Rhodia Chimie & Rhodia, Inc. v. PPG Industries Inc.

United States Court of Appeals for the Federal Circuit

04-1246

RHODIA CHIMIE and RHODIA INC.,

Plaintiffs-Appellants,

v.

PPG INDUSTRIES INC.,

Defendant-Appellee.

Eric H. Weisblatt, Burns, Doane, Swecker & Mathis, L.L.P., of Alexandria,
Virginia, argued for plaintiffs-appellants. With him on the brief were Monte M. Bond,
Norman H. Stepno, Todd R. Walters, and Bruce J. Boggs, Jr. Of counsel on the brief
were N. Richard Powers, James D. Heisman, and Rudolph E. Hutz, Connolly, Bove,
Lodge & Hutz, L.L.P., of Wilmington, Delaware. Of counsel were Erin M. Dunston,
Burns, Doane, Swecker & Mathis, L.L.P., and James D. Heisman, Connolly, Bove,
Lodge & Hutz, L.L.P.

John M. Skenyon, Fish & Richardson P.C., of Boston, Massachusetts, argued for
defendant-appellee. With him on the brief was Jolynn M. Lussier.

Appealed from: United States District Court for the District of Delaware

Judge Kent A. Jordan
 United States Court of Appeals for the Federal Circuit

04-1246

RHODIA CHIMIE and RHODIA, INC.,

Plaintiffs-Appellants,

v.

PPG INDUSTRIES INC.,

Defendant-Appellee.

_______________________

DECIDED: April 11, 2005
_______________________

Before NEWMAN, CLEVENGER, and GAJARSA, Circuit Judges.

GAJARSA, Circuit Judge.

Rhodia Chimie and Rhodia, Inc. (collectively "Rhodia") appeal from a decision by

the United States District Court for the District of Delaware granting summary judgment

on Rhodia's claims of patent infringement in favor of defendant PPG Industries, Inc

("PPG"). Rhodia Chimie & Rhodia, Inc. v. PPG Indus. Inc., Civ. Action No. 01-389 (D.

Del. Jan. 23, 2004) ("Summary Judgment Opinion"). Rhodia also appeals the district

court's decision to exclude as untimely certain evidence proffered by Rhodia. Because

the district court properly construed the disputed claim terms and did not abuse its

discretion in excluding Rhodia's proffered evidence, we affirm in part the court's

decision. We conclude, however, that the evidence properly before the court created a
genuine issue of material fact regarding one of PPG's accused products and therefore

we reverse in part for further proceedings consistent with this opinion.

I. BACKGROUND

Rhodia is an international chemical company that is the assignee of United

States Patent Number 6,013,234 ("the '234 patent"). The '234 patent discloses and

claims certain essentially spheroidal precipitated silica particulates and their process of

manufacture. Only one of the product claims of the '234 patent and none of its process

claims were asserted in the instant litigation. Rhodia markets the silica particulate

covered by the terms of the '234 patent under the trademark "Micropearl." Micropearl

silica is used as a filler to reinforce elastomeric products such as automobile tires and

as a carrier in the nutraceutical industry.

The initial application that led to the '234 patent was filed in April 1980.1

Conventional elastomeric fillers in use at that time, such as carbon black, were

inherently dusty and did not flow easily. The '234 patent was designed as an

improvement to granulated silica and silica powders. The form of silica described in the

'234 patent has an "essentially spheroidal" geometry of a certain mean particle size and

morphology that distinguishes it from the prior art. '234 patent, Abstract. Claim 1 of the

'234 patent, the only claim at issue here, reads in its entirety:

Dry, dust-free and non-dusting, solid and homogenous atomized
precipitated silica particulates essentially spheroidal in geometrical
configuration, said particulates having a mean particle size in excess of
150 microns, a fill density in compacted state in excess of 0.200, a BET
surface area ranging from 100 to 350 m2/g, and a CTAB surface area
ranging from 100 to 350 m2/g.

1
The '234 patent, which issued January 11, 2000, was the culmination of
eleven continuation applications filed between October 23, 1981 and April 28, 1994.

04-1246 2
'234 patent, col. 13, ll. 61-67 (emphases added). The underlined terms are disputed by

the parties.

In addition to the claim language identified above, the specification of the '234

patent contains ten examples of silica products and the results of several tests making

comparisons among those products. The test results were designed to show ways that

a person of ordinary skill could understand or comprehend the advantages of the

claimed invention and differentiate it from the prior art. The cited tests considered both

the flowability and the dusting properties of the different silica products. Flowability was

identified as a "relative measurement" and defined as "the time required for the product

to flow into appropriate receptable [sic] having a calibrated aperture under slight

vibration." '234 patent, col. 4, ll. 29-32.

