Patent litigation in chemistry
In chemistry, the difficulty of a dispute often lies in the evidence. Showing that a product falls within a claimed formula, that a patented process has been used or that a composition meets a claimed parameter requires rigorous analysis and an evidence strategy designed from the outset.
Issues specific to the sector
Selection inventions, Markush-type general formulae, measured parameters and crystalline forms raise novelty and inventive step questions specific to chemistry. The measurement method set out in the patent, or the lack of one, often decides the outcome.
Where the patent covers a process for obtaining a product, the burden of proof may be reversed, in particular if the product is new (Article L. 615-5-1 of the French Intellectual Property Code, Article 55 of the Agreement on a Unified Patent Court).
Saisie-contrefaçon allows samples to be taken. The confidentiality of industrial processes must then be protected throughout the proceedings.
How we act
- Infringement actions concerning products, compositions and processes, for claimants and defendants.
- Nullity actions, coordinated where appropriate with oppositions conducted before the EPO by patent attorneys.
- Building the evidence: seizures, analyses, expert reports and protection of trade secrets.
- Disputes over licences and know-how.
Is a process or composition at issue? Let us discuss it.
Selected matters
Green chemistry: formulation litigation
Acting for a green chemistry company in patent litigation concerning chemical formulations. Analysis of the technical file and preparation of the litigation strategy and pleadings.
Chemistry: infringement and preservation of evidence
Assisting a chemicals company in patent litigation concerning chemical compositions. Preparation of the pleadings on the merits and of the proceedings relating to the saisie-contrefaçon, the safekeeping of documents and challenges to the evidence measures.
Further reading and publications
- Dhenne Avocats succeeds for Salveco, analysis by the firm.
- The saisie-contrefaçon, the French weapon foreign patentees forget, analysis by the firm.
- Droit des brevets (patent law treatise), LexisNexis, 2024.
Frequently asked questions
How can infringement of a chemical process be established?
The marketed product does not always reveal the process used. Testing, manufacturing records and evidence measures should be selected in light of the claimed features.
What role should experimental testing play?
A test should answer a specific question and be reproducible. Its protocol, assumptions and limitations matter alongside the result presented to the court.
Can patents and trade secrets form part of the same process strategy?
The strategy distinguishes what the patent discloses from what remains confidential. The retained confidential information and its protective measures should be documented.