T 0172/20 - Commerical product as prior art

Key points

• Quotes from machine translation. " The Respondent [opponent] asserts that the commercial PSU polymers Ultrason® S 3010 and Ultrason® S 6010 described in A5 would anticipate the novelty of claim 3"
• " The Board cannot agree with the Respondent's line of argument "
• "The burden of proving lack of novelty thus generally lies with the opponent (ie the respondent). An exception to this rule would be where the polymer of claim 3 was defined by an unusual parameter [] However, this is not the case since the polydispersity [as specified in the claim] is a very common parameter for characterizing polymers,"
• For inventive step: "the question of whether there is a technical effect compared to the PSU polymers of A5 is controversial."
• "The appellant [patentee] is of the opinion that the technical problem is to provide improved PSU polymers which have improved mechanical properties, particularly when processed into hollow fiber membranes. In particular, it is shown in A20 and A22 that PSU polymers according to claim 3 have higher epsilon breaking values ​​than the PSU polymers of comparative examples V12 and V15, which each represent the PSU polymers "Ultrason® S3010" and "Ultrason® S6010"
• "the first question is whether comparative examples V12 and V15 actually represent the polymers "Ultrason® S3010" and "Ultrason® S6010". a) In the present case, the parties did not provide a direct comparison with "Ultrason® S3010" or "Ultrason® S6010". Instead, the appellant submitted, inter alia, the comparative examples C12 and C15, which would make such a comparison possible. "
• "The [patentee] asserts that the commerical products Ultrason® S3010 and Ultrason® S6010 advertised in document A5 are manufactured using potassium carbonate with a volume-average particle size in the range of 28 to 50 µm (see A21, penultimate paragraph). The PSU polymers of comparative examples V12 and V15 were produced using potassium carbonate with a volume-average particle size of approx. 35 μm and are therefore directly comparable with Ultrason® S3010 and Ultrason® S6010. "
• "The board notes, however, that the PSU polymers Ultrason® S3010 and Ultrason® S6010 are commercial products of the appellant. Knowledge of how these products were manufactured is therefore solely subject to the complainant's power of disposal and knowledge. In particular, the respondent and the board have no way of knowing under which process conditions and in particular with which potassium carbonate (if potassium carbonate was used) these PSU polymers were produced. Thus, for answering the present question (whether the comparative examples C12 and C15 are representative for Ultrason® S3010 and Ultrason® S6010), all the evidence is in the sphere of the [ patentee]."
• "[] when all the evidence is within the control of a party, a strict standard of proof must be applied (see Case Law of the Boards of Appeal, supra, III.G.4.3.2 b)). The principle of "complete" proof ("with a probability bordering on certainty") applies. In the present case, proof of the manufacturing process for the PSU polymers Ultrason® S3010 and Ultrason® S6010 must be provided with a probability bordering on certainty."
• "The Board therefore does not have sufficient evidence that the process for producing the PSU polymers Ultrason® S3010 and Ultrason® S6010 corresponds to the production process for the comparative examples of A22."
• " In the absence of suitable comparative examples with the PSU polymers of A5, the board must come to the conclusion that a technical effect compared to the products Ultrason® S3010 and Ultrason® S6010 has not been made credible. The objective technical problem is therefore to provide an alternative PSU polymer."
• The claims are held to lack an inventive step.
• As a comment, G 1/92 held that: "The chemical composition of a product is state of the art when the product as such is available to the public and can be analysed and reproduced by the skilled person".
• Update 05.07.2023: this post was pre-scheduled and was not modified in view of G 1/23.

