New Cover Gas to be Adopted for Die-Casting
Production of Magnesium Parts

Taiyo Nippon Sanso Corporation (TNSC) has developed an
environmentally-friendly cover gas for magnesium
fabrication, through joint research with Tokai Rika Co.,
Ltd. The new cover gas, named MG Shield
®
-- whose principal
component is fluoroketon -- will be used (for the first
time in Japan) in the magnesium die-casting process at the
Otowa Plant of Tokai Rika. TNSC will also provide the
plant with carbon dioxide for dilution purposes, as well
as with the necessary gas supply equipment and piping.
We received an award (involving a financial
subsidiary in fiscal 2005) from the Ministry of Economy,
Trade and Industry for our success in developing a system
employing this new magnesium cover gas, thanks to its
contribution to the prevention of global warming.
Conventionally, sulfur hexafluoride (SF
6
), a gas with a GWP
(global warming potential) 22,200 times that of carbon
dioxide, has been employed as the cover gas for the
prevention of magnesium flaring (combustion) in the
magnesium die-casting process. Developed specifically to
serve as a substitute for SF
6
, MG Shield
®
has approximately
the same GWP as carbon dioxide, and its use instead of SF
6

would thus do much to retard the global warming process.

1. Main features of MG Shield
®

1) GWP
≒
1
2) It is delivered in cylinders, and can be handled in the
same way as existing cover gases.
3) Thanks to the fact that it incorporates the
fluoroketon-based fireproofing agent Novec™612 (made by

Sumitomo 3M), MG Shield
®
displays the same effectiveness in
preventing flaring as SF
6
.

2. Effectiveness
If the use of SF
6
at Otowa Plant is completely discontinued
in favor of MG Shield
®
as a substitute, this would be
equivalent to the reduction of carbon dioxide emissions in
the amount of 45,000 tons per year.

3. Schedule for use in die-casting production of
magnesium-alloy components in the near future
Oct. 2005 – Feb. 2006: Practical tests on commercial model
to begin (one production line) at Otowa Plant
Feb. 2006 onward: New gas to be applied step-by-step to
all lines at Otowa Plant.

4. Plans for marketing of MG Shield
®

Five years from now, we project sales of MG Shield
®
in the
region of 1,000 cylinders per annum.