Appeal No. 2003-1718
Application No. 09/344,295
lines 15-21), prior art single ply roofing membrane systems
typically include two propylene-ethylene-copolymer sheets bonded
to each other and a woven polyester reinforcing mesh or scrim
located intermediate the propylene-ethylene-copolymer sheets.
The appellants explain, however, that because polyester meshes
are hydrophilic and are not chemically compatible with
propylene-ethylene-copolymer sheets, their use in roofing
membranes has certain drawbacks (wicking of water into the
membranes along unsealed edges of the membranes and inability to
recycle scrap membrane). (Id. at page 1, line 31 to page 2,
line 10.) The appellants state that “the present invention may
reduce the wicking problem associated with polyester scrim
reinforced membranes and can be recycled both during the
production process, if the membrane is out of specification, and
after the membrane’s useful service life in the field.” (Id. at
page 2, lines 27-31.) Further details of this appealed subject
matter are recited in representative claim 1, the only
independent claim on appeal, reproduced below:
1. A recyclable, reinforced roofing membrane for
use in single ply roofing systems, comprising:
first and second propylene-ethylene-copolymer
sheets wherein the propylene-ethylene-copolymer of the
sheets is polymerized from a polypropylene and
ethylene-monomer blend comprising about 30% to about
70% by weight polypropylene and about 30% to about 70%
by weight ethylene-monomer; and a hydrophobic
polypropylene reinforcing mesh intermediate the first
2
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