EPO
The link to the decision is provided after the jump, as well as (an extract of) the text of the decision.

https://www.epo.org/law-practice/case-law-appeals/recent/t200172du1.html

Reasons for decision

1. Main request - Novelty

1.1 The Respondent asserts that the commercial PSU polymers Ultrason® S 3010 and Ultrason® S 6010 described in A5 would anticipate the novelty of claim 3 (see A5, page 4, left column, first paragraph). The polydispersity (Mw/Mn) of these Ultrason® products is 3.5 or 3.7, measured using gel permeation chromatography with tetrahydrofuran (THF) as the solvent and against polystyrene (PS) as the standard (see A5, page 5, table). Although the measurement method for the polydispersity according to claim 3 uses a different solvent (dimethylacetamide instead of THF) and a different standard (PMMA instead of PS), there are no differences in the product. In other words, the Respondent considers that the PSU polymers cannot be new only because a different measurement method is used to determine the polydispersity. In addition, the PSU of A5 are suitable for the production of membranes, which speaks for a polydispersity of less than 4 (see patent in suit, paragraph [0011]). Furthermore, the Respondent takes the view that the burden of proof has been reversed with regard to polydispersity. The polydispersity is an unusual parameter. With reference to decision T 0131/03, it was therefore the task of the appellant as patent proprietor to prove that the claimed polydispersity represented a distinguishing feature compared to A5. Furthermore, the Respondent takes the view that the burden of proof has been reversed with regard to polydispersity. The polydispersity is an unusual parameter. With reference to decision T 0131/03, it was therefore the task of the appellant as patent proprietor to prove that the claimed polydispersity represented a distinguishing feature compared to A5. Furthermore, the Respondent takes the view that the burden of proof has been reversed with regard to polydispersity. The polydispersity is an unusual parameter. With reference to decision T 0131/03, it was therefore the task of the appellant as patent proprietor to prove that the claimed polydispersity represented a distinguishing feature compared to A5.

1.2 The appellant considers that A5 does not disclose a PSU polymer with a polydispersity (Mw/Mn) in the range of 2.0 to <= 4, measured by gel permeation chromatography with dimethylacetamide as solvent and against narrow distribution PMMA as standard. The respondent had not shown that the PSU polymers Ultrason® S 3010 and Ultrason® S 6010 were characterized by a polydispersity as claimed.

1.3 The Board cannot agree with the Respondent's line of argument for the following reasons:

1.3.1 First there is the question of the burden of proof. The Respondent argues that polydispersity is an unusual parameter. The patent proprietor therefore bears the burden of proving that polydispersity is a distinguishing feature compared to A5.

1.3.2 According to the settled case law of the Boards of Appeal, each party to the proceedings bears the burden of proving the facts they allege (see Case Law, 10th edition, July 2022, Section IC3.5.1). The burden of proving lack of novelty thus generally lies with the opponent (ie the respondent). An exception to this rule would be where the polymer of claim 3 was defined by an unusual parameter (see Case Law, supra, Section IC5.2.3). However, this is not the case since the polydispersity is a very common parameter for characterizing polymers, as A5 shows (see A5, page 5, table). The board therefore considers that the respondent bears the burden of showing that

The respondent referred to decision T 0131/03 without explaining to what extent it was applicable to the present case. The board considers that this decision, following the case-law cited above, concerns a case where an unusual parameter is used as a limiting feature (see guiding sentence of T 0131/03). However, this is not the case with claim 3 of the main request for the reasons set out above.

1.3.3 The question of the novelty of claim 3 compared to A5 is also discussed. According to settled case law, the claimed subject-matter must be directly and unambiguously derived from the state of the art so that a lack of novelty can be concluded. In other words, there must be no doubt - and not just probability - that the claimed subject-matter was directly and unequivocally disclosed in the prior art (Case Law of the Boards of Appeal, supra, Section IC4.1).

1.3.4 In the present case, A5 discloses two PSU polymers ("Ultrason® S3010" and "Ultrason® S6010"), which are characterized in that their polydispersity is 3.5 and 3.7, respectively, with the polydispersity

by gel permeation chromatography (GPC) with THF as solvent and against polystyrene (PS) as standard

measured (see A5, page 5).

