T1553/19

18.11.2022


The appeal of the patent proprietor is against the decision of the opposition division regarding maintenance of European patent No. 2 337 805 in amended form.
Claim 1 of the main request read as follows:
"1. Polymerizable liquid compositions of polyurethane type made up of two components (A) and (B), where component (A) contains at least one cycloaliphatic diisocyanate monomer or a mixture of a cycloaliphatic diisocyanate monomer and a prepolymer obtained by reaction, in the presence of an acid phosphate ester catalyst, between said cycloaliphatic diisocyanate monomer and one or more polyols having two or more hydroxy groups per molecule and a molecular weight comprised between 50 and 2000 g/mole; the second component (B) contains one or more polyols having a molecular weight comprised between 50 and 2000 g/mole and a functionality between 2 and 5; in absence of polyalkoxylated tertiary diamines and metal organic catalysts, said components (A) and (B) being present in weight ratio varying between 1:1 and 2:1;
said polymerizable liquid compositions further comprising an acid phosphate ester catalyst".
The opposition division decided that the subject-matter of claim 1 of the main request was novel over the compositions according to examples 5 to 7 of D1 because the latter compositions mandatorily contained some tetrabutyl titanate catalyst. The presence of tetrabutyl titanate was considered excluded from the polymerisable composition being claimed due to the requirement "in absence of (...) metal organic catalysts". According to the decision, the latter feature was to be interpreted in its broadest sense, which was done when the term "metal organic catalyst" was read as meaning "any compound having a metal atom bound to an organic group".
The issue in dispute is assessing whether or not the feature "in absence of (...) metal organic catalysts" mandatorily excludes the presence of "tetrabutyl titanate" from the compositions being claimed.
The term "metal organic catalysts", as specified in claim 1, has no accepted and unambiguous definition in the art.
The Board considers that the patent in suit neither provide a clear and unambiguous definition of the term "metal organic catalyst", nor specify that tetrabutyl titanate is a "metal organic catalyst". Therefore, it cannot be concluded that the skilled person would conclude that tetrabutyl titanate must not be present in the compositions being claimed.
Under these circumstances, according to established case law, the normal rule of claim construction is that the terms used in a claim should be given their broadest technically sensible meaning in the context of the claim in which they appear. This means that, in the present case, the broadest meaning of the feature "in absence of (...) metal organic catalyst" has to be established.
The Board is of the opinion that the term "metal organic catalyst" can not only be read as meaning "any compound having a metal atom bound to an organic group", but that it can also be read as being only related to a more restricted group of components, namely organometallic compounds comprising a metal-carbon bond as indicated in D2 (first sentence of the entry "Metall-organische Verbindungen"), which is a standard technical dictionary in the field of chemistry. This is first derivable from the similarity of the terms "metal organic catalyst" and "organometallic compounds" (which is indicated at the end of the entry "Metall-organische Verbindungen" to constitute the corresponding English translation) in the English language. In addition, this is also confirmed by the arguments put forward by the appellant themselves during the prosecution of the file, according to which the wording "absence of ... metal organic catalysts" meant "absence of organometallic catalysts".
It is pointed out that the above conclusion is not reached considering that the term "metal organic compound" and "organometallic compound" are equivalent, but considering that the term "metal organic compound" may, among others, be possibly read as meaning "organometallic compound".
In view of the above, the Board is satisfied that a possible reasonable meaning of the feature "in the absence of ... metal organic catalysts" only excludes the presence of compounds comprising a metal-carbon bond from the compositions being defined in claim 1. According to that reading, tetrabutyl titanate can be present in the compositions being claimed.
In the Board's view, the normal rule of claim construction of reading a feature specified in a claim in its broadest technically meaningful sense corresponds to determining the broadest scope encompassed by the subject-matter being claimed according to a technically sensible reading. In the case of a feature defined in a positive manner, which imposes the presence of a specific element (e.g. a component), this is effectively achieved by giving to the element in question its broadest technically sensible meaning. However, for a feature defined in a negative manner, which excludes the presence of a specific element, the broadest scope of the claim corresponds to the narrowest (i.e. most limited) technically sensible definition of the element to be excluded. Applying that concept to the present case means that the broadest technically sensible reading of claim 1 is obtained by reading the components to be excluded ("metal organic catalysts") in the most limited way.
In view of the above, the subject-matter of claim 1 of the main request is not novel over example 7 of D1 and, for that reason, the main request is not allowable