The tests conducted to assess the properties of the claimed invention included:

(1) a pour test which constituted a side-by-side comparison of the flowability of the

Micropearl silica versus the prior art; and (2) tests to measure the level of dust formed

by the various silica particulates, including a test using the DIN 53 583 standard (the

"DIN test"). The DIN test is a German standard developed to measure certain physical

properties of carbon black by determining the fines (dust) and weight loss by abrasion

according to a defined procedure.

In June 2001, Rhodia sued PPG for willful infringement of claim 1 of the '234

patent. Rhodia identified three silica products made by PPG that it alleged infringed its

patent rights. The three accused products were identified as Hi-Sil SC60M, SC72, and

SC72C.

04-1246 3
 The district court held a Markman hearing regarding the construction of the terms

of Claim 1. The primary disputed term at issue in this appeal is the limitation "dust-free

and non-dusting."2 PPG asserted that the term "dust-free and non-dusting" should be

interpreted literally to mean "no dust cloud whatsoever." Conversely, Rhodia argued

that a person of ordinary skill in the art would not ascribe such a meaning to the claim

term, particularly in light of the results of the pour test showing that the invention

produced some dust. Rhodia advocated construing "dust-free and non-dusting" to

mean "very low dust."

The court construed the disputed term as follows:

"dust-free and non-dusting" means "a level of dust formation associated
with the silica particulates of the '234 patent, as measured in percentage
weight according to DIN 53 583, that has a fines content value less than or
equal to 13 and weight loss by abrasion value less than or equal to 0.5."

Rhodia Chimie v. PPG Indus. Inc., Civ. Action No. 01-389, slip op. at 21-22 (D. Del. Oct.

9, 2003) ("Claim Construction Opinion"). The court clarified its reference to DIN 53 583

with a detailed explanatory footnote:

'DIN 53 583' is an industrial standard provided by the Deutsches Institut
fur Normung e.V., a self-governing institution of trade and industry
responsible for the preparation of National Standards in Germany, for
measuring the fines content and weight loss by abrasion of palletized
carbon black used as fillers in the rubber processing industry. The
inventors of the '234 patented silica made specific reference to that
standard as a means of measuring the dust qualities of their silica. I am
referring specifically to DIN 53 583 dated November 1969.

Id. at 14 n.3.

2
We also address the proper construction of the term "atomized
precipitated silica particulates" in Section III.C infra. As explained below, the
construction of this second disputed term was not dispositive to the district court's
decision, but may be relevant on remand.

04-1246 4
 The court's construction of "dust-free and non-dusting" was a reflection of its

determination that the term was ambiguous because it could not be read literally to

mean that the invention creates no dust at all. Id. at 14. The court was concerned,

however, that Rhodia's proposed definition of the term to mean "very low dust" was a

relative phrase which would not meet the statutory requirement that the claims

"particularly point out and distinctly claim the subject matter which the applicant claims

as his invention." Id. (citing 35 U.S.C. § 112 ¶ 2). In order to resolve the perceived

ambiguity of the claim term in a manner that preserved the term's validity, the court

adopted "a construction based upon the only meaningful guidance provided in the

patent," namely the DIN test. Id.

Following the court's rejection of Rhodia's motion to reconsider the Claim

Construction Opinion, the parties expressly agreed to close all discovery related to case

dispositive motions on November 5, 2003, with the filing of all such motions to follow

immediately thereafter. Trial was scheduled to begin on February 23, 2004.

In accordance with the pre-trial schedule, PPG filed motions for summary

judgment on the issues of invalidity, unenforceability and non-infringement of the '234

patent. On December 1, 2003, in conjunction with its opposition to PPG's motions,

Rhodia filed a request for a continuance to extend the time for discovery in order to

complete DIN testing and produce evidence supporting its claim for infringement.

Between December 22, 2003 and January 9, 2004, Rhodia served PPG with three

expert reports providing evidence of infringement through DIN testing results.

Subsequently, the court issued an order excluding Rhodia's DIN testing evidence

as untimely. On January 23, 2004, the court issued an opinion granting PPG's motion

04-1246 5
for summary judgment of non-infringement on the basis that Rhodia had not established

that PPG's products included the "dust-free and non-dusting" limitation of claim 1.

Summary Judgment Opinion, slip op. at 7. In so holding, the court determined that

PPG's products did not literally infringe the '234 patent and that prosecution history

estoppel barred Rhodia from asserting that the accused products infringe under the

doctrine of equivalents. Id. at 7-9. Because it found dispositive the issue of whether

PPG's products meet the "dust-free and non-dusting" limitation, the court did not reach

the other question raised by PPG's motions, namely whether the accused products

meet the "atomized precipitated silica particulates" limitation.

Rhodia appeals the district court's grant of summary judgment and exclusion of

its evidence. This court has jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).

