T 0948/02 05-04-2005

Summary of Facts and Submissions

I. The grant of European patent No. 0 360 746 in respect of European patent application No. 89 810 680.2, filed on 12 September 1989 and claiming priority of 21 September 1988 of an earlier application in the United Kingdom (8822150), was announced on 17 July 1996 (Bulletin 1996/29). The above patent application had been transferred with effect from 22 March 1993 from the original Applicant to the later Patent Proprietor (FMC Corporation (UK) Ltd.). The patent was granted with 14 claims.

Independent Claim 1 as granted read as follows:

"1. Cotelomer compounds having the formula I:

FORMULA I

and salts there of wherein A1 is a random polymeric residue comprising at least one unit of formula II:

FORMULA II

and at least one unit which differs from a unit of formula II and which has the formula III:

FORMULA III

X1 is hydrogen, C1-C4 alkyl, phenyl, an alkali metal- or alkaline earth metal atom, a ammonium ion or an amine residue;

m and n are integers such that the sum of m and n is an integer of from 2 to 100, the ratio n:m being from 99 to 1:1 to 99, provided that the resulting cotelomer is water-soluble;

R1 is -OX2 wherein X2 may be the same as or different from X1 and is hydrogen, C1-C4 alkyl, phenyl, an alkali metal- or an equivalent of an alkaline earth metal atom, or an ammonium or an amine residue, or X1 and X2 together may be a multivalent metal atom forming a neutral complex with anionic moieties of the cotelomer molecule, or X1 and X2 may be linked by a -CH2-CH2- residue to form a ring structure;

R2 is hydrogen, or methyl;

X3 is the same as or different from X1 and X2 and is hydrogen, C1-C4 alkyl, an alkali metal- or an equivalent of an alkaline earth metal atom, or an ammonium or an amine residue;

R3 is hydrogen, or a residue -CO2R6 wherein R6 is hydrogen or a straight- or branched chain C1-C8 alkyl residue;

R4 is hydrogen or a residue -CO2R6 wherein R6 is hydrogen,

R5 is a residue -CO2R7 in which R7 is hydrogen, a straight or branched C1-C8 alkyl residue, a straight or branched C1-C8 alkyl residue substituted by one or two carboxylic acid groups, or is a phenyl residue, a phenyl residue substituted by hydroxyl or SO3X4, or is an hydroxyl, acetomethyl, -SO3X4, or -PO3(X4)2 in which X4 is hydrogen, an alkali metal or an equivalent alkaline earth metal, a residue -CONR9R10 in which R9 and R10 are the same or different and each is hydrogen, a straight- or branched chain C1-C8 alkyl, hydroxymethyl, or a residue -CH(OH)CO2X4, - C(CH3)2CH2SO3X4, -C(CH3)2CH2CO2X4 or -C(CH3)2CH2PO3(X4)2 in which X4 has its previous significance, or -N(R11)COCH3 in which R11 is hydrogen or straight- or branched C1-C4 alkyl, or R5 with R3 may form a carboxylic anhydride moiety -CO.O.CO-.".

Independent Claim 6 related to a process for the production of cotelomer compounds of the above formula I, and independent Claim 9 concerned a method of treating an aqueous system by adding such a compound of formula I or a salt thereof.

The remaining claims were appendant to their respective preceding independent claim. Thus, Claims 2 to 5 and 14 related to further elaborations of the cotelomer of Claim 1, Claims 7 and 8 to further elaborations of the process as defined in Claim 6, and Claims 10 to 13 concerned elaborations of the method of Claim 9.

II. The wording of Claims 1, 2, 6, 7 and 8 as originally filed, which played a role in these proceedings, had been as follows:

"1. Cotelomer compounds having the formula I:

FORMULA I

and salts thereof wherein A1 is a random polymeric residue comprising at least one unit of formula II:

FORMULA II

and at least one unit which differs from a unit of formula II and which has the formula III:

FORMULA III

X1 is hydrogen, C1-C4 alkyl, phenyl, an alkali metal- or an equivalent of an alkaline earth metal atom, an ammonium ion or an amine residue;

m and n are integers such that the sum of m and n is an integer of from 2 to 100, the ratio n:m being from 99 to 1:1 to 99, provided that the resulting cotelomer is water-soluble;

