Installing windows with vacuum-insulated triple glass is one of the best ways to boost building insulation. But the windows are heavy. A compromise would be to use two sheets of glass and, instead of a third, a light and transparent material for the middle layer. Scientists have long been searching for such a material. A new type of aerogel, invented in Japan, may be the solution.
Named superfunctional air, or Sufa, the aerogel is up to 98% air. It is transparent with excellent insulation properties. Developed by Kazuki Nakanishi, a professor at Nagoya University’s Institute of Materials and Systems for Sustainability, it is made from methyl trialkoxysilane, unlike other aerogels that mostly use tetraalkoxysilane as their main raw material. Nakanishi is moving forward with commercialization of the product. The company he launched, Tiem Factory, is now building a plant in Japan to mass-produce Sufa.
For about the past 15 years, Japan has been animated by a fear of losing its technological edge. Supported by government funding, Japan’s academic institutions and private sector have been working together to come up with new types of polymers. Their efforts are starting to bear fruit. The new materials now emerging are fostering a sense of renewal in the country’s plastics sector, and they may help Japan gain global leadership in some new markets.
Of the breakthrough materials recently invented in Japan, Sufa is probably the furthest along in development. Tiem Factory is completing construction of its first plant, in Ibaraki Prefecture north of Tokyo. Making use of $9 million provided by the Japanese government and a consortium of nine Japanese firms, it will produce aerogel monoliths suitable for use inside windows. Nakanishi and his backers expect strong demand in Japan, where the government is about to implement stringent regulations on home insulation.
Featuring excellent heat-retention properties, aerogels are the world’s lightest solid materials. But their widespread use in construction has been constrained by a high cost of production. In particular, the production of monolithic sheets of aerogel large enough for use in windows requires the use of expensive, high-pressure, high-temperature dryers. Otherwise, when aerogels are left to dry at room temperature, they lose their skeletal structure and become useless.
The advantage of Sufa is that it dries on its own. According to Masahiro Yamaji, president of Tiem Factory, Sufa’s cost of production is about one-sixtieth that of aerogels from the two major manufacturers, Cabot and Aspen Aerogels, primarily because no fancy drying machine is required.
And Sufa has other advantages, he says. It is softer than other aerogels, returns to its original shape when pressed, and is less likely to break during handling. And critically for use in windows, its transparency approaches that of glass. Working with YKK AP, an affiliate of the zipper manufacturing giant YKK, Tiem Factory is gearing up to mass-produce aerogel monoliths as wide as 1 m, a world first.
Even though Tiem Factory has yet to begin production, its managers are confident that Sufa will be a success. The firm is already contemplating production bases in the US, Europe, and Asia outside Japan, Yamaji says. Moreover, working with another firm, the company has developed a powdered Sufa for use as an insulation material in electric vehicles. Weight is a major factor affecting the range and performance of electric cars, while heat control is a must. Top car companies, searching for better ways to control both heat and weight, are already working with Tiem Factory, Yamaji says.
Sufa is only one of several novel materials soon to be commercialized in Japan. Advanced Softmaterials, a spin-off from the University of Tokyo, focuses on what it calls slide-ring materials. They were created by University of Tokyo engineering professor Kohzo Ito out of polyrotaxanes, which, in this case, are made by slipping rings of cyclodextrin along a string of polyethylene glycol and capping the ends with adamantane. Cross-linking the cyclodextrins of multiple polyrotaxanes creates a tough, flexible material with excellent elasticity, the firm says, because the cross-link points can slide freely and disperse stress.
Advanced Softmaterials gets technical and financial support from big Japanese companies, including Toray Industries, Ube Industries, and Sumitomo Rubber. CEO Yumiki Noda expects that the firm will reach $45 million in sales by 2023 owing to slide-ring materials’ wide variety of applications.
The materials are currently produced in commercial quantities at an Ube facility, and Toray has tested them under different conditions. By adding them to a nylon polymer, Toray created a material with six times the elongation of stand-alone nylon. A bending test showed the alloy to be 20 times as resistant to deterioration, the companies say. The alloy also displayed excellent crash-energy absorption. The characteristics led Toray researchers to conclude that the materials could be used in the manufacture of car bumpers, particularly those that are mostly made with carbon fiber–reinforced plastic.
Meanwhile, Toyoda Gosei, an affiliate of Toyota Motor, is developing medical applications for slide-ring materials. The firm created a rubber that shrinks when electric voltage is applied, while exhibiting little energy loss and performing at a wide range of temperatures. With these features, the rubber is useful for making dielectric actuators and sensors. Toyoda Gosei is designing a cardiac surgery–training simulator, due for launch this fall, featuring sensors made with slide-ring materials.
Intelligent Surfaces, also a spin-off from the University of Tokyo, has developed yet another new polymer, based on 2-methacryloyloxyethyl phosphorylcholine. Sometimes called poly-MPC, it is currently entering the commercialization phase, primarily for medical applications. The main feature of poly-MPC is its ability to imitate the structure of biological membranes. The material can be used in artificial blood vessels, stents, catheters, contact lenses, and artificial teeth, and even as a plumbing pipe liner.
Because poly-MPC mimics biological membranes, it can be coated on medical implants to raise their biocompatibility, Intelligent Surfaces says. The Japanese firm Kyocera Medical is using poly-MPC as a coating for artificial joints. The material can be cleaned with just water and resists staining, making it suitable for use as a coating on contact lenses, the firm says.
Similarly, coating dental implants and crowns with poly-MPC improves comfort and reduces the chance of bad breath because food doesn’t stick to the teeth, according to Intelligent Surfaces. In addition, CEO Yoshihiro Kiritoshi says food and beverage manufacturers have started to use poly-MPC to coat their water and sewage pipes. Because the polymer is easily cleaned with just water, it can raise hygiene and regulatory compliance in factories.
It’s still early days for Intelligent Surfaces and other small Japanese firms that are developing innovative materials. But their emergence is bringing optimism to the country’s polymer industry.
In the decades that followed the 1989 crash of Japan’s real estate market, the country invested little in R&D. In an effort to reverse the decline, recent governments have raised spending on basic research and encouraged industry-academia collaboration. Although Japan still lags behind the US in this respect, it now has a network of academics and potential industry partners covering almost all of the country.
Ito, the professor who founded Advanced Softmaterials, credits the firm’s success so far to the Japanese government’s efforts to launch technologies out of academia and encourage academic-industry interaction. “Through this project we proved that basic research by academia can connect to R&D by companies,” he says.
In fact, Ito sees a thawing of the R&D freeze and a new age of polymer innovation in Japan. “We have started to establish an all-Japan network,” he says. “When it is completed and works well as one team, a real spring in the Japanese plastic industry will come.”
Katsumori Matsuoka is a freelance writer based in Japan.