II. DISCUSSION

A. Standard of Review

We review a district court's grant of summary judgment de novo, reapplying the

same standard used by the district court. Ethicon Endo-Surgery, Inc. v. U.S. Surgical

Corp., 149 F.3d 1309, 1315 (Fed. Cir. 1998). Summary judgment is appropriate if,

drawing all factual inferences in favor of the nonmoving party, there is no genuine issue

as to any material fact and the moving party is entitled to judgment as a matter of law.

Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).

Courts determine patent infringement by construing the patent's claims and then

applying that construction to the accused process or product. Markman v. Westview

Instruments, Inc., 52 F.3d 967, 976 (Fed. Cir. 1995) (en banc), aff'd, 517 U.S. 370

(1996). Claim construction is a question of law reviewed without deference on appeal.

04-1246 6
Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed. Cir. 1998) (en banc). In

determining whether summary judgment resolving the issue of literal infringement is

proper, the court considers whether a "reasonable jury could find that every limitation

recited in the properly construed claim either is or is not found in the accused device."

Bai v. L&L Wings, 160 F.3d 1350, 1353 (Fed. Cir. 1998). Application of prosecution

history estoppel to limit the doctrine of equivalents presents a question of law that this

court reviews without deference. Glaxo Wellcome, Inc. v. Impax Labs., Inc., 356 F.3d

1348, 1351 (Fed. Cir. 2004).

Evidentiary rulings are procedural matters that do not raise issues unique to

patent law, therefore this court applies the law of the appropriate regional circuit in

reviewing such rulings. ATD Corp. v. Lydall, Inc., 159 F. 3d 534, 548 (Fed. Cir. 1998).

According to the law of the Third Circuit, which controls here, exclusion of evidence by

the district court is reviewed by an appellate court for abuse of discretion. Glass v.

Philadelphia Elec. Co., 34 F.3d 188, 191 (3d Cir. 1994).

B. Claim Construction of "dust-free and non-dusting"

Courts construe claim terms in order to assign a fixed, unambiguous, legally

operative meaning to the claim. Liquid Dynamics Corp. v. Vaughan Co., Inc., 355 F.3d

1361, 1367 (Fed. Cir. 2004). Claim construction begins with the intrinsic evidence of

record, looking first to the claim language itself to define the scope of the patented

invention. Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996).

"When the claim language itself lacks sufficient clarity to ascertain the scope of the

claims," we look to the written description for guidance. Deering Precision Instruments,

L.L.C. v. Vector Distrib. Sys., Inc., 347 F.3d 1314, 1324 (Fed. Cir. 2003). We consult

04-1246 7
the written description "to determine whether the inventor has used any terms in a

manner inconsistent with their ordinary meaning. The specification acts as a dictionary

when it expressly defines terms used in the claims or when it defines terms by

implication." Vitronics, 90 F.3d at 1582. Finally, we refer to the prosecution history,

when it is of record, to discern the applicant's express acquiescence with or distinction

of the prior art as further indication of the scope of the claims. Liquid Dynamics, 355 F.

3d at 1368.

Here the district court determined that the disputed term "dust-free and non-

dusting" could not be read literally to mean that the invention creates no silica dust at

all. Claim Construction Opinion, slip op. at 10. It reached this conclusion recognizing

that the test results detailed in the written description indicate that the invention itself

produces some dust, but less dust than the prior art. '234 patent, Figs. 3-6 & Tables I &

II. Because a literal construction of the term "dust-free and non-dusting," which PPG

advocates to mean "no dust cloud whatsoever," would not read on the preferred

embodiment, we agree with the district court that a person of ordinary skill in the art

would not interpret this term in that manner. As we have frequently stated, a

construction that "would not read on the preferred embodiment . . . would 'rarely if ever

[be] correct and would require highly persuasive evidentiary support.'" Interactive Gift

Express, Inc. v. Compuserve Inc., 231 F.3d 859, 876 (Fed. Cir. 2000) (quoting Vitronics,

90 F.3d at 1583); Hoechst Celanese Corp. v. BP Chems. Ltd., 78 F.3d 1575, 1578 (Fed.

Cir. 1996); see also Modine Mfg. Co. v. United States Int'l Trade Comm'n, 75 F.3d

1545, 1550 (Fed. Cir. 1996) ("a claim interpretation that would exclude the inventor's

device is rarely the correct interpretation"). The specification, prosecution history and

04-1246 8
prior art contain no "highly persuasive evidentiary support" that would require reaching

such an unlikely construction. Modine Mfg., 75 F.3d at 1550.

Relying on the use of the term in the written description, Rhodia proposes that

the term "dust-free and non-dusting" should be construed to mean that the level of dust

"is very low when compared to other silica forms." As the district court recognized, this

definition is "a relative phrase, including within its ambit a desirable characteristic of the

invention," which can only be understood in comparison to the prior art. Claim

Construction Opinion, slip op. at 10. Accordingly, we look to the written description to

determine the scope afforded to the comparative phrase very low levels of dust.

