Ex Parte Weeks

Board of Patent Appeals and Interferences

Apr 28, 2010

10528610 (B.P.A.I. Apr. 28, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte RONALD J. WEEKS
____________

Appeal 2009-010872
Application 10/528,610
Technology Center 1700
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Decided: April 29, 2010
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Before ROMULO H. DELMENDO, JEFFREY T. SMITH, and
JEFFREY B. ROBERTSON, Administrative Patent Judges.

DELMENDO, Administrative Patent Judge.

DECISION ON APPEAL
Appeal 2009-010872
Application 10/528,610

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Appellant appeals under 35 U.S.C. § 134(a) from a final rejection of
claims 1, 3-9, 11, 13-20, 22, and 24-28 (Second Revised Appeal Brief filed
October 2, 2008, hereinafter “App. Br.,” at 2; Final Office Action mailed
August 23, 2007). We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.

STATEMENT OF THE CASE
Appellant states that the invention relates to “polymer compositions
uniquely suited for extrusion coating having minimum ‘neck-in’ and
excellent sealing characteristics (for example, low heat seal initiation
temperatures) and toughness properties” (Spec. 1, ll. 18-20).
Claim 1 reads as follows:
1. A polymer composition comprising
(A) from 60 to 80 weight percent of a mixture of at least
one homogeneously branched polyethylene and at least one
heterogeneously branched polyethylene wherein the mixture of
(A) comprises from 40 to 75 weight percent of the
homogeneously branched polyethylene and from 25 to 60
weight percent of the heterogeneously branched polyethylene[
and]
(B) from 20 to 40 weight percent of at least one low
density polyethylene polymer having a melt strength at least
twice that of mixture (A).
(App. Br. 8; Claims App’x.)
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The Examiner relied upon the following as evidence of
unpatentability (Examiner’s Answer mailed December 19, 2008, hereinafter
“Ans.,” 3):1
Chum 5,677,383 Oct. 14, 1997
Bamberger 6,384,158 B1 May 7, 2002

The Examiner rejected claims 1, 3-9, 11, 13-20, 22, and 24-28 under
35 U.S.C. § 103(a) as unpatentable over the combined teachings of Chum
and Bamberger (Ans. 3-4).

ISSUE
The Examiner found that Chum describes mixture (A), as recited in
claim 1, in the form of a polymer blend comprising 5-95 wt% of at least one
homogeneously branched ethylene interpolymer having at least one
comonomer and 95-5 wt% of at least one second heterogeneously branched
ethylene interpolymer having at least one second comonomer (Ans. 3).
Although Chum teaches that the interpolymers making up the blend are
branched (i.e., not “linear” in the traditional sense), the Examiner relies on
Chum’s unconventional lexicography to assert that these interpolymers are
“linear polyethylenes” within the contemplation of Bamberger’s discussion
of the prior art (Ans. 4).

1 The Examiner refers to JP 10168245 and JP 57128729 (Ans. 3, 6). These
references, however, have not been included in the statement of rejection as
part of the relied-upon evidence. Accordingly, we do not consider these
references. In re Hoch, 428 F.2d 1341, 1342 n.3 (CCPA 1970) (“Where a
reference is relied on to support a rejection, whether or not in a ‘minor
capacity,’ there would appear to be no excuse for not positively including
the reference in the statement of rejection.”).
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Nevertheless, the Examiner acknowledged that Chum does not
describe component (B) (i.e., a “low density polyethylene [LDPE] polymer
having a melt strength at least twice that of mixture (A)”), as recited in claim
1 (Ans. 4). To account for this difference, the Examiner relied on
Bamberger, which is said to teach that it was known to add low levels of a
LDPE to a linear polyethylene (LPE) in order to increase its melt strength
(Ans. 4). Furthermore, the Examiner found that Bamberger teaches that
“LDPE is known in the art to have a melt strength 2-3 times greater than that
of LLDPE [linear low density polyethylene]” (Ans. 4). The Examiner then
concluded that it would have been obvious to one of ordinary skill in the art
to add a LDPE into Chum’s polymer blend to improve its melt strength, thus
arriving at Appellant’s claimed subject matter (id.).
Appellant concedes that Chum’s blend corresponds to mixture (A) of
claim 1 (i.e., a blend of branched polyethylenes). Appellant contends,
however, that the Examiner failed to demonstrate that a person of ordinary
skill in the art would have considered Chum’s blend to be a linear
polyethylene that may be improved by adding low amounts of an LDPE in
accordance with the prior art discussed in Bamberger (Reply Brief,
hereinafter “Reply Br.,” filed February 17, 2009 at 3; App. Br. 6). Appellant
further asserts that “there is no teaching in [Bamberger] that the LDPE
should be chosen to have at least twice the melt strength of the LLDPE
portion [i.e., mixture (A)]. . .” (App. Br. 5-6).
Thus, a dispositive issue is:
Has the Examiner identified a reason that would have prompted a
person of ordinary skill in the art to combine Chum with Bamberger in the
manner claimed – i.e., add a LDPE to Chum’s polymer blend of
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homogeneously branched” and “heterogeneously branched” ethylene
interpolymers, wherein the LDPE has a melt strength that is at least twice
that of Chum’s polymer blend, as required in independent claims 1, 11, 24,
and 25?

