Saturday 4 December 2010

Interpretative Spotlight: “Resulting”


Independent claim 1 of the opposed patent read:

A process for producing an epoxidized product of olefins, which comprises (a) a preparation process of an alcohol medium solution of hydrogen peroxide produced by catalytically reacting hydrogen with oxygen in an alcohol single medium using a halogen compound of the platinum group metal without requiring formaldehyde and (b) an oxidation process of olefins using the resulting medium solution of hydrogen peroxide in the presence of an oxidizing catalyst.

The opponent appealed the decision of the Opposition Division rejecting the opposition.

[2.1] The [opponent] has challenged novelty of the subject-matter of claim 1 of the patent in suit in view of the disclosure in document D1, particularly examples 4 and 5 of that document.

[2.2] Document D1 describes the preparation of epoxides from olefins, hydrogen and oxygen using an oxidation catalyst on the basis of titanium or vanadium silicates containing specific platinum group metals, whereby these metals are present in at least two different bond energy states (document D1, claim 7). Examples 4 and 5 of document D1 disclose the single-step preparation of propylene oxide from propene, hydrogen and oxygen in the presence of an oxidation catalyst prepared according to examples 1 and 2 of document D1. The oxidation catalyst is suspended in butanol (example 4) or methanol (example 5) in a pressurized glass reactor and contacted for 30 minutes with hydrogen gas. Thereafter, a gaseous mixture of propene, hydrogen, oxygen and nitrogen is introduced. Chromatographic analysis shows the formation of mainly propane and small amounts of propylene oxide.

The oxidation catalyst in examples 4 and 5 of document D1 has been prepared by impregnating a titanium silicate with a Palladium(II)-tetraminochloro complex followed by partial reduction. In the finished catalyst, three bond energy states of the Pd-3d5/2 photoelectrons were identified by means of X-ray photoelectron spectroscopy, which formally correspond to the oxidation states +2, +1 and 0.

[2.3] According to the [opponent], claim 1 of the patent in suit encompasses a process for producing an epoxidized product of olefins whereby the processes a) and b) are performed simultaneously as disclosed in examples 4 and 5 of document D1. In its opinion, the wording of the claim merely indicates a causal correlation between both processes. It does not however imply that the processes a) and b) are necessarily separated in space and time.

The [opponent] argued that it is part of the general knowledge of the person skilled in the art that a process with two process steps can be run in such a way that both steps are carried out in the same apparatus and the same reaction medium. In this way, the solution of the intermediate in the reaction medium obtained in the first step can be used without isolation of the solution in the second step.

The person skilled in the art would therefore understand claim 1 of the patent in suit in such a way as to include the single-step process of examples 4 and 5 of document D1.

Furthermore, the [opponent] argued that claim 1 of the contested patent as it stands is clear and that therefore there is no need for interpretation, and in particular there is no justification for a narrower interpretation of its meaning and scope. Such a narrow interpretation is also not in accordance with the description of the patent in suit. In support the [opponent] referred to paragraph [0012] of the contested patent.

[2.4] The Board is not convinced by the [opponent’s] arguments. Claim 1 of the disputed patent refers to the production of an epoxidized product of olefins comprising two processes: a) the catalytic reaction of hydrogen and oxygen in an alcoholic single-medium in the presence of a catalyst to form an alcohol single-medium solution of hydrogen peroxide and b) the oxidation of olefins in the presence of a catalyst using the resulting medium solution of hydrogen peroxide. In the understanding of the Board the wording of the claim, and in particular the wording “using the resulting medium solution of hydrogen peroxide”, clearly refers to the use of the product, namely the hydrogen peroxide solution, obtained at the end, i.e. as the result, of the first process as one of the starting products in the second process. It does not describe a situation where both processes take place simultaneously and hydrogen peroxide, which may be formed in situ, immediately reacts with the available propene.

This understanding of the Board is also confirmed by the description of the contested patent. Nowhere in the description is there an indication that the consecutive running of steps a) and b), which is the way in which the skilled reader would normally understand the wording of the claim, is merely a preferred option. In paragraph [0021] it is explicitly mentioned that “In the present invention the alcohol medium solution of hydrogen peroxide thus obtained is used in an epoxidation reaction step of olefins as the following step”. Thus, the skilled person, despite any general knowledge he may have as to how two-step processes could in theory be conducted, has no reason to interpret claim 1 of the contested patent differently from the way in which he would normally understand it. The Board cannot see either in what sense paragraph [0012] supports the [opponent’s] interpretation of claim 1, since the content of the cited paragraph is identical to the wording of claim 1 of the contested patent.

[2.5] In view of the above, the Board concludes that in the process according to the present invention the processes a) and b) are at least separated in time. The subject-matter of claim 1 of the patent in suit is therefore not anticipated by the single-step process according to examples 4 and 5 of document D1 and meets the requirement of A 54.

Should you wish to download the whole decision (T 743/07), just click here.

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