T 0774/22 - When room temparature is no CGK

Key points

• "The board has come to the conclusion that the invention as defined in granted claim 2 is not sufficiently disclosed because, as evidenced by the opponent, essential information necessary to obtain the claimed PCC material comprising nanofibers and/or nanochain-like agglomerates is not provided in the patent. "
•  "The experimental results submitted by the opponent [] show that such a material can only be obtained if step c) is carried out at a temperature of around 20 C. In contrast, when the carbonation is carried out at 11 C or 50 C, no PCC having nanochain-like agglomerates or nanofibers can be obtained. It follows that, although the carbonation temperature is essential for carrying out the invention, this information is missing from the patent."
• Paragraph [0080] of the patent, Example 1, is silent on the temperature: 
• "CaO is reacted with water such that dry Ca(OH)2 is obtained. The reaction is controlled such that 1 molar equivalent of water is reacted per one molar equivalent of CaO and the water content of the dry Ca(OH)2 is less than 2 %. The dry Ca(OH)2 is contacted with water to provide a milk of lime. CO2 is bubbled into a milk of lime presenting a solid concentration of 15 wt. % in the presence of a crystallization controller consisting of a mixture of polyacrylic acid and sodium polyacrylate. The resulting PCC slurry presents a concentration of 19 wt. % and is then filtered, dried and milled to obtain a dry PCC (Formulation 2). The PCC contains nanochain like agglomerates, combined to form microshell like aggregates." 
• "The proprietor further pointed out that the experiments at least demonstrated that the invention could be carried out if the carbonation temperature is set at a value of around 20 C. This is not disputed by the Board, however for an invention to be sufficiently disclosed, it is not sufficient that it can be shown at a later stage how it can be carried out. Rather, this teaching must be provided in the patent itself."
• "It could of course be argued that in the absence of any indication concerning the temperature in step c), it would be obvious for the skilled person to carry out the carbonation at room temperature. The board recognises that this is one possibility, but it is not the only one. "
• "For instance, since step (b), preceding step (c), is carried out at a temperature of preferably 10-60 C (par. 0050 - note, this is the general part of the description) and since the slurry produced in step (b) can be used directly for the carbonation step (c), without any teaching in the patent to cool down the slurry, or heat it up prior to its treatment with CO2, any temperature in the range 10-60 C could be chosen for carrying out the subsequent step (c). It follows that, when repeating example 1 of the patent, a product according to claim 2 could only be obtained by chance provided that the skilled person selected the correct temperature - i.e. 20 C - for carrying out step (c)." Example 1 is silent on the temperature used.
• The steps are: "a) a step of providing CaO, which is reacted with water to form dry Ca(OH)2;
  b) a step wherein the dry Ca(OH)2 of step a) is contacted with water to form a slurry; and
  c) a step wherein the slurry of Ca(OH)2 from step b) is carbonated with CO2.""
•  Too be clear, I trust the Board had good reasons for the decision, though perhaps the decision could have benefitted from additional reasoning. Is room temperature an obvious choice in the particular field, when Example 1 is silent on the temperature? Or perhaps the proprietor did not present the argument that in the absence of express instructions on the temperature in Example 1, the skilled person would use room temperature?
• Or, possibly , the broadening of the range to 10 - 60 C in para [0050] of the description is seen as misleading in this particular case by including non-working embodiments? Would the patent have been fine if no temperature range had been mentioned? 
• 
  

EPO 

The link to the decision can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t220774eu1