Carbon fiber research goes back to the late 19th century, when Thomas Edison carbonized bamboo to make filaments for early light bulbs. These were quickly replaced by tungsten, and carbon fiber remained a scientific curiosity for decades.
By the 1950s, researchers at Union Carbide in the United States were producing the first modern carbon fibers using rayon as the base material. The process worked, but it was inefficient: only about 20% of the rayon ended up as carbon, and the resulting fibers were limited in shape and application. A more efficient path was needed.
Dr. Akio Shindo's breakthrough at GIRIO
In April 1959, Dr. Akio Shindo (1926–2016), a carbon researcher at GIRIO since 1952, read a short article in the Japanese industrial newspaper Machine Design about the US rayon-based process. He spotted an opportunity the American researchers had dismissed: polyacrylonitrile (PAN), a synthetic polymer that had proved difficult to work with.
Five months later — by September 1959 — Dr. Shindo had developed a working process. By using PAN as the precursor material, he achieved a carbon yield of 50–60%, nearly three times that of the rayon method. In broad terms, his process involved spinning purified PAN into fibers, stabilizing them at 250°C, then carbonizing them at around 1,000°C in an air-exposed environment — a detail that proved essential to fiber quality.
The resulting fibers were stronger, more flexible and more heat-resistant than any carbon fiber produced before. Crucially, they could be formed into three-dimensional shapes without losing those properties — enabling applications from aircraft bodies to bicycle frames to tennis rackets. Today, PAN-based fibers account for the overwhelming majority of all carbon fiber produced worldwide.
The 1959 patent: enabling technology transfer
On 7 September 1959, Dr. Shindo filed a domestic patent application with the Japan Patent Office (JPO), followed by international filings. The patent was granted in 1962 as Japanese Patent No. 304892. At the time, GIRIO was just beginning to build a formal approach to intellectual property (IP) — a shift driven by Director General Tadashi Sengoku, who had taken office in 1958 with a clear focus on IP rights.
The rationale for patenting was straightforward and instructive. First, publication of the patent would disclose the technology to the wider industrial community, signaling to Japanese companies that a breakthrough was available for licensing. Second, a granted patent enabled a formal technology transfer: licensees could benefit from Dr. Shindo's continued support, and GIRIO could generate revenue to reinvest in research. In a post-war Japan focused on economic recovery and international competitiveness, IP was treated as a bridge between public research and private industry.
PAN carbon fiber also catalysed parallel breakthroughs abroad. For example, in 1964, scientists at the UK's Royal Aircraft Establishment filed a patent for a high-strength, high-modulus variant (GB 1,110,791), held by the Ministry of Defence and licensed through the National Research Development Corporation to Rolls-Royce, Morganite and Courtaulds — a similar public-research-to-industry licensing model to the one GIRIO pursued in Japan.
From Tokai Electrode to Toray: the licensing journey
GIRIO's first two licensees were Tokai Electrode and Nippon Carbon, both carbon-fiber veterans. They received non-exclusive licenses to the PAN patent in 1963. But although both had deep carbon expertise, neither could manufacture PAN yarn — the essential precursor material.
That changed in 1970, when Toray Industries — then Japan's largest synthetic-fiber manufacturer — entered into its own licensing agreement with GIRIO. Toray had opened a dedicated carbon fiber research and manufacturing facility in 1961, and by 1970 it had the precursor capability that its predecessors lacked. Toray then negotiated a second deal with Tokai Electrode and Nippon Carbon to acquire their accumulated R&D in exchange for royalties — consolidating the know-how needed to scale. Commercial production of Toray's carbon fiber began in 1971.
Commercial demand arrived unexpectedly. In October 1972, American golfer Gay Brewer won the Taiheiyo Club Masters using clubs with carbon fiber shafts, and the Japanese press reported extensively on it. Toray launched a carbon fiber golf shaft line in 1973, and demand outpaced supply almost immediately. By the end of 1974, Toray's monthly output had more than doubled, and the company was expanding into tennis rackets, fishing rods and other consumer goods — alongside its growing aerospace and defense business.
Toray today: 100 years of advanced-materials leadership
In April 2026, Toray celebrated the 100th anniversary of its founding under the centennial theme "Pioneering Change for the World." What began in 1926 as a single-product rayon yarn company is now a global leader in advanced materials, with approximately 48,000 employees, more than 300 affiliated companies worldwide, and annual revenues of around 2.5 trillion yen.
Toray's business today spans fibers and textiles, resins and chemicals, films, electronics and information materials, carbon fiber composite materials, pharmaceuticals and medical products, and water-treatment membranes. Its TORAYCA™ carbon fiber — the direct commercial descendant of Dr. Shindo's 1959 invention, and one of the subjects of hundreds of Toray patent filings on PATENTSCOPE — remains the company's flagship advanced material.
As of 2025, Toray is the world's largest carbon fiber manufacturer, holding a leading share of the global high-strength carbon fiber market and with a combined Group production capacity approaching 58,000 tons per year of regular-tow and large-tow fibers across manufacturing sites in Japan, the United States (including a major plant in Spartanburg, South Carolina), France and South Korea. TORAYCA™ fibers are qualified on major aerospace programs — including the Boeing 787 — and increasingly support the clean-energy transition through applications in hydrogen tanks, electric vehicles and wind turbines. Toray Group companies Zoltek (large-tow industrial carbon fibers) and Toray Advanced Composites round out the company's global composites portfolio.
Japan is home to several of the world's top carbon fiber producers, led by Toray alongside Teijin (Tenax™ carbon fibers) and Mitsubishi Chemical Group (PYROFIL™ carbon fibers) — continuing the industrial legacy the 1959 patent helped create.
The legacy of one filing decision
Dr. Shindo's patent is a textbook example of how research IP can catalyze an entire industry. The patent disclosure made the breakthrough visible, while the licensing strategy made it transferable and commercially viable. And the result — PAN-based carbon fiber composites — now underpins everything from commercial aviation to sustainable energy storage.
