PTAB

IPR2023-01372

Omega Liner Company, Inc. v. Buergofol GmbH

Title: Tubular Film and the Use Thereof
Brief Description: The `’882 patent` relates to an insertion tube for trenchless sewage pipe renovation, commonly known as a Cured-in-Place-Pipe (CIPP) liner. The technology centers on a multilayered inner tubular film featuring a special coating that includes a "migrating compound" (such as wax) to facilitate a clean release of the film from the resin after it has been cured inside the host pipe.

Prior Art Relied Upon: Hummel (International Publication No. WO 2011/157356).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Hummel, which discloses a multi-layer UV CIPP liner, taught every element of the challenged claims. Specifically, Hummel described a CIPP liner with inner and outer tubes and a resin-impregnated carrier material. For the key "coating" limitation of claim 1, Petitioner asserted that Hummel’s teaching of treating the external layers of its inner film with additives like waxes, lubricants, and surfactants (which are "migrating compounds") inherently created the claimed coating when incorporated into the film's outermost layer.
- Key Aspects: Petitioner explicitly stated this ground was presented under the Patent Owner's own expected claim construction of "coating," which allegedly covers compounds incorporated into a film layer. The anticipation argument for dependent claims rested on Hummel’s disclosures of specific film thicknesses (claim 4), layer compositions including polyamide and thermoplastic olefins (claim 5), barrier layers (claim 6), and the use of wax as a lipophilic compound (claims 10 and 11).

Prior Art Relied Upon: Hummel (WO 2011/157356) and Schuhmann (WO 2011/054434).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative to anticipation. Hummel provided the base CIPP liner structure. Schuhmann, which is analogous art directed to release films for tacky resins, was argued to supply any missing element of the "coating" limitation. Schuhmann explicitly taught release films that are "coated on one side with the lipophilic compound" or films where a "migrated lipophilic compound" (like wax) provides occupancy on the surface to create a release effect.
- Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Schuhmann's release coating technology with Hummel's CIPP liner to solve the well-known problem of ensuring the inner film peels away from the cured resin cleanly and without tearing. The motivation was argued to be particularly strong because the lead inventor of the ’882 patent, Dr. Kurt Stark, is also a named co-inventor on the Schuhmann reference, which was not before the Examiner.
- Expectation of Success: Applying a known release coating from Schuhmann to a known CIPP liner from Hummel to achieve an improved release effect was a predictable modification using standard techniques.

Prior Art Relied Upon: Hummel (WO 2011/157356) and Nagai (Japanese Application Publication No. JP2002-1819).
Core Argument for this Ground:
- Prior Art Mapping: As in the other grounds, Hummel provided the foundational CIPP liner. Nagai was introduced to teach the "coating" limitation, as it discloses a CIPP liner where a release agent (e.g., silicone, wax, fatty acid) is explicitly applied to the inner film's surface to form a release layer. This layer prevents the film from adhering to the cured resin.
- Motivation to Combine: A POSITA would be motivated to apply Nagai's direct teaching of using a release agent like wax or silicone to Hummel's CIPP liner. Both references are in the same field and address the same fundamental need for easy, tear-free removal of the inner film after curing the resin.
- Expectation of Success: The use of release agents is a conventional and predictable method for preventing adhesion. Applying the specific release agents from Nagai to the Hummel liner would have a high expectation of success in achieving the desired release properties.
Additional Grounds: Petitioner asserted an additional obviousness challenge against claim 3 over Hummel alone, arguing it would have been obvious to a POSITA, based on general knowledge, to add a thermoplastic elastomer (TPE) layer to Hummel's film to improve its mechanical properties like elasticity.

Petitioner focused its arguments on the term "coating" as recited in claim 1[1e]. For the purposes of the IPR petition, Petitioner adopted the Patent Owner's broad construction from parallel litigation.
This construction was understood to encompass both (1) a migrating compound (like wax) incorporated into the outermost layer of the inner tubular film, and (2) a migrating compound applied over the external side of the inner film. This broad interpretation was central to Petitioner's arguments that the prior art satisfied the claim limitation either through incorporation (Hummel) or direct application (Schuhmann, Nagai).

"Migrating Compound" is Not Novel: Petitioner argued that the patent's core inventive concept—a "migrating compound"—is not a unique invention but rather a well-known class of additives, like wax, used in plastics for decades. These additives are known to naturally migrate to a polymer's surface to act as lubricants and release agents.
Inventor's Knowledge of Prior Art: The petition heavily emphasized the biographical connection between the ’882 patent inventor, Dr. Kurt Stark, and the prior art. It was noted that Dr. Stark was a co-inventor on the Schuhmann reference and worked for the same parent company as the inventor of Hummel, suggesting direct knowledge of the very technologies asserted to render his patent invalid.

§314(a) / Fintiv: Petitioner argued against discretionary denial by noting it had filed a *Sotera* stipulation, agreeing not to pursue the same invalidity grounds in the parallel district court litigation if the IPR is instituted. It further argued that the Fintiv factors favored institution because the litigation was in its early stages with no trial date set, the challenged claims in the IPR were broader than those asserted in litigation, and the petition presented a compelling case for unpatentability.
§325(d): Petitioner contended that denial under §325(d) was improper because the primary prior art references (Hummel, Schuhmann, and Nagai) were never presented to or considered by the USPTO Examiner during the original prosecution. Therefore, the arguments and evidence in the petition were not cumulative of the prior prosecution record.

Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 3-7, and 10-13 of Patent 9,657,882 as unpatentable.