1.3.5 However, the polydispersity of this PSU measured using the method defined in claim 3 is not disclosed in A5. In this respect, the board agrees with the opposition division that the measuring method can have an influence on the molecular weight and thus on the polydispersity of the PSU (see decision under appeal, point II.2.5.2.2). Finally, it is noted that, for the sake of clarity, patent applicants are usually asked to indicate in the claims the method of measuring a parameter (see Case Law, supra, Section II.A.3.5). Thus, case law usually assumes that the measurement method can have an influence on the results.

1.3.6 Since the polydispersity values ​​specified in A5 (3.5 and 3.7) are relatively close to the upper limit defined in claim 3 (<4), it cannot be assumed without a doubt that the polydispersity of the PSU of A5 has a value of 2.0 to less than or equal to 4 when measured by GPC against narrow distribution PMMA (rather than PS) as standard and dimethylacetamide (rather than THF) as solvent. In particular, the Respondent (who bears the burden of proof on the issue of lack of novelty) has not provided any evidence to dispel these doubts.

1.3.7 Even if the patent in suit teaches that PSU polymers with polydispersities (Q) of > 4 are only conditionally suitable for the production of membranes, said PSU are still not completely ruled out (see paragraph [0011] of the patent in suit). It can therefore not be concluded with certainty that the PSU of A5 must have a polydispersity as claimed just because these PSU are used in membranes.

1.3.8 In summary, the board concludes that A5 does not directly and unambiguously disclose a PSU polymer characterized by a polydispersity (Mw/Mn) in the range of 2.0 to < 4 as measured by gel permeation chromatography with dimethylacetamide as the Solvent and against narrow distribution PMMA as standard. The subject-matter of claim 3 is thus novel over A5.

2. Main request - Inventive step

2.1 Closest prior art

The parties and the opposition division have chosen A5 as the closest prior art. The Chamber sees no reason to deviate from this choice.

2.2 Differentiator

When assessing inventive step, the parties took the view that the subject-matter of claim 3 differs from the PSU polymers "Ultrason® S3010" and "Ultrason® S6010" of A5 in that the PSU polymer

"a polydispersity (Mw/Mn) in the range of 2.0 to <= 4 as measured by gel permeation chromatography using dimethylacetamide as the solvent and against narrow-distribution polymethyl methacrylate as the standard"

having.

The board also has no reason to deviate from this view (only reference is made to the assessment of novelty).

2.3 Technical task

However, the question of whether there is a technical effect compared to the PSU polymers of A5 is controversial.

2.3.1 The appellant is of the opinion that the technical problem is to provide improved PSU polymers which have improved mechanical properties, particularly when processed into hollow fiber membranes. In particular, it is shown in A20 and A22 that PSU polymers according to claim 3 have higher epsilon breaking values ​​than the PSU polymers of comparative examples V12 and V15, which each represent the PSU polymers "Ultrason® S3010" and "Ultrason® S6010" ( see the complainant's letter of 10 January 2023, page 6, fourth and fifth paragraphs; A22, table).

2.3.2 The Respondent is of the opinion that documents A20 to A22 do not contain enough information to assess whether Comparative Examples C12 and C15 are actually representative of the PSU polymers of A5. In the absence of suitable comparative examples, the only problem to be solved compared to A5 is the provision of an alternative PSU polymer.

