Monday, 28 November 2011

T 1605/07 – No Selection

The patent proprietor filed an appeal against the decision of the Opposition Division to revoke the opposed patent.

Claim 1 of the main request before the Board read (in English translation):
1. Process for the anodic electro-dipcoating of conducting surfaces by dipping in an aqueous anodic electro-dipcoating bath and connecting up as the anode characterised in that an aqueous anodic electro-dipcoating bath is used that contains 1 to 15 wt. %, referred to the binder solids of the electro-dipcoating bath, of one or more phosphoric acid epoxy esters and/or phosphonic acid epoxy esters with an acid number of 10 to 40 that are obtained by reacting one or more monomeric, oligomeric or polymeric epoxy compound(s) with phosphoric acid or phosphonic acids or their esters or mixtures thereof in the presence of one or more alcohols, chosen from the group consisting of n-butanol, tert.-butanol, sec.-butanol, isopropanol, n-propanol, methanol, ethanol and/or hexanol.
The discussion of the novelty of this claim contains some interesting statements on numerical ranges.

*** Translation of the German original ***

[3.1] The [opponent] has contested the novelty of claim 1 in view of document D1.

Document D1 discloses anionic electro-dipcoating compositions containing phosphoric acid epoxy esters obtained by reacting of phosphoric acid with an epoxy resin […]. The reaction is carried out in an organic solvent that is miscible with water, such as acetone, butanol, isopropanol, and similar organic solvents. However, ether alcohols are preferably used […]. Example 1 of document D1 discloses the production of a phosphoric acid epoxy ester in the presence of 2-butoxy ethanol, example 5 a method for the anodic electro-dipcoating of steel panels as the anode, by using an aqueous anodic electro-dipcoating bath containing the phosphoric acid epoxy ester produced in example 1.

However, the feature of an acid number of 10 to 40 for the phosphoric acid epoxy ester is not disclosed in document D1.

[3.2] The [opponent] submitted that this feature corresponded to a specific selection from the general disclosure of document D1. As such it did not comply with the principles applied by the Boards of appeal in their established case law concerning the novelty of selection inventions. In particular, the selected domain of 10 to 40 was not sufficiently remote from the value of 41.5 mentioned in example 1 of document D1. Moreover, the value would further decrease or even go below the upper limit of 40 if example 1 was carried out with the alcohols isopropanol and butanol, which were suggested in document D1, because, as explained by the [patent proprietor], mixed esters were formed when using the claimed alcohols, to which butanol and isopropanol belonged as well. As a matter of fact, the formation of mixed esters with free hydroxyl groups of phosphoric acid would lead to lower acid numbers. Moreover, there was no evidence for any particular effect related to the selected range of 10 to 40 besides the influence on dispersibility known from document D1.

The [opponent] admitted that there was no disclosure of an acid range with exact limits, but he referred to column 4, lines 4 to 14 of D1.

In this passage, in the context of binder systems, acid numbers of 12 to 60 were mentioned as preferred values for electro-dipcoating deposition. Admittedly, this domain was disclosed for other compositions but they had acid groups serving the same purpose, i.e. making dispersion possible, very much like the phosphoric acid epoxy esters. Therefore, one might expect the same acid numbers for the phosphoric acid epoxy esters. Therefore, the range selected according to the invention was not a narrow sub-range either.

[3.3] The Board does not share the opinion of the [opponent].

As far as the acid number is concerned, document 1 does not disclose a range having a specific upper and lower limit such that the claimed range would constitute a selection. It only discloses one single value of 41.5 in example 1, which is clearly outside the claimed range. Apart from that, document D1 only contains a general statement that the presence of the phosphoric acid (group) leads to a measurable acidity which is or can be advantageous for dispersibility and subsequent curing […] Therefore, the present case does not correspond to the selection of a sub-range of numerical values from a greater range but to the choice of a specific feature, i.e. an acid number of 10 to 40, from a generic disclosure, i.e. a generally disclosed acidity. However, according to the established case law of the Boards of appeal a generic disclosure does not destroy the novelty of the specific disclosure.

The acid number range of 12 to 60 in column 4 of document D1 cited by the [patent proprietor] clearly refers to the preferred range of the specific copolymers mentioned therein. There is no indication for a combination of this range with the phosphoric acid epoxy esters. The notion of dispersibility mentioned for both the copolymers and for the phosphoric acid epoxy esters cannot be construed to be such an indication. Copolymers of monomers containing olefinic carboxyl groups and substances carrying hydroxyl groups on the one hand and phosphoric acid epoxy esters on the other hand are completely different classes of substances and, therefore, also have different properties, e.g. a different solvation and dispersion behaviour. The fact that according to document D1 both compound groups are dispersible in water, wherein a certain acidity is apparently advantageous, does not mean that the acid numbers necessarily have to be identical. Therefore, document D1 does not directly and unambiguously disclose a range of acid numbers of 12 to 60 for the phosphoric acid epoxy esters. When transferring the preferred acid number range for copolymers (12-60) to phosphoric acid epoxy esters, the [opponent] makes an a posteriori interpretation of document D1 based on the knowledge of the invention, in order to arrive at a method according to claim 1 of the main request.

Concerning the [opponent’s] assertion that when example 1 of document D1 is reworked using the alcohols explicitly mentioned in column 2 (isopropanol and butanol), the reaction product could result in an acid number below 40, it has to be noted that the [opponent], who bears the burden of proof, has not submitted any trials which could corroborate his assertion. He rather relies on assertions of the [patent proprietor], i.e. the alleged formation of mixed esters, but he simultaneously questions them as being unproven. There are no documents available to the Board which would clearly and unambiguously prove that reworking of example 1 with isopropanol or butanol leads to a reaction product having an acid number in the claimed range. Therefore, the assertion of the [opponent] is mere speculation.

To download the whole decision (in German), click here.

The file wrapper can be found here.