R1 is -OX2 wherein X2 may be the same as or different from X1 and is hydrogen, C1-C4 alkyl, phenyl, an alkali metal- or an equivalent of an alkaline earth metal atom, or an ammonium or an amine residue, or X1 and X2 together may be a multivalent metal atom forming a neutral complex with anionic moieties of the cotelomer molecule, or X1 and X2 may be linked by a -CH2-CH2- residue to form a ring structure;

R2 is hydrogen, C1-C4 alkyl or C1-C4 alkyl substituted by one or two carboxyl groups;

X3 is the same as or different from X1 and X2 and is hydrogen, C1-C4 alkyl, an alkali metal- or an equivalent of an alkaline earth metal atom, or an ammonium or an amine residue;

R3 is hydrogen, methyl or a residue -CO2R6 wherein R6 is hydrogen, a straight- or branched chain C1-C8 alkyl residue or a straight- or branched chain C1- C8 alkyl residue substituted by a hydroxy group;

R4 is hydrogen, a straight- or branched chain C1-C4 alkyl residue, hydroxymethyl or a residue -CO2R7 wherein R7 is hydrogen, a residue of formula

FORMULA

a residue of formula -[CH2-CH(R8)O]zH, in which R8 is hydrogen, methyl or phenyl and z is an integer from 1 to 20, or R7 is a straight- or branched chain C1-C8 alkyl residue or a straight- or branched chain C1-C8 alkyl residue substituted by hydroxy or -SO3X4 in which X4 is hydrogen or an alkali metal- or an equivalent of an alkaline earth metal atom;

R5 is a residue -CO2R7 in which R7 has its previous significance, a straight or branched C1-C8 alkyl residue, a straight or branched C1-C8 alkyl residue substituted by one or two carboxylic acid groups, or is a phenyl residue, a phenyl residue substituted by hydroxyl or S03X4, or is an acetyl residue, hydroxymethyl, hydroxyl, acetomethyl, -SO3X4, -CH2SO3X4 or -PO3(X4)2 in which X4 has its previous significance, a residue -CONR9R10 in which R9 and R10 are the same or different and each is hydrogen, a straight- or branched chain C1-C8 alkyl, hydroxymethyl, or a residue -CH(OH)CO2X4, -C(CH3)2CH2SO3X4, -C(CH3)2CH2CO2X4 or -C(CH3)2CH2PO3(X4)2 in which X4 has its previous significance, or -N(R11)COCH3 in which R11 is hydrogen or straight- or branched C1-C4 alkyl, or R5 with R3 may form a carboxylic anhydride moiety -CO.O.CO-.

2. Cotelomer compounds of formula I according to claim 1 wherein R2 is hydrogen or methyl.

6. Cotelomer compounds of formula I according to claim 2 wherein R3 is hydrogen or a residue -CO2R6 in which R6 is hydrogen or C1-C8 alkyl; R4 is hydrogen or -CO2R6 in which R6 is hydrogen or C1-C8 alkyl; and R5 is -CO2R7 in which R7 is hydrogen, C1- C8 alkyl or C1-C8 alkyl substituted by a hydroxy group, or R5 is C1-C8 alkyl or C1-C8 alkyl substituted by one or two carboxyl groups, or R5 is phenyl, or phenyl substituted by hydroxyl or SO3X4, or is hydroxyl, acetomethyl, -SO3X4 or -PO3(X4)2 in which X4 is as defined in claim 1, -CONR9R10 wherein R9 and R10 are as defined in claim 1, or -N(R11)COCH3 in which R11 is as defined in claim 1, or R5, with R3, forms a carboxylic anhydride moiety -CO.O.CO-, R1 is as defined in claim 1; and the sum of m and n ranges from 2 to 32.

7. Cotelomer compounds of formula I according to claim 1 wherein R3 and R4 are each hydrogen or carboxyl and R5 is carboxyl, C1-C8 alkyl or C1-C8 alkyl substituted by one or two carboxyl groups, or R5 is phenyl or phenyl substituted by hydroxyl or SO3X4, or is hydroxyl, acetometyl, -SO3X4 or -PO3(X4)2 in which X4 has its previous significance, -CONR9R10 wherein R9 and R10 are as defined in claim 1 or -N(R11)COCH3 in which R11 is as defined in claim 1.

