T 2284/09 23-01-2013

Summary of Facts and Submissions

I. The appeal by the patent proprietor lies from the decision of the opposition division announced on 24 September 2009 and posted on 20 October 2009 revoking European patent number EP-B1-1 062 263 (granted on European patent application number 99913253.3, derived from international application number PCT/EP1999/01628, published under the number WO 1999/047582).

II. Claim 1 of the application as filed read as follows:

"Process for the preparation of an odour-lean polyether polyol from a polyether polyol starting product which is obtained by reacting a starting compound having a plurality of active hydrogen atoms with one or more alkylene oxides, which process comprises the steps of:

(a) contacting the neutralised or unneutralised polyether polyol product with an excess of an acid having a pKa of less than 5, preferably less than 3, under hydrolysis conditions,

(b) contacting the reaction mixture with water under hydrolysis conditions, and

(c) recovering the odour-lean polyether polyol."

Claims 2-6 were dependent on claim 1.

III. The patent was granted with a set of 6 claims, whereby claim 1 read as follows, additions compared to claim 1 of the application as filed being indicated in bold, deletions in [deleted: strikethrough ]:

"Process for the preparation of an odour-lean polyether polyol from an unneutralised polyether polyol starting product which is obtained by reacting a starting compound having a plurality of active hydrogen atoms with one or more alkylene oxides, which process [deleted: comprises ]consists of the steps of:

(a) contacting the [deleted: neutralised or ]unneutralised polyether polyol product with [deleted: an excess an acid having ]between 0.001 and 0.5 mole of free acid per kg of polyether polyol which acid has a pKa of less than 5, [deleted: preferably of less than 3 ]at a temperature of 80 to 130ºC [deleted: under hydrolysis conditions ],

(b) contacting the reaction mixture with water at a temperature of 80 to 130ºC [deleted: under hydrolysis conditions ], and

(c) recovering the odour-lean polyether polyol."

Claims 2-6 were dependent on claim 1.

IV. Notices of opposition against the patent were filed on 20 June 2005 (Opponent O1) and 21 June 2005 (Opponent O2).

Opponent O1 invoked the grounds of opposition pursuant to Art. 100(a) EPC (lack of novelty, lack of inventive step).

Opponent O2 invoked the grounds of opposition pursuant to Art. 100(a) (lack of novelty, lack of inventive step) and Art. 100(c) EPC.

V. The decision of the opposition division was based on the claims of the patent as granted as the main request and three sets of claims as auxiliary requests filed with a letter dated 22 September 2009.

Claim 1 of the first auxiliary request differed from claim 1 of the main request by amendments to parts (a) and (b) of the claim, the insertions being indicated below in bold:

"(a) contacting the unneutralised polyether polyol product with between 0.001 and 0.5 mole of free acid per kg of polyether polyol which acid has a pKa of less than 5, under hydrolysis conditions at a temperature of 80 to 130ºC,

(b) contacting the reaction mixture of step (a) with water under hydrolysis conditions at a temperature of 80 to 130ºC, wherein such amount of water is added that a two-phase system can be formed, and".

Claim 1 of the second auxiliary request also differed from claim 1 of the main request by amendments to parts (a) and (b). Insertions are indicated in bold, deletions in [deleted: strikethrough ]:

"(a) contacting the unneutralised polyether polyol product with such amount of acid that the amount of free acid will be between 0.001 and 0.5 mole [deleted: of free ]acid per kg of polyether polyol which acid has a pKa of less than 5, at a temperature of 80 to 130ºC,

(b) contacting the reaction mixture of step (a) with water at a temperature of 80 to 130ºC, wherein such amount of water is added that a two-phase system can be formed, and".

The wording of the third auxiliary request is not relevant to the present decision.

The opposition division held that claim 1 of the main request did not meet the requirements of Art. 123(2) EPC. According to the application as filed, the process involved the addition of an excess of acid, i.e. the sum of a certain amount of acid in order to neutralise the unneutralised polyether polyol and an additional amount that would be present as free acid. The term "free acid" as employed in the original application referred to the acid which had not reacted with any compound in the reaction medium and which was present along with the neutralised polyether polyol in an amount of 0.001 to 0.5 mol/kg. The expression "contacting the unneutralised polyether polyol product with between 0.001 and 0.5 mole of free acid per kg of polyether polyol" in claim 1 as granted could only be interpreted as the addition of 0.001 to 0.5 mole of free acid which had not yet reacted with any component in the reaction medium to the unneutralised polyether polyol. The application as filed however did not disclose any such process meaning that the claim did not meet the requirements of Art. 123(2) EPC.

With respect to the first auxiliary request the division held that the added feature "under hydrolysis conditions" did not introduce any limitations to the subject matter compared to the main request. The phrase "contacting the unneutralised....0.001 and 0.5 mole of free acid..." would still be interpreted in the same manner as for the main request, with the further limitation that the amount of acid added was sufficient to neutralise the unneutralised polyether polyol and result in an excess of acid. The excess of acid so remaining was however not defined. Consequently the first auxiliary request also did not meet the requirements of Art. 123(2) EPC.

The second auxiliary request met the requirements of Art. 123(2) EPC. Regarding the difference between claim 1 of the second auxiliary request and claim 1 of the patent as granted the opposition division held that claim 1 of the second auxiliary request defined the addition of an excess of acid such that the amount of free acid would be within the defined ranges. Thus claim 1 of the second auxiliary request defined, compared to claim 1 of the patent as granted, a further amount of acid added to the reaction medium, corresponding to the amount necessary to neutralise the unneutralised polyether polyol. Consequently claim 1 of the second auxiliary request did not lead to the same, or a restricted scope of protection as compared to the patent as granted, meaning the requirements of Art. 123(3) EPC were not satisfied.

