Courtaulds has obtained a Summary Judgement in the US courts over its alleged breach of Lenzing's US patent in respect of the one process step in the manufacture of lyocell fibre, which also sells under the Courtaulds brand name of Tencel.
The Judge held Lenzing's patent to be invalid and that Courtaulds should be awarded costs.
Lenzing said the Judge rejected its patent for failure to disclose the best mode of the invention. The best mode requirement is unique to the US-patent law. Lenzing intends to appeal against the US decision.
This decision is unrelated to the pending litigation before the European Patent Office in Munich and the UK. In May 1994, Akzo and Caurtaulds' opposition against the European Patent was rejected by the European Patent Office, against which both Courtaulds and Akzo have appealed.