8. Cotelomers of formula I according to claim 1 which are free of readily-hydrolyzable ester groups.".

III. On 17 April 1997, a Notice of Opposition was filed in which revocation of the patent in its entirety was requested on the ground that none of the claims defined patentable subject-matter (Article 100(a) EPC). To this end, the Opponent relied initially on thirteen, later on fourteen documents including

D1: GB-A-0 996 737,

D6: US-A-4 681 686 and

D13: DE-A-30 44 214.

Novelty objections were raised against the above granted claims, in particular, on the basis of D1 and D13. Nor was an inventive step seen by the Opponent with regard to a number of citations in conjunction with D6. In a letter dated 15 February 2002 (page 3, item c), the objection of lack of inventive step was further elaborated by the Opponent with regard to D13 and/or D1 with or without D6 and some further documents, not having been relevant in these appeal proceedings.

In the course of the opposition proceedings, both parties filed experimental reports and explanatory comments thereon. Reference will be made to all the reports in further detail herein below.

Taking effect on 4 April 2001, the patent in suit was further transferred from the Patent Proprietor, to whom the patent had been granted, to a new Patent Proprietor.

At oral proceedings held before the Opposition Division on 17 April 2002, the new Patent Proprietor filed two new sets of claims to replace all previous claims, including two sets of claims (referred to as Annex A and Annex B), which had been filed with the letter dated 8 December 1997 as Conditional Submissions One and Two, and a suggested amendment of the first of these previous sets of claims (letter dated 2 April 2002, page 6).

Claim 1 of the new Main Request differed from its granted version (section I, above) by the new further limited definition of R5 reading as follows:

"R5 is acetomethyl or a residue -CONR9R10 in which R9 and R10 are the same or different and each is hydrogen, a straight- or branched chain C1-C8 alkyl, hydroxymethyl, or a residue -CH(OH)CO2X4, -C(CH3)2CH2SO3X4, -C(CH3)2CH2CO2X4 or -C(CH3)2CH2PO3(X4)2 in which X4 has its previous significance, or -N(R11)COCH3 in which R11 is hydrogen or straight- or branched C1-C4 alkyl.".

In Claim 1 of the new Auxiliary Request, R5 was further limited also to exclude acetomethyl.

The further claims remained unchanged.

According to the Minutes of the oral proceedings, the Opponent objected to these new requests under Article 123(2) EPC. Moreover, it took the view that, in view of the new claims, D13 was the closest state of the art to be considered for inventive step, because it related to the same problem as the patent in suit and provided almost the same solution therefor. The Patent Proprietor, however, "considered D6 as 'structurally' the closest prior art. The problem was to provide new cotelomers with an improved performance in the treatment of water." The skilled person would not have combined D6 with D13, "as none of these documents gave a hint to use either a phosphonic group instead of a phosphenic group of D6 or to transfer the side chains of D6 to D13". Any combination of the two documents could only be based on hindsight (Minutes, section 4).

IV. In the decision orally announced at the end of the above oral proceedings and issued in writing on 27 June 2002, the patent was revoked.

Contrary to the arguments of the Opponent, the Opposition Division found that the requirements of Articles 123(2) and (3) EPC were met by both sets of claims as amended (Main Request and Auxiliary Request; section III, above), because the definition of the claimed compounds of formula I had only been limited in respect of group R5, ie of only one list of definitions. A new selection would have appeared only if deletions out of at least two lists had been effected.

Moreover, it was held that the subject-matter claimed was novel over each of D1, D6 and D13.

However, having regard to the fact that the technical problem to be solved vis-à-vis the closest state of the art, D6, was seen in the provision of an alternative to prior art cotelomers which had excellent corrosion and scale inhibition properties, the claimed cotelomers were found to lack an inventive step, since it had been obvious to arrive at these compounds from the combination of D6 and D13.

Both the decision (item I.10) and the minutes (item 1) contained, without further details or comments, a short mention of comparative tests submitted by the Patent Proprietor in the above oral proceedings.

V. On 5 September 2002, a Notice of Appeal was filed by the above new Patent Proprietor/Appellant against this decision. The prescribed fee was paid on the same date. The Statement of Grounds of Appeal was received on 6 November 2002 together with three sets of claims representing a Main, a first and a second Auxiliary Request, respectively.

