Quinn Packaging Ltd v Linpac Packaging Ltd & Anor

For inventive step, a skilled person may recognise a useful technical idea within a disclosure even where other aspects are impractical or of no interest. The assessment is fact-sensitive, and a long-felt want may make the skilled person more likely to identify the solution.

A disclosure of adhesive applied as a bead may disclose a layer formed when the bead is compressed during sealing. A claimed numerical range lacks inventive step where it is arbitrary and unsupported by any technical advantage. Amendments under the Patents Act 1977 are impermissible if they extend the protection conferred, assessed by the protection actually provided rather than merely by the literal scope of amended wording.

Quinn sought revocation of two patents concerning plastic food containers with adhesive applied to a peripheral sealing flange. The patents were owned separately by Linpac and Faerch. Quinn alleged that the relevant claims lacked inventive step over Australian Patent No. 638092, referred to as Ono.

The court considered whether Ono disclosed the use of adhesive on a peripheral flange, whether its teaching was limited to autoclave-resistant containers or a particular embodiment, and whether a bead of adhesive could amount to a layer after sealing. It also considered the obviousness of denesting features, multilayer APET containers and specified adhesives, together with Linpac’s application to amend its patent under the Patents Act 1977.

1. The Linpac and Faerch Patents were invalid for lack of inventive step over Ono. Permission to amend the Linpac Patent was refused because the proposed amended claims would still lack inventive step.

2. Ono was not confined to containers capable of withstanding autoclaving, nor to the Figure 1 embodiment. Its claims and description disclosed an alternative process in which adhesive was applied when the cover was sealed. The skilled person would understand the disclosure to include adhesive applied in continuous closed lines on a peripheral flange around the container.

3. The distinction between a bead and a layer did not establish inventiveness. When a bead was compressed by application of the lid, it became a layer of adhesive between the flange and the lid. The amount and material could be selected to provide a sufficient seal, with peelability optional.

4. The disclosure of the flange and adhesive idea was not buried in irrelevant or impractical detail. A skilled person, particularly one aware of the long-felt want for improved sealing and reduced skeletal waste, would recognise it as a solution. Even if other aspects of Ono were unsuitable, those aspects would not necessarily distract from the useful idea.

5. Linpac claim 5 lacked inventive step. Its 20–100 micrometre range was arbitrary and was unsupported by evidence of any technical advantage. The court applied the reasoning on arbitrary parameter ranges in LG Philips LCD Co Ltd v Tatung (UK) Ltd [2006] EWCA Civ 1774; [2007] RPC 21.

6. The denesting features in proposed claim 6 were obvious. Figure 3 of Linpac 2A could disclose information not stated in the text where the figure was not contradicted or amended. Lowering a denesting area below the flange was an obvious way to avoid adhesive being applied to it. Proposed claim 7 consequently also lacked inventive step.

7. Faerch claim 1 lacked inventive step because multilayer APET materials were routine and Ono supplied the missing idea of applying adhesive to a peripheral flange. Claim 7 also lacked inventive step: although commercially satisfactory adhesive recipes might have involved development, the broad claimed combination of an ethylene copolymer or terpolymer with wax did not itself require invention.

8. Under sections 75 and 76(3) of the Patents Act 1977, the proposed amendments were assessed by the protection conferred by the patent. Extending literal claim scope did not necessarily extend protection. The proposed deletion concerning location adjacent to a corner did not do so because the relevant wording was permissive rather than limiting. However, on a literal construction, the amended claims would extend protection to a denesting area covered with adhesive.