Filtering infringement through partial invalidity: Water filtration disputes reach the Athens Court of Appeal
3-Member Athens Court of Appeal (18th chamber), No. 281/2025
The Athens Court of Appeal, under judgment No. 281/2025, upheld a first instance ruling in a patent dispute between two competing water filtration companies. The Court confirmed the partial invalidity of the defendant’s national (GR) patent while misleading advertisement (unfair competition) claims were rejected over time bar.
Key Facts
The appellant (and plaintiff) has been distributing water filters under the distinctive sign “Multipure” in Greece since 1984. The appellees (and defendants), a company and its legal representative, distribute antimicrobial water filters under the distinctive sign “Camelot”. The second defendant (natural person) also owns (the now “clipped’) GR Patent No. 1009305, “Water filtration device for antimicrobial protection using antimicrobial copper or its alloys,” valid until 2037.
The plaintiff’s action challenged the validity of the patent of lack of novelty and inventive step, mainly on the grounds that the antimicrobial properties of copper were well known at the time of filing and the claimed technical features were already part of the “state of the art”.
The plaintiff further alleged misleading advertisement on the part of the defendants over their claim that their products were a “global innovation” and a “patented invention”
Findings on Patent Validity
The Court first affirmed that the GR Patent Office makes no substantive examination of a national patent application and grants a patent, so long as certain formalities are met.
It then went on to examine all four claims (1st claim being the main claims and claims 2 – 4 being dependent claims) of the patent.
According to the Court, Claim 1 teaches two filtration apparatus, (a) a water filtration apparatus of various types and sizes which is made wholly or partly of antimicrobial copper or an antimicrobial copper alloy and consists of a Base (1), a shell (2), a water inlet (3), a water outlet (4), a compact water filtration filter (5) and b) a pre-technique level apparatus (Figure 2); to which a disc made of antimicrobial foil (6) is attached inside the base (1) or a tubular antimicrobial copper component (7) around the perimeter of the filter (5).
The technical advantage would be that antimicrobial copper parts have by nature the ability to neutralize or limit the growth of pathogenic microorganisms in water filtration systems.
Claim 2 of the patent teaches an antimicrobial copper plating of the inner or outer surface of the apparatus of Claim 1.
Claim 3 teaches the fitting of an antimicrobial copper foil or antimicrobial copper alloy disc to the base of the apparatus, whereas Claim 4 describes the construction of the entire apparatus or part thereof from antimicrobial copper or antimicrobial copper alloy or the addition of a tubular sheath of antimicrobial copper or antimicrobial copper alloy around the filter stem, which filters the water.
As per the first instance court’s ruling, the Court of Appeal held the 1st claim invalid, but (somewhat surprisingly) maintained the validity of the dependent claims 2 and 3, further invalidating only dependent claim 4. The Court concluded that the surviving claims solved a specific technical problem—simultaneous disinfection of both the device and the water—in a way that was not obvious to the expert in the field.
Misleading Advertisement – Unfair Competition
Greek unfair competition law dating back to 1914 (adopted on the guard-rails of the German UWG of 1896) provides for an 18-month limitation period, triggered as from the time becomes aware of the act and the person responsible. The unfair competition claim was raised (via the main infringement action) after the said point in time had lapsed and was therefore rejected.
In a rather common judicial practice in patent validity cases, the Court offset the legal costs between the parties.
The judgment (in Greek) can be read here.
