Monday 18 April 2011

T 2213/08 – Unlimited?


Claims 1 and 23 of auxiliary request 4 before the Board read:
1. A manufacturing method of water-absorbent agent powders from water-absorbent resin powders having a carboxyl group in which surface regions are crosslinked by a crosslinking agent having an epoxy group, a residue of the crosslinking agent being present in the water absorbent resin powders, characterized in that the water-absorbent resin powders have a water content of <10% by weight and in that the water-absorbent resin powders are post-processed by adding water as a nucleophilic reagent to the heated water-absorbent resin powders in powder form, wherein the nucleophilic reagent is used in an amount of from 1 to 30 parts by weight based on 100 parts by weight of the water-absorbent resin powders."


23. Water-absorbent agent powders, characterized by comprising at least partially porous water-absorbent resin powders having a carboxyl group, wherein said water-absorbent agent powders are crosslinked by a crosslinking agent having an epoxy group, an amount of a residue of the crosslinking agent is not more than 2 ppm, and an absorbency under load of 50 g/cm**(2) with respect to a physiologic saline solution is not less than 25 g/g, and wherein said water-absorbent agent powders are obtainable by a manufacturing method as said [sic] forth in any of the preceding claims.
In what follows the Board deals with the sufficiency of disclosure of this request:

[6.1] The objection raised by [the opponent] concerning sufficiency of the Auxiliary Request 4 relates to the use of the wording “not less than 25 g/g” when defining the absorbency under load of the water-absorbent agent powders of Claim 23. In its opinion this open-ended range was unduly broad so that it would embrace values of absorbency under load such as 50 g/g, which are not known. The patent specification did not disclose how these values could be obtained and therefore did not enable the full scope of the invention to be carried out.

In this context, [the opponent] referred to decision T 1008/02, wherein it is stated that a single value cannot be considered to provide sufficient support for a claim to a range of absorbency under load having no upper limit.

[6.2] This objection of [the opponent] is based on an erroneous interpretation of the subject-matter covered by the claims. It is clear for a skilled reader that a claim such as present Claim 23 including an open-ended range is limited in practice. In fact, values of the parameter not obtainable in practice would not be regarded by the skilled reader as being covered by the claim and thus could not justify an objection of insufficiency of disclosure (see Case Law of the Boards of Appeal of the EPO, 6th edition 2010, Section II.A. 6.1; see also T 1018/05 [2.3] and T 297/90 [2.2], both cited therein).

[6.3] In the present case the patent specification includes a detailed description of the claimed method and specific examples resulting in water-absorbent powders having the desired properties, including values of absorbency under load up to 26 g/g. Moreover Appellant 01 has amended the claim by incorporating the feature “obtainable by a manufacturing method as said [sic] forth in any of the preceding claims”. The skilled reader would immediately understand the practical implication of this limitation, namely that the method of producing the water-absorbent agent powders sets the actual limits of the absorption under load.

[6.4] [The opponent] neither questioned the examples in the patent in suit nor submitted experimental evidence showing that the invention could not be performed. Consequently, the board is satisfied that the requirement of sufficiency of disclosure is met.

[6.5] In reaching this conclusion the board also considered decision T 1008/02 cited by [the opponent]. In that decision the board concluded that the auxiliary request under consideration did not fulfil the requirements of sufficiency because none of the examples showed the claimed properties, in particular an absorbency under load of “at least 27 ml/g”, and no evidence had been produced that super-absorbent having the required properties were available to the skilled person (see points [3.3] and [3.4] of the reasons). Thus, the situation in that case differs from the present one where the patent provides four examples with values of absorbency of not less than 25 g/g.

Insofar as [the opponent] relied on the “obiter dictum” in the last paragraph of point [3.5] of T 1008/02
“However, this single value cannot be considered to provide sufficient support for a claim to a range for the AUL value starting at 24 ml/g, but having no upper limit.”,
it is pointed out that also such a situation is different from the present case, where the claim is drafted in the form of a product-by-process and the specification includes two examples fulfilling the requirements of the claim.

As set out above, the method of producing the water-absorbent agent powder implies the practical limits of the parameter having no upper limit.

It is also noted that sufficiency of disclosure was not the reason for the rejection of the request discussed in T 1008/02 [3.5].

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.

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