       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

 KNAUF INSULATION, INC., FORMERLY KNAUF
 INSULATION LLC, KNAUF INSULATION, SPRL,
                 Appellants

                           v.

        ROCKWOOL INTERNATIONAL A/S,
                    Appellee
             ______________________

                      2016-1184
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/000,674.
                  ______________________

              Decided: February 27, 2017
               ______________________

    JOSHUA PAUL LARSEN, Barnes & Thornburg LLP, In-
dianapolis, IN, argued for appellants.

    DAVID CLAY HOLLOWAY, Kilpatrick Townsend &
Stockton LLP, Atlanta, GA, argued for appellee. Also
represented by COURTNEY DABBIERE, DEAN W. RUSSELL,
TIFFANY L. WILLIAMS.
                ______________________

    Before REYNA, TARANTO, and HUGHES, Circuit Judges.
2              KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S



REYNA, Circuit Judge.

     Knauf Insulation, Inc. (“Knauf”) appeals from the de-
cision of the United States Patent Trial and Appeal Board
(“Board”) affirming the rejection of claims 21–26 of U.S.
Patent No. 7,854,980 (“’980 patent”) as obvious under 35
U.S.C. § 103. The Board determined that claims 21–26
are inherent in the prior art. Because the Board’s deci-
sion is supported by substantial evidence, we affirm.
                        BACKGROUND
                   1. The ’980 Patent

     The ’980 patent relates to certain packaged mineral
fiber insulating material. J.A. 30. Fiber insulation
requires a binder component to hold its fibers together.
The ’980 patent states that, prior to 2010, the industry
standard for fiber insulation binding was based on phenol
formaldehyde. ’980 patent, col. 1 ll. 18–20. Although
formaldehyde provided some desirable qualities in insula-
tion, the industry began to look to other binding agents in
light of formaldehyde’s environmental effects. Id. col. 1
ll. 20–24. One potential replacement for formaldehyde
was polyester, but it proved not to be sufficiently strong,
particularly when exposed to moisture. Id. col. 1 ll. 25–
29.

    Another potential alternative is melanoidins. The
’980 patent discloses “a packaged mineral fiber insulating
material” that allegedly improved on the prior art by
using melanoidins instead of formaldehyde to bind the
mineral fibers. According to the ’980 patent, melanoidins
provide the necessary binder strength for use on an
industrial scale—a quality previously not thought possi-
ble without using formaldehyde. J.A. 30.
KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S             3



    Knauf is the assignee of the ’980 patent, which issued
in 2010 with claims 1–20. J.A. 26. Claim 1 was repre-
sentative of the original ’980 patent:
        1. A mineral fiber insulating material com-
    prising mineral fibers and less than about 15% by
    weight of an organic binder, wherein
        a) the organic binder is a formaldehyde free
    product of curing an aqueous solution having a pH
    of greater than 5 when applied to the mineral fi-
    bers,
        b) the mineral fiber insulating material has a
    recovered thickness of at least about 95% as de-
    termined according to Annex A of British stand-
    ard BS EN 823: 1995,
         c) the mineral fiber insulating material having
    an ordinary parting strength of at least about 95
    g/g,
        d) the mineral fiber insulating material hav-
    ing a weathered parting strength of at least about
    75 g/g, and
       e) the mineral fiber insulating material is
    packaged.
’980 patent, col. 6, ll. 42–55.

    Rockwool International A/S (“Rockwool”) competes
with Knauf in manufacturing insulation materials. In
2012, Rockwool requested inter partes reexamination of
the ’980 patent from the United States Patent and
Trademark Office (“PTO”). After the PTO granted Rock-
wool’s request, Knauf sought to amend the patent by
adding claims 21–29. Claim 26 is representative of
Knauf’s proposed amendment:
        26. A mineral fiber insulating material, com-
    prising: mineral fibers and less than about 15% by
4              KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S



    weight of an organic thermoset binder disposed
    upon the mineral fibers, wherein:
         (a) the organic thermoset binder is a formal-
    dehyde free product of curing an aqueous solution,
    consisting essentially of dextrose and ammonium
    salt of citric acid wherein (i) the solution has a pH
    of greater than 5 when applied to the fibers and
    (ii) the binder includes melanoidins produced by a
    Maillard reaction which occurs during curing,
        (b) the mineral fiber insulating material has
    recovered thickness of at least about 95% as de-
    termined according to Annex A of British stand-
    ard BS EN 823 1995,
         (c) the mineral fiber insulation material has
    an ordinary parting strength of at least about 95
    g/g.
        (d) the mineral fiber insulating material has a
    weather parting strength of at least about 75 g/g,
    and
       (e) the mineral fiber insulating material is
    packaged.
J.A. 1472 (emphasis added).
    This case centers on the Maillard reaction described
in claim 26(a), which occurs when a reducing sugar, an
amine, and a polycarboxylic acid combine to produce
melanoidins. A Maillard reaction is distinct from a sepa-
rate chemical process called esterification. Knauf argues
that the prior art discloses a mixture of components that
will result in esterification to the exclusion of a Maillard
reaction. Rockwell responds that esterification, even if it
occurs, will not preclude a Maillard reaction.
KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S            5



