T 1626/16 28-09-2018

Summary of Facts and Submissions

I. This appeal lies from the decision of the examining division refusing European patent application No. 10169036.0.

II. The decision was based on four sets of claims, namely a main request filed by letter dated 19 July 2011, a first auxiliary request filed by letter dated 23 December 2015 and second and third auxiliary requests, both filed on 27 January 2016 during the oral proceedings before the examining division.

Independent claims 1 and 9 of the main request read as follows:

"1. An electrophotographic toner that includes a latex, a colorant and a releasing agent, wherein the electrophotographic toner further comprises zinc (Zn), iron (Fe) and silicon (Si), wherein the [Zn]/[Fe] ratio is in the range of about 5.0 x 10**(-2) to about 2.0, wherein the [Si]/[Fe] ratio is in the range of about 5.0 x 10**(-4) to about 5.0 x 10**(-2), and wherein [Zn], [Fe] and [Si] denote the intensities of Zn, Fe and Si, respectively, as measured by an X-ray fluorescence spectrometry."

"9. A method of preparing an electrophotographic toner, comprising:

mixing primary latex particles, a colorant dispersion and a releasing agent dispersion together to thereby produce a mixed solution;

adding an agglomerating agent to the mixed solution to thereby produce a primary agglomerated toner; and

coating the primary agglomerated toner with secondary latex particles to provide a secondary agglomerated toner,

wherein the secondary latex particles are prepared by polymerizing at least one polymerizable monomer, and

wherein the electrophotographic toner comprises zinc (Zn), iron (Fe) and silicon (Si), wherein the [Zn]/[Fe] ratio is in the range of about 5.0 x 10**(-2) to about 2.0, the [Si]/[Fe] ratio being in the range of about 5.0 x 10**(-4) to about 5.0 x 10**(-2), [Zn], [Fe] and [Si] denoting the intensities of Zn, Fe and Si, respectively, as measured by an X-ray fluorescence spectrometry."

III. The examining division refused the application on the grounds that the subject-matter of the claims of all requests extended beyond the content of the application as filed and thus contravened Article 123(2) EPC. The examining division did not deal in its decision with any other patentability issues.

With respect to the main request, the examining division considered that the only amendment made to the subject-matter of independent claims 1 and 9, namely the replacement in the [Zn]/[Fe] ratio of the limit value "2.0 x 10**(-2)" by the limit value "2.0", was not a correction allowable under Rule 139 EPC. According to the examining division, although it might have been obvious that an error had occurred regarding the upper limit of the value range of that ratio, it was not evident that nothing other than the proposed correction could have been intended. Thus, the subject-matter of the independent claims of the main request extended beyond the content of the application as filed and consequently contravened the requirements of Article 123(2) EPC.

As regards auxiliary requests 1 and 2, the examining division considered that the values of the [Zn]/[Fe] ratio provided in the examples of the patent application did not allow the amendment of the value ranges of the [Zn]/[Fe] ratio in the independent claims of these requests. Nor did the examples or the application as filed provide adequate support for the [Zn]/[Fe] ratio values in claim 1 of auxiliary request 3. Thus, the subject-matter of the independent claims of the auxiliary requests also extended beyond the content of the application as filed and contravened the requirements of Article 123(2) EPC.

IV. On 11 April 2016 the applicant (in the following: the appellant) filed notice of appeal. The statement setting out the grounds of appeal was filed on 20 June 2016. The appellant requested that the decision under appeal be set aside and that a patent be granted based on the claims of either the main request or any of the first to fourth auxiliary requests, all filed with the statement setting out the grounds of appeal.

The claims of the main request are the same as the claims of the main request before the examining division (see point II above).

The claims of auxiliary request 1 correspond to the claims of the main request with the sole difference that in the independent claims 1 and 9 the [Zn]/[Fe] ratio has been defined as being "in the range of 0.21 to 1.0".

Independent claim 1 of auxiliary request 2 reads as follows:

"1. A method of preparing an electrophotographic toner, comprising:

mixing primary latex particles, a colorant dispersion and a releasing agent dispersion together to thereby produce a mixed solution;

adding an agglomerating agent to the mixed solution to thereby produce a primary agglomerated toner; and

coating the primary agglomerated toner with secondary latex particles to provide a secondary agglomerated toner,

wherein the secondary latex particles are prepared by polymerizing at least one polymerizable monomer, and

wherein the electrophotographic toner comprises zinc (Zn), iron (Fe) and silicon (Si), wherein the [Zn]/[Fe] ratio is in the range of 0.21 to 1.0, the [Si]/[Fe] ratio being in the range of about 5.0 x 10**(-4) to about 5.0 x 10**(-2), [Zn], [Fe] and [Si] denoting the intensities of Zn, Fe and Si, respectively, as measured by an X-ray fluorescence spectrometry,

wherein the primary latex particles and the secondary latex particles are each prepared using a polyester resin alone or using a mixture of a polyester resin and a polymer prepared by polymerizing at least one polymerizable monomer,

wherein the agglomerating agent comprises a Si- and Fe- containing metal salt, and wherein a Zn- containing compound is used as a catalyst in polymerizing the latex."