The written description includes ten examples of different forms of silica selected

to illustrate the advantages of the invention. '234 patent, col. 3, l. 40 – col. 8, l. 48.

Varying combinations of the examples were subjected to testing designed to quantify

certain physical properties in order to document and reveal the patentable

characteristics of the claimed invention. The resultant physical properties of the ten

examples are accumulated in Tables I and II of the '234 patent "such that the

physiochemical properties of the various final products can be compared." '234 patent,

col. 7, ll. 23-24. It is worth noting that, with the exception of particle size, all the physical

properties for which numerical ranges are specifically provided in Claim 1, namely fill

density, BET surface area and CTAB surface area, are outlined in Tables I and II. "Dust

formation and abrasion as in DIN 53 583, in % by weight" appears in the last row of

each of each table.

Although ten examples of silica products are referenced in the written

description, the parties agree that only two of the examples constitute a product of the

04-1246 9
issued claims: Examples 5 and 10. Example 5 is twice referred to as the product of the

invention: "As additional illustrations of the product according to the invention, Fig. 1 is

an enlarged photograph of a pellet according to the invention (Example 5)," Id., col. 8, ll.

50-51, and "the product according to the invention (Example 5)," Id., col. 9, ll. 2-3.

Example 10 is a refined version of Example 5. Id., col. 8, l. 45. Thus, although ten

examples are addressed in the description, the preferred embodiment of Example 5 is

repeatedly described as the invention itself. See id., col. 8, ll. 50-51 & col. 9, ll. 2-3.

The written description identifies two tests that were conducted to assess the

tendency of the different examples to form dust. The first test was conducted on

Examples 1, 2, and 4, whereas the second test was conducted on Examples 4, 5, 9 and

10. The first test used stable, fluidized beds of Examples 1, 2 and 4 and applied a

vector gas to them to assess "the quality of the resulting product . . . expressed in terms

of the formation of dust therefrom and its resistance to attrition." Id., col. 6, ll. 47-49.

The description of this test concluded with the statement: "[d]ust formation and abrasion

were also measured in accordance with the standard DIN 583 [sic]." Id., col. 6, ll. 66-

67.

Results according to the DIN 53 583 standard were provided for Examples 4, 5, 9

and 10. Id., Tables I and II. Because the only measurement of the dust produced by

Examples 5 and 10 was articulated in terms of the DIN 53 583 standard, the district

court properly incorporated that articulation into its construction of the term "dust-free

and non-dusting." The results of the DIN testing showed that Example 5 produced more

dust than Example 10. Accordingly, the court defined the outer limit for the level of dust

created by the invention by reference to the DIN test results for Example 5.

04-1246 10
 We agree with the district court that the reference to the DIN test results for

Example 5, as provided in the written description, reconciles the ambiguous claim

language with the inventor's disclosure. Comark Communications, Inc. v. Harris Corp.,

156 F.3d 1182, 1187 (Fed. Cir. 1998) (indicating that interpreting claim language in light

of the specification is proper when a term is "so amorphous that one of skill in the art

can only reconcile the claim language with the inventor's disclosure by recourse to the

specification"). As such, the court's construction of the term "dust-free and non-dusting"

does not contravene the basic teaching that limitations from the specification should not

be imported to the claims. Id. at 1186-87; see also E.I. Du Pont De Nemours & Co. v.

Phillips Petroleum Co., 849 F.2d 1430, 1433 (Fed. Cir. 1988) (counseling that it is

improper to read a limitation "into a claim from the specification wholly apart from any

need to interpret what the patentee meant by particular words or phrases in the claim").

Furthermore, this construction is consistent with the proposition that "when the preferred

embodiment is described in the specification as the invention itself, the claims are not

necessarily entitled to a scope broader than that embodiment." Modine Mfg., 75 F.3d at

1551.

Rhodia challenges the court's construction on the grounds that the DIN 53 583

standard is not the only means by which to assess the amount of dust produced by the

invention in comparison to the prior art. It asserts that the pour test, which was applied

to Example 5, could also be used to determine the level of dustiness identified in the

claim. The written description provides the following summary of the pour test:

The test comprises placing one liter of the product to be studied in an
Erlenmeyer flask having a neck 4.4 cm in diameter. The flask is rocked
and the flowability of the product visually observed. The height from which

04-1246 11
 the product is spilled is 63 cm. The experiment is shown in Fig. 3 at the
very instance that the product begins to flow/spill, and then, in the
subsequent photographs, every two seconds thereafter.

It will be seen from the first photograph that the product according to the
invention has a fluid appearance and was more freely flowing from the
very outset. It can then clearly be seen that the product according to the
invention not only flows better than a product in powder form (that
prepared as in Example 2), but also flows better than a granulated product
as prepared in Example 4. The granulated product is in the center of the
photographs while the product according to the invention (Example 5) is at
the right hand side thereof.

