Ex parte BAE

Board of Patent Appeals and Interferences

Oct 19, 2001

08772351 (B.P.A.I. Oct. 19, 2001)

1
The opinion in support of the decision being entered today was
not written for publication and is not binding precedent of
the Board.
Paper No. 25
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte KOOK J. BAE
__________
Appeal No. 1999-2808
Application 08/772,351
___________
ON BRIEF
___________
Before OWENS, WALTZ and PAWLIKOWSKI, Administrative Patent
Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the examiner’s final rejection of
claims 2-22, 25-28 and 30-33, which are all of the claims
remaining in the application.
THE INVENTION
The appellant’s claimed invention is directed toward a
composition, useful for food contact or medical contact
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applications, comprising a polyvinyl chloride resin and a
specified low toxicity stabilizer for that resin. Claim 30 is
illustrative:
30. A composition of matter comprising:
(i) a food contact or medical contact polyvinyl chloride
resin; and
(ii) a low toxicity stabilizer suitable for use with
food contact and medical applications, for providing heat
stability to the polyvinyl chloride resin, wherein the
stabilizer consists essentially of: (a) about 10 to about 40
parts by weight of a zinc carboxylate having the formula
(RCO ) Zn, wherein R is an aliphatic, cycloaliphatic or2 2
aromatic hydrocarbon containing from about 6 to about 22
carbon atoms; (b) about 40 to about 80 parts by weight of an
alkyl ester of thiodipropionic acid having the formula
S(CH CH CO R ) wherein R is an alkyl having from about 6 to2 2 2 2 11
about 22 carbon atoms; and (c) about 5 to about 20 parts by
weight of a phenolic antioxidant,
the composition of matter being essentially free of
calcium fatty acid salts.
THE REFERENCES
Ackerman 3,262,896 Jul. 26, 1966
Rhodes 3,575,905 Apr. 20, 1971
Vijlbrief 3,586,514 Jun. 22, 1971
Minagawa et al. (Minagawa) 4,221,700 Sep. 9, 1980
Penneck et al. (Penneck) 1,001,344 Aug. 18, 1965
(Great Britain patent specification)
Jerzy Wypych, “Mechanism of Action of PVC Thermal
Stabilizers”, 23 J. Appl. Polym. Sci. 39-54 (1979).
Appeal No. 1999-2808
Application 08/772,351

The examiner’s reliance upon an article to Stapfer et1
al. is withdrawn in the examiner’s answer (page 4).
3
THE REJECTION
Claims 2-22, 25-28 and 30-33 stand rejected under 35
U.S.C. § 103 as being unpatentable over Penneck taken with
Ackerman, Rhodes, Wypych, Minagawa and Vijlbrief.1
OPINION
We reverse the aforementioned rejection.
Penneck discloses polyvinyl chloride stabilized with a
mixture of an organometallic compound, a sulfur-containing
organic or organometallic compound, and an organic antioxidant
(page 1, lines 43-79; page 2, lines 12-13 and 34-35). In an
example (12), a mixture of zinc stearate and calcium stearate
is used as the organometallic component. The disclosed
sulfur-containing organic compounds include dilauryl
$$’thiodipropionate (page 3, line 39), and the disclosed
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Application 08/772,351

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organic antioxidants include phenols (page 3, lines 51-55).
Ackerman teaches that zinc stabilizers for halogen-
containing resins, within a very short time, blacken and char
the resin to be stabilized (col. 1, lines 43-47). Ackerman
teaches that this blackening and charring can be delayed by
using zinc stearate in combination with stearates of alkali or
alkaline earth metals, but that mixtures of zinc stearate and
barium stearate, which produce by far the best results,
undesirably yellow and discolor the resin (col. 1, line 48 -
col. 2, line 9). Ackerman uses zinc soaps in combination with
potassium soaps, each soap preferably being a salt of a fatty
acid containing 6-12 carbon atoms (col. 2, lines 10-14 and 41-
48). The examiner does not rely upon any evidence that
potassium soaps were considered in the art at the time of the
appellant’s claimed invention to be suitable for use in food
contact or medical contact applications.
Rhodes teaches that “even the addition [to zinc-
containing stabilizers] of substantial amounts of alkaline
earth or alkali metal salts, such as salts of calcium, barium
or potassium, or other conventional plastics additives, such
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Application 08/772,351