2.3.3 For the chamber, the first question is whether comparative examples V12 and V15 actually represent the polymers "Ultrason® S3010" and "Ultrason® S6010".

a) In the present case, the parties did not provide a direct comparison with "Ultrason® S3010" or "Ultrason® S6010". Instead, the appellant submitted, inter alia, the comparative examples C12 and C15, which would make such a comparison possible. For the sake of completeness, it should be mentioned that comparative examples C11 and C13 were also mentioned (as a comparison to “Ultrason® S6010”). However, these play no additional role in the following assessment of the facts.

b) Since a direct comparison with Ultrason® materials is not available, the Chamber must answer the question to what extent comparative examples V12 and V15 actually represent "Ultrason® S3010" and "Ultrason® S6010".

c) The complainant asserts that the sales products Ultrason® S3010 and Ultrason® S6010 advertised in document A5 are manufactured using potassium carbonate with a volume-average particle size in the range of 28 to 50 µm (see A21, penultimate paragraph). The PSU polymers of comparative examples V12 and V15 were produced using potassium carbonate with a volume-average particle size of approx. 35 μm and are therefore directly comparable with Ultrason® S3010 and Ultrason® S6010. In addition, the other process parameters of the comparative examples from document A22 for the production of the PSU polymers would correspond to the process parameters for the production of the PSU polymers Ultrason® S3010 and Ultrason® S6010 of document A5.

d) The board notes, however, that the PSU polymers Ultrason® S3010 and Ultrason® S6010 are commercial products of the appellant. Knowledge of how these products were manufactured is therefore solely subject to the complainant's power of disposal and knowledge. In particular, the respondent and the board have no way of knowing under which process conditions and in particular with which potassium carbonate (if potassium carbonate was used) these PSU polymers were produced. Thus, for answering the present question (whether the comparative examples C12 and C15 are representative for Ultrason® S3010 and Ultrason® S6010), all the evidence is in the sphere of the appellant.

e) According to settled case law, when all the evidence is within the control of a party, a strict standard of proof must be applied (see Case Law of the Boards of Appeal, supra, III.G.4.3.2 b)). The principle of "complete" proof ("with a probability bordering on certainty") applies. In the present case, proof of the manufacturing process for the PSU polymers Ultrason® S3010 and Ultrason® S6010 must be provided with a probability bordering on certainty.

f) However, the complainant only submitted an affidavit according to which the sales products Ultrason® S 3010 and 6010 were manufactured using potassium carbonate with a volume-average particle size D[4,3] in the range of 28 to 50 µm (see A21). Even if the Chamber does not question this, this alone is not sufficient to provide complete proof of the complete manufacturing process of the PSU polymers Ultrason® S3010 and Ultrason® S6010. In particular, it is not established what other process conditions and steps were used to produce these products. Nor can this gap be filled by merely pointing out in the statement of grounds of appeal

g) The Board therefore does not have sufficient evidence that the process for producing the PSU polymers Ultrason® S3010 and Ultrason® S6010 corresponds to the production process for the comparative examples of A22.

h) The complainant also argued that the VC of comparative examples C12 and C15 was almost identical to the VC of the polymers Ultrason® S3010 and Ultrason® S6010. In this regard, the board agrees with the respondent that the identity of the VZ alone is not sufficient to ensure the identity of the polymers. It can namely be seen in A22 that PSU polymers with identical VN nevertheless have different properties (see Examples V1 and 7). So it is not credible that the comparative examples C12 and C15 correspond to the polymers Ultrason® S3010 and Ultrason® S6010 just because the VZ are almost identical.

i) In summary, the Chamber comes to the conclusion that there is insufficient evidence that the comparative examples presented in A20 and A22 represent the PSU polymers Ultrason® S3010 and Ultrason® S6010.

2.3.4 In the absence of suitable comparative examples with the PSU polymers of A5, the board must come to the conclusion that a technical effect compared to the products Ultrason® S3010 and Ultrason® S6010 has not been made credible. The objective technical problem is therefore to provide an alternative PSU polymer.

2.4 Obviousness of the solution

It remains to be assessed whether the claimed invention would have been obvious to a person skilled in the art in view of the closest prior art and the objective technical problem.

2.4.1 In accordance with the contested decision, the Respondent takes the view that it is obvious from A5 or A4 to set the polydispersity of the PSU polymers between 2 and 4.

