Referral G 1/23 (T 438/19): Clarification On How To Construe G 1/92?

This appeal concerns the decision of the Opposition Division rejecting the opposition against European patent EP2626911. Its claim1 specifies a material that is suitable for encapsulating a solar cell and comprises certain polymer constituents, physical properties and a specific aluminum content. In the case under appeal, the Board found that the inventive step of the subject matter of claim1 hinges on the question whether the product ENGAGE^®8400 was "made available to the public" within the meaning of Art.54(2)EPC.

It was undisputed that documents D1, D2, D5/5a (all except D5 having been published before the earliest priority date) demonstrate that the copolymer ENGAGE^®8400, which was commercially available before the earliest priority date, comprises all the properties of the claimed material except its aluminum content. D1 specifically referenced D18 as a document describing the preparation of ENGAGE^®8400, and D18 discloses a level of aluminum overlapping with