The new Main Request and the new first Auxiliary Request differed from their respective previous versions (section III, above) only in that, in each Claim 1, the clause "in which X4 has its previous significance" had been replaced by "in which X4 is hydrogen, an alkali metal or an equivalent alkaline earth metal". In Claim 1 of the second Auxiliary Request, the meaning of R5 had been restricted to the residue -CONR9R10 and to further limited definitions of R9 and R10.

In the Statement of Grounds of Appeal, the Appellant disputed the findings in the decision under appeal concerning the issue of inventive step. Additionally, it filed experimental data, thereby pointing out that these data had already been submitted in the above oral proceedings, in order to demonstrate an improved effectiveness of compounds within the restricted scope of the claims over those of D6 (cf. section IV, last paragraph, above).

VI. In a letter dated 23 July 2003, the Respondent disputed the arguments of the Appellant, maintained its objection of lack of novelty over D1, and reiterated its objection of lack of inventive step, specifically, with regard to D13 alone and D13 in combination with D6, respectively. Moreover, the experimental results provided by the Appellant were disputed.

In particular, the Respondent argued that by removing the possibility of R5 being COOH or COOCH3 in any one of the new requests, the Appellant had tried to render the claimed subject-matter novel over D13, but had not demonstrated an inventive step for the remaining claimed phosphono-cotelomers (on the basis of phosphorous acid or its derivatives as the telogen) over those known from D13, eg by providing comparative data to this end. Furthermore, with regard to the various different substituents grouped together under the single grouping R5, the Respondent argued that it was evident that the Appellant and the Primary Examiner of the Examining Division, who had allowed the basic application to progress to grant, must have considered that a person skilled in the art would have viewed all the R5 substituents as having the alleged benefits of the claimed invention, in particular, since the worked examples did not represent the full range of the R5 substituents. Moreover, a further experimental report was submitted with this letter.

VII. The above issues were further disputed between the parties (i) in a letter of the Appellant, dated 4 March 2005, including additional experimental results and new copies of claims according to the Main and first Auxiliary Requests already on file and a further amended set of claims according to a new second Auxiliary Request (dealt with further below), and (ii) a letter of the Respondent, dated 30 March 2005. With respect to the above Requests, the Respondent stated that it would make no objections with regard to novelty.

VIII. As mentioned above, a number of experimental reports and, furthermore, explanatory submissions to these reports were filed by both parties in the course of the opposition and appeal proceedings (numbered Reports 1 to 6, herein below):

1. In Attachment A to the Opponent's letter dated 1. July 1998, acrylamide and methyl acrylate were copolymerised by means of sodium persulphate in the presence of sodium phosphite pentahydrate, thereby following, according to the Opponent, the process of D1, Example 1. Further details of this Attachment A were given in a Declaration by Mr Weinstein submitted by the Opponent as a facsimile with its letter dated 15 February 2002. The original of the declaration was filed with a short letter dated 21 February 2002.

2. With the letter of 2 April 2002, the present Patent Proprietor/Appellant submitted an unsigned Declaration by Mr Wilson ("Attachment A"; its signed version was filed with a short letter dated 5 April 2002) containing three experiments, the products of which were evaluated with regard to the CaCO3 inhibition threshold test (therein, the amounts were given in grams, unlike Example 1 of the patent in suit referring to parts by weight):

Experiment 1 was a repetition of the experiment of Opponent's Attachment A (Report 1, above).

Experiment 2 was identified as a repetition of Example 1 of the patent in suit, with 60 g of ethyl acrylate, 17.2 g of vinyl acetate, 7.3 g of di-t-butyl peroxide and 26.6 g of diethyl phosphite (Example 1: 27.6 parts by weight), a final yield of 34.3 g (Example 1: 45 parts by weight) and a 1-ppm-CaCO3 inhibition threshold value of 56.3 (the product of Example 1 was used in Example 2 of the patent in suit to give a value of 52).

Experiment 3 corresponded to Experiment 2, above, with the modification that 51.7 g of methyl acrylate and 14.2 g of acrylamide were used as the monomers.

Moreover, an Exhibit 5 "DATA DEMONSTRATING THE MULTIFUNCTIONALITY OF BELCLENE 494 AND IMPROVEMENTS OVER BELSPERSE 164 (a phosphinated homopolymer of acrylic acid)" was filed to "show the advantages of a phosphonated cotelomer over a phosphinated homopolymer" (Exhibit 5: page 2).

