PTAB

IPR2021-01295

Trienda Holdings LLC v. desgagné Brown Et AsSociés Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Polyethylene Compositions
  • Brief Description: The ’276 patent discloses polyethylene compositions created by blending four specific polyethylene resins—two virgin and two post-consumer recycled—along with a polyethylene antioxidant. The claims recite specific ranges for properties like high load melt index (HLMI), melt flow index (MFI), particle size distribution, and density for each resin component.

3. Grounds for Unpatentability

Ground 1: Obviousness over Harris and Nakayama - Claims 1-15 are obvious over Harris in view of Nakayama.

  • Prior Art Relied Upon: Harris (Application # 2008/0114131) and Nakayama (Patent 7,601,423).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Harris disclosed a method for producing melt-blended polyethylene compositions by combining up to six resins, including virgin and recycled high-density polyethylene (HDPE). Harris allegedly taught a four-resin blend with properties that meet or overlap with nearly all limitations of claim 1, including a first virgin high molecular weight (HMW) resin with a bimodal distribution and specific HLMI, a second virgin resin with a specified MFI and HLMI, and two post-consumer recycled (PCR) resins with properties analogous to the virgin resins. Harris also taught the inclusion of antioxidants. The only limitation Petitioner contended Harris did not explicitly disclose was the particle size distribution of less than 50 µm for the virgin resins.
    • Motivation to Combine: Petitioner asserted that Nakayama taught a method for preparing polyethylene resins as microparticles with a particle size distribution of less than 25 µm to improve blend homogeneity. A person of ordinary skill in the art (POSITA) would combine the teachings of Harris and Nakayama because resins with significant viscosity differences, such as those in Harris, are difficult to mix homogeneously. A POSITA would have been motivated to use the smaller microparticles taught by Nakayama to improve the ease of mixing and final product consistency for the composition taught by Harris.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because Nakayama explicitly stated its microparticles are suitable for conventional molding processes like the extrusion methods used in Harris.

Ground 2: Obviousness over Thomas, Starita, and Nakayama - Claims 1-15 are obvious over Thomas in view of Starita and Nakayama.

  • Prior Art Relied Upon: Thomas (a 2011 report on recycled polyethylene pipe), Starita (Application # 2005/0004316), and Nakayama (Patent 7,601,423).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Thomas disclosed a four-resin polyethylene blend for corrugated pipe that included two virgin resins, two PCR resins, and an antioxidant, similar to the claimed composition. To the extent Thomas did not explicitly teach every claimed property range, Starita provided the missing elements. Starita taught blending various HMW and low molecular weight (LMW) HDPE components (both virgin and recycled) to optimize properties like environmental stress crack resistance (ESCR) and processability. Starita specifically disclosed a bimodal HMW HDPE component with an HLMI range (0.01 to 1 g/10 min) that overlaps with the claimed range for the first virgin resin and an LMW HDPE component with an MFI range that overlaps with the claimed second virgin resin.
    • Motivation to Combine: A POSITA would modify the four-resin blend of Thomas using the specific resin components taught by Starita to achieve improved ESCR and processability at a lower cost, which were known goals in the art. For example, a POSITA would substitute Thomas's HMW resin with Starita's bimodal HMW HDPE to increase ESCR. The motivation to further incorporate Nakayama's teachings on particle size was to enhance the homogenization of the resulting blend, as argued in Ground 1.
    • Expectation of Success: Petitioner contended that a POSITA would have reasonably expected success in this combination, as it involved optimizing a known composition (Thomas) with known components (Starita) to achieve predictable improvements in well-understood properties.

4. Key Claim Construction Positions

  • "particle size distribution": Petitioner argued this term, recited in claims 1, 7, 8, 13, and 15, should be construed to mean the size of the primary particles (or "fluff") created in the polymerization reactor, not the size of post-processing pellets. This construction was based on intrinsic evidence in the ’276 patent that refers to particles and agglomerates formed "in the reactor." Petitioner asserted the claims are obvious under this construction and, alternatively, would also be obvious if the term were construed to mean pellet size.

5. Key Technical Contentions (Beyond Claim Construction)

  • Result-Effective Variables: A central technical argument underpinning both grounds was that the claimed parameters—density, molecular weight, modality, melt flow (MFI/HLMI), particle size distribution, and the ratio of recycled-to-virgin content—were all well-known "result-effective variables." Petitioner argued that a POSITA would have understood how to adjust each of these variables to optimize the trade-off between a final product's mechanical properties (e.g., strength, stiffness) and the composition's processability and cost. Therefore, arriving at the claimed ranges was merely the result of routine optimization, not invention.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-15 of Patent 10,570,276 as unpatentable under 35 U.S.C. §103.