United States Gypsum Company v. New NGC, Inc.

Filing 114

REPORT AND RECOMMENDATIONS regarding Claim Construction. Please note that when filing Objections pursuant to Federal Rule of Civil Procedure 72(b)(2), briefing consists solely of the Objections (no longer than ten (10) pages) and the Response to the Objections (no longer than ten (10) pages). No further briefing shall be permitted with respect to objections without leave of the Court. Objections to R&R due by 9/19/2018. Signed by Judge Sherry R. Fallon on 9/5/2018. (lih)

IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF DELAWARE
UNITED STATES GYPSUM COMPANY,)
)
Plaintiff,
)
)
V.

)

Civil Action No. 17-130-JFB-SRF

)
)
)
)

NEW NGC, INC.,
Defendant.

REPORT AND RECOMMENDATION
I.

INTRODUCTION
In this patent infringement action filed by plaintiff United States Gypsum Company

("USGC") against defendant New NGC, Inc. ("NGC"), USGC alleges infringement of United
States Patent Nos. 6,342,284 ("the '284 patent"); 6,632,550 ("the '550 patent"); 7,425,236 ("the
'236 patent"); 7,758,980 ("the '980 patent"); 7,964,034 ("the '034 patent"); 8,142,914 ("the '914
patent"), and 8,500,904 ("the '904 patent") (collectively "the patents-in-suit"). (D.I. I) Presently
before the court is the matter of claim construction. This decision sets forth the court's
recommendations of constructions for the disputed claim terms discussed in the briefing and at
the Markman hearing held on July 18, 2018.

II.

BACKGROUND
USGC develops and manufactures gypsum products used to construct walls, ceilings,

roofs and floors of various types of buildings. (D.I. 1 at ,-i 4) NGC is a direct competitor of
USGC in manufacturing, marketing and selling gypsum products. (Id. at ,-i 5)

The patents-in-suit are a group ofrelated patents with overlapping specifications 1 and
common inventors, which are directed to gypsum products with increased resistance to sag, less
density, and other improved properties. ('284 patent, col. 3:54-55; col. 5:31-33) During the
Markman hearing, counsel categorized the challenged claims into four groups. (7/18/18 Tr. at
5: 15-7: 1) The composition claims describe the components of a composition used to create a set
gypsum product. ('284 patent, claim 1) The product claims of the patents-in-suit involve mixing
calcium material with water and various enhancing materials to form a set gypsum product.
('284 patent, claim 10) The method claims involve steps to mix and form the set gypsum. ('236
patent, claim 2) The final category includes product-by-process claims, which recite the gypsum
board product made by particular method steps identified in the rest of the claim. ('284 patent,
claim 40)

III.

LEGAL STANDARD
Construing the claims of a patent presents a question of law, although subsidiary fact

finding is sometimes necessary. Teva Pharms. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831, 837-38
(2015) (citing Markman v. Westview Instruments, Inc., 52 F.3d 967, 977-78 (Fed. Cir. 1995),
aff'd, 517 U.S. 370, 388-90 (1996)). "It is a bedrock principle of patent law that the claims of a
patent define the invention to which the patentee is entitled the right to exclude." Phillips v.
AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (internal quotation marks omitted). "[T]here
is no magic formula or catechism for conducting claim construction." Id at 1324. Instead, the
court may attach the appropriate weight to appropriate sources "in light of the statutes and
policies that inform patent law." Id.

1

Although the specifications of the patents-in-suit are substantially similar, they do not share a
common specification. (D.I. 74 at 3 n.5)
2

The words of the claims "are generally given their ordinary and customary meaning,"
which is "the meaning that the term would have to a person of ordinary skill in the art in question
at the time of the invention, i.e., as of the effective filing date of the patent application." Phillips,
415 F.3d at 1312-13 (internal citations and quotation marks omitted). "[T]he ordinary meaning
of a claim term is its meaning to the ordinary artisan after reading the entire patent." Id. at 1321
(internal quotation marks omitted); see also Eon Corp. IP Holdings v. Silver Spring Networks,
Inc., 815 F.3d 1314, 1320 (Fed. Cir. 2016). Claim terms are typically used consistently
throughout the patent, and "usage of a term in one claim can often illuminate the meaning of the
same term in other claims." Phillips, 415 F.3d at 1314 (observing that "[o]ther claims of the
patent in question, both asserted and unasserted, can also be valuable sources of enlightenment ..
. [b]ecause claim terms are normally used consistently throughout the patent ... ").
It is likewise true that "[d]ifferences among claims can also be a useful guide .... For

example, the presence of a dependent claim that adds a particular limitation gives rise to a
presumption that the limitation in question is not present in the independent claim." Id. at 131415 (internal citation omitted). This "presumption is especially strong when the limitation in
dispute is the only meaningful difference between an independent and dependent claim, and one
party is urging that the limitation in the dependent claim should be read into the independent
claim." SunRace Roots Enter. Co., Ltd. v. SRAMCorp., 336 F.3d 1298, 1303 (Fed. Cir. 2003)
(citing Ecolab Inc. v. Paraclipse, Inc., 285 F.3d 1362, 1375 (Fed. Cir. 2002).
Other intrinsic evidence, including the patent specification, "is always highly relevant to
the claim construction analysis. Usually, it is dispositive; it is the single best guide to the
meaning of a disputed term." Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.
Cir. 1996). "[T]he specification may reveal a special definition given to a claim term by the

