Sekisui Chemical Co. Ltd. (Tokyo, Japan) announced that, in response to the global trend of tighter regulations regarding perfluoroalkyl and polyfluoroalkyl substances (PFAS) and growing demand for reducing environmental impact, the Urban Infrastructure & Environmental Products Co. had been developing a new technology for PFAS-free pipe materials for ultrapure process applications in the manufacturing of advanced semiconductors. As a certain level of progress has been established in the development of this technology, Sekisui Chemical will start to formally propose it to customers.
Ultrapure water manufacturing system used to conduct the demonstration test at Kurita Innovation Hub; the blue pipes are the pipes under demonstration (Source: Sekisui Chemical)
In the semiconductor and flat panel display (FPD) industries, the ultrapure water being used needs to be supplied without lowering its water quality. The types of pipe materials for this purpose include those that use resin materials — hard polyvinyl chloride (PVC), polypropylene (PP), and fluorocarbon resins (polyvinylidene fluoride or PVDF, polytetrafluoroethylene or PTFE, and perfluoroalkoxy or PFA) — as well as those that use metallic materials in the form of metal pipes with special surface treatment. The modern semiconductor industry, with the progress of ultra-miniaturization, requires pipe materials that can suppress the elution of inorganic and organic matter as far as possible.
PFAS substances are difficult to break down in nature. Among PFAS, the manufacture, import, and such of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) are already prohibited. As of now, PVDF, PTFE, and other materials used in fluorocarbon resin pipes and fittings for ultrapure process applications are not within the scope of regulation in Japan. However, in Europe and the United States, studies are being conducted to comprehensively subject PFAS to regulation. Together with other initiatives, there is a global trend of tighter regulations regarding PFAS across all industry sectors, necessitating materials innovation. Fujufilm recently announced its development of a novel PFAS-free resist material for semiconductors.
Sekisui Chemical launched Eslon Clean Pipe — a hard PVC pipe material for transporting ultrapure water — in 1984. Since then, the product has been used in a wide range of applications. This time, a special olefin resin pipe material has been developed as a new low-elution material replacing fluorocarbon resins. In November 2022, a demonstration using an actual ultrapure water manufacturing system was started jointly with Kurita Water Industries Ltd. (Tokyo) Compared to existing fluorocarbon resin pipe materials, this special olefin resin pipe material can reduce CO2 emissions during manufacturing by approximately 80%. Furthermore, in response to the global trend of PFAS regulation, Sekisui Chemical started working on developing PFAS-free pipes and fittings for ultrapure process applications.
With the establishment of this PFAS-free technology, Sekisui Chemical will start to formally propose it to customers and will aim for market launch within fiscal 2026. The company will also undertake development toward the early realization of creating valves, gaskets, and other pipe materials that are totally free from PFAS in the area of ultrapure process applications.