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DE – “Thickening polymer I” and “Thickening polymer II”

17 Sep 2015

Bundesgerichtshof“Thickening polymer I” and “Thickening polymer II”, Bundesgerichtshof, Germany, 5 May 2015 and 7 July 2015. Case No's X ZR 60/13 and X ZB 4/14

The Federal Patent Court Bundesgerichtshof decided in its decision “Verdickerpolymer I” (Thickening polymer I, docket n° X ZR 60/13) that in order to destroy novelty of a patent, it is not necessary that all possible combinations of the claim were known in the state of the art. The patent claimed a composition of an associative thickener, a surfactant and water. The associative thickener should be selected from polyurethanes, polyesters, modified cellulosics, poIyester-urethanes, polyether-alpha olefins and polyether-polyols; the surfactant had to be selected from anionic and non-ionic surfactants and mixtures thereof, the rest being water.

In the state of the art, there was known a composition of a polyurethane thickener and a non-ionic surfactant, in the amounts claimed in patent claim 1, with the remainder being water. The patentee argued that only one possible combination falling under the patent claim was known in the state of the art, whereas all other possible combinations were not known. However, he did not disclaim a combination of a polyurethane, a non-ionic surfactant and water.


In this situation, the Federal Supreme court held that the combination shown in the state of the art (polyurethane, non-ionic surfactant, water) destroys novelty for the whole patent claim (see para 31). Otherwise it would lead to a situation where state of the art becomes part of a new patent claim.

With respect to the same patent, the Federal Supreme Court held in the decision “Verdickerpolymer II” (Thickening polymer II, docket n° X ZB 4/14) that a party being sued for patent infringement is not entitled to be party in a parallel reinstatement proceeding, pending with the German Patent and Trademark Office (GPTO). In fact, the defendant in the infringement proceeding found out that the patent was not valid at the time of the filing of the infringement action, since the patentee had failed to deliver a German translation of the new patent specification after EPO opposition. The patentee started a reinstatement proceeding and the defendant in the infringement proceeding requested to be a party of that proceeding.

The Federal Supreme Court held that despite the fact that an infringement action was pending, the defendant in the infringement proceeding is not entitled to be a party of the reinstatement proceeding, since the German Patent Act clearly says that this is a unilateral proceeding between the Patentee and the GPTO.

Read the decisions (in German) here (Thickening polymer I) and here (Thickening polymer II)

Head note: Konstantin Schallmoser, Preu Bohlig & Partner