DCT
1:25-cv-02135
Shoei Chemical Inc v. Nanoco Tech Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shoei Chemical Inc. (Japan) and Shoei Electronic Materials, Inc. (Delaware)
- Defendant: Nanoco Technologies Ltd. (United Kingdom)
- Plaintiff’s Counsel: Latham & Watkins LLP
- Case Identification: 1:25-cv-02135, E.D. Va., 11/21/2025
- Venue Allegations: Venue is asserted under 35 U.S.C. § 293, which provides for jurisdiction over a foreign patentee in the U.S. District Court for the Eastern District of Virginia if the patentee has not designated an agent for service of process within the United States.
- Core Dispute: Plaintiffs seek a declaratory judgment that their quantum dot products and manufacturing methods do not infringe four patents owned by Defendant related to nanoparticle synthesis using molecular cluster compounds.
- Technical Context: The technology concerns quantum dots (QDs), which are semiconductor nanocrystals whose electronic and optical properties are size-dependent, making them significant for advanced electronic displays and other applications.
- Key Procedural History: This action follows a prior lawsuit filed by Nanoco against Shoei's customer, LG Electronics, in the Eastern District of Texas. In that now-settled case, Nanoco alleged that LG products containing Shoei's QDs infringed the same four patents. Nanoco’s infringement contentions in the prior case reportedly formed the basis for its infringement claims, creating the "actual controversy" that Shoei asserts is necessary for this declaratory judgment action.
Case Timeline
| Date | Event |
|---|---|
| 2004-04-30 | Earliest Priority Date for ’828, ’423, and ’365 Patents |
| 2005-08-12 | Earliest Priority Date for ’557 Patent |
| 2009-09-15 | U.S. Patent No. 7,588,828 Issued |
| 2010-09-28 | U.S. Patent No. 7,803,423 Issued |
| 2011-01-11 | U.S. Patent No. 7,867,557 Issued |
| 2013-09-03 | U.S. Patent No. 8,524,365 Issued |
| 2025-04-24 | Nanoco files complaint against LG Electronics in E.D. Tex. |
| 2025-08-29 | LG moves to transfer the E.D. Tex. case |
| 2025-09-16 | Nanoco serves Preliminary Infringement Contentions in LG case |
| 2025-10-02 | Nanoco serves discovery requests targeting Shoei in LG case |
| 2025-11-21 | Nanoco v. LG case voluntarily dismissed |
| 2025-11-21 | Shoei files this Complaint for Declaratory Judgment |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,588,828 - "PREPARATION OF NANOPARTICLE MATERIALS", Issued Sep. 15, 2009
The Invention Explained
- Problem Addressed: The patent’s background section notes that conventional methods for producing semiconductor nanoparticles (quantum dots) can result in surface defects and "dangling bonds," which lead to low quantum efficiencies and particle agglomeration (’828 Patent, col. 1:56-65, col. 2:3-7). Synthesizing uniform populations of high-quality nanoparticles has proven difficult to control and scale.
- The Patented Solution: The invention proposes a method where nanoparticle growth is initiated from a pre-defined "molecular cluster compound" that acts as a template or seed (’828 Patent, col. 3:23-28). By using these well-defined molecular clusters as nucleation sites, the invention claims to bypass the uncontrolled, high-temperature nucleation step common in other methods, thereby enabling the growth of a more uniform, or "monodisperse," population of nanoparticles (’828 Patent, col. 3:39-42, Fig. 3).
- Technical Importance: This templated growth approach suggests a pathway to more scalable production of higher-quality quantum dots with more uniform size distribution, a critical factor for achieving precise color characteristics in display applications.
Key Claims at a Glance
- Independent Claim 1 (Product Claim): A nanoparticle comprising:
- a molecular cluster compound incorporating ions from groups 12 and 16 of the periodic table, and
- a core semiconductor material provided on said molecular cluster compound, wherein the core semiconductor material incorporates ions from groups 13 and 15 of the periodic table.