           2. Examiner Decision and Prior Art
    The PTO Examiner upheld original claims 1–20 but
rejected as obvious amended claims 21–29. Specifically,
the Examiner found these claims obvious over two prior
art references that disclosed melanoidins formed by a
Maillard reaction: U.S. Patent No. 6,878,800 (“Huse-
moen”); and WIPO Publication No. 2006/044302 (“Hel-
bing”).
                      A. Husemoen
    The Husemoen patent is entitled, “Binder for Mineral
Wool Products.” J.A. 877. Although it is undisputed that
Husemoen does not explicitly disclose melanoidin produc-
tion, the Examiner determined that Husemoen discloses a
binder of an amine, a polycarboxylic acid, and a reducing
sugar sufficient to cause a Maillard reaction. J.A. 1653
(“The binder taught by HUSEMOEN is formed by similar
reactants: amine, citric acid and glucose syrup; therefore,
it would form a reaction product that includes melanoidin
products cross-linked with the polycarboxylic acid (citric
acid).”) (citations omitted). Husemoen teaches that its
additives “may be mono-, di-, and polysaccharides, such
as” glucose syrup and twelve other possibilities. Glucose
syrup is one of two sugars among Husemoen’s non-
exhaustive list. The Examiner found that because Huse-
moen discloses glucose syrup, Husemoen inherently
discloses the production of melanoidins.
                         B. Helbing
    Helbing is a WIPO publication dated April 27, 2006
and entitled, “Polyester Binding Compositions.” It dis-
closes “formaldehyde-free, thermally-curable, alkaline,
aqueous binder compositions.” J.A. 783. Like Husemoen,
Helbing does not expressly disclose melanoidin produc-
tion. Instead, it teaches insulating material comprised of
a binder produced by curing and drying an aqueous
solution. The solution, in turn, consists of a carbohydrate,
6              KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S



an amine, and a polycarboxylic acid. Thus, the Examiner
found that Helbing’s disclosure of the solution describes
the three reactants necessary for a Maillard reaction.
                    3. Board Decision
    On the basis of its conclusions on the Husemoen and
Helbing references, the Examiner upheld claims 1–20 and
rejected claims 21–29. Knauf cancelled claims 27–29.
Both parties then appealed to the Board.
     In reviewing the Examiner’s rejection of claims 21–26,
the Board noted that “the rejection is based on ‘inheren-
cy,’ a theory invoked when a publication does not express-
ly describe a limitation in a claim, but the claim
limitation would necessarily result by following the guid-
ance in the publication.” J.A. 11.
    The Board affirmed the Examiner’s finding of inher-
ency, writing, “Husemoen describes mixing all three of the
claimed reactants together and then curing the mixture
on fibers, the same steps as described in the ’980 patent.
Based on the identity between the reactants and process
steps, it is reasonable to conclude that at least some
melanoidin would be formed.” J.A. 16 (citation omitted).
The Board faulted Knauf for “not point[ing] to any specific
conditions or amounts of reactants disclosed in the ’980
patent which would enable melanoidin formation and
which would distinguish the reaction that would proceed
in Husemoen.” Id. The Board also rejected Knauf’s
assertion that the chemical process of esterification would
prevent a Maillard reaction, noting that Knauf failed to
prove that esterification “would interfere with or hinder a
Maillard reaction, or affect the resulting melanoidin.” Id.
at 16–17.
    Turning to Helbing, the Board found that:
    A preponderance of the evidence establishes that
    all three reactants present in a Maillard reac-
    tion—a carbohydrate (He11), an amine which is
KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S              7



    ammonia (He5, He12), and a polycarboxylic acid
    (He4, He5, He10) are described by Helbing as pre-
    sent in a reaction mixture. The reactants are
    mixed and then cured (He14) as required by
    claims 21–26. Because of the identity of reactants
    and process steps, there is factual basis and rea-
    son to believe that Helbing 302’s binder product
    would contain melanoidins as required by the
    claims.
Id. at 21. The Board also rejected Knauf’s argument that
Helbing’s components would result in esterification and
thus prevent a Maillard reaction from occurring. Id. at
22. It noted that even if Helbing’s components increased
the likelihood of esterification, the sugar would still react
with the amine to produce melanoidins. Id.
    The Board also affirmed the Examiner’s allowance of
claims 1–20 on grounds not relevant here. Knauf timely
appeals the rejection of claims 21–26. We have jurisdic-
tion under 35 U.S.C. § 141 and 28 U.S.C. § 1295(a)(4)(A).
                         DISCUSSION
                  1. Standard of Review
     The ultimate legal conclusion of whether a claim
would have been obvious pursuant to 35 U.S.C. § 103 is
based on underlying factual determinations. Rambus Inc.
v. Rea, 731 F.3d 1248, 1251–52 (Fed. Cir. 2013). “The
factual determinations include (1) the scope and content
of the prior art; (2) the differences between the claims and
the prior art; (3) the level of ordinary skill in the art; and
(4) objective evidence of nonobviousness.” Id. at 1252
(citing Graham v. John Deere Co., 383 U.S. 1, 17–18
(1966)).
    We review the legal conclusion of obviousness de novo,
but we uphold the Board’s factual findings as long as they
are supported by substantial evidence. Id. at 1251.
Substantial evidence “means such relevant evidence as a
8              KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S