'234 patent, col. 8, l. 54 – col. 9, l. 3. According to Rhodia, the results of the pour test,

which appear in the patent only as a series of pictures, can serve as an alternative

means of distinguishing the level of dust produced by the invention from the prior art

and therefore it is inappropriate to limit the term "dust-free and non-dusting" to the DIN

specifications. In support of this interpretation, Rhodia relies heavily on statements

made during the prosecution of the patent showing that the pictures of the pour test

were cited as evidence of the "non-dusting and free-flowing properties."

Rhodia's argument ignores the written description of the patent and the

fundamental purpose of the claims, which is to define the scope of the patented

invention. Liquid Dynamics, 355 F.3d at 1368. Although the pour test may also provide

evidence of the dust produced by the various forms of silica, the results presented in the

patent were only identified as evidence of the products' flowability. See '234 patent, col.

8, ll. 56-57. There is no language in either the claims or the written description that

teaches application of the pour test to determine the level of dust production claimed by

the invention and Rhodia's statements made during the prosecution of the patent cannot

serve to fill that gap. "Although the prosecution history can and should be used to

understand the language used in the claims, it . . . cannot 'enlarge, diminish, or vary' the

04-1246 12
limitations in the claims." Markman v. Westview Instruments, Inc., 52 F.3d 967, 980

(Fed. Cir. 1995). Although the pour test and the stabilized fluid bed test may provide

alternative means for assessing dust production, it remains that the only articulation of

the dustiness of the claimed invention is made with reference to the DIN 53 583

standard.

Rhodia chose to define the term "dust-free and non-dusting" solely by reference

to characteristics of the prior art and the only comparison of those characteristics was

explained according to the DIN 53 583 standard. It was not improper for the district

court to limit the scope of this relative term to the only disclosure on the subject made in

the patent. We affirm the claim construction of the district court.

C. Summary Judgment of Non-infringement

Applying its construction of the term "dust-free and non-dusting" to the three

accused products, the district court determined that none of the three met the limitation

as defined. Accordingly, it found that the accused products did not literally infringe the

'234 patent. Summary Judgment Opinion, slip op. at 6-7. The court also found that

Rhodia was not entitled to any scope of equivalents with respect to the limitation "dust-

free and non-dusting" because the limitation was added during prosecution in order to

avoid the prior art. Id. at 8-9. Rhodia challenges the court's infringement findings, both

as to literal infringement and infringement under the doctrine of equivalents.

Rhodia attacks the court's finding of no literal infringement on evidentiary

grounds. First, it argues that it was improperly denied the opportunity to submit

evidence showing the results of its testing under the DIN 53 583 standard.

Alternatively, Rhodia asserts that even without the excluded DIN test results, the

04-1246 13
evidence submitted raised a genuine issue of material fact such that the district court

erred in entering summary judgment of non-infringement.

Rhodia's assertion that the district court abused its discretion in excluding its DIN

testing evidence is without merit. Rhodia claims that because the machinery for

conducting DIN testing was not readily available, it was not able to produce the

necessary results and related expert report in the four weeks between the time the court

issued its Claim Construction Opinion and the close of discovery. Accordingly, it

believes that it was entitled to an extension of discovery in order to respond to the

court's construction of "dust-free and non-dusting" by reference to the DIN 53 583

standard.

Rhodia's argument was presented to and rejected by the district court, which

found that it was unreasonable for Rhodia to delay investigation into DIN testing until

after the issuance of the Claim Construction Opinion. See Rhodia Chimie v. PPG

Indus. Inc., Civ. Action No. 01-389, slip op. at 1 (D. Del. Jan. 23, 2004) ("Order Denying

Reconsideration of Evidentiary Decision"). The court found that Rhodia was on notice

at least as early as the summer of 2003 that the court considered the DIN 53 583

standard relevant to the construction of the disputed term. Id. at 2. In support of that

finding, the court noted that it inquired into the English translation of the DIN 53 583

standard in July 2003 and then, in August 2003, it explicitly invited the parties to provide

input on the construction of the term "dust-free and non-dusting" in light of that

standard. Id. Because Rhodia submitted its DIN testing evidence seven weeks after

the close of discovery and the passing of the deadline for filing case dispositive motions

and six weeks prior to trial, the Court held that PPG would be substantially and unfairly

04-1246 14
prejudiced if such evidence was admitted. See Rhodia Chimie v. PPG Indus. Inc., Civ.

Action No. 01-389, slip op. at 2 (D. Del. Jan. 16, 2004) ("Order Excluding Evidence").

