Anan Kasei Co Ltd & Anor v Neo Chemicals And Oxides Ltd & Anor

A patent claim is not insufficient merely because its boundary involves questions of degree. Insufficiency arises where, after applying the available interpretative tools, the skilled person cannot ascertain the criterion for deciding whether subject matter falls within the claim.

A product claim must be enabled across its full width and must not extend to embodiments owing nothing to the patentee’s technical contribution. The challenger bears the burden of establishing that such embodiments exist.

A parent company may be jointly liable for its subsidiary’s torts where its participation goes beyond constitutional control and forms part of a common design. Patent pleading rules allowing exemplary infringements do not relieve a claimant of proving the material facts defining that common design.

The claimants owned a patent for ceric oxide retaining a specified surface area after high-temperature calcination. The High Court held the patent valid and infringed in [2018] EWHC 843 (Pat). The defendants appealed solely on insufficiency, contending that the expression “consisting essentially of” created uncertainty and that the product claim exceeded the patentee’s technical contribution.

Two procedural appeals concerned an application to join the UK defendant’s Canadian parent. The claimants alleged that the parent companies had participated in a common design with the UK company and that the Canadian parent had assumed its predecessor’s liabilities. The lower courts permitted only a limited claim relating to seized goods and refused the proposed claim concerning the earlier parent-company period.

The central issues were the standards for uncertainty and excessive claim breadth, and whether the proposed wider joint-tortfeasance claims disclosed triable issues.

1. The patent appeal was dismissed. The expression “consisting essentially of” meant that no additional ingredient could materially affect the product’s essential characteristics. A claim may have a boundary involving questions of degree without being insufficient. The objection arises where the criterion for deciding whether subject matter falls within the claim cannot be ascertained. Kirin Amgen [2004] UKHL 46 concerned that form of conceptual uncertainty, not ordinary fuzziness at a claim boundary.

2. The statutory inquiry under section 72(1)(c) of the Patents Act 1977 was whether the specification enabled a person skilled in the art to perform the invention. It was not whether a purchaser without process information could determine infringement. The evidence showed that a skilled person could assess whether added ingredients materially affected the product. Any remaining difficulty concerned only the precise edge of the claim.

3. A specification must enable the invention across the full width of the claim. The claim must not encompass embodiments which owe nothing to the patentee’s technical contribution. Nevertheless, the challenger bears the burden of proving that the claim contains such embodiments. Biogen [1997] RPC 1 and Lundbeck [2009] UKHL 1 did not establish that every product class or functionally expressed claim was insufficient. Neo had not proved that any product satisfying the claim could not be made using the patent’s teaching and common general knowledge.

4. Both procedural appeals were allowed. Under MCA Records [2001] EWCA Civ 1441, ordinary constitutional control by a director or parent will rarely establish joint tortfeasance. Liability may arise where participation in the wrongful acts goes beyond such control. The evidence made it arguable that the parent companies exercised executive control over the cross-group business and participated in a wider common design covering the UK subsidiary’s infringements.

5. The documents also made it arguable that the Canadian parent assumed its predecessor’s liabilities under a court-approved arrangement. The claim concerning the earlier parent-company period could therefore proceed.

6. Paragraph 4.1 of the Practice Direction to Part 63 of the Civil Procedure Rules 1998 permits a patentee to plead and prove examples of each type of infringement. It does not dispense with proof of the material facts defining the scope of a common design. Here, however, a wider common design was independently arguable.

Peter Jackson LJ and Lewison LJ agreed with Floyd LJ. Lewison LJ added that the relevant defect is best described as uncertainty rather than ambiguity.

• Court of Appeal: In [2019] EWCA Civ 1646, dismissed the appeal against the finding that the patent was sufficient and allowed both procedural appeals concerning the proposed claims against the Canadian parent.
• High Court, Intellectual Property List: HHJ Hacon, sitting as a Deputy High Court Judge, held on 19 March 2019 that the pleaded joint-tortfeasance claim against the Canadian parent was confined to acts concerning specified seized goods. That decision was reversed.
• High Court, Intellectual Property List: Mr Caddick QC, sitting as a Deputy High Court Judge, held on 18 December 2018 that liability concerning the seized goods was arguable, but refused the proposed claim concerning the predecessor parent’s acts and liabilities. The refusal was reversed.
• High Court, Intellectual Property List: In [2018] EWHC 843 (Pat), Mr Roger Wyand QC, sitting as a Deputy High Court Judge, held the patent valid and infringed. The appeal against rejection of the insufficiency challenge was dismissed.