T 1969/14 12-04-2018

Reasons for the Decision

Main request

1. Article 123(2) EPC

1.1 The opposition division's decision according to which the requirements of Article 123(2) EPC were satisfied is contested by the appellant in respect of claims 1 and 4.

1.2 Claim 1 differs from claim 1 as originally filed in that:

(a) the polymer composition is stated to be dry and to contain 1 % or less of water, by weight based on the total weight of the polymer composition;

(b) the measuring method of the Tg characterising the multistage polymer (component (i)) is specified;

(c) the anion of the phosphate salt of the multivalent cation (component (ii)) is defined more specifically and is limited so as to "consist of" phosphorous and oxygen atoms;

(d) the alkaline phosphate (component (iii)) is defined more specifically and is limited to alkaline metal cations and phosphate anions "consisting of" phosphorous and oxygen atoms or being a partially neutralised salt of a phosphate acid.

1.3 The appellant's objections in respect of claim 1 are directed to above amendments (a), (c) and (d).

1.3.1 Regarding amendment (a): it is concurred with the opposition division's finding according to which that amendment is derivable from the passages at page 15, lines 1-3 of the application as filed: since that passage is disclosed in a general manner, it applies to any embodiment of the application as filed, in particular those according to original claim 1. In that respect, it makes no doubt that the passage at page 15, lines 1-3 of the application as filed is directed to "any" polymer according to the invention. The fact that in that sentence the antecedent "a" is used for the polymer is not held to make any difference as compared to other passages of the application as filed in which the antecedent "the" is used for the polymer (e.g. page 16: lines 23 and 27-32; page 17, lines 1, 3, 17, 23 and 32-33), in particular because the sentence at page 15, lines 1-3 is unambiguously directed to polymers "according to the present invention".

In view of the above, the question whether or not examples 1 to 6 of the patent in suit are directed to a dry polymer composition or not, is not relevant for the present issue.

1.3.2 Regarding amendment (c): it is agreed with the opposition division's view according to which the amendment is directly and unambiguously derivable from the passage at page 6, lines 22-25 of the application as filed. Said passage provides a definition of the term "phosphate" for the whole application, which applies in particular to claim 1 thereof. No argument was further provided by the appellant to refute the opposition division's finding according to which it was derivable from the application as filed that the term "is made up of" meant "consists of", in particular in view of the sentence at page 6, lines 28-30 (distinction with components further comprising hydrogen). Besides, in the Board's view, the term "is made up of" would generally be understood by the skilled person as meaning "consists of".

1.3.3 Regarding amendment (d): for the same reasons as for amendment (c), amendment (d) is directly and unambiguously derivable from the passages at page 6, lines 25-26 and 22-23 of the application as filed. Although the term "phosphate" is indicated in the first sentence of the passage at page 6, lines 22-25 as being limited to anions consisting of phosphorous and oxygen, that definition is unambiguously expanded for "alkaline phosphate" in the sentence at page 6, lines 28-30. It makes no doubt that the skilled person would unambiguously understand that the term "phosphate" and "alkaline phosphate" are defined differently in the application as filed, namely in accordance with features (ii) and (iii), respectively, of claim 1 of the operative main request.

1.4 Claim 4 differs from claim 4 of the application as filed in that the expression "wherein said polymer composition contains little or no phosphorous compound that is not an orthophosphate salt" was replaced by "wherein the amount of phosphorous compound ... either is none or is 1% or less by weight ... composition".

Said amendment is based on page 7, lines 18-24 of the application as filed. Considering that the latter passage is disclosed in a general manner, it would be read as applying to any embodiment of the application as filed, in particular to original claim 4.

1.5 In view of the above, there is no reason for the Board to deviate from the opposition division's conclusion according to which the main request satisfies the requirements of Article 123(2) EPC.

2. Article 123(3) EPC

2.1 Article 123(3) EPC precludes amending the claims during opposition proceedings in such a way as to extend the protection conferred by the patent as granted. Therefore, in order to decide whether or not an amendment of the patent in suit satisfies the requirements of Article 123(3) EPC it is necessary to compare the protection conferred by the granted claims with that of the operative claims after amendment.

2.2 It was not shown by the appellant, in particular during the oral proceedings before the Board, that there existed at least a composition according to operative claim 1 which would not be encompassed by granted claim 1.

2.3 The appellant's objection is directed to the amendment made in claim 1 and in paragraph 67 of the patent in suit defining that the polymer composition is dry, i.e. it contains "1% or less water, by weight based on the total weight of the polymer composition", which was not indicated in granted claim 1 and was only optional in paragraph 67 of the patent in suit.