- Independent Claim 14 (Method Claim): A method of producing nanoparticles, comprising:
- providing a nanoparticle precursor composition comprising group 13 ions and group 15 ions; and
- effecting conversion of the precursor into nanoparticles in the presence of a molecular cluster compound incorporating group 12 and 16 ions under conditions permitting seeding and growth.
- The complaint notes that Nanoco also identified claims 3-5 and 8-14 as infringed in the prior litigation (Compl. ¶25).
U.S. Patent No. 7,803,423 - "PREPARATION OF NANOPARTICLE MATERIALS", Issued Sep. 28, 2010
The Invention Explained
- Problem Addressed: The patent addresses the same fundamental challenges in nanoparticle synthesis as the ’828 Patent: achieving uniform particle shape, size distribution, and high quantum efficiencies in a scalable manner (’423 Patent, col. 2:59-61).
- The Patented Solution: The patent claims a method of producing nanoparticles by converting a precursor composition into nanoparticle material "in the presence of a molecular cluster compound" that is different from the precursor species (’423 Patent, col. 4:43-47). The method relies on the molecular cluster to act as a seed for controlled growth. Claim 25 further specifies a two-stage temperature process, where precursors and the cluster are first dissolved at a lower temperature before being heated to a higher temperature sufficient to initiate growth (’423 Patent, Claim 25).
- Technical Importance: The method provides a procedural framework, including specific temperature controls, for implementing the templated growth concept to achieve monodisperse nanoparticle populations.
Key Claims at a Glance
- Independent Claim 1 (Method Claim): A method of producing nanoparticles comprising:
- effecting conversion of a nanoparticle precursor composition to a material of the nanoparticles, said precursor comprising a first precursor species and a separate second precursor species;
- wherein said conversion is effected in the presence of a molecular cluster compound different from the precursor species under conditions permitting seeding and growth.
- Independent Claim 25 (Method Claim): A method as in Claim 1, further comprising the steps of:
- dissolving the molecular cluster compound and precursor composition in a solvent at a first temperature; and
- increasing the temperature to a second temperature sufficient to initiate seeding and growth.
- The complaint notes that Nanoco also identified claims 4, 6-8, 12, 14-16, 22, and 24 as infringed in the prior litigation (Compl. ¶35).
U.S. Patent No. 7,867,557 - "NANOPARTICLES", Issued Jan. 11, 2011
- Technology Synopsis: The patent describes a method for producing multi-layer nanoparticles with a core-shell-shell structure. The process begins by converting a core precursor composition to form a nanoparticle core in the presence of a "molecular cluster compound," followed by the sequential deposition of two distinct semiconductor shell layers (’557 Patent, Abstract; Claim 1).
- Asserted Claims: Independent Claim 1 (Compl. ¶47).
- Accused Features: Shoei’s methods for manufacturing nanoparticles are alleged by Nanoco to practice the claimed multi-layer synthesis method (Compl. ¶48).
U.S. Patent No. 8,524,365 - "PREPARATION OF NANOPARTICLE MATERIALS", Issued Sep. 3, 2013
- Technology Synopsis: The patent claims a nanoparticle product comprising a "molecular cluster compound" and a "core semiconductor material disposed on the molecular cluster compound." A key limitation is that the core semiconductor material must comprise one or more elements that are not present in the molecular cluster compound (’365 Patent, Abstract; Claim 1).
- Asserted Claims: Independent Claim 1 (Compl. ¶56).
- Accused Features: Shoei’s quantum dot products are alleged by Nanoco to be the nanoparticle structure claimed by the patent (Compl. ¶57).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are Shoei's quantum dots ("Accused Products") and its proprietary processes for manufacturing them ("Accused Methods") (Compl. ¶16).
Functionality and Market Context
- Shoei's QDs are described as nanoscale electronic materials that are sold to customers, such as LG Electronics, for incorporation into consumer electronic products including TVs, monitors, laptops, tablets, and mobile phones (Compl. ¶¶5, 15-16). The complaint identifies Shoei as a "world-leading supplier" of these materials, suggesting a significant market position (Compl. ¶5).