Rhodia presents no authority in support of its assertion that the district court's

decision to exclude its evidence as untimely was an abuse of discretion. When a party

fails to obey an order regarding discovery, Federal Rule of Civil Procedure 37 provides

district courts with broad discretion to "make such orders in regard to the failure as are

just," which includes "prohibiting the party from introducing designated matters in

evidence." Fed. R. Civ. Proc. 37(b)(2). While recognizing the severity of a decision to

exclude critical evidence for failure to comply with a pretrial order, the Third Circuit will

not disturb the trial court's decision "absent a clear abuse of discretion." Semper v.

Santos, 845 F.2d 1233, 1237 (3d Cir. 1988). The Third Circuit typically considers four

factors in evaluating whether the district court properly exercised its discretion. In re

TMI Litig., 193 F.3d 613, 721 (3d Cir. 1999). Those factors are: (1) the prejudice or

surprise in fact of the party against whom the excluded evidence would have been

submitted; (2) the ability of that party to cure the prejudice, (3) the extent to which

waiver of the discovery deadline would disrupt the orderly and efficient trial of the case

or of other cases in the court, and (4) bad faith or willfulness in failing to comply with the

district court's order. See id. (citing Meyers v. Pennypack Woods Home Ownership

Assoc., 559 F.2d 894, 904-05 (3d Cir. 1977)).

None of the cited factors counsel in favor of finding that the district court abused

its discretion. PPG filed timely case dispositive motions according to a schedule

specifically agreed to by Rhodia after the issuance of the Claim Construction Opinion.

The admission of Rhodia's untimely evidence would have undermined, if not negated

04-1246 15
PPG's motions for summary judgment and disrupted the scheduled trial. Because

Rhodia did not submit its request for a continuation of discovery until well after the

deadline had passed and its response to PPG's motions was due, PPG had no

opportunity to correct the prejudice created by Rhodia's failure to comply with the district

court's order. Rhodia offers no explanation as to why it postponed engaging in DIN

testing until the eve of the close of discovery and why it failed to bring its problems in

conducting such testing to the attention of the court in a timely manner. Under the

circumstances, we cannot say that the district court abused its discretion in excluding

Rhodia's untimely evidence.

Rhodia also argues that, even without considering its untimely DIN testing

evidence, the district court erred in entering summary judgment finding no literal

infringement. It rests this argument on evidence provided by PPG showing DIN 53 583

results for SC60M within the range established by the court's claim construction. PPG

argues that this evidence was irrelevant because the results were produced prior to the

issuance of the '234 patent and Rhodia produced no evidence linking the sample tested

to PPG's post-issuance commercial practices. In support of its theory requiring the

establishment of a linkage, PPG relies on Chiuminatta Concrete Concepts, Inc. v.

Cardinal Industries, Inc., 145 F.3d 1303 (Fed. Cir. 1998). In Chiuminatta, we affirmed

the district court's conclusion that a study performed after a patent's filing date was not

relevant to determining whether the patent was obvious. Id. at 1313. We held that a

post-filing date report was insufficient to raise a genuine issue of material fact regarding

the state of the prior art unless evidence was produced that demonstrated the

relationship of the report to the prior art. Id. Relying on that holding, PPG argues that

04-1246 16
Rhodia's production of pre-issuance evidence without more was insufficient to raise a

genuine issue of material fact as to whether PPG's post-issuance products infringed.

PPG's reliance on Chiuminatta is misplaced. A determination of obviousness, as

was at issue in Chiuminatta, turns on the scope and content of the art prior to the filing

date of the patent application. SIBIA Neurosciences, Inc. v. Cadus Pharm. Corp., 225

F.3d 1349, 1355-56 (Fed. Cir. 2000). Thus, as a prima facie matter, a report drafted

after a patent application was filed would not inform the necessary inquiry into the scope

and content of the prior art. In contrast, although a patent cannot be infringed by acts

done before its issuance, evidence regarding pre-issuance activities may be relevant to

establishing that post-issuance products constitute infringement. See Hoover Group,

Inc. v. Custom Metalcraft, Inc., 66 F.3d 299, 303 (Fed. Cir. 1995) (holding that pre-

issuance engineering drawings and templates used to build accused products sold after

the issuance of the patent could be relied on to show infringing characteristics). PPG's

challenge to the link between PPG's accused product and the silica product tested in

the report relied upon by Rhodia does not show that the report is irrelevant, but rather

raises questions of fact, the resolution of which will determine the weight to be afforded

the evidence.

Although the existence of a pre-issuance report indicating that SC60M produced

DIN 53 583 results in the range defined by the court's claim construction does not

establish infringement, it does create a genuine issue of material fact as to whether the

post-issuance form of SC60M infringes. Accordingly, the trial court erred as a matter of

law in entering summary judgment of non-infringement for PPG's SC60M and we

reverse for further proceedings limited to that product. Rhodia has identified no

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evidence establishing a genuine issue of material fact in regards to the other two

accused products and therefore there is no reason to reverse the court's decision for

SC72 or SC72C.