FINDINGS OF FACT (“FF”)
1. Chum teaches a polymer blend comprising: (A) at least one
“homogeneously branched substantially linear ethylene/α-olefin
interpolymer”; and (B) “a heterogeneously branched ethylene
polymer” (col. 1, ll. 21-31).
2. Chum indicates to one skilled in the relevant art that Chum is
using the term “branched” or “linear” in a non-traditional sense
(col. 3, ll. 12-17; col. 6, l. 65 to 7, l. 3).
3. In the “Background of the Invention” section, Bamberger states
that “[i]t is common practice in the industry to add low levels of
an LDPE to an LPE [i.e., linear polyethylene] to increase melt
strength, to increase shear sensitivity, i.e., to increase flow at a
given horse power; and to reduce the tendency to melt fracture”
(col. 1, ll. 50-55).
4. Bamberger discloses:
At equivalent molecular weights, the melt
strength of polymers made with the inventive
catalyst is equivalent to the melt strength of
LDPE’s (and LD/LL blends), and is typically 2-3
times higher than that of polymers made with
conventional Ziegler-Natta titanium-based
catalysts or with other metallocene catalysts
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capable of producing narrow MWD’s [col. 12, ll.
6-12].

PRINCIPLES OF LAW
“Section 103 forbids issuance of a patent when ‘the differences
between the subject matter sought to be patented and the prior art are such
that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.’” KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 406
(2007).
While KSR explains that an obviousness “analysis need not seek out
precise [prior art] teachings,” it nonetheless did not dispense with the need
for evaluating the evidence to determine whether a person having ordinary
skill in the art would have had “an apparent reason to combine the known
elements in the fashion claimed.” Id. at 418.

ANALYSIS
We agree with Appellant that the Examiner failed to establish a prima
facie case of obviousness (App. Br. 4-5).
As pointed out by Appellant (Reply Br. 3), the Examiner has not
established that a person of ordinary skill in the art would have regarded
Chum’s polymer blend to be a linear polyethylene (LPE) of the type that
may be improved by adding low amounts of low density polyethylene
(LDPE) in accordance with the prior art process discussed in Bamberger’s
“Background of the Invention” section. Chum plainly teaches that the blend
comprises branched ethylene polymers and even states that the term “linear”
appearing in Chum’s disclosure is used in a non-traditional sense (FF 1 and
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2). The Examiner, however, did not offer any evidence or sufficient
technical reasoning establishing that Chum’s polymer blend of “branched”
polymers is in fact a linear polyethylene of the type contemplated in the
prior art process discussed in Bamberger’s “Background of the Invention”
section (FF 3).
Furthermore, while Bamberger states that a LDPE of a given
molecular weight typically has a melt strength 2-3 times that of certain
unspecified polymers made with conventional Ziegler-Natta Ti-based
catalysts or with metallocene catalysts capable of producing polymers
having narrow MWDs (molecular weight distributions) (FF 4), the Examiner
has not demonstrated that Chum’s polymer blend would necessarily have the
same melt strength as a polymer made with the unspecified conventional
Ziegler-Natta Ti-based or metallocene catalysts (App. Br. 6). Indeed,
Bamberger even states that LDPEs have melt strengths equivalent to certain
“LD/LL blends” (FF 4).
For these reasons, we cannot uphold the Examiner’s rejection.

CONCLUSION
The Examiner has not articulated a reason based on rational
underpinnings that would have prompted a person of ordinary skill in the art
to combine the references in the manner claimed.

DECISION
The Examiner’s decision to reject appealed claims 1, 3-9, 11, 13-20,
22, and 24-28 under 35 U.S.C. § 103(a) as unpatentable over Chum and
Bamberger is reversed.
Appeal 2009-010872
Application 10/528,610

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No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

REVERSED

bim

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