Appeal No. 2002-0184 -2-
Application No. 09/058,537
THE INVENTION
The invention is directed to a mixture of thermoplastic polymers consisting
essentially of tetrafluoroethylene units and specified amounts of perfluoroalkyl vinyl ether
moieties. The mixture contains a mixture of a low molecular weight polymer together with
a higher molecular weight polymer as determined by the melt flow indexes. A specified
ratio of the melt flow index of the low molecular weight polymer to the higher molecular
weight polymer is required by the claimed subject matter. Additional limitations are
described in the following illustrative claims.
THE CLAIMS
Claims 1, 7 and 17 are illustrative of appellants’ invention and are reproduced
below.
1. A mixture of thermoplastic PFA fluoropolymers consisting essentially of units of
tetrafluoroethylene, from 0.5 to 10 mol % of units of one or more perfluoro alkyl vinyl
ethers having from 1 to 4 carbon atoms in the perfluoroalkyl radical and up to about 5
mol % of other fluoromonomers not containing hydrogen, the mixture comprising:
-at least 10 % by weight of the mixture and not more than 90 % by weight of the
mixture of at least one component A) with a melt flow index (MFIA) $ 30 g/10 min. and
- not more than 90 % by weight of the mixture and at least 10 % by weight of the
mixture of at least one component B) with a melt flow index (MFIB) # 15 g/10 min.,
the components being selected in such a way that the ratio of MFIA to MFIB is in the
range from 80 to 2500.
7. A mixture according to claim17 wherein the ratio of the molecular weight of
the high molecular weight component to the low molecular weight component is $ 3.5.
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