A brochure was also included, referring to Belclene® 494 ("Attachment B"; ©1994 FMC Corporation), a "novel" product first marketed in the same year (the accompanying letter: page 6, Chapter C).

3. A second declaration by Mr Weinstein, discussing the results of Opponent's Attachment A (Report 1, above) and the experimental data in Mr Wilson's Declaration (Report 2, above), was filed by the Opponent with the letter of 12 April 2002.

4. Together with the Statement of Grounds of Appeal, "Comparative Test I with Document D6" was submitted to compare the properties of "Compound 19 in D6" with "Belclene 494 (comprised by the opposed patent)" as tested in the Calcium Carbonate Threshold Test of Example 35 of D6 and a "Test Method to Determine the Corrosion Control Activity of Polymers".

Furthermore, "COMPARATIVE TEST II", also enclosed, included four experiments. It contained the statement "Examples 1 and 2 are made in a similar manner to example 1 from EP360746B1 and examples 3 and 4 made in a similar manner to that described in D6. Examples 1 and 2 are phosphonocarboxylic acids and examples 3 and 4 are the equivalent phosphinocarboxylic acids." These examples were then described under the headings of "Experiment 1" to "Experiment 4".

Experiment 1 was based on methyl acrylate and acrylamide and corresponded to the Experiment 3 in Report 2, above, except for 27.6 g instead of 26.6 g of di-ethyl phosphite being used. The CaCO3 inhibition thresholds at 1, 2 and 4 ppm, respectively, were, nevertheless, identical to those in Report 2 (at 2 ppm: 90 and at 4 ppm: 100) with a slight deviation at 1 ppm (Report 2: 83.8, Report 4: 84).

Experiment 2 differed from Experiment 2 of Report 2 in that 27.6 g of diethyl phosphite (instead of 26.6 g) was used, nevertheless, giving the same final yield of 34.3 g and the same 1-ppm- CaCO3 inhibition threshold value (56.3) as Experiment 2 in Report 2, above.

In both of these experiments, the phosphonic acid and carboxylic ester groups in the respective liquid products of the reaction were hydrolysed to the corresponding free acid groups as described in Example 1 of the patent in suit (and in Report 2).

In Experiment 3, acrylic acid and acrylamide were telomerised with sodium hypophosphite.

Experiment 4 described the telomerisation of acrylic acid and vinyl acetate with sodium hypophosphite.

The resulting products were then tested in the Calcium Carbonate threshold Test (according to Example 2 of the patent in suit) and in the Test Method to determine the Corrosion Control Activity of Polymers. In these tests, the products of Experiments 3 and 4 were referred as "Product from D6". Experiments 1 and 2 showed improved results in comparison to Experiments 3 and 4 in both tests.

Additionally, the same tests were also carried out with products according to Examples 1, 2 and 19 of D6 in comparison with Belclene 494, referred to at the bottom of the last page of this report as "a phosphonated copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulphonic acid sodium salt (AMPS)".

5. In a Declaration by Mr Shulman, filed with the Respondent's letter dated 23 July 2003, tests according to the method disclosed in Example 2 of the patent in suit were reported, which were based on experimental cotelomers "synthesized according to US ... (hereafter D6) modified, as appropriate, according to DE ... (hereafter D13) or EP ..." (ie the patent in suit). In particular, a phosphino- cotelomer was synthesised by repeating Example 6 of D6 and, by repeating that example but with the modifications that sodium hypophosphite was replaced by dimethyl phosphite (as used in Example 33 of D13; experiment "SH 3742") and orthophosphorous acid (another telogen mentioned in the patent in suit), respectively, two phosphono-cotelomers were prepared.

6. Counter-experiments to the latter declaration (in the form of a further Declaration by Mr Wilson) were submitted by the Appellant with the letter dated 4 March 2005. In addition to the repetition of the above three experiments (as described in the Shulman Declaration), "SH 3742" was repeated with the subsequent hydrolysis step as described in Example 1 of the patent in suit.

