T 2004/14 - Absorbent article with parameter

Key points

• This opposition appeal concerns an invention for an absorbent article (hygiene product). Claim 1 of the main request defines that "the liquid storage area (106) accounts for at least 75% of the total absorption capacity of the product".
• The Board finds this parameter to cause a problem under Article 83 (not merely clarity), which is unsurprising in this field of technology (see e.g. T 0626/14).
• " The parameter "absorption capacity" does not have a standard meaning within the technical field of absorbent products. It was not disputed that there is no indication in the disclosure of the patent as a whole regarding how this absorption capacity is defined and how it should be measured." 
• " In the absence of any indication in the patent in regard to the method (and the test conditions) of determining the absorption capacity the skilled person is not able to reliably and repeatably determine the crucial condition set out in claim 1. The patent therefore does not disclose the invention defined in claim 1 in a manner sufficiently clear and complete for it to be carried out by a skilled person."

EPO T 2004/14 -  link

Reasons for the Decision

1. Main request - sufficiency of disclosure

1.1 Claim 1 of the main request defines that "the liquid storage area (106) accounts for at least 75% of the total absorption capacity of the product".

1.2 When wishing to determine if the liquid storage area accounts for at least 75% of the total absorption capacity of the claimed product, the skilled person must be able, on the basis of the disclosure as a whole and using its common general knowledge, to reliably determine the absorption capacity of the liquid storage area and the total absorption capacity of the entire product.

1.3 The parameter "absorption capacity" does not have a standard meaning within the technical field of absorbent products.

It was not disputed that there is no indication in the disclosure of the patent as a whole regarding how this absorption capacity is defined and how it should be measured.

It was acknowledged by the respondent that several methods for measuring the absorption capacity of an absorbent product were known to the skilled person, such as the liquid retention tests mentioned in D12, points 5 and 6, or in D1, D2, D4. As explained in the statement of D12, paragraph 6, these liquid retention tests may:

i) include interstitial fluids (e.g. the method described in D4), i.e. fluid absorbed or held in interstitial spaces of an absorbent product, for example between the fibers of one of its absorbent components, which is taken into account in the determination of the product's absorption capacity,

ii) exclude some of the interstitial fluids (e.g. the method described in D2), for example by applying vertical drainage of interstitial fluids by gravity, or

iii) exclude most of the interstitial fluids (e.g. the blotter-method described on page 4, lines 31 to 45, of the patent application annexed of D12), by applying an external load on the product.

In all of the exemplified methods above the absorption capacity is essentially determined by a comparison of the weight of a product in its dry state, i.e. before absorption of fluid, and of its final weight loaded with absorbed fluid, where its final weight is determined according to the above methods after drainage or not of interstitial fluid. The determination of the relative absorption capacity ("at least 75%") defined by the crucial feature cited above could be obtained by a determination of the total absorption capacity of the entire product and a determination of the absorption capacity of only the absorbent body.

The Board can agree that a skilled person would exclude liquid retention tests comprising vertical drainage (under point ii) above) such as the one of D2. These do not seem to be appropriate for draining a product according to the invention, since they do not resemble the way that a user would wear such a product. However, tests falling under categories i) and iii) do still remain.

It is plausible that procedures taking into account interstitial fluids result in an increased value for the absorption capacity. The measured values for the absorption capacity would thus vary depending on the nature of the materials constituting the product and the test method chosen. The Board finds that, contrary to the respondent's argument, no experimental data is needed. In fact, as exemplified by the materials suggested in paragraph [0033] of the patent, a liquid storage area made of superabsorbent material, where liquid is absorbed in a medium forming a gel, is less susceptible to applied pressure than a secondary absorption area made of a fibre wadding of synthetic fibres. The absorption capacity of such a liquid storage area, made of a superabsorbent polymer, would not vary substantially for the methods mentioned above. The total absorption capacity of the absorbent product including a superabsorbent liquid storage area and additionally a fibrous secondary absorption area, would thus vary depending on whether interstitial fluid retained in the fibrous secondary absorption area were included or whether most of the interstitial fluid would be expelled from it for the determination of the total absorption capacity. Furthermore, regarding methods of determination in which most of the interstitial fluid would be excluded (category under point iii) above), the value of the total absorption capacity would then still depend on the undetermined factors influencing the amount of expelled interstitial fluids, e.g. under which external pressure or load the interstitial fluid should be drained from the product. The relative absorption capacity of the liquid storage area compared to the product's total absorption capacity depends consequently on the method of determination and the test conditions (e.g. level of external pressure or load applied).

In the absence of any indication in the patent in regard to the method (and the test conditions) of determining the absorption capacity the skilled person is not able to reliably and repeatably determine the crucial condition set out in claim 1. The patent therefore does not disclose the invention defined in claim 1 in a manner sufficiently clear and complete for it to be carried out by a skilled person.