Rhodia also argues that it is entitled to show that PPG's products infringe under

the doctrine of equivalents. It asserts this argument despite its acknowledgement that

the limitation "dust-free and non-dusting" was added during prosecution to distinguish

the claimed invention from the prior art. Rhodia claims that this amendment does not

bar it from asserting equivalents under the doctrine of Festo Corp. v. Shoketsu Kinzoku

Kogyo Kabushiki Co., Ltd., 535 U.S. 722, 733 (2002). Under Festo, a narrowing

amendment made to satisfy a requirement of the Patent Act may give rise to an

estoppel. Id. at 736. Such a narrowing amendment creates a presumption that the

patentee surrendered the territory between the original claims and the amended claims.

Id. at 741. The patentee may rebut that presumption by showing that the alleged

equivalent was unforeseeable at the time the amendment was made, that the alleged

equivalent was tangential to the purpose of the amendment, or that there was some

other reason suggesting that the patentee could not reasonably be expected to have

described the insubstantial substitute in question. Id. at 740-41. Rhodia argues that its

amendment of Claim 1 to include the limitation "dust-free and non-dusting" does not

estop it from asserting infringement under the doctrine of equivalents because the

equivalent in question was tangential to the purpose of the amendment.

This court has held that the primary consideration in determining when an

amendment bears only a tangential relation to the equivalent in question is "whether the

reason for the narrowing amendment was peripheral, or not directly relevant, to the

04-1246 18
alleged equivalent." Insituform Tech., Inc. v. CAT Contracting, Inc., 385 F.3d 1360,1370

(Fed. Cir. 2004) (citing Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 344

F.3d 1359, 1365 (Fed. Cir. 2003) (en banc)). Here, Rhodia argues that the prosecution

history shows that the limitation "dust-free and non-dusting" was added to Claim 1 of the

'234 patent to distinguish the invention of precipitated silica particulates from the prior

art of "powdered or granulated [or otherwise shaped] silicas." According to Rhodia,

because the accused products are "spray-dried silica microspheres" and not "powdered

or granulated silicas" they are not within the distinguished prior art and therefore the

narrowing amendment is not directly relevant to the accused equivalents.

Rhodia misunderstands the scope of the inquiry into the relationship between the

narrowing amendment and the accused equivalent. As we have stated, "an amendment

made to avoid prior art that contains the equivalent in question is not tangential," Festo,

344 F.3d at 1369. It does not follow, however, that equivalents not within the prior art

must be tangential to the amendment. Here, Rhodia amended its claim to incorporate

numerous limitations identifying the specific characteristics that distinguished its

invention from the prior art, including the trait that it was "dust-free and non-dusting."

Rhodia's articulation of these characteristics was not limited to the form of the silica

produced and therefore, Rhodia presumptively surrendered all forms of silica with dust

levels too great to be considered "dust-free and non-dusting." As a claimed

improvement over the prior art, the relative dustiness of Rhodia's invention was at issue

during prosecution and thus the reason for the narrowing amendment cannot be said to

be tangential to an equivalent that has that characteristic. Talbert Fuel Sys. Patents Co.

v. Unocal Corp., 347 F.3d 1355, 1360 (Fed. Cir. 2003) (holding that a narrowing

04-1246 19
amendment to address issues raised during prosecution was the "direct, not tangential,

reason" for the narrowing amendment). Accordingly, we hold that Rhodia has not

rebutted the presumption that it surrendered the range between its original claim and its

amended claim and is therefore estopped from asserting infringement under the

doctrine of equivalents.

C. Additional Issues

Although the district court's final judgment of non-infringement was based solely

on the absence of evidence that PPG's products contain the limitation "dust-free and

non-dusting," PPG had presented an alternative argument for summary judgment on the

ground that its accused products do not include the limitation "atomized precipitated

silica particulates." Despite disposing of the case on the "dust-free and non-dusting"

limitation, the court expressly included its construction of "atomized precipitated silica

particulates" into its Summary Judgment Opinion. Accordingly, the parties fully briefed

the dispute regarding the construction of "atomized precipitated silica particulates"

before this court. Furthermore, as discussed above, a limited remand of this case is

necessary and the construction of this second term may be determinative in the future

proceedings. Under these circumstances, we conclude that judicial economy would

best be served by our reviewing this second claim construction issue. Microsoft Corp.

v. Multi-tech Sys., Inc., 357 F.3d 1340, 1351 n.6 (Fed. Cir. 2004) (reviewing the

construction of all disputed claim terms, not just the ones necessary to resolve the

appeal).