Independent claims 1 and 9 of auxiliary request 3 read as follows:

"1. An electrophotographic toner that includes a latex, a colorant and a releasing agent, wherein the electrophotographic toner further comprises zinc (Zn), iron (Fe) and silicon (Si), wherein the [Zn]/[Fe] ratio is in the range of 5.0 x 10**(-4) to 5.0 x 10**(-1), wherein the [Si]/[Fe] ratio is in the range of about 5.0 x 10**(-4) to about 5.0 x 10**(-2), and wherein [Zn], [Fe] and [Si] denote the intensities of Zn, Fe and Si, respectively, as measured by an X-ray fluorescence spectrometry."

"9. A method of preparing an electrophotographic toner, comprising:

mixing primary latex particles, a colorant dispersion and a releasing agent dispersion together to thereby produce a mixed solution;

adding an agglomerating agent to the mixed solution to thereby produce a primary agglomerated toner; and

coating the primary agglomerated toner with secondary latex particles to provide a secondary agglomerated toner,

wherein the secondary latex particles are prepared by polymerizing at least one polymerizable monomer, and

wherein the electrophotographic toner comprises zinc (Zn), iron (Fe) and silicon (Si), wherein the [Zn]/[Fe] ratio is in the range of 5.0 x 10**(-4) to 5.0 x 10**(-1), the [Si]/[Fe] ratio being in the range of about 5.0 x 10**(-4) to about 5.0 x 10**(-2), [Zn], [Fe] and [Si] denoting the intensities of Zn, Fe and Si, respectively, as measured by an X-ray fluorescence spectrometry."

The claims of auxiliary request 4 are not relevant for the present decision.

V. On 20 March 2018 the board dispatched a summons to oral proceedings. In the accompanying communication the board indicated the relevant points to be discussed during the scheduled oral proceedings. The board also gave the preliminary view that the main request and auxiliary requests 1 and 2 were not allowable since the claimed subject-matter did not fulfil the requirements of Article 123(2) EPC. By contrast, the amendments made to the claims of the third auxiliary request fulfilled the requirements of Article 123(2) EPC so that this request could serve as a basis for revising the present application.

Lastly, the board noted that it would seem appropriate to remit the case to the examining division for further prosecution as no other patentability issue had been dealt with in the appealed decision.

VI. On 24 September 2018, at the appellant's request, the registry of the board informed it that the board would decide on the appeal at the oral proceedings scheduled for 28 September 2018 taking into account the preliminary views expressed in its communication.

VII. On 28 September 2018 oral proceedings were held before the board in the absence of the appellant.

VIII. The arguments presented by the appellant in its written submissions, in so far as they are relevant for this decision, may be summarised as follows:

- With regard to the main request, the proposed correction of the [Zn]/[Fe] ratio range in the subject-matter of the independent claims satisfied the requirements of Rule 139 EPC because it was evident that the [Zn]/[Fe] ratio value "2.0 x 10**(-2)" was erroneous and that the intended value was "2.0" and nothing else. This correction, which required nothing more than the omission of the multiplication factor 10**(-2), allowed the claims to cover all inventive examples and to exclude all comparative examples. Therefore the value of "2.0" was obvious for the skilled person and did not amount to an arbitrary selection. Furthermore, this was corroborated by the disclosure of the priority document and the correction allowed in the grant proceedings before the USPTO. Consequently, the amendment in the subject-matter of the independent claims fulfilled the requirements of Article 123(2) EPC.

- With regard to auxiliary requests 1 and 2, the narrowing of the [Zn]/[Fe] ratio range in the subject-matter of the independent claims was based on the values taken from the examples of the application as filed. Thus, the amendment in the subject-matter of the independent claims of these requests did not contravene the requirements of Article 123(2) EPC. The skilled person would understand that a range of values between two working examples, in the absence of any comparative example with a value falling therein, also belonged to the claimed scope of the invention.

- With regard to auxiliary request 3, the [Zn]/[Fe] ratio range in the subject-matter of the independent claims was disclosed on page 29, lines 2 to 4, of the application as filed. Consequently, the subject-matter of the independent claims of auxiliary request 3 fulfilled the requirements of Article 123(2) EPC.