Fosroc International Ltd v WR Grace & Co - Conn

For added matter, the court compares the disclosure of the application as filed with that of the amended patent and asks whether subject matter relevant to the invention has been added. An amendment may select a combination already disclosed by the claims and specification; it does not add matter merely because the amended claim gives that combination greater prominence or because an alleged synergistic effect is relied upon. Obviousness is assessed by identifying the skilled person, common general knowledge, inventive concept, differences from the prior art and whether those differences required invention. Research which the skilled person might conduct, without motivation or expectation of success, does not ordinarily establish obviousness. Secondary indicia, including an unexpected result and the failure of the art to discover the invention, remain relevant but must be kept in their proper place.

Fosroc sought revocation of European Patent (UK) No 0 415 799, owned by Grace. Grace applied unconditionally to amend the claims. The proposed amendment deleted the broad original claims and limited the patent to a hydraulic Portland cement composition containing TIPA and a set accelerator comprising TEA.

Fosroc objected that the amendment added matter, contrary to section 76 of the Patents Act 1977 and Article 123(2) of the European Patent Convention. It also alleged lack of inventive step and insufficiency. The principal issue was whether the amended combination had been disclosed in the application as filed and, if so, whether the combination was obvious in light of the cited prior art and common general knowledge.

1. Added matter. The applicable comparison was between the disclosure of the patent as filed and the amended patent, applying the approach in Bonzel v Intervention [1991] RPC 553. The claims formed part of the disclosure, although their full scope did not necessarily disclose every matter falling within them. The skilled reader could identify TIPA and TEA as the claimed combination from the claim structure and Example 5. Selecting that combination did not require hindsight or introduce a new feature. The amendment was therefore allowable under section 76 of the Patents Act 1977 and Article 123(2) EPC.
2. The amendment did not add a synergistic effect for the first time. Any disclosure concerning synergy remained the same after amendment.
3. Construction and skilled person. The term “hydraulic Portland cement composition” included a composition in which the additive was introduced into wet concrete. The patent was addressed to technical staff in a cement plant, concrete manufacturer or additive manufacturer who had an interest in, and capacity to test, proposals to improve concrete strength.
4. Inventive step. Applying the structured approach in Pozzoli v BDMO SA [2007] EWCA Civ 588, none of Dewey 1, Dewey 2, Müller or Ray made the amended claim obvious. Dewey did not motivate the skilled person to investigate TIPA when TEA appeared to be the best compound. Müller produced ambiguous and conflicting results under unrepresentative conditions. Ray’s TIPA data was incidental and inadequate. The proposed research was exploratory, lacked a credible expectation of success and depended on hindsight. The long failure of the art to uncover the combination was a material secondary indication.
5. The data in Example 5 established, on the balance of probabilities, that TEA increased 28-day strength in combination with TIPA although it did not do so alone. That finding was principally a secondary indication of non-obviousness.
6. Claim 1 as amended was valid. The subsidiary claims and insufficiency objections did not require determination. The amendment was allowed, subject to an indication in the specification that only Example 5 represented the invention as now claimed.

First-instance decision of the High Court (Patents Court). No prior or subsequent appellate decision is stated in the judgment.