2.3. Conciseness and number of claims

Abstract

In T 1152/21 the board concluded that claim 1 of auxiliary requests 9b and 10a did not meet the requirements of Art. 84 EPC.

Claim 1 of auxiliary request 9b included the term "cooling to an appropriate temperature". The board found that the skilled person could not assess whether a particular temperature was an "appropriate temperature", since the wording of the claim did not allow them to determine the conditions under which a temperature was an "appropriate temperature". Therefore, the claim was not clear.

The patent proprietor (appellant) had submitted that the skilled person was very familiar with heating and cooling steps, which were inherent to any (re)crystallisation process. It was a routine task for the skilled person to determine said appropriate temperature by reasonable trial-and-error experiments. Hence, the feature "appropriate temperature" was a functional feature related to a process step which could easily be performed in order to obtain the desired result. The board did not agree. It held that the patent proprietor's submission was relevant for sufficiency of disclosure rather than for the clarity of the claim. The relevant issue was what was covered by claim 1 of auxiliary request 9b, not whether the skilled person could reproduce the claimed method.

Auxiliary request 10a included in claim 1 the following terms: "heating to about 70°C", "heating at about 70°C", "heating the organic layer to about 120°C", "cooling to about 80°C", "maintaining the mixture at about 80°C for about 3 hours" and "gradually cooling to about 10°C".

The board noted that the term "about" in the context of said claim was associated with a specific temperature or a specific time. It could be that the term "about" was intended to cover measurement errors. However, measurement errors were covered for any value of any technical parameter to be measured and given in any claim (without the need for the term "about") since patents were in the field of technology, not mathematics, and a value could only be as precise as it could be measured according to the general technological convention. Thus, following this interpretation, the term "about" was superfluous and claim 1 was not concise, contrary to what was required by Art. 84 EPC. Alternatively, the term "about" could be intended to denote a range broader than the measurement error range. Following this second interpretation, it could not be determined how broad the range could be in claim 1 and what the exact limits of this range were. In this case, the term "about" in said claim was not clear, again contrary to what was required by Art. 84 EPC.

The patent proprietor had submitted that the term "about" was clear in light of the description of the patent since paragraph [0020] gave a clear definition of the term. According to the board, the claims have to be clear as such, i.e. without taking the description into account to interpret any unclear term. Even if it were accepted that the description could be consulted in the context of Art. 84 EPC, paragraph [0020] of the patent read as follows: "[...], the term "about" means within a statistically meaningful range of a value, such as a stated concentration range, time frame, molecular weight, particle size, temperature or pH. Such a range can be within an order of magnitude, typically within 20%, more typically within 10%, and even more typically within 5% of the indicated value or range". In the board's view, the term "statistically meaningful range" did not clearly define a range and for that reason was unclear. Even if it were accepted that, as submitted by the patent proprietor, the term "statistically meaningful range" was specified by relative variations in percent, said term would still be unclear since the following sentence contained various different percentages ("typically within 20%, more typically within 10%, and even more typically within 5% of the indicated value or range"). Contrary to the patent proprietor's submission that the skilled person would choose the broadest range, there was no teaching in this following sentence to choose the percentage within 20% of the indicated value, in view of the lower preference of the term "typically" compared with the two other terms "more typically" and "even more typically".

The patent proprietor further submitted that the term "about" was to be considered clear in light of the Guidelines F-IV, 4.7.1 – March 2021 version. The board pointed out that this chapter related to the interpretation of terms such as "about", not to the assessment of the clarity of such terms. Thus, the board found that the patent proprietor's submission was not convincing.