reasonable mind might accept as adequate to support a
conclusion.” In re Mouttet, 686 F.3d 1322, 1331 (Fed. Cir.
2012) (citations omitted).
     “[I]nherency may supply a missing claim limitation
in an obviousness analysis.” PAR Pharm., Inc. v. TWI
Pharms., Inc., 773 F.3d 1186, 1194–95 (Fed. Cir. 2014).
But “the use of inherency, a doctrine originally rooted in
anticipation, must be carefully circumscribed in the
context of obviousness.” Id. at 1195. Inherency “may not
be established by probabilities or possibilities. The mere
fact that a certain thing may result from a given set of
circumstances is not sufficient.” In re Oelrich, 666 F.2d
578, 581 (C.C.P.A. 1981).
    A party must, therefore, meet a high standard in
    order to rely on inherency to establish the exist-
    ence of a claim limitation in the prior art in an ob-
    viousness analysis—the limitation at issue
    necessarily must be present, or the natural result
    of the combination of elements explicitly disclosed
    by the prior art.
PAR Pharm., 773 F.3d at 1195–96.
                       2. Analysis
    The Board agreed with the Examiner that claims 21–
26 of the ’980 patent were inherent in both Husemoen and
Helbing and therefore would have been obvious under 35
U.S.C. § 103.
    The Board found that Helbing inherently discloses a
Maillard reaction. According to the Board, Helbing dis-
closes the three necessary reactants for a Maillard reac-
tion, and any esterification would not preclude a Maillard
reaction. J.A. 21–22. Specifically, it first noted the “iden-
tity of reactants and process steps” between Helbing and
the ’980 patent. J.A. 21. It then rejected Knauf’s argu-
ment that a higher likelihood of esterification precludes
the possibility of a Maillard reaction.
KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S             9



    Knauf argues that the Board erred because Helbing
teaches only a “mere possibility” of a Maillard reaction.
Knauf Br. at 21. Knauf concedes that Helbing discloses
the three reactants necessary for a Maillard reaction. See
id. at 22; J.A. 1486 (acknowledging that “HELBING
teaches the inclusion of citric acid, ammonia and corn
syrup in the formation of the formaldehyde free binder,
which are known Maillard reactants and therefore result
in at least one Maillard reaction product”). However, it
argues that the process of esterification is “far more likely
to occur” than a Maillard reaction. Knauf Br. at 23.
Knauf further argues, without citation, that esterification
“may proceed to the exclusion of” a Maillard reaction. Id.
And it emphasizes that Helbing discloses additional
reactants beyond Maillard reactants. Thus, according to
Knauf, the Examiner’s finding that Helbing and the ’980
patent share “identity between the reactants and process
steps” is not supported by substantial evidence. Id. at 25.
We disagree.
    Substantial evidence supports the Board’s conclusion.
As the Board found, Helbing discloses an amine, a poly-
carboxylic acid, and a reducing sugar capable of forming a
Maillard reaction. See, e.g., J.A. 796 (Helbing Example 4);
J.A. 19–21 (describing Helbing’s disclosure of an amine,
acid, and sugar); J.A. 21 (noting the “identity of reactants
and process steps” between Helbing and the ’980 patent).
Knauf admitted as much before the Board. J.A. 1486. In
light of this admission, Knauf presented no evidence that
Helbing’s additional reactants would prevent a Maillard
reaction.
     There is no dispute that Helbing discloses esterifica-
tion. J.A. 2491. But the record evidence does not show
that esterification would necessarily prevent a Maillard
reaction. In fact, Helbing discloses a Maillard reaction in
competition with esterification. See J.A. 883 (col. 12
ll. 13–15). The Board concluded that even a high proba-
bility of esterification would not foreclose a Maillard
10               KNAUF INSULATION, INC.   v. ROCKWOOL INT’L A/S



reaction, noting that the sugar “will still react with an
amine or ammonia because the reactants are present.”
J.A. 22. In other words, not only does Helbing contain the
three components of a Maillard reaction, it discloses a
Maillard reaction, and Knauf did not demonstrate that
esterification forecloses a Maillard reaction. As a result,
substantial evidence supports the Board’s conclusion that
a Maillard reaction is a natural result of Helbing. 1
    Knauf also argues on appeal that the Board improper-
ly shifted the burden from Rockwool to Knauf without
requiring Rockwool to show a prima facie case of inheren-
cy. Assuming, without deciding, that the Board recited
the wrong legal standard, we find any possible error to be
harmless and accordingly do not address this argument.
                        CONCLUSION
    Because substantial evidence supports the Board’s
factual findings that claims 21–26 are inherent in Hel-
bing, we affirm the Board’s decision.
                        AFFIRMED
                           COSTS
     No costs.




     1  Because substantial evidence supports the Board’s
finding of inherency as to Helbing, we need not address
the Board’s finding that Husemoen inherently discloses a
Maillard reaction.