3

patentee that differs from the meaning it would otherwise possess. In such cases, the inventor's
lexicography governs." Phillips, 415 F.3d at 1316 (citing CCS Fitness, Inc. v. Brunswick Corp.,
288 F.3d 1359, 1366 (Fed. Cir. 2002)). It bears emphasis that "[e]ven when the specification
describes only a single embodiment, the claims of the patent will not be read restrictively unless
the patentee has demonstrated a clear intention to limit the claim scope using words or
expressions of manifest exclusion or restriction." Liebel-Flarsheim Co. v. Medrad, Inc., 358
F.3d 898, 906 (Fed. Cir. 2004) (internal quotation marks omitted), aff'd, 481 F.3d 1371 (Fed.
Cir. 2007). The specification "is not a substitute for, nor can it be used to rewrite, the chosen
claim language." SuperGuide Corp. v. DirecTV Enters., Inc., 358 F.3d 870, 875 (Fed. Cir.
2004).
In addition to the specification, a court "should also consider the patent's prosecution
history, if it is in evidence." Markman, 52 F.3d at 980. The prosecution history, which is also
"intrinsic evidence," "consists of the complete record of the proceedings before the PTO [Patent
and Trademark Office] and includes the prior art cited during the examination of the patent."
Phillips, 415 F.3d at 1317. "[T]he prosecution history can often inform the meaning of the claim

language by demonstrating how the inventor understood the invention and whether the inventor
limited the invention in the course of prosecution, making the claim scope narrower than it
would otherwise be." Id
A court also may rely on "extrinsic evidence," which "consists of all evidence external to
the patent and prosecution history, including expert and inventor testimony, dictionaries, and
learned treatises." Markman, 52 F.3d at 980. For instance, technical dictionaries can assist the
court in determining the meaning of a term to those of skill in the relevant art because such
dictionaries "endeavor to collect the accepted meanings of terms used in various fields of science

4

and technology." Phillips, 415 F.3d at 1318. In addition, expert testimony can be useful "to
ensure that the court's understanding of the technical aspects of the patent is consistent with that
of a person of skill in the art, or to establish that a particular term in the patent or the prior art has
a particular meaning in the pertinent field." Id Nonetheless, courts must not lose sight of the
fact that "expert reports and testimony [are] generated at the time of and for the purpose of
litigation and thus can suffer from bias that is not present in intrinsic evidence." Id
("[C]onclusory, unsupported assertions by experts as to the definition of a claim term are not
useful to a court."). Overall, while extrinsic evidence may be useful to the court, it is less
reliable than intrinsic evidence, and its consideration "is unlikely to result in a reliable
interpretation of patent claim scope unless considered in the context of the intrinsic evidence."

Id at 1318-19.
Finally, "[t]he construction that stays true to the claim language and most naturally aligns
with the patent's description of the invention will be, in the end, the correct construction."

Renishaw PLC v. Marposs Societa' Per Azioni, 158 F.3d 1243, 1250 (Fed. Cir. 1998). It follows
that "a claim interpretation that would exclude the inventor's device is rarely the correct
interpretation." Osram GmbHv. Int'! Trade Comm'n, 505 F.3d 1351, 1358 (Fed. Cir. 2007).
IV.

CONSTRUCTION OF DISPUTED TERMS
1. "set gypsum" ('284 patent, claims 4, 5, 6, 12, 26, 29, 32, 33, 34, 40; '550 patent claims
1, 54, 55; '236 patent, claim 2; '980 patent, claims 1, 6, 7; '914 patent, claim 1; '034
patent, claims 1, 8; '904 patent, claims 1, 15)

USGC
a crystallized gypsum
structure produced from the
rehydration of calcium sulfate
hemihydrate into calcium
sulfate dihydrate by mixing
with water

NGC
calcium sulfate dihydrate

5

Court
calcium sulfate dihydrate

I recommend that the court adopt NGC's construction, which is supported by the intrinsic
evidence. The specifications of the patents-in-suit expressly define "set gypsum" as "calcium
sulfate dihydrate," providing that "[m]any well known useful products contain set gypsum
(calcium sulfate dihydrate) as a significant, and often as the major, component," and explaining
that "the terms, 'set gypsum' and 'hydrated gypsum,' are intended to mean calcium sulfate
dihydrate." 2 ('284 patent, col. 1:42-44; col. 4:33-34; see also col. 7:53-54; 12:65-67; 13:65-67)
"When the specification explains and defines a term used in the claims, without ambiguity or
incompleteness, there is no need to search further for the meaning of the term." Sinorgchem Co.,
Shandong v. Int'! Trade Comm 'n, 511 F.3d 1132, 1138 (Fed. Cir. 2007) (quoting Multiform
Desiccants, Inc. v. Medzam, Ltd., 133 F.3d 1473, 1478 (Fed. Cir. 1998)). Viewing the
specifications of the patents-in-suit as "the single best guide to the meaning of [the] disputed
term," I recommend that the court construe "set gypsum" to mean "calcium sulfate dihydrate."
Phillips v. AWHCorp., 415 F.3d 1303, 1315 (Fed. Cir. 2005) (quoting Vitronics Corp. v.
Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)).
2. "set gypsum-containing product," "set gypsum product," and "set gypsum
material" ('550 patent, claims 1, 54, 55; '034 patent, claims 1, 7-8; '904 patent,
claims 1-4, 6, 8, 11-13, 15, 18; '236 patent, claim 2)
USGC
No construction necessary
apart from the term "set
gypsum"
If construed: a product
containing set gypsum

NGC
a product containing calcium
sulfate dihydrate, including
but not limited to gypsum
boards, reinforced gypsum
composite boards, plasters,
machinable materials, joint

2

Court
No construction necessary
apart from the term "set
gypsum"

