Sudarshan Chemical Industries Ltd v Clariant Produkte (Deutschland) GmbH

In patent amendment cases, added matter is assessed by asking whether the skilled person would learn anything about the invention from the amended specification that was not disclosed, expressly or implicitly, in the application as filed. Excluding part of a disclosed invention is permissible where it adds no new technical teaching. A disclaimer cannot restore novelty against directly relevant prior art by introducing a new teaching about the invention. Claims may also fail for obviousness where the proposed use or process is a routine implementation of prior art, even if the precise combination of routine variables was not previously made. For groundless-threats purposes, a threat communicated to a manufacturer may also threaten its customers. A corporate patentee’s relevant knowledge may include the properly informed patent attorney and inventor, not merely the employee who sent the letter.

Clariant appealed from the Patents Court decision of John Baldwin QC, sitting as a Deputy High Court Judge, which invalidated claims 6 to 8 of its patent for a beta form of Pigment Yellow 191, refused proposed amended claims and a disclaimer, and found the threats claim established. Sudarshan had challenged the patent on the basis that the claimed pigment and uses were anticipated or obvious over the earlier process patent, including its wet-cake intermediate, and had sought relief for threats to itself and its customers.

On appeal, Clariant accepted that several claims failed in light of the wet cake, but challenged the findings on obviousness, added matter, the disclaimer, threats to customers and the statutory knowledge defence. The central issues were whether the proposed uses were obvious, whether the amendments added subject matter, whether the disclaimer was clear and permissible, and how sections 70(1), 70(2A)(b) and 70(4) of the Patents Act 1977 operated.

Appeal dismissed. Kitchin LJ gave the judgment of the court; Floyd LJ and Moore-Bick LJ agreed.

1. The judge was entitled to find, on the expert and factual evidence, that using Pigment Yellow 191 wet cake to pigment polymers was obvious. The absence of previous sales did not establish non-obviousness. It might be powerful evidence in an appropriate case, but its significance depended on the circumstances, and no adequate technical explanation for the absence of sales had been given.
2. It was also obvious to take wet cake, dry-grind it and then water-treat it. The evidence described this as standard process development. Since water treatment converted the pigment into the beta form, proposed claim 13 was obvious.
3. The judge erred in holding that proposed claims 12 and 13 added matter. Following Nokia OKJ (Nokia Corporation) v IPCom GMBH [2012] EWCA Civ 567, the question under s.76 of the Patents Act 1977 was whether the skilled person would learn anything about the invention from the amended specification that could not be learned from the application as filed. Subject matter was added unless clearly and unambiguously disclosed, explicitly or implicitly. A limitation which merely excluded disclosed subject matter, without adding a new teaching, was permissible. The claims nevertheless remained unallowable because they were obvious.
4. The disclaimer was rightly refused. The requirement of clarity under s.14(5)(b) was fundamental. Relative terms were permissible only where their meaning was clear to the skilled addressee. Here, drying conditions materially affected the polymorphic composition, so the expression describing material which had not been dried gave the monopoly an ambiguous scope. The disclaimer also added technical disclosure by teaching that the wet cake contained the supposedly new beta polymorph and that wet and dry forms differed. The prior art was directly relevant, not accidental. The principles in LG Philips LCD Co Ltd v Tatung (UK) Ltd and others [2006] EWCA Civ 1774 and Napp Pharmaceutical Holdings Ltd v Ratiopharm GmbH [2009] EWCA Civ 252 were applied.
5. The Gillette defence substantially succeeded. Combining the earlier process patent with a commercial sample was permissible where both were prior art and it was obvious to make that combination. The old and new processes were routine and obvious implementations involving ordinary optimisation of process variables. The court left open the particular issue concerning the Colormatrix sample because it was unnecessary to decide it.
6. Under s.70(1) of the Patents Act 1977, a threat need not be communicated directly to the person against whom proceedings would be brought. Following Skinner & Co v Perry (1893) 10 RPC 1 and the subsequent authorities, s.70(4) did not alter that established meaning. Section 70(2A)(b) did not protect Clariant: applying Meridian Global Funds Management Asia Ltd v Securities Commission [1995] 2 AC 500, the relevant corporate knowledge included that of the properly informed patent attorney and the inventor. The order below was upheld.

• Court of Appeal (Civil Division): [2013] EWCA Civ 919 — appeal dismissed.
• Patents Court, High Court: John Baldwin QC, sitting as a Deputy High Court Judge, invalidated claims 6 to 8, refused the proposed amendments and disclaimer, and found the threats claim established: [2012] EWHC 1569 (Ch).