Lenzing Lyocell fibre patent revoked by EPO (1996)

This is an update: the earlier abstract being replaced by the complete article as it now appears on the web.

The Appeals Board of the European Patent Office (EPO) has ruled that a Europe-wide patent - one of a number of patents applied to the manufacture of lyocell solvent spun cellulosic fibre - which was previously obtained by Lenzing, is invalid. No right of appeal is being given to the judgement.

Litigation to negate the patent was initiated by Courtaulds in September 1994. The patent was revoked on the grounds that the method of manufacture was 'obvious'.

Lenzing said other patents covering advances in lyocell technology are not affected and that the EPO decision will not affect the start of lyocell production facilities in Burgenland, Austria.

The cellulosic fibre is sold by Courtaulds under the trade name Tencel. Courtaulds deputy ceo Gordon Campbell commented: 'We are pleased with the result, which completely vindicates our position. However, we strongly believe that both Courtaulds and Lenzing should now put this issue behind them.'

Lenzing is still awaiting the outcome of its US appeal which will be heard at the end of 1996.

Anon., Eur. Chem. News, vol. 65, no. 1716, 13-19 May 1996, p. 8

This patent litigation was quite a big issue in the 90's and this is the first time it has made an appearance in this blog.  Here's a 1998 summary of the issue:

Lenzing obtained a patent in the USA for a lyocell process, some aspects of which had been operated by Courtaulds for many years, and indeed were used in production at Courtaulds Tencel® plant in Mobile. Courtaulds naturally objected, and applied for summary dismissal of both the US and the subsequent European patent. In Europe, the Munich court would not allow the Lenzing patent to be dismissed summarily and the case went to trial. Courtaulds won, and Lenzing's European patent was disallowed with no right of appeal. 

In the USA, the Lenzing patent was summarily dismissed, but Lenzing appealed successfully, winning the right to another costly trial. At this point the two companies reached a settlement out of court. The lyocell patent estates of both companies were pooled, to be available royalty-free to both companies. It is perhaps worth noting that the settlement only covered patented technology. There was to be no sharing of "know-how" gained in the operation of the process, which at the time, had only been commercialized by Courtaulds.

From "Regenerated Cellulose Fibres"