IX. Oral proceedings were held on 5 April 2005.

(a) At the beginning of the hearing, the parties were given some provisional, preliminary remarks concerning the question of whether the sets of claims on the file complied with the requirements of Article 123(2) EPC. Whilst in comparison to the granted version, the compounds of formula I had been limited in the course of the opposition proceedings only with respect to the meanings of group R5, further limitations had already been made during the examination proceedings in respect of, in particular, R4, R6 and R7.

Hence, the basis for the specific combinations of definitions of the compounds now claimed in the application as originally filed was to be established without including additional information not directly and unambiguously derivable from the application as filed.

It was pointed out to the parties that the patent in suit contained not a single example within the scope of the claims of any one of the valid requests on file.

Specific reference was made to the arguments of the Respondent referred to in section VI, above, in particular to those concerning D13 and the amendments in the claims suggested by the Patent Proprietor/Appellant in order to avoid the anticipatory disclosure of that document.

Hence, in the Board's view, the question arose of whether the limitation of the claims in comparison to their initial version amounted to the provision of a new selection not derivable in this form from the application as filed.

(b) In the subsequent discussion concerning the above issues, the Appellant maintained the point of view it had already maintained during the opposition proceedings, which had been accepted in the decision under appeal (section IV, above), ie that the patent in suit had only been amended in respect of one list of definitions. Moreover, these amendments had not resulted in one single product but still encompassed a multitude of cotelomers, so that no individualisation occurred. Such amendments had already been allowed in a number of decisions of the Boards of Appeal.

Whilst it had been true that other definitions of symbols used in formula I had been amended during the examination proceedings, the Examining Division had accepted that those modifications had complied with the requirements of Article 123(2) EPC and had, consequently, granted the patent in suit, since those amendments had been based on preferred elaborations in the description and the original claims.

During subsequent opposition proceedings, the Patent Proprietor should not, in the Appellant's view, be prevented from meeting new objections raised in those proceedings on the basis of documents of which it had not been aware when filing the patent application forming the basis of the patent in suit.

By the restrictions in the claims during the opposition and appeal proceedings, only less preferred parts of the previously claimed subject- matter had been abandoned to meet the objections raised by the Opponent/Respondent. Reference could be made to the preferred elaborations according to Claims 2 and 6 or to Claim 7, as originally filed, which provided the basis for these limitations.

These restrictions in the claims did not, however, amount to a shift of the core of the claimed invention. Rather, the essence of the claimed invention remained the same, ie the provision of new cotelomers which had improved corrosion and scale inhibition properties when used in aqueous systems, in particular in comparison to the phosphino-cotelomers of D6 which had been the initial basis for the draft of the application from which the patent in suit was derived.

Thus, it had been shown in Comparative Tests I and II that switching from phosphino-telomers of D6 to the phosphono-telomers according to the patent in suit resulted in significant improvements of the properties necessary for the above use. Thus, Belclene© 494 (mentioned above), which complied with the definitions in present Claim 1, showed clear improvements in this respect in comparison to the products of Examples 1, 2 and 19 of D6 (section VIII, Report 4, above, wherein the products of Examples 2 and 19 had been based on the same taxogens, ie the same polymerisable compounds having ethylenic unsaturation). Since the cotelomers of D13 were not comprised in the definitions of the claims, it had not been deemed necessary to compare the claimed subject-matter with D13, which document had not, in the decision under appeal, been considered as the closest state of the art. Neither an implicit nor an explicit disclosure of the compounds now claimed was contained in documents D6 or D13.

As regards an objection concerning the fact that some of the experiments submitted during the opposition and appeal proceedings had included a hydrolysis of their products, others however not, the Appellant referred to page 6, lines 45 to 49 of the patent in suit (corresponding to page 6, lines 25 to 29 of the A-publication) where "hydrolysis had strongly been recommended" and to the fact that the definitions in Claims 1 had already included the free acid groups.

(c) In the course of the discussion considering the individual amendments carried out in comparison to the claims as originally filed and having regard to the above objection raised by the Respondent concerning the question of hydrolysis, the Appellant replaced the claims of all pending requests by six new sets of claims, constituting a new Main and five new Auxiliary requests. These amendments found, according to the Appellant, their basis in original Claims 7 and 8 (section II, above) and on page 5, line 11 of the application as published.

