Conducting a Broad Range of
Businesses Leveraging C5 Fractions

Zeon Corporation was founded in 1950 with capital contribution from Furukawa Electric Co., Ltd., Yokohama Rubber Co., Ltd., and Nippon Light Metal Company, Ltd. It started business with the manufacturing of PVC, using PVC manufacturing technologies acquired from U.S.-based B.F. Goodrich Chemical Company. The Company subsequently developed its proprietary technologies to extract butadiene, isoprene, and other raw materials for synthetic rubbers and plastics, which it currently handles while continuing to manufacture and sell diverse petrochemical products.

The Elastomer Business (Zeon's Core Business)

• Synthetic rubbers
• Synthetic latexes
• Chemical products (petroleum resins, thermoplastic elastomers)

Specialty Materials Business (Zeon's Recently Developing Venture)

• Specialty chemicals (synthetic aroma chemicals, other specialty chemicals)
• Imaging and electronics materials (polymerized toner)
• Specialty plastics (cyclo-olefin polymers)
• Specialty components (optical films)
• Energy materials (binders for lithium-ion batteries)
• Medical materials and devices

The core business of Zeon Corporation consists of materials and products that include various components extracted from the C4 and C5 fractions in naphtha as raw materials, and it uses Zeon's proprietary technologies. We manufacture synthetic rubbers and synthetic latexes by extracting highly pure butadiene from C4 fractions using our proprietary GPB process. In addition to synthetic rubbers, we manufacture petroleum resin, cyclo-olefin polymers, and synthetic aroma chemicals by extracting isoprene, piperylene, dicyclopentadiene, and 2-butyne from C5 fractions while also using GPI technology.

The manufacture of synthetic rubbers has largely driven Zeon Corporation's growth. Initially, we only manufactured butadiene-derived synthetic rubbers that use C4 fractions as raw materials. Then, having expanded the synthetic rubbers business, we started the C5 business by manufacturing C5-derived isoprene rubber with the same chemical composition as natural rubber. However, while butadiene accounts for about 40% of C4 fractions, isoprene accounts for only about 10% of C5 fractions. If we were unable to effectively use components of C5 fractions other than isoprene, we would not be able to generate profits from the C5 business. We have therefore focused on research and development for effectively using C5 components. The GPI process to extract C5 components is also a proprietary technology, enabling us to develop diverse businesses under the umbrella of the comprehensive use of C5.

GPB Process

The GPB process was developed by Zeon Corporation as a proprietary technology. GPB stands for Geon Process of Butadiene. The technology is used to extract highly pure butadiene from C4 fractions, which are a byproduct of the production of ethylene, through extractive distillation. The GPB process has received the Okochi Memorial Grand Production Prize and other recognition as the most economical technology for manufacturing high-quality butadiene. Furthermore, the technology has been provided to and used in 47 plants in 19 countries around the world.

About the Process

The C4 fractions used as a raw material contain over 40% butadiene, over 50% of butane and butene, and several percentage points of C4 acetylene. These fractions in the form of gas are fed to the middle stage of the No. 1 extractive distillation column. A DMF solution is fed from the top of the column, and butane and butene are subsequently extracted from the top of the column as byproducts. Butadiene in the liquid at the bottom of the column is transported to the first stripper. It is separated from the DMF solution, and acetylene is removed from the bottom of the column. Methyl acetylene and butene, which have similar solubility to butadiene, are subsequently removed, yielding highly pure butadiene.

GPB Flow Chart

GPI Process

In the wake of its development of the GPB process, Zeon Corporation developed the GPI process as another proprietary technology. GPI stands for Geon Process of Isoprene. This technology is used to economically manufacture highly pure isoprene, dicyclopentadiene, piperylene, and amylene from C5 fractions, which are byproducts generated when manufacturing ethylene by thermal cracking of naphtha through extractive distillation. The development of the C5 business at the Zeon Corporation Mizushima Plant is based on the GPI Process, which received the Okochi Memorial Production Prize.

About the Process

The C5 fractions used as raw material contain about 15% isoprene, about 20% cyclopentadiene, and about 10% piperylene, along with some levels of C5 olefin and acetylene. The fractions are fed to the middle stage of the first extractive distillation column by way of a pre-distillation column. The DMF solution is fed from the top of the column and components that are insoluble by DMF are extracted from the top. Components soluble by DMF are transported to a high boiling point substance removal column. Dicyclopentadiene, piperylene, and high boiling point C5 components are extracted from the bottom of the column. The components are subsequently separated into dicyclopentadiene, piperylene, and others.
Components that exit from the top of the high boiling point substance removal column are transported to the low boiling point substance removal column after acetylene has been removed at the second extractive distillation section. Isoprene is extracted from the bottom of the column and low-boiling point C5 fractions are extracted from the top. The Mizushima Plant uses the components extracted by these processes as raw materials to manufacture C5-related products.

GPI Flow Chart