Anan Kasei v Neo Chemicals: why a patent win didn’t pay out for overseas sales
Anan KaseivNeo Chemicals & Oxides
- Court
- Court of Appeal
- Judgment
- 17 January 2023
- Citation
- [2023] EWCA Civ 11
Proving UK infringement doesn't automatically get you paid for the sales it later led to abroad.
Anan Kasei (linked to Rhodia) had already proved Neo Chemicals infringed its UK patent, but the Court of Appeal refused damages for the huge overseas sales that followed. Neo Chemicals won on this point.
What happened
Anan Kasei, linked to Rhodia, held a UK patent for a form of cerium oxide used in catalytic converters. Neo Chemicals had already been found to infringe that patent by supplying samples and early product in the UK to a customer, JM. Those UK supplies led JM to approve Neo's product, after which JM went on to buy large quantities of the same product for use outside the UK, where Rhodia's patent gave no protection. Rhodia claimed damages running into tens of millions of euros for those overseas sales, arguing the UK infringement had set the whole chain of events in motion.
What did the court decide in Anan Kasei v Neo Chemicals & Oxides?
The Court of Appeal agreed that patent damages aren't blocked just because the sales happened outside the UK, in principle a patentee can claim for losses caused by UK infringement wherever those losses land. But the UK infringing supplies had to be a proximate cause of the overseas sales, not just a "but for" trigger. The trial judge had found several intervening steps, including the car maker's own approval process and the fact that both Rhodia and Neo ended up qualified as suppliers, broke that chain. The court upheld that finding and dismissed Rhodia's appeal. It also rejected a late attempt by Neo to challenge Rhodia's standing to claim as exclusive licensee.
What we learned from this
- What I'd take from this is that winning the infringement argument is only half the job. If you want damages for sales that happened later or elsewhere, you need to show the infringement actually drove those sales, not just that it happened first in the sequence.
- Keep clear evidence of how a customer's buying decision was made. If approval processes, dual sourcing or later renegotiated orders sit between the infringement and the sale, that can break the causal link.
- Overseas sales aren't automatically out of reach for a UK patent claim, but the legal test for causation is stricter than simple cause and effect.
Things to be aware of
- This was a fact heavy causation finding reviewed only for error of principle, so it doesn't set a blanket rule against recovering damages for overseas sales in every case.
- The court was clear there's no territorial bar to patent damages in principle, the result here turned on the specific evidence about how the customer made its purchasing decisions.
The businesses involved
Anan Kasei Co Limited
Claimant patentee linked to Rhodia, holder of the UK patent for high surface area cerium oxide used in catalytic converter manufacture.
Neo Chemicals & Oxides (Europe) Limited
Registered in England and Wales since June 1994, based in London, still active. Holds no trademarks on the UK trademark register. Found to have infringed the claimant's UK patent by supplying cerium oxide samples and product to a customer in the UK.
- Companies House
- 02944664 Active
- Incorporated
- June 1994
- Registered office
- London
- Business activity
- Activities of production holding companies
- UK trademarks
- 0
What happened next
- The case followed a 2022 High Court inquiry into damages, held after the earlier finding that Neo had infringed Rhodia's patent for high surface area cerium oxide.Source: 11Southsquare
What others said about it
- Wolters Kluwer's patent blog noted that damages inquiries in patent cases rarely reach the Court of Appeal, making this judgment important guidance for how causation is assessed.Source: Wolters Kluwer, March 2023
How we can help
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This page is for information purposes only and does not constitute trademark advice or guidance. Summary drafted with AI assistance from the published judgment and checked by The Trademark Helpline (how we write these). Judgment: [2023] EWCA Civ 11 on Find Case Law, published under the Open Justice Licence. Company details from Companies House; trademark counts from the UK trademark register. Last reviewed 26 October 2026. Report an error.
