T 66/07 – Extracting Limits From Examples

I have the impression that the question of intermediate generalisation is more and more present in recent decisions of the Boards. The present decision is far from spectacular but it allows to study a nice case involving temperature ranges.

[2] In the decision under appeal, two different reasons were given for the revocation of the patent in suit, namely that the amendment of the temperature ranges, i.e. the replacement of the range of “50 -120°C” at all occurrences in the independent claims to the process and to the polymer per se of both former requests under consideration at that time by the new range of “100-120 °C”, did not fulfil the requirements of A 123(2). […]

[5.3] As regards the question of whether the lower limit of the range of 100 to 120°C […] has directly and unambiguously a clear basis of the disclosure in the examples must be considered separately and in detail herein below.

[5.3.1] The [patent proprietor] referred to T 962/98 [2.5] according to which the use of a feature taken from the examples for restricting the scope of a claim would be allowable, if a skilled person could recognise without any doubt from the application as filed that this feature was not closely related to the other characteristics of the worked examples and could be applied directly and unambiguously to the more general context (T 962/98, which followed T 201/83). The [patent proprietor] saw these prerequisites fulfilled in the present case, so that the value of 100°C disclosed in each of the examples in the context of the boiling point of each reaction mixture would, therefore, form an allowable basis for the amendment of the polymerisation temperature in each of Claims 5 and 8 of the Main Request.

[5.3.2] By contrast, the [opponents] took a different view and argued that the extraction of the value of 100°C from the examples did not comply with the above requirements as formulated in T 962/98.

[5.3.3] In the case underlying decision T 962/98, each Claim 1 in question had been amended with reference to the argument that the amendment was properly supported by the disclosure of one example. The claims referred to a method comprising the dilution of a concentrate composition “with a diluent”, wherein the composition comprised “a carrier” comprising, besides a conveyor lubricant comprising four specific chemical compounds identified by their chemical names, effective amounts of “a quaternary ammonium cationic compound” and “an amphoteric surfactant” (T 962/98 [V]).

The example which, in the [patent proprietor’s] opinion supported its amended method claims, concerned a concentrate composition comprising, besides all of the above four specific chemical compounds as the conveyor lubricant component, distilled water, isopropanol, acetic acid, the monosodium salt of lauryliminodipropionic acid and coco-alkyldimethylbenzylammonium chloride.

The Board found that

“It is, therefore, not possible to conclude without any doubt whether or not, those four surfactants either

(a) can be singled out of the composition of Example 1D and used with other carriers than a mixture of water and isopropyl alcohol, with an antimicrobial agent other than cocoalkyldimethylbenzyl, ammonium chloride or with an amphoteric surfactant other than lauryliminodipropionic acid monosodium salt or, to the contrary, whether they

(b) are only adapted to the specific composition disclosed in Example 1D.

The skilled reader is given no guidance, either in Example 1D itself, or in the more general description as to which components of Example 1D should be retained unchanged, and which can be varied at will. He will know that it will be possible to vary the example, but there is no clear guidance as to within what limits such variation will be possible. Certainly there is nothing to tell him that just the four surfactants recited in claim 1, but not other components recited in Example 1D, are essential.”

and that

“This situation of doubt is in contradiction with the requirement that an amendment be directly and unambiguously derivable from the application as filed.” 

Consequently, it did not allow the requested amendment and dismissed the appeal.

[5.3.4] The present situation is comparable with the circumstances in that case, in that, as pointed out by the [opponents], the boiling point is clearly linked to the particular composition of a given example. The [patent proprietor] has, however, amended its claims on the basis of a generalisation of the boiling temperatures of the examples, irrespective of their further particulars, by applying this generalised value to the full scope of the claims.

[5.3.5] Thus, whilst the examples related to the preparation of polyacrylic homopolymers with the only exception in Example A-6 concerning a copolymer of acrylic and methacrylic acids in a 6/4 molar ratio, the general description of the polymerisation mixtures encompasses the possibility that originally up to 50 weight % of the monomer composition (now restricted to 10 weight % […]) are monomers other than (meth)acrylic acid or their salts (see the long list of different types of comonomers, such as e.g. vinyl acetate and vinylsulfonic acid […]). Furthermore, the (meth)acrylic acids and some acidic comonomers may be used in their neutralised form as salts with mono- or divalent metal ions […].