The new Main and first Auxiliary Requests were modifications of the previous Main Request, the new second and third Auxiliary Requests were derived from the previous first Auxiliary Request, and the previous third Auxiliary Request formed the basis for the new fourth and fifth Auxiliary Requests. The wording of Claim 1 of the Main Request, and the passages differing therefrom in the auxiliary requests are given herein below.

X. Since no further comments were given by the parties to the above issues, the debate about the requirements of Article 123(2) EPC was closed for all requests, and the parties were asked to confirmed their respective requests.

The Appellant requested that the decision under appeal be set aside and the patent be maintained on the basis either of the Main Request or one the Auxiliary Requests 1 to 5 as filed during the oral proceedings (section IX(c), above), Claim 1 of the Main Request reading as follows:

"Cotelomer compounds having the formula I:

FORMULA I

and salts there of wherein A1 is a random polymeric residue comprising at least one unit of formula II:

FORMULA II

and at least one unit which differs from a unit of formula II and which has the formula III:

FORMULA III

X1 is hydrogen, C1-C4 alkyl, phenyl, an alkali metal- or alkaline earth metal atom, a ammonium ion or an amine residue;

m and n are integers such that the sum of m and n is an integer of from 2 to 100, the ratio n:m being from 99 to 1:1 to 99, provided that the resulting cotelomer is water-soluble;

R1 is -OX2 wherein X2 may be the same as or different from X1 and is hydrogen, C1-C4 alkyl, phenyl, an alkali metal- or an equivalent of an alkaline earth metal atom, or an ammonium or an amine residue, or X1 and X2 together may be a multivalent metal atom forming a neutral complex with anionic moieties of the cotelomer molecule, or X1 and X2 may be linked by a -CH2-CH2- residue to form a ring structure;

R2 is hydrogen, or methyl;

X3 is the same as or different from X1 and X2 and is hydrogen, C1-C4 alkyl, an alkali metal- or an equivalent of an alkaline earth metal atom, or an ammonium or an amine residue;

R3 is hydrogen, or a residue -CO2R6 wherein R6 is hydrogen;

R4 is hydrogen or a residue -CO2R6 wherein R6 is hydrogen, R5 is acetomethyl, or a residue -CONR9R10 in which R9 and R10 are the same or different and each is hydrogen, a straight- or branched chain C1-C8 alkyl, hydroxymethyl, or a residue -CH(OH)CO2X4, -C(CH3)2CH2SO3X4, -C(CH3)2CH2CO2X4 or -C(CH3)2CH2PO3(X4)2 in which X4 is hydrogen, an alkali metal or an equivalent alkaline earth metal, or -N(R11)COCH3 in which R11 is hydrogen or straight- or branched C1-C4 alkyl.".

Claim 1 of the 2nd Auxiliary Request differed therefrom by the definition of R5, reading as follows:

"R5 is a residue -CONR9R10 in which R9 and R10 are the same or different and each is hydrogen, a straight- or branched chain C1-C8 alkyl, hydroxymethyl, or a residue -CH(OH)CO2X4, -C(CH3)2CH2SO3X4, -C(CH3)2CH2CO2X4 or -C(CH3)2CH2PO3(X4)2 in which X4 is hydrogen, an alkali metal- or an equivalent alkaline earth metal, or -N(R11)COCH3 in which R11 is hydrogen or straight- or branched C1-C4 alkyl."

In Claim 1 of the 4th Auxiliary Request, the only difference from the above versions of that claim was an amended definition of R5, reading as follows:

"R5 is a residue -CONR9R10 in which R9 and R10 are the same or different and each is hydrogen, a residue -CH(OH)CO2X4, -C(CH3)2CH2SO3X4, -C(CH3)2CH2CO2X4 or -C(CH3)2CH2PO3(X4)2 in which X4 is hydrogen, an alkali metal- or an equivalent alkaline earth metal, or."

The remaining dependent Claims 2 to 14 in each of the above requests were identical to the granted version of these claims.

Claim 1 of each of the 1st, 3rd and 5th Auxiliary Requests differed from Claim 1 of the above respective preceding request (as shown before) by the addition of the following clause at the end of the claim reading:

"which cotelomer compounds are free of readily- hydrolyzable ester groups."

The remaining dependent Claims 2 to 13 corresponded to Claims 2 to 4 and 6 to 14 as granted.

The Respondent requested that the appeal be dismissed.