T 0971/08 10-01-2012

Reasons for the Decision

1. Entitlement to the priority D5 (Articles 87 and 88 EPC)

In accordance with Article 87 EPC a European patent application is only entitled to priority in respect of "the same invention" as was disclosed in the previous application. In its decision G 2/98 (supra) the Enlarged Board of Appeal stated that the concept of "the same invention" was to be interpreted narrowly and equated it with "the same subject-matter" in Article 87(4) EPC 1973. This means that the priority of a previous application in respect of a claim in a European patent (application) is to be acknowledged only if the person skilled in the art can derive the subject-matter of the claim directly and unambiguously, using common general knowledge, from the previous application as a whole (see Case Law of the Boards of Appeal, 6th edition 2010, chapter V.B.1 to V.B.1.9).

Furthermore, according to the established case law a generic disclosure implicitly encompassing two or more alternative embodiments cannot generally give rise to a right of priority to one specific embodiment, if the latter is neither explicitly nor implicitly disclosed (see Case Law of the Boards of Appeal, 6th edition 2010, chapter V.B.1.9).

1.1 D5 is the US application 09/469 259 from which the European patent application filed on 4 December 2000 and underlying the patent in suit claims the filing date of 21 December 1999 as effective date, pursuant to Article 89 EPC.

1.2 The respondent's arguments that the priority is validly claimed from D5 for the subject-matter claimed in the independent claims 1, 38, 40 and 41 of the patent as maintained cannot hold for the following reasons.

1.3 First of all, it is not true that it is the essence of the invention of D5 to use the two (or one) pretreatment composition(s) on unphosphated metal substrates and that the application on unphosphated metal substrates is implicit from the statement "It would be desirable to provide a simplified pretreatment process free of heavy metals for coating metal substrates, including mixed metal substrates such as are commonly found on today's automobile bodies. Such a pretreatment process, when combined with a lead-free electrodeposition process, would represent a heavy-metal free alternative for providing corrosion resistance to metal substrates" (see page 2, lines 22 to 27).

1.3.1 This conclusion of the Board is induced by the fact that D5 with respect to the field of the invention states: "This invention relates generally to corrosion-resistant substrates and, more particularly, to ferrous and non-ferrous metal substrates having environmentally friendly chrome-free and nickel-free coatings thereon which inhibit corrosion of the metal substrate" (see page 1, lines 19 to 22).

Therefore already from the introductory portion of the description of D5 it is clear that the most general teaching of the invention is not restricted to environmentally friendly chrome-free and nickel-free coatings, but that only particular embodiments might be restricted to these specific coatings.

1.3.2 The following description of the background of the invention in D5 mentions that conventional phosphate conversion coating compositions typically contain heavy metals such as nickel and that post-rinses contain chrome, while cationic electrodeposition compositions typically contain lead as pigment or soluble salt (see page 1, line 25 to page 2, line 10) and that nickel-free phosphate coating compositions and chrome-free rinsing compositions are highly desirable but that the latter are often suitable for use over a limited number of substrates or over substrates that must be phosphated first (see page 2, lines 11 to 21).

This passage in D5 does not support the respondent's position either since it only teaches the person skilled in the art which problems the prior art is confronted with and confirms to him that environmentally friendly compositions and processes should avoid nickel and chrome which represent non-desired heavy metals.

1.3.3 The conclusion of point 1.3.1 above is also fully supported by the description of the invention of D5 given in its independent claims 1, 39, 42 and 43 which is not restricted to such environmentally friendly nickel-free and chrome-free compositions and processes:

"1. A coated metal substrate comprising: (a) a metal substrate; (b) a first pretreatment composition deposited upon at least a portion of the substrate, the first pretreatment composition comprising a transition element-containing material which comprises a transition element selected from the group consisting of Group IIIB elements, Group lVB elements, lanthanide series elements and mixtures thereof; and (c) a second pretreatment composition comprising a reaction product of at least one epoxy-functional material or derivative thereof and at least one material selected from the group consisting of phosphorus-containing materials, amine-containing materials, sulfur-containing materials and mixtures thereof deposited upon at least a portion of the first pretreatment composition."

