Denso Corp. (Kariya, Japan), will begin mass volume manufacturing of what will be the first automotive radiator tanks based largely on an organic compound derived from castor oil.
The list of 'green' alternative materials being used in the automotive industry continues to grow longer, as one of the world's leading Tier 1 suppliers of automotive systems, Denso Corp. (Kariya, Japan), has targeted this spring to begin mass volume manufacturing of what will be the first automotive radiator tanks based largely on an organic compound derived from castor oil. The radiator tanks (the top and bottom of the radiator; see photo) will be molded for vehicles worldwide.
"In addition to increasing installations of the new radiator tank to more vehicles, Denso aims to incorporate the new resin into a wide range of products in an effort to reduce the use of limited oil resources, reduce CO2 emissions during a product's life cycle and help prevent global warming," said Akio Shikamura, managing officer responsible for Denso's Thermal Systems Business Group, in a statement.
The resin is produced by a chemical reaction between two organic compounds, one derived from castor oil and the other a more typical plastic derived from petroleum. Castor oil is extracted from castor bean seeds. The castor oil-derived portion of the resin accounts for about 40% of the resin by weight, and glass fiber or other reinforcing materials or additives can be compounded into the material. The resin was developed by Denso and DuPont Kabushiki Kaisha, the name since 1993 of DuPont's Japanese business unit, which is headquartered in Tokyo.
Castor oil and castor seeds have played a part in the plastics industry for many years, with for example the Rilsan polyamide 11 developed by plastics supplier Arkema in 1942 being 100% based on it. That material, which is available in both extrusion and injection molding grades, was approved two years ago to carry fuel in European-made cars. DuPont unveiled its Zytel polyamide at the world's largest plastics trade show, the K, in October 2007. The renewably sourced grades of Zytel long-chain polyamides are based on sebacic acid from castor oil. PA 10.10 is 100% renewably sourced and PA 6.10 is more than 60% renewably sourced.
These materials see use in applications such as the Denso radiator tanks, where temperature resistance, low permeability, or mechanical properties are important. Also at that trade show, BASF unveiled Ultramid Balance PA 6.10, a polyamide based 60% on castor-oil-derived sebacic acid. The material is said to offer low density (compared to most polyamides), low-temperature impact resistance, and good dimensional stability due to low water absorption. Also at that K show, Arkema introduced two additional materials, Pebax Rnew TPEs and Platamid Rnew thermoplastic hot melt adhesives, both based to some degree on castor oil.—[email protected]