However, said amendment effectively limits the scope of protection of granted claim 1 by limiting the subject-matter being claimed to those compositions containing 1 wt.% water or less. Same is valid for the amendment made in paragraph 67 of the description (substitution of "may be" by "is").

2.4 In view of the above, the appellant's objection is rejected.

3. Article 100(b) EPC

3.1 The opposition division's conclusion according to which the requirements of sufficiency of disclosure were fulfilled is contested by the appellant.

3.2 In order to meet the requirement of sufficiency, an invention has to be disclosed in a manner sufficiently clear and complete for it to be carried out by the skilled person in the whole area claimed without undue burden, on the basis of the information provided in the patent specification and, if necessary, using common general knowledge. This means in the present case that the skilled person should in particular be capable to prepare a dry polymer composition according to independent claim 1 and to carry out a process according to independent claim 7.

3.3 The appellant argued that D23 showed that it was not possible to dry a polymer composition as defined in claim 1 to a water content of 1 wt.% or less based on the teaching of the patent in suit, in particular paragraph 116 thereof.

However, as indicated in section 3.2 above, sufficiency of disclosure is not assessed on the teaching of the patent in suit only but also taking account of common general knowledge. In that respect, drying a polymer composition is a routine laboratory measure, as argued by the respondent, which can be performed in various ways as e.g. indicated in paragraph 66 of the patent in suit. Regarding the drying experiment carried out in D23 on a composition prepared according to the teaching of the patent in suit, should the skilled person not achieve an amount of water of 1 wt.% or less as defined in claim 1, it makes no doubt that it would be possible to modify the method according to usual laboratory measures e.g. by waiting longer, adding vacuum or reducing the sample height to achieve the required dryness, as argued by the respondent. Under those circumstances, it was not shown that it would not be possible to dry polymer compositions as defined in operative claim 1 by using any of the methods known in the art, particular those specified in paragraph 66 of the patent in suit.

3.4 The appellant argued that the patent in suit did not disclose how to obtain the phosphate salt of the multivalent cation that consists of phosphorous and oxygen atoms only (feature (ii) of operative claim 1), whereby the appellant's objection was primarily based on the conclusion that the examples of the patent in suit did not lead to the formation of such a phosphate salt because they were carried out using a solution of Na2HPO4.

3.4.1 In that respect, contrary to the line of defence apparently adopted during the opposition proceedings and to the indications provided in the patent in suit (paragraphs 131-133 and Table of paragraph 134), the respondent acknowledged, in particular during the oral proceedings before the Board, that examples 1-3 of the patent in suit did not mandatorily illustrate the subject-matter of operative claim 1 because it could not be ascertained that they satisfied feature (ii). Under those circumstances, the examples of the patent in suit on their own are not sufficient to demonstrate that the patent in suit provides enough information to carry out the invention.

3.4.2 However, the respondent argued that the experimental procedure used in those examples was applicable to the preparation of the claimed dry polymer compositions using appropriate reagents and the appellant has not provided any evidence to refute that argument.

Besides, as indicated in section 5.2 of the contested decision, the skilled person is further provided with information how to prepare compositions comprising component (ii) as now claimed in paragraphs 8 and 58-69 of the patent in suit, in particular by using a sufficient excess of alkaline phosphate as indicated in paragraph 68. Also, there is no evidence on file that it is not possible to prepare a composition or to carry out a process as now claimed on the basis of that information.

3.4.3 In the Board's view, the question whether or not the skilled person may determine the amount of alkaline phosphate effectively present in the dry composition being claimed is not an issue of sufficiency of disclosure (as apparently considered by the opposition division in section 5.2 of the decision and by the appellant) but rather a question of clarity or of infringement (does a given composition fall under the scope of the operative claims or not?). Therefore, that argument of the appellant is not persuasive.

3.4.4 Considering that the respondent accepted in appeal that examples 1-3 of the patent in suit were not mandatorily according to the operative set of claims, the question of the reproducibility of those specific examples as based e.g. on D25 cannot support a lack of sufficiency of disclosure in the absence of evidence that it is not possible to carry out the invention on the basis of the information in the patent and the common general knowledge.

3.5 In view of the above, there is no reason to overturn the opposition division's decision in respect of sufficiency of disclosure.

4. Article 84 EPC

4.1 According to decision G 3/14, the claims of the amended patent may be examined for compliance with the requirements of Article 84 EPC only when, and then only to the extent that the amendment introduces non-compliance with Article 84 EPC.

4.2 The appellant's objection is related to the question if the claims of the main request are supported by the examples, in particular in respect of the definitions of the phosphate mentioned in the claims. Considering that those definitions correspond to features (ii) and (iii) of the operative claims, which are identical to features (ii) and (iii) of granted claim 1, the appellant's objection is not directed to an amendment made to the granted claims. Therefore, the claims of the main request cannot be examined pursuant to Article 84 EPC in that respect.