"39. A method for preparing a coated metal substrate, comprising the steps of: (a) treating a surface of a metal substrate with a first pretreatment composition comprising a transition element-containing material which comprises a transition element selected from the group consisting of Group IIIB elements, Group IVB elements, lanthanide series elements and mixtures thereof; and

(b) applying a second pretreatment composition comprising a reaction product of at least one epoxy functional material or derivative thereof and at least one material selected from the group consisting of phosphorus-containing materials, amine-containing materials, sulfur-containing materials and mixtures thereof over at least a portion of the first pretreatment composition to form a substrate having a pretreated surface."

"42. A coated metal substrate comprising: (a) a metal substrate; (b) a pretreatment composition deposited upon at least a portion of the substrate, the pretreatment composition comprising (1) a transition element containing material which comprises a transition element selected from the group consisting of Group IIIB elements, Group IVB elements, lanthanide series elements and mixtures thereof; and (2) a reaction product of at least one epoxy-functional material or derivative thereof and at least one material selected from the group consisting of phosphorus-containing materials, amine-containing materials, sulfur-containing materials and mixtures thereof deposited upon at least a portion of the first pretreatment composition."

"43. A method for preparing a coated metal substrate, comprising the step of treating a surface of a metal substrate with a pretreatment composition comprising (1) a transition element-containing material which comprises a transition element selected from the group consisting of Group IIIB elements, Group IVB elements, lanthanide series elements and mixtures thereof; and (2) a reaction product of at least one epoxy functional material or derivative thereof and at least one material selected from the group consisting of phosphorus-containing materials, amine-containing materials, sulfur-containing materials and mixtures thereof over at least a portion of the first pretreatment composition to form a substrate having a pretreated surface."

These claims 1, 39, 42 and 43 of D5, which form the basis of the claims 1, 38, 40 and 41 of the main request (as maintained), neither exclude a phosphated metal substrate, nor nickel and chrome or any lead-containing electrodepositable coating composition.

1.3.4 When asked by the Board at the oral proceedings why the independent claims do not contain any restrictions concerning nickel and chrome, if that were the essence of the invention, the respondent answered that this feature would now be implicit from the use of "an unphosphated metal substrate" in the claims of the patent as maintained. This argument cannot hold for the reasons that follow.

From the detailed description of D5 it is evident that the claimed pretreatment process can be applied to two alternative types of substrates, namely:

i) unphosphated metal substrates, or

ii) phosphated metal substrates (see page 7, lines 7 to 16).

The quoted passage on page 7, lines 7 to 12 of D5 discloses "Optionally, a phosphate-based conversion coating can be applied to the metal substrate. Suitable phosphate conversion coating compositions include those known in the art, such as zinc phosphate, optionally modified with nickel, iron, manganese, calcium, magnesium or cobalt. Useful phosphating compositions are described in U.S. Patents …" and thus contradicts the respondent's argument that D5 in essence would relate to the treatment of unphosphated metal substrates.

From this passage it can also be derived that such a phosphating treatment does not necessarily result in the incorporation of heavy metals such as nickel (although such an embodiment is explicitly included in the teaching of D5, see above) in the zinc phosphate since it may also be modified by e.g. iron, calcium or magnesium. The latter elements are not mentioned among those to be avoided according to the background of the invention (see point 1.3.2 above).

It is thus not evident that phosphating should be avoided and that an unphosphated metal substrate has to be treated in order to avoid nickel and chrome since there exist phosphating compositions being heavy metal free in that sense of D5. The person skilled in the art is therefore not automatically led to an unphosphated metal substrate, but can avoid heavy metals by making another selection when applying a phosphate coating according to the environmental needs.

1.4 From these claims 1, 39, 42 and 43 it is also apparent that there exist two further alternatives for applying the claimed pretreatment composition, namely:

iii) either in a two-step procedure wherein first the pretreatment composition comprising the transition element-containing material is deposited upon the substrate and thereafter a second pretreatment composition comprising the reaction product of the at least one epoxy functional material is deposited upon at least a portion of the first pretreatment composition, or

iv) in a one-step procedure comprising a single pretreatment composition comprising the transition element-containing material and the said reaction product of the at least one epoxy functional material.

This conclusion is supported by the detailed description of D5 which first discloses the two-step procedure (see e.g. page 7, line 13 to page 22, line 8) and then shortly describes the alternative one-step procedure with a single pretreatment composition (see page 22, lines 9 to 11).