1.4 The respondent's arguments, that even without an indication the skilled person would still recognize the blotter-method of D12 as the only possible method, whereas D4 was not a suitable method since it was only applicable to non-ambulatory heavily incontinent persons, cannot be accepted by the Board. In fact, the introduction of D4 states that the method was tested inter alia on non-ambulatory female users. It continues to state that its applicability to other groups is "unknown", i.e. it has never been carried out with other groups. These statements thus do not exclude its use in tests of similar products intended for other groups.

The third paragraph of the introduction mentions that user performance of the product is affected inter alia by the position and motion of the user or by the number of parts of the product. The paragraph warns that the test cannot differentiate between these features. However, this also applies to the blotter-method as well as the other liquid retention tests referred in D12 and does therefore not disqualify the methods of D4 to be considered by the skilled person. The Board notes that D4 is an ISO-standard, directed to whole product testing of urine absorbing aids and would clearly present one of the methods considered by the skilled person required to determine the absorption capacity of such products covered also by claim 1.

Moreover, the product of claim 1 does not have any feature that would exclude the use of the claimed product by heavily incontinent, non-ambulatory subjects. Paragraph [0029] of the patent in suit mentions the (non-ambulatory) night use of the product, i.e. the invention of claim 1 also applies to non-ambulatory subjects.

The blotter-method in the annex of D12 is thus not the only applicable test known by the skilled person and it is not clear for the skilled person, on the basis of the disclosure as a whole and using its common general knowledge, how absorption capacity should be determined or which test should be applied to determine it.

1.5 Even if the skilled person were to consider the blotter-method, at least the value for the draining pressure to be applied in order to expel interstitial fluids would still be lacking.

The argument that twenty-four patent publications disclosed the blotter-method being performed with the pressure of 17,6 grams per square centimeter so that the skilled person would have recognised that this was the value to be used, does not convince the Board. Unlike the method of D4, the blotter-method is not a standardized test comprising specific instructions for its procedure and requires the choice of an appropriate drainage pressure to be applied, which could be different according to the application and type of user group intended to apply the product.

In addition, all the twenty-four patents are solely from two corporations, as acknowledged by the respondent (who did not state either that it generally employed this test for the relevant purpose). It is likely that, when applying such a non-standardized method as the blotter-method, different test laboratories from different companies with different internal processes would perform the test under different conditions, which is exactly what standards aim to avoid. Further, the proportion between the twenty-four patents and the total number of patents disclosing blotter-methods is also unknown, making it impossible to assess the relevance of this number of publications and the relevance of the pressure value indicated therein.

Thus, even assuming that the blotter-method should be used, it is not clear for skilled person, on the basis of the disclosure as a whole and using its common general knowledge, what the required pressure to determine the absorption capacity should be.

1.6 The argument from the respondent, that the level of absorbed liquids indicated in the description (column 6, lines 16 to 20 of the patent) would guide the skilled person to select a suitable test, does not convince the Board. These values are only possible estimations of the capacity required for panty liners and sanitary towels. In fact, it is stated in the same paragraph further below that, for night use and incontinence pads, a greater (unspecified) capacity may be desirable. The skilled person would thus not interpret the indicated values as restrictive or indicative in any way.

Further, none of the tests discussed above has any indication of suitability or limitation regarding the amount of liquid to be absorbed. Thus the skilled person would not be guided to any particular absorbency test when faced with the possible capacity values for panty liners and sanitary towels indicated in the description.

1.7 The alternative argumentation of the respondent that only with the relationship between the absorption capacity of the liquid storage area and the total absorption capacity of the product being claimed, any of the suitable methods could be used, is also not found convincing by the Board. As mentioned already above, the absence of a clear definition for absorption capacity also affects the ratio between the absorption capacity of the liquid storage area and of the whole product.

1.8 The invention according to claim 1 of the main request does therefore not fulfill the requirement of Article 83 EPC. The main request is thus not allowable.

2. Auxiliary requests 1 to 5

2.1 Claim 1 of each of the auxiliary requests 1 to 5 includes the crucial feature "liquid storage area (106) accounts for at least 75% of the total absorption capacity of the product". In absence of any argument from the respondent in support of these requests beyond those already presented with respect to the main request on the matter of sufficiency of disclosure, the Board finds for the same reasons as the main request that the invention according to claim 1 of each of the auxiliary requests 1 to 5 is not disclosed in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.

2.2 Since claim 1 of each of the auxiliary requests 1 to 5 does not meet the requirement of Article 83 EPC, the auxiliary requests 1 to 5 are also not allowable.

Order

For these reasons it is decided that:

1. The decision under appeal is set aside.

2. The patent is revoked.