2.4.2 The complainant is of the opinion that A5 and A4 do not suggest solving the task for the following reasons:

i) On the basis of document A5, the person skilled in the art does not receive any indication of the solution to the objective technical problem on which it is based.

ii) A4 does not concern hollow fiber membranes.

iii) The task set in A4 was to improve the chlorine resistance of composite flat membranes. In addition, A4 does not allow any conclusions to be drawn about the mechanical properties of the modified PSU polymer.

iv) A4 does not relate to a PSU polymer as claimed, but to polyethersulfone polymers (PESU polymers).

v) The method of A4 is only suitable for polysulfone polymers with a number average molecular weight of 43,000 g/mol to 54,000 g/mol. If the person skilled in the art nevertheless applied the teaching of A4 to the products Ultrason® S3010 and Ultrason® S6010 according to document A5, then in the case of Ultrason® S3010, which has a number-average molecular weight of approx. 15,000 g/mol, no PSU polymer would be formed left over. The same applies to the PSU polymer Ultrason® S6010 with a number-average molecular weight of approx. 16,000 g/mol. The process disclosed in A4 is therefore uneconomical and unsuitable for the commercial large-scale production of PSU polymers.

2.4.3 The board cannot agree with the appellant's line of argument for the following reasons.

As already mentioned, the problem to be solved is simply to provide an alternative PSU polymer. Thus, one skilled in the art would have considered documents dealing with alternative PSU polymers.

The person skilled in the art knows from A5 that other polysulfone polymers with a polydispersity of 2 to 4 (measured by GPC against PMMA as standard and dimethylacetamide as solvent) are suitable for membranes (see A5, page 5, Ultrason® E and Ultrason® P polymers). However, the question arises as to whether, starting from A5, the person skilled in the art would have been able to provide a PSU polymer with the claimed polydispersity.

A4 discloses a process which enables the person skilled in the art to increase the molecular weight of polymers, for example by fractional precipitation, and thereby reduce the polydispersity (see A4, column 5, lines 13-18). In Example 1 a process is disclosed in which a PESU polymer with a calculated polydispersity of 1.99 is prepared from a PESU polymer with a calculated polydispersity of 3.98 by successive precipitations (see A4, column 5, lines 25-26 and lines 47-49). In the process, the low-molecular polymer fraction is separated off. Furthermore, contrary to the appellant's contention, the teaching of A4 includes not only PESU polymers but also PSU polymers (see A4, column 4, lines 3-15 and column 8, lines 19-27).

The board would agree with the appellant's argument v) if the skilled person actually had to apply the entire teaching of A4 (i.e. according to claim 1 of A4 provide a PSU polymer with a number average molecular weight (Mn) of at least 59 000 g/mol would have to). However, in the present case the problem to be solved is simply to provide an alternative PSU polymer starting from the products of A5. As already mentioned, it is known from A4 how the polydispersity of polysulfone polymers can be gradually reduced. In Example 1 of A4, 4 consecutive precipitations are needed to reduce the polydispersity from 4 to 2. Assuming the polydispersity of Ultrason® S3010 or Ultrason® S6010 was slightly above 4 (as suggested by the appellant), one skilled in the art would only make as many precipitations as are required to lower the polydispersity below 4. Contrary to the opinion of the appellant, the skilled person does not have to need and apply the entire teaching of A4 for this.

The fact that the A4 process may be uneconomical is irrelevant here. Rather, what matters is the fact that A4 provides one skilled in the art with a method to reduce the polydispersity of a PSU polymer.

2.4.4 In summary, the skilled person who wanted to provide an alternative PSU polymer with a polydispersity ranging from 2 to 4 (measured by GPC against narrow distribution PMMA as standard and dimethylacetamide) as mentioned in A5 itself for some products , would have found at least one method in A4 to provide such a PSU polymer. The board is thus of the opinion that the solution proposed in claim 3 is not inventive compared to A5 in combination with A4.

3. Auxiliary requests 1 to 4 - admission