The record reflects that "set gypsum" is defined as "calcium sulfate dihydrate" in multiple other
patents beyond the patents-in-suit in the present litigation, supporting NGC's contention that its
proposed construction is consistent with the understanding of a person of ordinary skill in the art.
(DJ. 74, Ex. 8 at col. 6:7-12; Ex. 9 at 2:58-62; Ex. 10 at col. 2:56-58)
6

treatment materials, and
acoustical tiles
I recommend that the court adopt USGC's proposal and decline to construe the terms
apart from the preceding construction of "set gypsum." In support of its proposed construction,
NGC stresses that its non-limiting list of products finds support in the specifications of the
patents-in-suit and prevents USGC from improperly distinguishing the prior art in a manner
inconsistent with the patentee's definition of "set gypsum." (D.I. 74 at 4-5) USGC contends that
NGC's proposed list of examples does not resolve any ambiguity in the claim term. (D.I. 77 at
14-15)
The disputed terms require no further construction. The recommended construction for
"set gypsum" is consistent with NGC's proposal to define the term as "a product containing
calcium sulfate dihydrate." The parties do not dispute that the non-limiting list of examples
included in NGC's proposed construction is consistent with the specifications of the patents-insuit. ('284 patent, col. 1: 11-16; 1:42-61) However, NGC does not explain how this open-ended
list clarifies the scope of the term. For these reasons, I recommend that no construction is
necessary for the disputed terms.
3. "calcined gypsum" ('284 patent, claims 10, 11; '550 patent, claims 1-3, 7, 8, 54, 55;
'236 patent, claim 2; '980 patent, claims 1, 2; '914 patent, claims 1-3; '034 patent,
claims 1, 2, 4, 7)
USGC
alpha calcium sulfate
hemihydrate, beta calcium
sulfate hemihydrate, watersoluble calcium sulfate
anhydrite, or mixtures of any
or all thereof

NGC
calcium sulfate hemihydrate
and/or calcium sulfate
anhydrite

7

Court
alpha calcium sulfate
hemihydrate, beta calcium
sulfate hemihydrate, watersoluble calcium sulfate
anhydrite, or mixtures of any
or all thereof

I recommend that the court adopt USGC's proposed construction, which is consistent
with the intrinsic record. According to NGC, the specifications of the patents-in-suit set forth
two variations of a definition for the disputed term, and the broader definition should control.
(D.I. 74 at 6-7) In support of its position, NGC points to a portion of the specifications reciting
"calcined gypsum (calcium sulfate hemihydrate and/or calcium sulfate anhydrite)." ('284 patent,
col. 1:63-64) USGC argues that this portion of the specification is not definitional, and instead
proposes construing the term consistent with the express definition in the specifications: "(as
used herein, the term, 'calcined gypsum,' is intended to mean alpha calcium sulfate hemihydrate,
beta calcium sulfate hemihydrate, water-soluble calcium sulfate anhydrite, or mixtures or any or
all thereof .... )." (Id at col. 4:29-32)
The specification of the '284 patent expressly defines "calcined gypsum" in accordance
with USGC's proposed construction: "(as used herein, the term, 'calcined gypsum,' is intended
to mean alpha calcium sulfate hemihydrate, beta calcium sulfate hemihydrate, water-soluble
calcium sulfate anhydrite, or mixtures of any or all thereof .... )." ('284 patent, col. 4:29-34)
USGC's proposed construction is also consistent with other portions of the written description
and the understanding of a person of ordinary skill in the art. The specification elsewhere
reiterates that "[t]he calcined gypsum employed in the invention ... can be alpha calcium sulfate
hemihydrate, beta calcium sulfate hemihydrate, water-soluble calcium sulfate anhydrite, or
mixtures of any or all thereof, from natural or synthetic sources." (Id at col. 9:6-12) The
portion of the specification identified as an alternative definition by NGC does not contain the
definitional language recited in the above passage. (Id at col. 1:63:64) Consequently, the
portion of the specification using clear definitional language controls. See The Medicines Co. v.

8

Teva Parenteral Medicines, Inc., C.A. No. 09-750-RGA, 2013 WL 3658020, at *5 (D. Del. July

11, 2013) (identifying the language "as used herein" as explicit definitional language).
NGC's reliance on the Federal Circuit's decision in Johnson Worldwide Associates, Inc.
v. Zebco Corp. does not alter the court's conclusion because the facts in Johnson Worldwide are

not sufficiently analogous to the circumstances presently before the court. 175 F.3d 985, 989
(Fed. Cir. 1999). Specifically, the Federal Circuit addressed "the question of when it is
permissible to narrow the scope of broad claim language by reference to embodiments described
and depicted in the balance of the specification," and ultimately concluded that narrowing a
claim term based on a description in a preferred embodiment, without definitional language, was
not permissible. Id. at 989-91. In contrast, the intrinsic evidence before the court in this matter
establishes that the patentee used definitional language to narrow the scope of the disputed term,
as opposed to inferring a narrowed scope from preferred embodiments in the written description.
Thus, unlike the circumstances in Johnson Worldwide, the use of "calcined gypsum" in
conjunction with definitional language in the '284 patent specification supports a "special and
particular definition created by the patent applicant" sufficient to limit the scope of the term.
Johnson Worldwide, l 75 F.3d at 991.
4. "a calcium sulfate material" ('284 patent, claims 1, 2, 40)

USGC
calcium sulfate anhydrite,
calcium sulfate hemihydrate,
calcium sulfate dihydrate,
ions of calcium and sulfate,
or mixtures of any or all
thereof

NGC
calcium sulfate hemihydrate
and/or calcium sulfate
anhydrite

Court
calcium sulfate anhydrite,
calcium sulfate hemihydrate,
calcium sulfate dihydrate,
ions of calcium and sulfate,
or mixtures of any or all
thereof

