Appeal No. 2001-0131
Application No. 08/977,110
degradative modes is sufficient basis to utilize an
alkali metal oxide, alone or with calcium stearate
when one or more antioxidants comprising a phenolic
antioxidant and [sic] an organic phosphite known to
be suitable as melt stabilizers are present in olefin
resins containing a polyester, polystyrene and PVC.
We cannot agree with the examiner’s analysis. Burns
discloses a stabilizer system for C2 to C8 olefin polymers
comprising at least one pentaerythritol phosphite compound and
at least one alkaline earth metal oxide (e.g., CaO). (Abstract;
column 1, lines 35-39; column 2, lines 8-10.) According to
Burns, the pentaerythritol phosphite compounds “provide
excellent color stability as well as suppress odors” but are
“very sensitive to moisture and consequently undergo degradation
at high temperatures.” (Column 1, lines 16-26.) Burns solves
the degradation problem of pentaerythritol phosphite, which is
said to be an otherwise excellent color stabilizer, by adding an
alkaline earth metal oxide. (Column 1, lines 35-39.) Burns
further teaches that a hindered phenol (e.g., octadecyl[(3-(3,5-
di-t-butyl-4-hydroxyphenyl)]propionate) may also be included.
(Column 2, lines 12-39.)
The present specification acknowledges that the recited
component “b)” is known as a stabilizer for plastics. (Page 9,
third and fourth paragraphs.)
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