The same conclusion applied to the third auxiliary request, the details of which are however not of relevance for the present decision.

Accordingly the patent was revoked.

VI. On 25 November 2009 the patent proprietor lodged an appeal against the decision, the prescribed fee being paid on the same date.

The statement of grounds of appeal was received on 23 February 2010. The requests underlying the decision under appeal (main request and first-third auxiliary request) were maintained.

VII. Opponent O2 - now the respondent - replied to the appeal with a letter dated 17 June 2010.

By letter of 6 August 2010 Opponent O1 withdrew its opposition.

VIII. On 2 November 2012 the Board issued a summons to attend oral proceedings. In a communication dated 13 November 2012 the Board set out its preliminary assessment of the case.

IX. The appellant made a further written submission with a letter dated 21 December 2012 in which retyped copies of the requests (main and first to third auxiliary requests) were submitted.

X. Oral proceedings were held before the Board on 23 January 2013. Following the discussion at the oral proceedings the appellant withdrew the third auxiliary request.

XI. The arguments of the appellant can be summarised as follows:

Main request:

The interpretation of "excess acid" employed in the appealed decision, i.e. as relating to the sum of the amount of acid required for neutralisation plus an extra portion, was wrong and there was no basis for any such interpretation in the application or in the patent. The term "free acid" in claim 1 as granted related to the amount of acid remaining after neutralisation, i.e. the "excess". Thus the terms "excess acid" and "free acid" meant the same thing and correspondingly were used interchangeably throughout the original application and the patent.

If, in contrast the term "free acid" was considered not to correspond to "excess acid" then there would be an inconsistency in the disclosure of the patent since throughout the description it was indicated that an excess of acid was required.

Thus according to the application as filed, contacting the unneutralised polyether polyol with "excess" acid was the same as contacting it with "free" acid.

Furthermore, pursuant to Art. 69(1) EPC the skilled person would refer to the description to establish the correct interpretation of the claim. The correct interpretation also emerged from and was consequently confirmed by the examples of the patent in suit.

First auxiliary request:

The requirement that the contacting steps (a) and (b) were carried out under "hydrolysis conditions" imposed the additional restriction that the acid had to be used in such quantities as to allow the hydrolysis reaction to proceed. The introduction of this wording assisted the skilled reader in interpreting the term "free acid" and thus confirmed what was in fact to be understood by the claim. The feature "two phase system" had a clear basis in the application as filed.

Second auxiliary request

The feature relating to the amount of acid had to be interpreted in identical manner to the main request meaning there was no extension of the scope of protection.

If the term "free acid" was considered not to correspond to "excess acid", then amounts of acid within claim 1 as granted would not result in an excess of acid meaning that the term "free acid" would be inconsistent with the remainder of the disclosure. Under such circumstances the skilled person would conclude that what was stated in claim 1 as granted was not that which was intended, and that the intended meaning was in fact that which was defined in claim 1 of the second auxiliary request. It was allowable to replace an inaccurate technical statement with an accurate statement of the technical feature involved (following T 108/91, 17 September 1992).

XII. The arguments of the respondent can be summarised as follows.

Main request

There was no disclosure of the exact wording of claim 1 in the application as filed. The essential question relating to "excess acid" was what was the minimum amount of acid to add for neutralisation, beyond which any further amount became "excess". According to the original application, after the polyether polyol had been neutralised by the addition of the corresponding amount of acid, any further acid added would remain present as free acid, which has not reacted with any component present in the reaction mixture. The term "excess" was defined with reference to the term "free acid". However the converse was not true, i.e. there was no definition of "free" with respect to "excess" and there was no reference to "excess" in granted claim 1.

Thus from the application as filed the skilled person understood to contact the polyol with an excess of 0.001 to 0.5 mole of acid, said amount being in addition to the amount required to neutralise the polyol. In contrast claim 1 of the patent as granted could only mean to contact the unneutralised polyol with 0.001 to 0.5 mole of free acid per kg of polyether. Thus the application as filed and claim 1 of the granted patent related to contacting the polyetherpolyol with different amounts of acid.

First auxiliary request

The amendment made compared to the main request was not allowable pursuant to R. 80 EPC since it did not address a ground of opposition.

The additional features of the claim were not disclosed in combination and their introduction gave rise to further objections with respect to Art. 123(2) EPC.

Second auxiliary request

According to claim 1 of the second auxiliary request the amount of acid to be added had been changed since it had been increased by the amount needed to neutralise the unneutralised polyether polyol. Thus the scope of protection of claim 1 of the second auxiliary request was broader than that of claim 1 of the patent as granted, contrary to the requirements of Art. 123(3) EPC.

Unlike the situation underlying T 108/91 the claims of the patent as granted were not manifestly inconsistent with the disclosure of the patent, in particular the examples. Thus there was no obvious error in the claims and hence no reason to consult the description to establish what the claims "should have" defined. Furthermore since T 108/91 predated G 1/93 it was questionable whether the findings of T 108/91 were still applicable.

XIII. The appellant (patent proprietor) requested that the decision under appeal be set aside and the patent be remitted to the first instance for further prosecution on the basis of the main request as granted, or one of the first and second auxiliary requests, both submitted with the letter of 21 December 2012.

The respondent (opponent) requested that the appeal be dismissed. In the case that at least one of the sets of claims was found to comply with the requirements of Article 123(2) and Article 123(3) EPC remittal to the first instance for further prosecution was requested.