NORFOLK (LN) — A federal judge in Virginia dismissed a patent declaratory judgment suit by Kuraray America Inc. against Sekisui Chemical Co. Ltd., ruling that the Japanese company’s foreign enforcement actions and a warning letter did not create a live controversy in the United States.
U.S. District Judge Jamar K. Walker granted Sekisui’s motion to dismiss under Federal Rule of Civil Procedure 12(b)(1) on May 12, finding that Kuraray America failed to demonstrate a "substantial controversy of sufficient immediacy and reality" to warrant federal jurisdiction.
The dispute centers on Sekisui’s patents related to interlayer films, specifically Patent Family A and Patent Family B. Sekisui sent a warning letter to Kuraray Co. on July 30, 2024, stating that Kuraray’s products, including Trosifol® The Wedge Acoustic, fell within the technical scope of its patents and that it would "be forced to consider legal action" if demands were not met.
Kuraray America, a U.S. subsidiary, filed suit in September 2025 seeking a declaration that six U.S. patents were invalid. The company argued that Sekisui’s lack of a commitment to forego U.S. enforcement left it operating under the "fear of litigation."
However, Judge Walker noted that within two months of the warning letter, Sekisui had already filed patent infringement actions in Korea and Germany. Since those September 2024 filings, Sekisui had not brought any additional related enforcement actions in the United States.
"The complaint does not allege any affirmative actions by Sekisui against any Kuraray entity—let alone Kuraray America specifically—since September 2024," Walker wrote. "Kuraray America's conclusive assertion that Sekisui's actions in Germany and Korea 'make[ ] the United States the next step' is devoid of support."
The court compared the situation to Allied Mineral Prods., Inc. v. Osmi, Inc., where the Federal Circuit found no actual controversy because the defendant had limited its actions to Mexico and directed no actions toward the plaintiff in the U.S.
Walker pointed out that Sekisui holds 20 patents in 16 jurisdictions stemming from one international publication but chose to enforce only three patents in two jurisdictions. "Given Sekisui's limited enforcement effort almost two years ago, the reference to ‘various countries under WO2007/132777’ is not alone enough to establish immediacy or reality," the judge wrote.
The court also rejected Kuraray’s argument that Sekisui’s failure to provide a "covenant not to sue" impacted the jurisdictional analysis, noting that Kuraray had not alleged it had asked for such an assurance.
Even if jurisdiction existed, Walker said he would have exercised his discretion to decline the case. He found the complaint devoid of allegations that Kuraray America faced a real choice between "either abandoning its [ ] products or running the risk of being sued for infringement."
The case is closed.