T 2133/21 - Broadest in context

Key points

•  "According to the legal approach to claim construction, it is a well-established principle laid down by Board of Appeal case law that a non-specific definition in a claim, here "prepolymer", must be given its broadest technical sensible meaning taking into account the context in which it appears, which also includes linguistic considerations."
  
  
• In this case, the proprietor argued for a broad claim interpretation, the opponent for a narrow one because  [short break as a brainteaser here]
  
  
• ...two of the examples in the patent exhibiting a certain technical effect were in accordance with the claim under the proprietor's broad interpretation.
  
  
• The Board agreed with the opponent's claim interpretation,
• finds the objectively solved technical problem to be the provision of an alternative,
• and concludes that the claim, therefore, includes obvious embodiments,
• such that the claimed subject-matter does not involve an inventive step.

EPO 

The link to the decision and an extract of it can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t212133eu1

4. A pivotal point in the reasons for the contested decision was that contrary to the patent proprietor's opinion, the feature "one or more polyurethane prepolymers having isocyanate moieties" (component (A)) whose amount in operative claim 1 is defined to be from 40 to 70 pbw would not designate a mixture comprising plasticizers in addition to the one or more urethane prepolymers as such. On that basis, the compositions of examples 4 and 5 of the granted patent which do not contain an amount of one or more urethane prepolymers per se within said range, but only a total amount of plasticizer and urethane prepolymers within that range would not represent compositions in accordance with claim 1 as granted.

4.1 The patent proprietor brought forward that granted claim 1 does not define component (A) as a "prepolymer", but as a "composition of one or more urethane prepolymers (...)". In their opinion, component (A) within the meaning of claim 1 should be understood to designate a composition containing one or more urethane prepolymers, which could include in addition to the oligomers formed, also non-reacted monomers, catalysts, stabilizers, as well as components required for improving the processability of the composition, such as plasticizers (statement of grounds of appeal, page 5, section 2.2.1). As a result, the compositions marked as examples 4 and 5 in the specification would be in accordance with the invention defined in granted claim 1, the amount of component (A) being within the range specified in granted claim 1. This interpretation of the term "prepolymer" would not only be supported by the understanding of that term in the present technical field, reference being made to documents E8 and E9, but also by paragraphs [0028] and [0039] of the specification (statement of grounds of appeal, page 5, sections 2.2.2 and 2.2.1, respectively).

This is contested by the opponent. In their opinion, the amount of component (A) of from 40 to 70 pbw refers to the amount of polymers having isocyanate groups, but not to a reaction mixture comprising said polymers and possibly, additional components. According to the opponent, plasticizers such as diisononyl phthalate are neither urethane prepolymers nor do they have isocyanate moieties (rejoinder, page 4, first to fourth full paragraphs).

4.2 According to the legal approach to claim construction, it is a well-established principle laid down by Board of Appeal case law that a non-specific definition in a claim, here "prepolymer", must be given its broadest technical sensible meaning taking into account the context in which it appears, which also includes linguistic considerations.

In the present case, it is as a preliminary remark noted that the patent proprietor's argument referring to component (A) being a "composition of one or more urethane prepolymers (...)" is based on a truncated definition of component (A) given in operational claim 1, i.e. an incorrect grammatical analysis of the wording of that claim. The word "composition" refers to the composition comprising components (A) to (D). It belongs to the definition of the amount of component (A) "from 40 parts to 70 parts by weight based on the weight of the composition". It does not define the nature of the "one or more urethane prepolymers having isocyanate moieties".

While it can be agreed with the patent proprietor that technical reality has to be taken into account when reading the term "prepolymer" used in granted claim 1, such reading, nevertheless, has to be based on the technical definition given in that claim. In this respect, neither component (A) itself, nor claim 1 is defined in terms of process features. Claim 1 merely defines a composition in terms of its constituents and their amounts.

On that basis, there is no reason to read into claim 1 that component (A) relates to the product obtained when preparing the urethane prepolymers having isocyanate moieties prepolymer, which method could possibly involve the presence of plasticizer.

In the Board's judgment the term "prepolymer" is for the skilled person self-explaining, it defines a polymer or oligomer whose molecules are able to undergo further polymerization.