The district court interpreted the term "atomized precipitated silica particulates" to

mean "that a pulverized slurry of precipitated silica is spray dried using a liquid pressure

04-1246 20
nozzle as an atomizer to form the claimed silica particulates." Claim Construction

Opinion, slip op. at 14-15. The court reached this construction by reference to the

prosecution history, where Rhodia distinguished the prior art by emphasizing that its

claimed silica particulates could be obtained only by applying liquid pressure nozzle

sprayers to a pulverized slurry. Id. at 15. Rhodia argues that its statements regarding

the use of liquid pressure nozzle sprayers and a pulverized slurry were directed at its

process claims, which appear at claims 16-28 of the '234 patent, and not its product

claims. Thus, Rhodia asserts, it was improper for the district court to rely on the

prosecution history to interpret product Claim 1 in light of argument directed at the

patent's process claims.

Rhodia's argument does not comport with well-established principles of claim

construction. The purpose of consulting the prosecution history in construing a claim is

to "exclude any interpretation that was disclaimed during prosecution." ZMI Corp. v.

Cardiac Resuscitator Corp., 844 F.2d 1576, 1580 (Fed. Cir. 1988). Accordingly, "where

the patentee has unequivocally disavowed a certain meaning to obtain his patent, the

doctrine of prosecution disclaimer attaches and narrows the ordinary meaning of the

claim congruent with the scope of the surrender." Omega Eng'g., Inc. v. Raytek Corp.,

334 F.3d 1314, 1324 (Fed. Cir. 2003). Such a use of the prosecution history ensures

that claims are not construed one way in order to obtain their allowance and in a

different way against accused infringers. Southwall Tech., Inc. v. Cardinal IG Co., 54

F.3d 1570, 1576 (Fed. Cir. 1995).

Over a series of responses to office actions, Rhodia amended Claim 1 to include

the term "atomized precipitated silica particulates." The amendments were made, in

04-1246 21
part, to traverse rejections based on U.S. Patent No. 3,383,172, which was issued to

Biegler et al., and U.S. Patent No. 4,094,771, which was issued to Brandt et al. The

Biegler art disclosed a "method for preparing silica in the form of hollow spheres," U.S.

Patent No. 3,383,172, Claim 1, whereas the Brandt art disclosed a "process for the

production of a sprayable, highly concentrated aqueous suspension of a precipitated

silicic acid," U.S. Patent No. 4,094,771, Claim 1.

Both the product and the process claims of the '234 patent were initially rejected

as unpatentable in light of the Biegler and Brandt prior art. Rhodia distinguished the

Biegler invention on the grounds that it disclosed a method for preparing silica in the

form of hollow spheres and was directed at pyrogenic silica, unlike Rhodia's claimed

invention of "precipitated silica." Furthermore, Rhodia noted that Biegler did not require

a pulverization step and "no slurry which has not been pulverized per applicants'

invention would be capable of ultimately providing a homogeneous and solid particulate

product, much less those precipitated silica beads having those particular physical and

chemical properties now set forth in all of applicant's newly presented claims."

Rhodia distinguished the Brandt invention on the grounds that "the spraying or

atomization of the suspension obtained by the process of Brandt et al. does not

necessarily lead to the claimed subject matter of the present invention . . . the silica

particulates are much smaller than the claimed atomized precipitated silica particulates

of the present application." Furthermore, Rhodia argued that Brandt does not specify

the type of nozzle or spray drying technique used in its process, whereas to obtain

Rhodia's "claimed silica particulates, liquid pressure nozzle sprayers must be used."

04-1246 22
 In light of the prosecution history, it is evident that Rhodia disclaimed products

created using non-pulverized slurries and atomization techniques other than liquid

pressure nozzle sprayers. There is no indication that Rhodia attempted to limit these

disclaimers to its process claims. Rhodia was required to distinguish both its product

and process claims from the inventions of Biegler and Brandt and it did so by focusing

on the necessity of using liquid pressure nozzle sprayers and pulverized slurries to

obtain its claimed product. Accordingly, we see no error in the district court's

construction of the term "atomized precipitated silica particulates" to mean that "a

pulverized slurry of precipitated silica is spray dried using a liquid pressure nozzle as an

atomizer to form the claimed silica particulates." We affirm that construction.

III. CONCLUSION

For the foregoing reasons, we affirm the district court's construction of the

disputed claim terms "dust-free and non-dusting" and "atomized precipitated silica

particulates." We also affirm the district court's exclusion of Rhodia's evidence as

untimely, its entry of summary judgment of no literal infringement for PPG products

SC72 and SC72C, and its finding of no infringement by equivalence because of

prosecution history estoppel for all three products. Because the district court erred in

holding that there was no genuine issue of material fact regarding the literal

infringement of PPG's product SC60M, we vacate the district court's grant of summary

judgment as to SC60M and remand for further proceedings consistent with this opinion.

IV. COSTS

No costs.

AFFIRMED-IN-PART, REVERSED-IN-PART and REMANDED

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