4.3 Since the decisions cited by the appellant in support of its objection that an operative claim as a whole might be objected pursuant to Article 84 EPC are all anterior to G 3/14 (in particular, decisions T 656/07 and T 459/09 were explicitly addressed in G 3/14), they were superseded by G 3/14, i.e. in as far as the conclusions reached therein might have deviated from the findings of G 3/14, those conclusions may not be adhered to any more. Therefore, the appellant's argument based on those decisions are not pertinent.

4.4 Since, the appellant did not show that any lack of clarity arose out of amendments made to the granted claims, there is no reason for the Board to deviate from the opposition division's conclusion according to which the requirements of Article 84 EPC were satisfied.

5. Article 54 EPC

5.1 Novelty objections were raised by the appellant in respect of operative product claims 1 to 6 in view of each of D1, D2, D7/D7c and D19/D19b, whereby a point of dispute between the parties was whether or not feature (iii) of operative claim 1 was directly and unambiguously disclosed in those prior art documents. Therefore, the analysis hereinafter concentrates on that feature.

5.2 Document D1

5.2.1 It is not disputed that feature (iii) is not explicitly disclosed in D1.

5.2.2 In order to compensate the lack of information regarding the amount of alkaline phosphate specified in feature (iii) the appellant filed D24, which was held to be a rework of example 1 of D1.

According to D24, a latex is first prepared according to column 8, lines 10-46 of D1. Then, a wet cake is recovered following the description of paragraph 108 of the A1 publication corresponding to the patent in suit (i.e. paragraph 115 of the patent in suit) and the amount of phosphorous was determined under three different conditions. However, considering that said procedure does not make part of D1, it has to be concluded that said part of D24 may not show that feature (iii) is implicitly disclosed in D1.

Also, it is indicated in D24 that the phosphorous amount was further determined on the dry powder obtained using the conditions described at column 7, lines 36-40 of D1. However, no disclosure in that sense is given in example 1 of D1.

Finally, the sole disclosure of a dry polymer composition given in example 1 of D1 is at column 9, line 4, whereby the drying step only takes place after a dewatering step and on the coagulated polymer. However, it does not appear that D24 is directed to such a composition, in particular because there is no disclosure if and how a coagulation step was carried out therein (column 8, lines 10-46 of D1, as cited in D24, only discloses the preparation of the latex; coagulation is disclosed at page 8, line 47 to page 9, line 2 of D1).

In view of the above, D24 does not constitute a fair rework of example 1 of D1. Therefore, D24 is of no help to refute the opposition division's finding according to which it was to be expected that the dewatering step would lead to levels of (water soluble) sodium pyrophosphate below 100 ppm (bottom of page 11 of the contested decision).

5.2.3 Under those circumstances, it cannot be concluded that feature (iii) is at least implicitly directly and unambiguously disclosed in example 1 of D1.

5.3 Document D2

Even if, to the appellant's benefit, it were to be considered that the pyrophosphate disclosed e.g. at column 6, line 54 or at column 7, line 50 may react with the multivalent cation of the coagulating agent or of the iron (II) component (D2: claims 4-8; column 3, lines 13-22 and 29-30; column 8, line 25; column 9, line 28-29) in order to form component (ii) according to operative claim 1, there is no evidence on file that feature (iii) of operative claim 1 is mandatorily satisfied. Further considering that D2 teaches a washing step after the coagulation was carried out (column 3, lines 55-57; column 8, lines 35-37; column 9, lines 38-40), it cannot be held, for the same reasons as for D1, that the dried compositions prepared in D2 mandatorily contain 100 ppm of an alkaline phosphate according to feature (iii) of claim 1.

5.4 Document D7/D7c

Also, the same conclusion as above is reached in respect of document D7/D7c. Even if it were to be considered that the teaching of D7c is that calcium phosphate is produced during the coagulation stage (paragraphs 7 and 9, second paragraph; examples 1-4 and comparative examples 1-2; paragraph 55, second paragraph), which corresponds to component (ii) according to operative claim 1, there is no evidence on file that feature (iii) of operative claim 1 is mandatorily satisfied, in particular following the washing stage carried out in the examples (paragraph 50, second paragraph).

5.5 Document D19/D19b

The same conclusion as above is drawn in respect of D19/D19b. Even if it were to be considered that the teaching of D19b is that a divalent alkaline-earth metal phosphate is produced during the coagulation stage (paragraph 13, first sentence of the second paragraph), which corresponds to component (ii) according to operative claim 1, there is no evidence on file that feature (iii) of operative claim 1 is mandatorily satisfied, in particular following the washing stage carried out in the examples (see e.g. page 8, example 1: last sentence of the second paragraph).