No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint does not provide a claim chart or sufficient detail to reconstruct Nanoco's specific infringement theory from the prior litigation. Instead, it presents a singular, overarching argument for non-infringement that applies to all four patents-in-suit. This argument is summarized below for the lead patents.
’828 Patent Infringement Allegations
| Claim Element (from Independent Claims 1 and 14) | Stated Basis for Non-Infringement | Complaint Citation | Patent Citation |
|---|---|---|---|
| a molecular cluster compound | Plaintiff asserts that its Accused Products and Accused Methods do not have or use "a molecular cluster compound" as recited in the claims. | ¶29 | col. 3:23-28 |
’423 Patent Infringement Allegations
| Claim Element (from Independent Claims 1 and 25) | Stated Basis for Non-Infringement | Complaint Citation | Patent Citation |
|---|---|---|---|
| a molecular cluster compound | Plaintiff asserts that its Accused Methods do not use "a molecular cluster compound" as recited in the claims. | ¶39 | col. 4:43-47 |
Identified Points of Contention
- Scope Questions: A central legal issue will be the definition of "molecular cluster compound." The patents define this term as relating to "clusters of three or more metal atoms and their associated ligands of sufficiently well-defined chemical structure" (’828 Patent, col. 3:32-36). The dispute may turn on whether this term requires a discrete, stable chemical entity used as a synthesis template, or if it can be construed more broadly to cover other types of precursor arrangements or reaction intermediates that may be present in Shoei’s accused methods.
- Technical Questions: A key factual question will be one of chemical mechanism. Does Shoei’s synthesis process for its QDs proceed via a mechanism that involves a "molecular cluster compound" acting as a template for nanoparticle growth, as required by the claims? Or does Shoei’s synthesis proceed via a different mechanism, such as direct nucleation from precursors, that would fall outside the patent claims? The answer will depend on evidence regarding the specific materials and processes that constitute the Accused Methods.
V. Key Claim Terms for Construction
- The Term: "molecular cluster compound"
- Context and Importance: This term appears in every asserted independent claim across all four patents-in-suit and is the sole basis for non-infringement articulated in the complaint (Compl. ¶¶29, 39, 48, 57). The construction of this term is therefore central to the entire dispute. Practitioners may focus on this term because its definition will determine whether Shoei's synthesis technology, which it presumably argues does not use such a compound, falls within the scope of Nanoco's patents.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party seeking a broader definition might point to the general definition in the specification, which describes "clusters of three or more metal atoms and their associated ligands of sufficiently well-defined chemical structure such that all molecules of the cluster compound possess approximately the same relative molecular formula" (’828 Patent, col. 3:32-38). An argument could be made that this language does not strictly require a pre-fabricated, isolated compound but could encompass certain precursor agglomerations formed in situ.
- Evidence for a Narrower Interpretation: A party seeking a narrower definition could argue that the patents consistently distinguish these "well-defined" compounds from the less-defined "nucleation sites employed in other methods" (’828 Patent, col. 3:40-42). This suggests the term requires a specific, identifiable chemical entity that serves as a "template to direct nanoparticle growth" (’828 Patent, col. 3:27-28), as exemplified by the specific chemical structures shown in the patent figures and examples (e.g., [HNEt3]4[Zn10S4(SPh)16]) (’828 Patent, Fig. 4E, col. 10:18-20).
VI. Other Allegations
The complaint is for a declaratory judgment of non-infringement and does not contain affirmative allegations of indirect or willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
The resolution of this declaratory judgment action will likely depend on the court's answers to two fundamental questions:
- A core issue will be one of definitional scope: can the term "molecular cluster compound," which the patents describe as a well-defined template for nanoparticle growth, be construed to cover the starting materials or reaction intermediates used in Shoei’s synthesis methods? The outcome of claim construction for this dispositive term will likely determine the case.
- A key evidentiary question will be one of chemical mechanism: what is the actual process by which Shoei’s nanoparticles are synthesized? The court will need to examine factual evidence regarding Shoei’s proprietary methods to determine if they utilize a chemical entity that functions as the "molecular cluster compound" required by the asserted claims, or if they operate via a distinct, non-infringing pathway.