Appeal No. 95-3536
Application 08/038,400
The Claimed Subject Matter
The claimed subject matter is directed to an extrusion process for making polyolefin articles
which includes a filtration system. The extrusion melt composition comprises the polyolefin, bis(2,4-
di-tert-butylphenyl)pentaerythroitol diphosphate stabilizer, and at least one epoxidized ester of an
unsaturated fatty acid. Appellant has discovered that this melt composition results in reduced filter
clogging. Claim 3 is representative of the claimed subject matter and reads as follows:
3. An extrusion process for making plastic articles, said process comprising:
a) forming a polyolefin composition comprising a polyolefin resin, a phosphite
stabilizer, and at least one epoxidized ester of a fatty acid,
b) melt extruding said composition through a filtration system to produce a filtered
polyolefin melt stream,
c) passing said melt stream through a die to make the plastic article, wherein said phosphite
is a bis(2, 4-di-tert-butylphenyl)pentaerythritol diphosphite.
Prior Art References
The following prior art references is relied upon by the examiner in support of the rejection
of the claims for obviousness:
Minagawa et al. (Minagawa) 4,371,647 Feb. 1, 1983
Moylan 4,832,882 May 23, 1989
Moore, Jr. (Moore) 4,888,369 Dec. 19, 1989
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