I recommend that the court adopt USGC' s proposed construction, which is consistent
with the intrinsic record. The parties' dispute centers on whether "calcium sulfate dihydrate"
9

and "ions of calcium and sulfate" should be included in the construction of the disputed term.
(D.I. 74 at 7) Where, as here, "a patentee explicitly defines a claim term in the patent
specification, the patentee's definition controls." Martek Biosciencies Corp. v. Nutrinova, Inc.,
579 F.3d 1363, 1380 (Fed. Cir. 2009) (citing Phillips v. AWH Corp., 415 F.3d 1303, 1321 (Fed.
Cir. 2005)). The express definition of the term in the specification confirms that "calcium sulfate
material" includes calcium sulfate dihydrate and ions of calcium and sulfate, in accordance with
USGC's proposed construction. Specifically, the written description states that calcium sulfate
material "is intended to mean calcium sulfate anhydrite; calcium sulfate hemihydrate; calcium
sulfate dihydrate; ions of calcium and sulfate; or mixtures of any or all thereof." (' 284 patent,
col. 3:66-4:2)
5. "enhancing materials" ('284 patent, claim 1, 2, 4, 40; '550 patent claim 1, 2, 3, 5, 9,
54, 55, 57; '236 patent claim 2; '914 patent claim 1, 2, 4; '034 patent claim 1, 2, 5, 7;
'904 patent claim 1, 3, 4, 6)
USGC
phosphoric acids, each of
which comprises 1 or more
phosphoric acid units; salts or
ions of condensed
phosphates, each of which
comprises 2 or more
phosphate units; and
monobasic salts or
monovalent ions of
orthophosphates

NGC
an additive that improves at
least one of: resistance to
permanent deformation,
strength, and dimensional
stability in set gypsumcontaining products

Court
phosphoric acids, each of
which comprises 1 or more
phosphoric acid units; salts or
ions of condensed
phosphates, each of which
comprises 2 or more
phosphate units; and
monobasic salts or
monovalent ions of
orthophosphates

I recommend that the court adopt USGC's construction, which is supported by the weight
of the intrinsic evidence. The parties' dispute focuses on whether the term should be defined as a
list of chemicals or, alternatively, by describing how the claimed "enhancing materials" function.

10

USGC's proposed construction is consistent with the guidance provided by the claim
language and specifications of the patents-in-suit. The asserted claims of the '284 patent recite
"one or more enhancing materials selected from the group consisting of: condensed phosphoric
acids, each of which comprises 2 or more phosphoric acid units, and salts or ions of condensed
phosphates, each of which comprises 2 or more phosphate units." ('284 patent, col. 31 :53-56;
col. 31 :63-66) Similarly, the specification of the '284 patent describes the preparation of set
gypsum as a mixture including "one or more enhancing materials chosen from: condensed
phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of
condensed phosphates, each of which comprises 2 or more phosphate units." ('284 patent, col.
3:58-62) The '284 patent specification goes on to explain that "enhancing materials can be
chosen from the group consisting of: phosphoric acids, each of which comprises 1 or more
phosphoric acid units, salts or ions of condensed phosphates, each of which comprises 2 or more
phosphate units, and mono basic salts or monovalent ions of orthophosphates." (' 284 patent, col.
4:4-9)
Contrary to NGC's contentions, the remaining patents-in-suit use the disputed term in a
manner consistent with its use in the '284 patent. The '550 patent has the same disclosure as the
'284 patent. ('550 patent, col. 1:6-11) The '980, '914, '034 and '904 patents are in the same
patent family as the '284 patent, and they incorporate by reference the specification of the '284
patent. ('980patent,col.1:4-17; '034patent,col.1:4-19; '914patent,col. l:4-22; '904patent,
col. 1:3-25) Although NGC challenges USGC's position regarding the incorporation by
reference of the '284 patent specification based on an alleged lack of particularity regarding
which material is incorporated, the Federal Circuit has held that language similar to that used in
the patents-in-suit is sufficient to incorporate by reference a previous patent into a continuation

11

or divisional application. See Dealertrack, Inc. v. Huber, 674 F.3d 1315, 1323 (Fed. Cir. 2012)
("The '817 patent incorporates the '403 patent using the following language: 'This is a division
of application Ser. No. 08/526,776 ("'776 Application"), filed Sep. 12, 1995, hereby
incorporated by reference. Now U.S. Pat. No. 5,878,403."').
Both parties direct the court to the Federal Circuit's decision in Aqua Tex Industries, Inc.
v. Techniche Solutions, which determined that AquaTex "incorporate[d] by reference the
teachings of three United States Patents to define the scope of the term 'fiberfill,"' rendering
these publications "highly relevant to one of ordinary skill in the art for ascertaining the breadth
of the claim term." 419 F.3d 1374, 1381 (Fed. Cir. 2005). A review of the patent at issue in
AquaTex, U.S. Patent No. 6,371,977 ("the '977 patent"), reveals that the patentee identified
"U.S. Pat. Nos. 5,104,725; 4,304,817; and 4,818,599; all of which hare [sic] incorporated by
reference" because they "disclose fiberfill fibers and blends suitable for certain applications of
the present invention." ('977 patent, col. 3:62-65) Although the AquaTex court incorporated the
three patents by reference for a specifically identified purpose in this instance, other binding
precedent from the Federal Circuit, such as Dealertrack, suggests that a broader incorporation by
reference is also appropriate in instances involving divisional or continuation applications. See
Dealertrack, 674 F.3d at 1323.
The cases cited by NGC regarding incorporation by reference are inapposite. In Zenon
Environmental, Inc. v. US. Filter Corp., the Federal Circuit found no incorporation by reference
of the entire prior art reference where the relevant language stated that
The vertical skein is not the subject matter of this invention and any prior art
vertical skein may be used. Further details relating to the construction and
deployment of a most preferred skein are found in the parent U.S. Pat. No.
5,639,373, and in Ser. No. 08/690,045, the relevant disclosures of each of which
are included by reference thereto as if fully set forth herein.

