LG Energy Solution Ltd v. Molecular Rebar Design LLC

1. Case Identification

• Case #: IPR2024-01005
• Patent #: 9,636,649
• Filed: June 7, 2024
• Petitioner(s): LG Energy Solution, Ltd.
• Challenged Claims: 1-23

2. Patent Overview

• Title: Dispersions Comprising Discrete Carbon Nanotube Fibers
• Brief Description: The ’649 patent relates to dispersions containing a plurality of oxidized, discrete, multiwall carbon nanotubes (CNTs) and at least one additive. The patent describes these dispersions as useful in composites with materials like elastomers and thermosets.

3. Grounds for Unpatentability

Ground 1: Obviousness over Sun - Claims 1-7, 11, 13-14, 17-19 are obvious over Sun.

• Prior Art Relied Upon: Sun (Application # 2010/0197832).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Sun teaches all elements of the challenged claims through its disclosure of a method to disperse CNTs in epoxy to form nanocomposites. Sun explicitly describes using "oxidized" and "multi-walled" CNTs. Petitioner contended that Sun’s process, which uses nanoplatelets to force nanotube bundles into individual tubes, results in "discrete" CNTs. Sun’s compositions include an "additive," such as the aqueous solvent in its initial dispersion or the epoxy monomer in its final nanocomposite. Petitioner further argued that Sun’s disclosed ranges for CNT aspect ratio ("at least about 10") and weight percentage ("0.01 wt% to 50 wt%") overlap with the ranges recited in the challenged claims (e.g., aspect ratio of 25 to 500), establishing a prima facie case of obviousness for those limitations. Dependent claims were mapped to Sun’s disclosure of specific additives (solvents, thermoset polymers like epoxy) and fillers (nanoplatelets).

Ground 2: Obviousness over Sun and Buretea - Claim 8 is obvious over Sun in view of Buretea.

• Prior Art Relied Upon: Sun (Application # 2010/0197832), Buretea (Patent 7,091,120).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the teachings of Sun's nanocomposite to address claim 8, which recites specific additives including polymeric plasticizers, glycols, and polyethers. Petitioner argued that while Sun provides the base dispersion of CNTs in a polymer matrix, Buretea teaches incorporating additives, specifically including plasticizers, into "nanowire-material composites" to modify their properties.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Sun’s nanocomposite with Buretea’s teaching of using plasticizers to achieve predictable and desirable results. The motivations cited included influencing the morphology, decreasing the flexural modulus, and affecting the melting and glass transition temperatures of Sun’s composite, thereby making it more versatile for various applications.
  • Expectation of Success: A POSITA would have had a high expectation of success because both references describe similar material systems (nanotube/polymer composites), and the incorporation of plasticizers to modify polymer properties was a well-known and routine technique in the art.

Ground 3: Obviousness over Farrugia and Narayan - Claims 1-8, 11-15, 17-19, and 21 are obvious over Farrugia in view of Narayan.

• Prior Art Relied Upon: Farrugia (Application # 2010/0124713), Narayan (Application # 2003/0213939).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Farrugia discloses a toner composition that constitutes a dispersion under the claims. This toner includes "functionalized" (oxidized), "discrete," and "multi-walled" CNTs dispersed in a polymer matrix (the additive). Farrugia teaches that a "high aspect ratio" is important for achieving enhanced electrical conductivity but does not quantify this ratio. Narayan was introduced to supply this teaching, as it discloses that CNTs with aspect ratios "greater than or equal to about 5" are suitable for imparting electrical conductivity to polymer composites.
  • Motivation to Combine: A POSITA, seeking to implement Farrugia’s toner with enhanced conductivity, would have been motivated to consult a reference like Narayan. Narayan directly addresses how to select CNT characteristics (specifically, aspect ratio) to achieve the very objective Farrugia described. The combination was presented as a straightforward implementation of a known design principle to achieve a predictable result.
  • Expectation of Success: Success was expected because the references share a common objective (increasing conductivity in polymer composites), utilize similar materials (e.g., polyesters, polyurethanes), and employ consistent CNT weight percentages. Narayan provided the specific, missing parameter needed to optimize the performance of Farrugia’s system.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 9-10, 15, and 21-23 are obvious over Sun and Kaji; claims 16 and 20 are obvious over Sun, Kaji, and Matsushita; and claims 22-23 are obvious over Farrugia, Narayan, and Nanya. These grounds relied on similar combination rationales, introducing secondary references to teach specific additives like wax (Kaji), fluororubber (Matsushita), and lubricants (Nanya).

4. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise discretionary denial under 35 U.S.C. §314(a) or §325(d).
• Fintiv Factors: Petitioner contended the factors favor institution. Key arguments included that the petition was filed diligently, months before the one-year bar, while the parallel district court litigation is in its early stages with minimal investment. Further, Petitioner stipulated that it would not pursue the same grounds in the district court if an inter partes review (IPR) is instituted.
• Advanced Bionics (§325(d)): Petitioner argued that denial under §325(d) is unwarranted because this petition presents new prior art and arguments. None of the primary references (Sun, Buretea, Kaji, Matsushita, Farrugia, Narayan, Nanya) were cited or applied during the original prosecution of the ’649 patent.

5. Relief Requested

• Petitioner requests institution of IPR and cancellation of claims 1-23 of the ’649 patent as unpatentable.