Moreover, a further particular of all those examples, on which the [patent proprietor] relied in order to justify the suggested amendment, is the fact that, in all the examples in Table 1 […], no monomer had initially been charged, but 100% of the monomers component had gradually been supplied to the reaction mixture. However, neither of Claims 5 and 8 includes such a requirement. Instead, the last paragraph of each of these claims requires 70 weight % or more of the total amount of the monomer component to be gradually supplied to the reaction system. In other words, up to 30 weight % of this component may be initially charged.

That the boiling point is not independent from the composition of the reaction system, e.g. from the amount of the monomer component, is illustrated by Comparative Example A-3 wherein part of the monomer component had initially been charged.

[5.3.6] Moreover and in particular, it must be noted that all examples relate to the polymerisation in ion-exchanged water, whilst in the claims reference is made to “an aqueous medium”, in general […]. It clearly includes “water alone; mixed solutions of water and water-soluble solvents” […]. Moreover, according to a preferred elaboration […], the water content is 40 weight % or more of the mixed solution, which means, that, in this preferred elaboration, the solvent may be present in an amount of up to 60 weight % of the aqueous medium […].

The water-soluble solvent which may thus even be the predominant component of the aqueous medium affects, of course, the boiling point of the “aqueous medium”.

[5.3.7] In view of these findings, it is evident to the Board that each of the temperature values in column (6) of Table 1, as further confirmed by the wording in the descriptions of each of the examples, refers to the individual “boiling point (…) of the system” of the respective given example. The accidental identity of the boiling temperatures in different examples does not disprove this finding.

In other words, the initially charged reaction systems e.g. of Examples A-2 and A-7, containing only ion-exchanged water, or Example A-1 containing only ion-exchanged water and about 2 weight % of sodium hypophosphite monohydrate […] had a boiling point of 100 °C, and the temperature was then “kept” in these examples at the individual boiling point of the respective specific reaction system lying somewhere between 100 and 105°C (in other cases, up to between 103 and 107°C) apparently by controlling the feed of the various reaction components, i.e. of the monomer(s), sodium persulphate and hypophosphite monohydrate in distinct concentrations dissolved in ion-exchanged water, to the reaction system. “After the end of dropping, the temperature was kept at the same temperature for 5 minutes to complete the aging.” The comparison of the identical statements in Examples A-1, A-2, A-7 […] and, moreover, in Comparative example A-3 […] makes it clear for the Board that that the formulation concerning the boiling point expressed in terms of e.g. “(100-105 °C)”, “(100-107 °C)” or “(103-105 °C)” (Comparative Example A-3) in Tables 1 and 2 refers in each case to the respective individual boiling temperature of the individual reaction system.

These findings are, for the Board, valid for the polymerisation reactions in all the examples, which were also conducted in a similar way as confirmed by formulations such as e.g. “A polyacrylic acid (…) was obtained by the same polymerization as of Example A-2 (or A-1) except that …” […]. The above values given in the individual examples cannot, therefore, be considered as referring to a temperature range or to a lower or upper limit of a temperature range which would be valid for the generality of all conceivable elaborations encompassed by the operative claims.

[5.3.8] Therefore, as held in T 962/98, it is also, in the present case, neither clearly and unambiguously nor directly derivable from the disclosure in the examples that the lowest temperature value provided in Table 1 would also be valid for the other reaction systems comprising other aqueous media and other monomer compositions as encompassed by Claims 5 and 8 under consideration.

[5.3.9] Consequently, the Board takes the view that the conditions for an admissible and allowable generalisation of the temperature value of 100°C for amending the lower limit of the two occurrences of a temperature range to “100-120 °C” in the last paragraph of each of Process Claim 5 and Product Claim 8 are not met. Rather, the amendment of these two claims does not fulfil the requirement for the allowability of an amendment taken from an example, as referred to in section 5.3.1, above, but extends beyond the content of the application as filed.

To read the whole decision, click here.