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as organic phosphites, hindered phenols, epoxidized oils and
the like, will not prevent sudden degradation” (col. 1, lines
68-72). Rhodes’ stabilizer contains a large amount of an aryl
alkyl phosphite and a small amount of a zinc salt or soap, and
is substantially free of metals which form colored sulfides
(col. 2, lines 32-42; col. 3, lines 7-10). The appellant
states that the claimed invention excludes phosphite
stabilizers (specification, page 5, lines 23-26). Thus, when
we give “consisting essentially of” in the appellant’s claims
its broadest reasonable interpretation in view of the
specification, see In re Zletz, 893 F.2d 319, 321, 13 USPQ2d
1320, 1322 (Fed. Cir. 1989); In re Sneed, 710 F.2d 1544, 1548,
218 USPQ 385, 388 (Fed. Cir. 1983), we consider it to exclude
phosphite stabilizers. Rhodes also teaches that including an
epoxidized soya oil in his resin composition significantly
retards thermal discoloration and somewhat increases the
concentration of zinc which can be used without causing sudden
degradation (col. 3, lines 28-35).
Wypych teaches that epoxy stabilizers, when used in
combination with zinc stearate, decrease the rate of polyvinyl
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chloride thermal degradation (pages 49 and 53).
The examiner relies upon Vijlbrief for a teaching that
zinc stearate, dilauryl thiodipropionate and phenolic
antioxidants were known to be suitable for use in polyvinyl
chloride containers which contact food (col. 2, lines 44-45
and 57; col. 3, lines 1-7), and relies upon Minagawa for an
example (5-2) in which the use of stabilizers increased the
time before yellowing and blackening of polyvinyl chloride
(answer, pages 5 and 8).
The examiner argues that in view of Wypych, it would have
been obvious to one of ordinary skill in the art to use an
epoxy stabilizer instead of a calcium soap to offset a zinc
soap’s deleterious effects (answer, page 8). Wypych, however,
does not disclose the relative effect of epoxy stabilizers
versus that of calcium soaps. Thus, he does not indicate that
epoxy stabilizers are suitable substitutes for calcium soaps
for offsetting the negative effects of zinc soaps used
stabilize polyvinyl chloride.
Moreover, Rhodes teaches that calcium salts or epoxidized
soya oils, when used in combination with zinc-containing
stabilizers, will not prevent sudden degradation of polyvinyl
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chloride (col. 1, lines 67-72). Rhodes uses a large amount of
an aryl alkyl phosphite in combination with a small amount of
a zinc salt or soap to retard polyvinyl chloride thermal
degradation, and optionally uses an epoxidized soya oil to
increase the effectiveness of the zinc-phosphite combination
(col. 2, lines 32-44; col. 3, lines 23-40). Ackerman also
teaches that combinations of zinc salts or soaps with
stearates of alkali or alkaline earth metals are not suitable
thermal stabilizers for polyvinyl chloride (col. 1, line 39 -
col. 2, line 9). Ackerman uses combinations of zinc soaps and
potassium soaps, optionally containing additional stabilizers,
one of which can be an epoxide, to stabilize polyvinyl
chloride (col. 2, lines 10-14; col. 3, lines 6-8 and 31-32).
Thus, the applied prior art teaches that alkaline earth
metal stearates or epoxy stabilizers, in combination with zinc
stearate, reduce the rate of thermal degradation of polyvinyl
chloride compared to the rate of thermal degradation when zinc
stearate is used alone, but that a combination of a zinc-
containing stabilizer and either a calcium salt or an
epoxidized oil will not prevent sudden degradation of
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polyvinyl chloride. Rhodes would have suggested using zinc
stearate in combination with epoxidized soya oil and an aryl
alkyl phosphite, with no calcium soap present, but phosphites
are excluded from the appellant’s claims. Ackerman would have
suggested using zinc soaps with an epoxy stabilizer and a
potassium soap, in the absence of a calcium soap, but the
examiner has not established that such potassium soaps were
considered in the art to be suitable for use in food contact
or medical contact resins.
The examiner has not explained why the applied prior art
would have fairly suggested, to one of ordinary skill in the
art, using a zinc soap in combination with an epoxy stabilizer
without also including in the stabilizer composition a
component which renders the stabilizer composition unsuitable
for use in food contact or medical contact resins.
Consequently, the examiner’s argument in support of the
rejection is not persuasive. Accordingly, we conclude that
the examiner has not carried the burden of establishing a
prima facie case of obviousness of the invention recited in
any of the appellant’s claims.
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Application 08/772,351

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Since no prima facie case of obviousness has been
established, we need not address the experimental results.
See In re Piasecki, 745 F.2d 1468, 1472, 223 USPQ 785, 788
(Fed. Cir. 1984); In re Rinehart, 531 F.2d 1048, 1052, 189
USPQ 143, 147 (CCPA 1976).
DECISION
The rejection of claims 2-22, 25-28 and 30-33 under 35
U.S.C. § 103 over Penneck taken with Ackerman, Rhodes, Wypych,
Minagawa and Vijlbrief, is reversed.
REVERSED
)
TERRY J. OWENS )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
THOMAS A. WALTZ )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
BEVERLY A. PAWLIKOWSKI )
Administrative Patent Judge )
Intellectual Property Law Group
Law Dept.
Appeal No. 1999-2808
Application 08/772,351

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Witco Corporation
Greenwhich, CT 06831-2559