12

506 F.3d 1370, 1379 (Fed. Cir. 2007). The Federal Circuit determined that this language did not
sufficiently incorporate by reference the entire disclosures of the prior art patents, because the
plain language of the statement "expressly limits the incorporation to only relevant disclosures of
the patents, indicating that the disclosures are not being incorporated in their entirety." Id In
contrast, the incorporation by reference language in the present case supports incorporation of
the full disclosure of patents within the same patent family regarding the same subject matter.
Moreover, in Droplets, Inc. v. E*TRADE Bank, the Federal Circuit addressed incorporation by
reference in the specific context of 35 U.S.C. § 120 regarding a priority claim, unlike the
circumstances presently before the court. 887 F.3d 1309, 1318-20 (Fed. Cir. 2018).
It is undisputed that the '236 patent does not incorporate the '284 patent by reference.
('236 patent, col. 1:4-14; 7/18/18 Tr. at 18:6-8) However, the disclosure of the '236 patent is
consistent with that of the other patents-in-suit. For example, the '236 patent specification
identifies "enhancing materials chosen from: condensed phosphoric acids, each of which
comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of
which comprises 2 or more phosphate units." ('236 patent, col. 3:61-64; 5:55-63; 6:7-11; 6:2124; 6:32-36; 6:43-46; 6:54-57) The data tables in the '236 patent are the same as those included
in the '284 patent. Likewise, claims 1 and 3 of the '236 patent claim a method of spraying or
soaking set gypsum "with a solution comprising one or more enhancing materials selected from
the group consisting of phosphoric acid; condensed phosphoric acids, each of which comprises
two or more phosphoric acid units; salts or ions of condensed phosphate, each of which
comprises two or more phosphate units; and monobasic salts or monovalent ions of
orthophosphates." ('236 patent, col. 31:10-15, 32:7-13) This claim language is consistent with

13

the broadest definition of "enhancing materials" identified in the specifications of the other
patents-in-suit. (D.I. 79 at~ 67)
NGC's proposed construction is overly broad because it encompasses conventional
additives which exceed the intended scope of the claim term. For example, the specification
identifies boric acid as a non-inventive additive, and compares samples with no additive as a
control group to inventive samples with an STMP additive and "comparative samples" with
"other additives." ('284 patent, col. 13:61-63) Table 2 of the '284 patent explains that
"additives employed in the comparative samples" fall "outside the scope of the invention,"
although they "have been employed to attempt to improve resistance of gypsum board to sagging
under conditions of high humidity." ('284 patent, col. 14:26-30) These conventional additives
include boric acid, which is shown in Table 2 to increase the sag resistance of gypsum board as
compared to the control group with no additives. ('284 patent, col. 14:46-50) Although the
specification expressly excludes conventional additives such as boric acid from the scope of
inventive additives constituting the term "enhancing materials," these additives fall within
NGC's proposed construction because they improve the sag resistance of gypsum-containing
products. For this reason, NGC's proposed construction does not find adequate support in the
intrinsic record.
NGC contends that USGC's proposed construction is not viable because the portions of
the specification supporting USGC's proposal apply only to post-set treatments of calcium
sulfate dihydrate. ('284 patent, col. 4:3-10; 30:60-67) However, the specification of the '284
patent defines enhancing materials used in pre-set formulations in a manner consistent with
enhancing materials used in post-set spray treatments: "[I]n general, any enhancing materials that
fall within the general definition of enhancing materials previously discussed will produce

14

beneficial results ... in treatment of calcined gypsum." ('284 patent, col. 27: 19-23) These
enhancing materials "are condensed phosphoric acids, each of which comprises 2 or more
phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or
more phosphate units." (Id. at col. 27:23-27) This definition finds further support in the claim
language of the '284 patent, which establishes that USGC's definition of enhancing materials
encompasses the subcategory of phosphoric acids and salts or ions of condensed phosphates
present in the claimed pre-set gypsum slurry. ('284 patent, col. 31 :50-57) The description of
enhancing materials in claim 1 of the '284 patent, which is directed to the composition of a
gypsum slurry, is therefore consistent with USGC's proposed construction.
NGC also alleges that USGC' s proposed construction is not viable because the
specifications of the patents-in-suit suggest that the combination of phosphoric acid in a gypsum
slurry worsens the sag resistance of the product, in contravention of the stated purpose of
enhancing materials to "increase[] resistance to permanent deformation (e.g. sag resistance)."
(D.I. 74 at 12-13; Ex. 1 at col. 1:16-29) Specifically, NGC relies on Table 13 of the '236 patent,
which identifies a mixture containing phosphoric acid as having an increase of 0.062 inches in
the ten day humidified sag deflection over the control group. (D.I. 74, Ex. 3 at Table 13)
However, the intrinsic record reveals that the data in Table 13 of the '236 patent does not render
USGC's proposed construction unworkable.
Claim 2 of the '236 patent is the only claim containing the disputed term that is broad
enough to encompass phosphoric acid in relation to a pre-set gypsum slurry, because the other
claims reciting "enhancing materials" in pre-set mixtures identify a particular subcategory of
enhancing material compounds encompassed by the claim language. (Compare '236 patent, col.
31:15-32:3, with '284 patent, col. 31:50-59) Also, claim 2 of the '236 patent is the only

