The UK Intellectual Property Office (UKIPO) can issue non-binding opinions on whether a patent is valid and/or infringed. The procedure allows an opponent to test validity or infringement issues without initiating full inter partes proceedings, but doesn't entirely avoid the risk of costs being awarded. This service has been available since 2005. There were 31 such requests in 2016, of which 21 were requests for opinions on validity, 9 on infringement and 1 on validity and infringement. Numbers for 2017 to date are similar.

Anyone can ask for such an opinion, but the patentee can request a review of the opinion.

In Decision O/318/17, our Reuben Jacob successfully petitioned for review of one such opinion, and a modest costs award was made.

The UK IPO Hearing Officer reviewed Opinion 23/16 and concluded that the Examiner had made an error of principle and had been wrong to conclude that UK patent GB 2478028B was invalid. We represented Linpac Packaging Limited ("Linpac"), the patent proprietor.

The patent concerned containers suitable for use in packaging, storage, transportation and/or display of a product, such as fresh food or a medical product. A process for making a container was also claimed. Ingenium IP Limited had requested an opinion on validity in light of nine patent documents which included document D2 (listed on the search report for the PCT application, but not considered in detail) and document D9 (not previously considered).

The invention provided a solution to the difficulty of attaching an effective sealing film to a container made from polyethylene terephthalate (PET), without the need for complex sheet structures (expensive and difficult to recycle) and minimising the risk of food contamination. This was achieved by providing a layer of adhesive only to the upper surface of the flange of a PET tray in order to seal a multi-layer film comprising a polypropylene (PP) and/or PE seal layer. The figure below shows a cross-sectional view of a typical container according to the invention:



The one independent claim (claim 1) of the patent was the only claim discussed during the hearing (reproduced below, with the hearing officer's emphasis):
  1. A container comprising a base and a continuous side wall extending substantially perpendicular to the base with a peripheral flange formed along the upper,inuse,edge of the continuous side wall, wherein the base and the continuous side wall consist essentially of polyethylene terephthalate (PET) wherein a layer of adhesive is located on an upper,inuse,surface of the peripheral flange and said layer of adhesive does not extend onto the vertical, in use, surfaces of the continuous side wall and does not extend onto the base wherein the container further comprises a lidding film which may be sealed to the peripheral flange to create a sealed space between the base, continuous side wall and lidding film; and wherein the lidding filmis a multi-layer film comprising a seal layer and the seal layer comprises polypropylene (PP) and/or PE.

The pertinent issues before the Hearing Officer related to:

  • the construction of "substantially perpendicular" and "vertical" in the examiner's opinion; and
  • whether D9 (US4538651A) clearly disclosed a sealing layer comprised of PP and/or PE.

An additional issue was raised, namely whether the examiner had been correct to disregard a machine translation (into English) of D2, but this was found to be irrelevant as an Australian equivalent of the D2 patent was available and had been considered.

The construction of "substantially perpendicular" and "vertical"

The Examiner had applied the 'Windsurfing' test for inventive step, construed claim 1 of Linpac's patent and concluded that the terms "substantially perpendicular to the base" and "vertical, in use, surfaces" simply meant surfaces which extended away from the base to create a space. However, the Hearing Officer found that the Examiner had erred in his construction of these particular terms. As the Hearing Officer noted, "perpendicular to the base" would mean an angle of 90° between the side wall and the base, and "substantially" introduced a range either side of 90°. The Examiner's construction would encompass an extremely broad range of angles (such as 30° or 45°), which would include embodiments with side walls that could not be described as 'vertical' or 'substantially vertical' on any reasonable interpretation.

Based (at least in part) on his construction, the Examiner had concluded that D2 demonstrated a lack of inventive step in the patent. Noting that the side walls of the container shown in figure 1 of D2 (below) appeared to be 30° to the vertical, the Hearing Officer had significant doubt as to whether the Examiner would have formed the same opinion in relation to D2 had he not erred in his construction of the patent claim.

The sealing layer disclosed in D9

The Examiner's opinion concluded that claims 1, 15 and 21 of Linpac's patent lacked novelty having regard to D9 (US4538651A). The toner cartridge disclosed in D9 undoubtedly included most of the features required by claim 1 of Linpac's patent, but there was some disagreement concerning strip 11 (the middle item in the below figure). Strip 11 was composed of two layers: (i) a layer of randomly oriented, bonded polyethylene fibres, and (ii) a low surface energy layer consisting of nylon or PET. In use, the second layer would face the contents of the container. As stated in the opinion of the Examiner, it was not entirely clear whether the second layer extended over the whole of the (lower) surface of strip 11, and in particular whether it extended over the boundary area (19) where the strip would be adhered to the base (10). The Examiner concluded that the boundary area (19) was not covered by the nylon (or PET) layer - because it was said to be "of low surface energy". According, he found that the boundary or seal layer would comprise PE, by virtue of the polyethylene fibres of the upper layer.

We submitted to the Hearing Officer that the low surface energy layer had to extend across the whole surface of the strip. Ingenium disagreed. The Hearing Officer found our argument more compelling; however, he decided that the significant ambiguity surrounding features claimed in document D9 made it impossible to say for certain whether or not the PE layer described in D9 functioned as a sealing layer. In the absence of a clear indication in the disclosure, it was not apparent how the Examiner had formed his opinion on the issue.

In view of the decision he had reached on the construction of "substantially perpendicular" and "vertical", and the significant ambiguity of features disclosed in D9, the Hearing Officer concluded that the Examiner had made an error of principle, and had reached a conclusion that was clearly wrong. He ordered that Opinion 36/16 should be set aside in whole, thereby terminating the proceedings under section 73(1A) to revoke the patent, and he awarded Linpac a contribution of £750 towards their costs.

Originally published October 17, 2017

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