In addition, it is noted that the appellant argued that in view of the preparation method of the polymer composition taught in D19/D19b, some of the ternary sodium phosphate (which is an alkaline phosphate according to feature (iii) of operative claim 1) used would remain not accessible to react with the divalent alkaline-earth metal according to the indication of paragraph 13 of D19b and would, thus, be present in the dried polymer composition. However, also in that respect, no evidence was provided in order to show that that preparation method would effectively result in an amount of at least 100 ppm of the alkaline phosphate in the dried polymer composition, in particular in any of the examples of D19/D19b in which specific preparation methods are described.

Also, since the examples of D19/D19b were carried out using an excess of magnesium relative to phosphate, it is questionable if any alkaline phosphate may remain, as argued by the respondent.

For those reasons, it cannot be concluded that D19/D19b directly and unambiguously discloses a dry polymer composition satisfying feature (iii) according to operative claim 1.

5.6 In view of the above, there is no reason to deviate from the opposition division's decision according to which none of D1, D2, D7/D7c and D19/D19b anticipated the subject-matter of operative claim 1. The same is valid for each of claims 2 to 4, which all depend on claim 1, and for claims 5 and 6, in view of their reference to claim 1.

6. Article 56 EPC

6.1 Although it was stated in section 9.1 of the statement of grounds of appeal that none of the claims of the operative main request satisfied the requirements of Article 56 EPC, a substantiated objection was only put forward against the product claims 1-6 (see sections 9.2 and 11.2). The subject-matter of operative claim 7 (process) was not objected to by the appellant.

6.2 Regarding operative claim 1, both parties agreed with the opposition division's findings regarding i) the choice of D19/D19b as the closest prior art and ii) the identification of the distinguishing feature of operative claim 1 over D19/D19b (feature (iii)). However, whereas the respondent agreed with the opposition division that the objective technical problem, i.e. the technical problem effectively solved over D19/D19b, resided in the provision of polymer compositions obtained by coagulation with a multivalent cation having improved yellowing and heat-ageing resistance which are comparable to those of spray-dried compositions, the appellant considered that the objective problem only resided in the provision of such polymer compositions having improved yellowing resistance properties (i.e. without the heat-ageing improvement).

6.3 The Board assumes, to the appellant's benefit, that the objective problem resides in the provision of polymer compositions obtained by coagulation with a multivalent cation having improved yellowing resistance properties. As under this assumption, it comes to the conclusion that the subject-matter of claims 1 to 6 is not rendered obvious by the available prior art (see section 6.4 below), it is not necessary for the Board to decide whether a further improvement (in heat-ageing resistance) is to be included in the formulation of the problem, as submitted by the respondent.

6.4 In that respect, as was indicated in the novelty analysis in respect of D19/D19b above, it cannot be concluded that it is directly and unambiguously disclosed in D19/D19b that the dried polymer compositions prepared therein contain at least 100 ppm of an alkaline phosphate according to feature (iii) of operative claim 1. Nor was it shown by the appellant that such compositions could effectively be obtained following the teaching of D19/D19b. As a consequence, since it cannot be ascertained that D19/D19b effectively discloses dry multistage polymer compositions comprising at least 100 ppm of an alkaline phosphate according to feature (iii), that document cannot be held to contain any hint that the yellowing resistance properties of the dried polymer compositions prepared therein may be improved when they contain at least 100 ppm of an alkaline phosphate according to feature (iii) of claim 1.

Since none of the other documents cited in the proceedings was shown to disclose directly and unambiguously dried polymer compositions comprising at least 100 ppm of an alkaline phosphate according to feature (iii) of operative claim 1 and therefore could not include a hint that this feature may be of relevance for the yellowing resistance properties, the same conclusion as for D19/D19b alone must be reached regarding the combination of any of those documents with D19/D19b.

Therefore, under the previous assumption regarding the formulation of the objective problem (see point 6.3 above), the subject-matter of operative claim 1 is not rendered obvious in the light of the teaching of the prior art. This would be all the more the case if a further improvement were included in the formulation of the technical problem.

6.5 For those reasons, the appellant's arguments provide no reason for the Board to overturn the opposition division's conclusion according to which the subject-matter of claim 1 is inventive over D19/D19b as closest prior art, which decision therefore holds good. The same is valid for each of claims 2 to 4, which all depend on claim 1, and for claims 5 and 6, in view of their reference to claim 1.

7. The respondent's main request being allowable, it is not required to deal with auxiliary requests 1 to 4 filed with letter of 16 March 2018.