15

challenged claim containing the disputed term that does not recite increased sag resistance in the
claim language itself. (Id) Table 13 recites other improved characteristics in compositions
containing phosphoric acid that are consistent with the desired effects of including an enhancing
material in the mixture, such as "increased strength, resistance to permanent deformation (e.g.,
sag resistance), and dimensional stability (e.g., non-shrinkage during drying of set gypsum)."
('236 patent, col. 1:30-32) Table 13 demonstrates that the use of phosphoric acid in a gypsum
slurry significantly improves the compressive strength of the product, despite the decrease in sag
resistance. ('236 patent, Table 13) Consequently, USGC's proposed construction accurately
encompasses the usage of "enhancing materials" in claim 2 of the '236 patent.
The extrinsic evidence also shows that a person of ordinary skill in the art at the time of
invention would understand the term "enhancing materials" in the manner proposed by USGC.
USGC's expert, Dr. Bruce, explained that the term "did not have an ordinary or customary
meaning in the field of set gypsum" at the time of the patent's earliest filing date, and that a
person of ordinary skill in the art would understand the term to be consistent with the specific
meaning used in the patents-in suit. (D.I. 79 at ,r,r 58-59) Similarly, Dr. Harlos indicated that
"[t]here is no suggestion in the patent specifications that all materials that potentially improve the
resistance to deformation, strength or dimensional stability ... of a set gypsum . . . are within
what the claim refer[red] to as 'enhancing materials,"' and NGC's proposed construction would
"[define] enhancing materials beyond the particular additives that the term ... [was] intended to
describe in the [p]atents-[i]n-[s]uit." (D.I. 79 at ,r,r 60, 68) For these reasons, I recommend that
the court adopt USGC's proposed construction of "enhancing materials."

16

6. "a sag resistance, as determined according to ASTM C473-95, of less than about 0.1
inch per two foot length of said board" ('284 patent, claims 1, 2, 4, 5, 10, 34, 40; '550
patent, claims 1, 54, 55; '980 patent, claim 4; '914 patent, claim 1; '034 patent,
claims 1, 7; '904 patent, claim 1)
USGC
an amount of sag, as
determined according to
ASTM C473-95, ofless than
0.125 inch per two foot
length of said board

NGC
a measured sag, as
determined according to
ASTM C4 73-95, of less than
0.11 inch per two foot length
of said board

Court
an amount of sag, as
determined according to
ASTM C473-95, of less than
0.125 inch per two foot
length of said board

I recommend that the court adopt USGC' s proposed construction, which finds support in
the extrinsic evidence. The parties' dispute focuses on the proper value of the amount of
variance represented by "about." According to NGC, the court should apply the confidence
interval for experimental error of+/- 5%, which is disclosed in the specification, to arrive at
0.105, rounded to 0.11. (D.I. 74 at 15) USGC contends that the sag resistance value should be
determined under the ASTM C473-95 test in accordance with the intrinsic record and the
understanding of a person of ordinary skill in the art, which do not require a narrow variance.
(D.I. 77 at 15-17)
The intrinsic record does not clarify the scope of the disputed claim term in this instance.
NGC advocates applying the confidence interval of +/-5% for experimental error identified in the
'284 patent specification. However, the written description of the '284 patent recites the
confidence interval in the context of a compressive strength measurement performed on a
SATEC testing machine. ('284 patent, col. 13:4-16) Nothing in the written description supports
extending the application of the confidence interval to the context of sag resistance.
The ASTM C473-95 standardized sag measurement procedure provides some guidance
regarding the scope of acceptable variance by specifying that measurements of sag resistance
should be estimated to the nearest

1
/i6

of an inch. (D.1. 74, Ex. 14 at, 51.2) Specifically, the
17

procedure entails "[m ]easur[ing] the humidified deflection of each specimen as the distance
between a straightedge placed on the top end edges of the board and the upper surface of the
board at its center. Take measurements to the nearest

1
/i6

in. (1.6 mm)." (Id.) Moreover, sag

values reported to the industry must be stated "as the average of the specimens to the nearest 1/s
in. (3.2 mm)." (Id. at ,r 52.1) Applying the standardized sag measurement procedure under the
ASTM C473-95 test to the disputed claim term, the extrinsic evidence supports USGC's position
that there is no statistically significant difference to a person of ordinary skill in the art between
sag measurements of 0.1 and 0.125 inches. (D.I. 79 at ,r,r 94-95) For this reason, I recommend
adopting USGC's proposed construction of the disputed term.

7. "mixture" ('284 patent, claims 1-4, 14, 40; '550 patent, claims 1-3, 6, 54-56; '236
patent, claim 2; '914 patent, claims 1, 2, 6, 8, 10; '034 patent, claims 1, 2, 7, 9; '904
patent, claims 1, 3, 4, 11-13, 15, 18)
USGC
No construction necessary
If construed: a combination
made by mixing

NGC
Physical combination of
substances that are not
chemically combined

Court
No construction necessary

I recommend that the court adopt USGC's proposal and conclude that no construction is
necessary. The intrinsic evidence does not support NGC's proposal to limit the term to a
physical combination of substances. Instead, the patents-in-suit consistently describe forming set
gypsum products from mixtures of calcined gypsum, water, and other ingredients, requiring
chemical reactions to combine the components.
The specification of the '284 patent describes how calcined gypsum, water, and other
components are mixed "to form set (i.e., rehydrated) gypsum by reaction of the calcined gypsum
with the water to form a matrix of crystalline hydrated gypsum (calcium sulfate dihydrate)."
('284 patent, col. 1:62-2:3) Likewise, claim 1 of the '550 patent describes "forming a mixture of
18

calcined gypsum, water, an accelerator, and one or more enhancing materials," which is then
maintained "under conditions sufficient for the calcined gypsum to form an interlocking matrix
of set gypsum." ('550 patent, col. 37:61-38:3) The extrinsic evidence establishes that the claim
language recites a chemical reaction because "one skilled in the art understands that water
contained in the recited mixture reacts with calcined gypsum of the mixture to form calcium
sulfate dihydrate. Both the calcium sulfate hemihydrate in calcined gypsum and the calcium
sulfate dihydrate consist of calcium sulfate molecules chemically bonded to water molecules."
(D.I. 79 at ,r 100) Therefore, limiting the mixture to a physical combination of substances would
be inconsistent with the claim language and specifications of the patents-in-suit.
8. "accelerator" ('550 patent, claims 1, 56; '236 patent, claim 2; '914 patent, claim 1;
'034 patent, claims 1, 9; '904 patent, claims 1, 8)
USGC
an additive effective to
increase the rate of formation
of set gypsum

