CABINET CHAILLOT

T1598/21 - Novelty of a product-by-process claim

A process feature in a product-by-process claim only contributes to the novelty of a product claim insofar as it gives rise to a distinct and identifiable characteristic of the product. Moreover, if a chemical product is not defined by structural characteristics but only by its method of manufacture, novelty can be established if evidence is provided that modification of the process parameters results in other products. It is sufficient for this purpose to show that distinct differences exist in the properties of the products

T1598/21
The appeal of the opponent lies from the decision of the opposition division rejecting the opposition against European patent No. 2 558 514.
Claims 1 and 9 read as follows:
"1. A method for producing an ultra-high intrinsic viscosity (IV) polyester resin having a final IV (IVf) of at least 0.9 dL/g, comprising:
solid-state polymerizing a polyester starting material having a starting IV (IVst) meeting the following relationship:
0.65 dL/g < IVst < 0.9 dL/g;
wherein the polyester starting material is a polyethylene terephthalate polymer, optionally containing one or more comonomers in amounts up to 30 mol%, wherein the polyester starting material has been prepared by melt polymerization up to the IVst with no more than 0.05 dL/g of IV lift due to solid-state polymerization, and wherein the polyester starting material is in solid form as a resin particle having been subjected to latent heat crystallization upon formation of the resin particle, and having a variation of IV of no more than 0.05 dL/g across any dimension of the resin particle, wherein the IV is measured according to the method given in the description."
"9. An ultra-high IV polyester resin prepared by the method of claim 1."
Claim 9 of the opposed patent is directed to an ultra-high IV polyester resin prepared by the method of claim 1.
The critical question to acknowledge or deny novelty is whether the process of claim 1 has an effect on the properties of the polyester resins derived therefrom that could distinguish them from the resins disclosed in D5.
According to established case law, a process feature in a product-by-process claim only contributes to the novelty of a product claim insofar as it gives rise to a distinct and identifiable characteristic of the product. Moreover, if a chemical product is not defined by structural characteristics but only by its method of manufacture, novelty can be established if evidence is provided that modification of the process parameters results in other products. It is sufficient for this purpose to show that distinct differences exist in the properties of the products.
In that respect, the Board has no reason to consider that the parties to the proceedings may not rely on additional experimental evidence to support their case, as alleged by the appellant. There are no apparent reasons why a patent proprietor should be denied the possibility to show by means of experimental evidence that differences exist between the subject-matter claimed and the disclosure of some piece of prior art of which they became aware only during opposition proceedings.
That being said, the Board takes the view that the evidence provided by the respondent is not sufficient to show that the polyester resins of D5 technically differ from any polyester resin prepared by the method of granted claim 1. The reasons therefore are the following:
Example 10 of document D5 discloses a PET resin having a final IV (IVf) of 1.32 dL/g corresponding to an "ultra-high IV polyester resin" as defined in present claim 1. D5 does not disclose a process according to granted claim 1. However, it is the respondent's position that examples 12 and 13 of the opposed patent (supplemented by the information provided in D19) provide evidence that properties of any PET resin prepared by the process of granted claim 1 are different from the properties of the PET resins of D5. Specifically, the step of latent heat crystallisation would have an effect on the final PET in terms of IV gradient across the polyester particles, IV lift rate and the final percentage of crystallisation.
In this respect, the Board agrees with the appellant that the comparison of example 12 with example 13 is not sufficient to prove the novelty of the subject-matter of claim 9 over example 10 of document D5. As noted in D19, the process of example 12 essentially differs from the process of claim 1 in that it does not fulfill the requirement "that the polyester starting material has been prepared by melt polymerization up to IVst with no more than 0.05 dL/g of IV lift due to solid-state polymerization".
Consequently, in the absence of suitable evidence that the PET resins of D5 having a final IV of at least 0,9 dL/g technically differ from any resin according to claim 9, the Board concludes that the subject-matter of said claim is not novel over example 10 of D5.
The patent is revoked.

 

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