T 1810/08 – High And Low

Only the opponent filed an appeal against the decision of the Opposition Division (OD) to maintain the patent in amended form.

Claim 1 as granted read:

1. A polyurethane latex composition, said composition comprising a polyurethane aqueous dispersion that has less than 20 percent pendant chains by weight based on total weight of solids, said polyurethane aqueous dispersion being free of volatile solvent and being suitable for being dried to form a pressure-sensitive-adhesive composition.

Claim 1 as maintained read:

1. A polyurethane latex composition, said composition comprising a polyurethane aqueous dispersion prepared from a formulation which includes high molecular weight monols and/or a stochiometric excess of polyols such that the polymer terminates in unreacted polyol chains which are not connected to other polymer molecules and which contains less than 20 percent pendant chains by weight based on total weight of solids, said polyurethane aqueous dispersion being free of volatile solvent and being suitable for being dried to form a pressure sensitive-adhesive composition. (my emphasis)

The Board found this claim to lack clarity:

[2.1] Claim 1 of the main request and auxiliary request 1 refers to a polyurethane latex composition comprising a polyurethane aqueous dispersion. By way of amendment after grant, the requirement has been introduced into claim 1 of both requests that this dispersion has to be prepared “from a formulation which includes high molecular weight monols”. Since the amendment has been made after grant and is based on a passage from the description, it has to be examined whether the amendment meets the requirements of A 84.

[2.2] There is no information in claim 1 of the two requests as to what molecular weights are embraced by the term “high molecular weight”. Moreover, no evidence was provided by the [patent proprietor] to establish that the skilled person, on the basis of his common general knowledge, would know what molecular weights are covered by this term.

[2.3] The [patent proprietor] argued that the term “high molecular weight” was defined in the description of the opposed patent and that, on the basis of this definition, the term in claim 1 was clear. The [patent proprietor] in particular relied on the statement in paragraph [0038] of the opposed patent that the molecular weight of a low molecular weight mono-functional active hydrogen compound is less than 600 atomic mass units. The [patent proprietor] argued that this definition of low molecular weight could only mean that the term “high molecular weight” in claim 1 of both requests referred to a molecular weight of 600 or more atomic mass units.

However, as is confirmed by decision T 1129/97 [2.1.2-3], it is the claim as such that has to be clear. For this reason alone, the [patent proprietor’s] argument must fail.

Moreover, it cannot be excluded that an intermediate molecular weight range exists in between the low molecular weight of less than 600 atomic mass units disclosed in the description of the opposed patent and the high molecular weight referred to in claim 1 of both requests. Consequently, the [patent proprietor’s] assumption that high molecular weights start where low molecular weights end does not necessarily hold true. No definition of high molecular weights can thus be derived from the description of the opposed patent. Also for this reason, the [patent proprietor’s] argument cannot succeed.

[2.4] Therefore, claim 1 of the main request and auxiliary request 1 lacks clarity with regard to the term “high molecular weight monols”. These requests thus are not allowable.

Consequently, the patent proprietor had to get rid of the unclear feature. However, as he had not filed an appeal, he faced a reformatio in peius problem. 

Auxiliary request 3 is interesting because its treatment by the Board makes us revisit the rules that govern this situation. 

Claim 1 of this request read:

1. A polyurethane latex composition, said composition comprising a polyurethane aqueous dispersion prepared from a formulation which includes high molecular weight monols and/or a stochiometric excess of polyols such that the polymer terminates in unreacted polyol chains which are not connected to other polymer molecules and said polyurethane aqueous dispersion being free of volatile solvent molecules and which contains less than 20 percent pendant chains by weight based on total weight of solids and being suitable for being dried to form a pressure sensitive-adhesive composition which is tacky due to being prepared by including a mono-functional active hydrogen oligomer with the reactants during the synthesis of the prepolymer or alternately reacting the oligomer with the prepolymer after the prepolymer has been prepared and/or a stochiometric excess of polyols such that the polymer terminates in unreacted polyol chains which are not connected to other polymer molecules. (my emphasis)

The Board finds this request to violate the prohibition of reformatio in peius:

[4.1] The prohibition of reformatio in peius implies that an amendment effected during appeal proceedings, which would put the opponent and sole appellant in a worse situation than if it had not appealed, must be rejected (G 4/93 and G 1/99). Therefore, in appeal proceedings where the opponent is the sole appellant, claim amendments that broaden the claim with regard to the corresponding claim found allowable by the OD are normally to be rejected.

Where a patent which has been maintained in amended form would however have to be revoked as a direct consequence of an inadmissible amendment held allowable by the OD, the proprietor, without violating the prohibition of reformatio in peius, may be allowed to file requests, as follows:

(a) in the first place, with an amendment introducing one or more originally disclosed features which limit the scope of the patent as maintained;

(b) if such a limitation is not possible, with an amendment introducing one or more originally disclosed features which extend the scope of the patent as maintained, but within the limits of A 123(3);

(c) finally, if such amendments are not possible, with a deletion of the inadmissible amendment, but within the limits of A 123(3) (see the headnote of G 1/99).

[4.1.1] In the present case, the feature “... prepared by including a mono-functional active hydrogen oligomer ...” was substituted in claim 1 of auxiliary request 3 for the feature “... prepared from a formulation which includes high molecular weight monols ...” in claim 1 of the request found allowable by the OD.

It is thus a mono-functional active hydrogen oligomer rather than a high molecular weight monol that is to be used as reactant according to claim 1 of auxiliary request 3. Apart from monols, the term “mono-functional active hydrogen oligomer” additionally covers e.g. mono-functional amines or thiols. This implies that by the amendment of claim 1 of auxiliary request 3, this claim has been broadened with regard to claim 1 of the request found allowable by the OD. This amendment thus puts the appellant (opponent) in a position that is worse than it was in under the contested decision. The amendment therefore goes against the prohibition of reformatio in peius.

[4.1.2] The [patent proprietor] argued that the amendment had been carried out in order to meet the board’s objection under A 84 raised against the term “high molecular weight monols”. Therefore, in the [patent proprietor’s] view, the amendment corresponded to one of the three options considered in G 1/99 not to violate the principle of reformatio in peius.

As has been set out above, this claim, by way of the amendment in claim 1 of auxiliary request 3, has been broadened compared to claim 1 of the request held allowable by the OD. The [patent proprietor’s] amendment thus corresponds to the second option referred to in G 1/99.

According to this decision, this second option does not violate the prohibition of reformatio in peius if a limitation according to the first option is not possible. In the present case, the first option would however have been available to the [patent proprietor]. More particularly, the [patent proprietor] could equally have restricted the high molecular weight monols in claim 1 of the request held allowable by the OD on the basis of the specific high molecular weight monols disclosed in the examples of the application as filed, e.g. the 1800 molecular weight hetero ethylene oxide/propylene oxide monol of example 1. Thereby, one or more originally disclosed features would have been introduced into claim 1 of the request held allowable by the OD which at the same time would have limited the scope of the patent as maintained.

As the first option thus would have been possible, the second option chosen by the [patent proprietor] does not escape the prohibition of reformatio in peius. In line with G 1/99, the amendment of the high molecular weight monol to a mono-functional active hydrogen oligomer in claim 1 of auxiliary request 3 therefore violates the prohibition of reformatio in peius. […]

Obviously, things would have been much easier for the proprietor if he had filed an appeal. Unless you are not adversely affected by the decision, never let the opponent be the only one to appeal.

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