NGC
plain and ordinary meaning

Court
an additive effective to
increase the rate of formation
of set gypsum

I recommend that the court adopt USGC's proposed construction, which is supported by
the intrinsic record. NGC withdrew its original proposed construction and now contends that the
term requires no construction. (D.I. 74 at 19) However, NGC does not identify the plain and
ordinary meaning of the term or explain its position that "not all 'accelerators' always result in
acceleration." (Id) USGC' s proposed construction is supported by the patent specifications,
which explain that "trimetaphosphate ion actually accelerates the rate of hydration of calcined
gypsum to form set gypsum," despite the fact that "it has been generally thought in the gypsum
art that phosphoric or phosphate materials retard the rate of formation of set gypsum." ('550

patent, col. 4:61-5: 1) Table 17 of the '550 patent discloses the use of an accelerator to reduce the
set time of gypsum slurry compositions. (Id., col. 35 :25-40) Because the patents-in-suit
19

consistently use the term "accelerator" to describe a substance that speeds up the rate of
formation of set gypsum, I recommend that the court adopt USGC's proposed construction.
9. "a composition comprising set gypsum ... wherein the composition comprises a
mixture of: ... calcium sulfate hemihydrate" ('284 patent, claim 4)
USGC
This claim element does not
require construction and is
not indefinite

NGC
This term is indefinite under
pre-AIA 35 U.S.C. § 112,
second paragraph

Court
This claim element does not
require construction and is
not indefinite

I recommend that the court adopt USGC's proposal that the term does not require
construction. Claim 4 of the '284 patent recites:
A composition comprising set gypsum and host particles, at least a portion of the
set gypsum being positioned in and about accessible voids in the host particles,
wherein the composition comprises a mixture of: the host particles having the
accessible voids therein; calcium sulfate hemihydrate, at least a portion of which
is in the form of crystals in and about the voids of the host particles; and one or
more enhancing materials selected from the group consisting of: condensed
phosphoric acids, each of which comprises 2 or more phosphoric acid units ....
('284 patent, col. 32:5-17) According to NGC, the term is indefinite because claim 4 of the '284
patent refers to both set gypsum and calcium sulfate hemihydrate, and a person of ordinary skill
in the art would therefore be confused as to whether the claim covers finished gypsum board or
gypsum slurry. (D.I. 74 at 20-21) However, the claim language does not suggest that the two
are mutually exclusive in this context, as indicated by inclusion of the word "comprising." (D.I.
79 at,, 126-29) Specifically, both set gypsum and calcium sulfate hemihydrate may be present
as calcium sulfate hemihydrate converts to set gypsum during the setting process. (7 /18/18 Tr. at
130:22-131 :8)

20

10. "when [said composition/the mixture] is cast in the form of½ inch gypsum board,
said board has a sag resistance, as determined according to ASTM C473-95, of less
than about 0.1 inch per two foot length of said board" ('284 patent, claims 1, 2, 4;
'550 patent, claims 1, 54, 55; '034 patent, claims 1, 7; '904 patent, claims 1)
USGC
This claim element does not
require construction and is
not indefinite

NGC
This term is indefinite under
pre-AIA 35 U.S.C. § 112,
second paragraph

Court
This claim element does not
require construction and is
not indefinite

I recommend that the court adopt USGC's proposal and conclude that the term is definite
and does not require construction. The parties dispute whether a person of ordinary skill in the
art would be capable of making wallboard of varying thicknesses using an identical gypsum
slurry composition. (D.1. 91, Ex. A at 2; 7/18/18 Tr. at 64:19-65:19) Moreover, the parties
disagree as to the impact of differences between papered versus unpapered board, and laboratory
versus commercial board, on the sag resistance of the product. (7/18/18 Tr. at 56:4-13)
The record supports USGC's contention that a person of ordinary skill in the art would be
able to evaluate whether an accused slurry, product, or method infringes a formulation used for

5/s inch boards.

In a June 12, 2017 Report and Recommendation on NGC's motion to dismiss

the complaint, the court held that:
[t]he reference to casting the mixture as a½ inch gypsum board is not a thickness
limitation for a board made by the claimed methods, but rather refers to an
objective test procedure for determining whether the mixture contains a sufficient
amount of enhancing material. Indeed, the ½ inch measurement in the claimed
patents references the industry standard for testing sag resistance and strength of
gypsum wallboards. It is not a limitation on the thickness ofUSGC's wallboard
products as NGC claims.
(D.1. 14 at 7) Consistent with the court's ruling, a person of ordinary skill in the art would
understand that the claim term does not restrict the thickness of the board produced by practicing
the claim, but instead states the required characteristics of the mixture used in forming the
product regardless of its form or thickness. (D .I. 79 at , 112)
21

Moreover, the evidence before the court establishes that a person of ordinary skill in the
art can use a gypsum mixture used to make

5
/s

inch or 3/ s inch boards for performance testing

under the ASTM C473-95 standard by adjusting the thickness parameter on a commercial
production line or by pouring the mixture into a ½ inch thick laboratory board mold to assess the
sag resistance. (D.I. 79 at ,r 118) According to USGC's expert, Dr. Bruce, "[c]hanging the
thickness from 5/s inch to ½ inch on a commercial production line can be accomplished without
changing the speed or the gypsum slurry formulation." (D.I. 85 at ,r 9) Specifically, a person of
ordinary skill in the art would "reduc[e] the flow rates of the ingredients into the mixer so that
the lower volume of the same gypsum slurry formulation needed to make the thinner ½ inch
board is deposited onto the line," and would "reduc[e] the dryer temperatures to accommodate
the reduced water load." (Id.) A person of ordinary skill in the art would adopt similar
modifications when testing the formulation for gypsum slurries used in making acoustic tiles.
(Id. at ,r,r 6-7) In these circumstances, "[i]t is not necessary to change the concentration of
accelerator or retarder in the composition ... because a formulation that has already been shown
to set to an acceptable degree at the faster line speed will also do so at the slower speed. Thus,
the formulation can remain the same." (Id. at ,r,r 11-12) The specification of the '284 patent
supports Dr. Bruce's assessment, describing the preparation of gypsum board samples cast into
trays with½ inch dimensions and dried in an oven. ('284 patent, col. 13:53-14:1)
NGC's expert, Dr. Harlos, contends that reformulation of the slurry is necessary to
accommodate the difference in thickness and amount of excess water. (D.I. 75 at ,r 20)
However, Dr. Harlos' analysis is based on running the½ inch wallboard through the kiln at the
same speed as 5/s inch wallboard, without accounting for potential modifications in the feed rate
to compensate for certain line speeds and board thicknesses. (Id.) As explained by Dr. Bruce, a

