HS Hyosung Advanced Materials Corp v. Kolon Industries Inc

1. Case Identification

• Case #: IPR2025-00663
• Patent #: 10,196,765
• Filed: February 27, 2025
• Petitioner(s): HS Hyosung Advanced Materials Corp.
• Patent Owner(s): Kolon Industries Inc.
• Challenged Claims: 1-6

2. Patent Overview

• Title: Hybrid Tire Cord
• Brief Description: The ’765 patent relates to a hybrid tire cord formed by twisting together a nylon yarn and an aramid yarn. The purported invention is a specific configuration where the aramid yarn is slightly longer and has a slightly lower twist number than the nylon yarn, allegedly resulting in improved physical properties.

3. Grounds for Unpatentability

Ground 1: Claims 1-6 are obvious over Nakayasu in view of Fritsch

• Prior Art Relied Upon: Nakayasu (Patent 5,558,144) and Fritsch (Application # 2003/0159768).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Nakayasu taught the foundational elements of claim 1, including a hybrid tire cord comprising a nylon primarily twisted yarn and an aramid primarily twisted yarn that are secondarily twisted together. Nakayasu also disclosed an embodiment where the aramid yarn has a 0.9% lower twist number than the nylon yarn, falling within the claimed range of 0.1% to 5% (limitation 1[e]). Petitioner asserted that Fritsch taught creating an "unbalanced configuration" in a cord by modulating tension during twisting, causing one yarn to be longer than the other to improve physical properties. Fritsch disclosed a 0.9% length differential ("Coring level"), which corresponds to the aramid yarn being 1.009 times the length of the nylon yarn and thus meets the claimed range of 1.005 to 1.025 (limitation 1[d]). The "merge structure" of limitation 1[f] was argued to be an inherent result of combining these known physical parameters. Dependent claims 2 and 3 were also alleged to be disclosed by the combination.
  • Motivation to Combine: A POSITA would combine Fritsch’s teaching of creating differential yarn lengths with Nakayasu’s known nylon-aramid hybrid cord. The motivation was explicit in Fritsch, which taught that this technique improved desirable physical properties, such as tensile strength retention, for cords useful as tire reinforcements. Fritsch itself contemplated the use of aramid and nylon yarns for its invention.
  • Expectation of Success: Petitioner asserted a high expectation of success because combining the references involved applying a known optimization technique (Fritsch's tension modulation) to a known product (Nakayasu's hybrid cord) to achieve a predictable improvement in performance.

Ground 2: Claims 4-6 are obvious over Nakayasu and Fritsch in further view of Tamura, Chung, Yokokura, Shepherd, and Rowan

• Prior Art Relied Upon: Nakayasu (Patent 5,558,144), Fritsch (Application # 2003/0159768), Tamura (Japanese Patent No. 2009-68549), Chung (Korean Patent Disclosure No. 10-2006-0126101), Yokokura (Application # 2010/071826), Shepherd (Patent 4,155,394), and Rowan (Application # 2005/0249949).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds on the assertion that the base cord structure of claim 1 is obvious over Nakayasu and Fritsch. Petitioner argued the additional functional limitations recited in dependent claims 4-6 are simply well-known, desirable performance characteristics that were already disclosed in the art for similar hybrid cords. The secondary references were cited to demonstrate that the claimed ranges for:
    • Strength at break and elongation (claim 4[a]) were taught by Tamura and Chung.
    • Strength maintenance percentage after disk fatigue of 90% or higher (claim 4[b]) was taught by Yokokura and Tamura.
    • Load at specified elongation (LASE) values (claim 5) were taught by Shepherd, Nakayasu, Tamura, and Fritsch.
    • Shrinkage of 1.5% to 2.5% (claim 6) was taught by Tamura, Chung, and Rowan.
  • Motivation to Combine: A POSITA, starting with the obvious base cord from Nakayasu and Fritsch, would have been motivated to optimize its manufacturing parameters to achieve the desirable performance metrics widely taught by the secondary references. These metrics represented known industry targets for producing durable, high-performance tire cords.
  • Expectation of Success: Petitioner argued success was highly predictable, as achieving these specific performance values was a matter of routine experimentation and optimization, not invention. The applicant’s own prosecution history, where it produced cords with the claimed properties using prior art methods, was cited as evidence of this.

4. Key Claim Construction Positions

• Petitioner argued that while no express constructions were required to find the claims unpatentable, it noted the importance of the term “merge structure having a partial covering structure” (claim 1[f]).
• For the purposes of the IPR, Petitioner adopted the Patent Owner's proposed construction from parallel litigation.
• Critically, Petitioner contended that the applicant, during prosecution, defined this structure not as an independent feature but as the direct and inherent result of achieving the claimed differences in yarn length and twist number.

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under Fintiv, asserting that the parallel district court trial date is scheduled for February 2026, months after the statutory deadline for a Final Written Decision.
• It was also argued that the district court case remains in its early stages, with minimal investment and no substantive orders issued, thus minimizing concerns of duplicative effort or inefficient use of resources.
• Petitioner further contended that the petition presents compelling merits based on key prior art (Nakayasu and Fritsch) that was never considered by the USPTO during the original prosecution, weighing against discretionary denial under 35 U.S.C. §325(d).

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-6 of Patent 10,196,765 as unpatentable.