22

person of ordinary skill in the art would alter the feed rate of ingredients into the mixer to adjust
the volume of slurry deposited onto the line during production, as opposed to modifying the
speed or the composition of the formulation itself. (D.I. 85 at ,-r,-r 9, 11-12)
Turning to the parties' dispute regarding the effect of papered versus unpapered board,
the '284 patent specification identifies two ways of preparing ½ inch gypsum board samples for
sag resistance testing: either as laboratory board or commercial board. ('284 patent, col. 13:4914:54; 14:56-16:26) The specification of the '284 patent recites one example of sag resistance
testing on commercial gypsum board in accordance with the conditions set forth in the ASTM
C473-95 standard. (Id., col. 18:58-19:14) Example 5 specifies that the tested boards were
"[p]aper-covered foamed gypsum boards ... prepared on a typical full scale production line in a
commercial gypsum board manufacturing facility." (Id. at col. 17:21-23)
The specification also contains an example illustrating that paper covers may be used on
laboratory boards in accordance with ASTM C473-95 testing requirements. (Id. at col. 16:3043) Specifically, Example 4 provides that "[l]aboratory prepared samples of typical papercovered gypsum boards produced in accordance with the invention were compared with control
boards .... The test ... is carried out in accordance with ASTM C473-95." (Id.) Although
Example 4 was directed to laboratory gypsum board nail pull resistance, as opposed to
humidified deflection, a person of ordinary skill in the art viewing the specification in its entirety
would be able to apply the papered laboratory board conditions of Example 4 to the humidified
deflection testing in accordance with ASTM C473-95 standards outlined in Example 5. NGC's
allegations regarding the distinctions between papered and unpapered board ignore the fact that
the specification supports the performance of ASTM C473-95 testing on papered laboratory
board. (Id.)

23

In sum, the disputed term recites the ASTM C473-95 standard, which is an objective test
for determining whether a gypsum composition can be used to make a gypsum board with the
specified sag resistance. The '284 patent specification demonstrates that the ASTM standard
may be applied to either laboratory or commercial gypsum boards, and laboratory board may
either be papered or unpapered. A person of ordinary skill in the art would be capable of making
wallboard of varying thicknesses using the identical gypsum slurry composition. In view of the
foregoing, I recommend that the court adopt USGC's proposal and determine that the disputed
term does not require construction.

V.

CONCLUSION
For the reasons set forth above, I recommend that the court construe disputed terms as

follows:

Claim Term
"set gypsum"
"set gypsum-containing product," "set
gypsum product," and "set gypsum material"
"calcined gypsum"

"a calcium sulfate material"

"enhanced materials"

"a sag resistance, as determined according to
ASTM C473-95, of less than about 0.1 inch
per two foot length of said board"
"mixture"
"accelerator"

Recommended Construction
calcium sulfate dihvdrate
No construction necessary apart from the term
"set gypsum"
alpha calcium sulfate hemihydrate, beta
calcium sulfate hemihydrate, water-soluble
calcium sulfate anhydrite, or mixtures of any
or all thereof
calcium sulfate anhydrite, calcium sulfate
hemihydrate, calcium sulfate dihydrate, ions
of calcium and sulfate, or mixtures of any or
all thereof
phosphoric acids, each of which comprises 1
or more phosphoric acid units; salts or ions of
condensed phosphates, each of which
comprises 2 or more phosphate units; and
monobasic salts or monovalent ions of
orthophosphates
an amount of sag, as determined according to
ASTM C473-95, ofless than 0.125 inch per
two foot length of said board
No construction necessarv
an additive effective to increase the rate of
formation of set gypsum
24

This claim element does not require
construction and is not indefinite.

"a composition comprising set gypsum ...
wherein the composition comprises a mixture
of: ... calcium sulfate hemihydrate"
"when [said composition/the mixture] is cast
in the form of ½ inch gypsum board, said
board has a sag resistance, as determined
according to ASTM C473-95, ofless than
about 0.1 inch per two foot length of said
board"

This claim element does not require
construction and is not indefinite

This Report and Recommendation is filed pursuant to 28 U.S.C. § 636(b)(l)(B), Fed. R.
Civ. P. 72(b)(l), and D. Del. LR 72.1. The parties may serve and file specific written objections
within fourteen (14) days after being served with a copy of this Report and Recommendation.
Fed. R. Civ. P. 72(b)(2). The objections and responses to the objections are limited to ten (10)
pages each. The failure of a party to object to legal conclusions may result in the loss of the right
to de novo review in the District Court. See Sincavage v. Barnhart, 171 F. App'x 924, 925 n.1
(3d Cir. 2006); Henderson v. Carlson, 812 F.2d 874, 878-79 (3d Cir. 1987).
The parties are directed to the court's Standing Order For Objections Filed Under Fed. R.
Civ. P. 72, dated October 9, 2013, a copy of which is available on the court's website,
http://www.ded.uscourts.gov.

Dated: September 5, 2018

25