1.5 The further independent claims 36 and 41 of D5 relate to preferred embodiments of claims 1 and 39 and define an additional weldable coating comprising an electroconductive pigment and a binder deposited on the pretreated surface, while the further independent claim 37 relates to an alternative embodiment of product claim 1 wherein the second pretreatment composition comprises an ester of a phosphorus-containing material deposited upon at least a portion of the first pretreatment composition.

1.5.1 Thus the subject-matter of claims 36 and 41 corresponds to the passage in the detailed description of D5 which discloses the optional weldable coating (see page 22, lines 22 to 27). The preferred embodiments of the weldable coating are thereafter described (see page 22, line 27 to page 27, line 26).

1.5.2 Therefore the invention of D5 encompasses yet two further alternatives of:

v) not applying a weldable coating, and

vi) applying a weldable coating.

According to preferred embodiments of the weldable coating the "Non-limiting examples of suitable electroconductive pigments include zinc (preferred), aluminium, iron, graphite, iron phosphide, nickel, tungsten and mixtures thereof" (see page 23, lines 3 to 5).

Thus it is evident that either an environmentally friendly weldable coating being nickel-free and chrome-free or a weldable coating containing nickel can be applied to the pretreated metal substrate. It is also clear that when applying a weldable coating the person skilled in the art yet again can make a further selection taking account of the environmental needs.

1.6 Dependent product claim 35 is the only claim of D5 defining an electrodeposited coating, which is however deposited upon at least a portion of the weldable composition. Claim 35 depends solely on claim 34 which defines a metal phosphate coating on the weldable composition; said claim 34 depends solely on claim 29 which defines the weldable coating and which depends solely on claim 1.

1.6.1 There exists only one passage in the detailed description at page 27, lines 8 to 16 of D5 concerning the electrodeposition of coating compositions. This passage is, however, embedded between other paragraphs explicitly relating to the weldable coating (compare page 27, lines 1 to 26) and it states "Since the coated metal substrate prepared according to the present invention is electroconductive, topcoating of the coated substrate by electrodeposition is of particular interest. Compositions and methods for electrodepositing coatings are well known to those skilled in the art and a detailed discussion thereof is not believed to be necessary. Useful compositions and methods are discussed in U.S. Patent No. 5,530,043 (relating to anionic electrodeposition) and U.S. Patents Nos. 5,760,107, 5,820,987 and 4,933,056 (relating to cationic electrodeposition) which are hereby incorporated by reference."

1.6.2 It is undisputed that this passage does not explicitly disclose any lead-free electrodepositable composition. It is further undisputed that among the four cited U.S. patents (which include D3 and D4) there are at least two relating to lead-containing electrodepositable coating compositions.

Consequently, D5 generally teaches the person skilled in the art to optionally deposit an electrodepositable coating composition onto metal substrates as defined in the independent claims 1, 39, 42 and 43. This teaching thus inherently comprises at least the further two alternatives of:

vii) electrodepositing a lead-containing coating composition, or

viii) electrodepositing a lead-free coating composition.

1.6.3 The said definition "… the coated metal substrate prepared according to the present invention …" of page 27, lines 8 to 10 is interpreted by the Board to refer to the aforementioned weldable coating but even if it were to be interpreted to refer only to the pretreatment coating applied onto the (unphosphated) metal substrate as disclosed in the examples of D5 it is not conclusively derivable that it is a lead-free coating composition which has to be applied.

1.6.4 According to the examples of D5 unphosphated metal substrates were treated with the pretreatment compositions A or B and then "electrocoated with ED6650, an electrodepositable coating commercially available from PPG Industries Inc." (see page 31, lines 2 to 13). The description of D5 is silent as to whether or not this electrocoating composition ED6650 is lead-free.

As a reaction to the Board's communication annexed to the summons to oral proceedings, which was entirely silent with respect to the examples and the composition ED6650, the respondent submitted with its letter dated 5 December 2011 for the first time in the entire proceedings the material safety data sheets D17 and D18 and argued that the electrocoating composition ED6650 is lead-free as evidenced by D17 in view of D18.

At the oral proceedings, when questioned by the Board as to how these two documents - D17 has a date of 3 May 2001 (i.e. more than 2 years after the filing date of D5) and relates to a cationic electrodepositable composition ED6650 not specifying any (hazardous) lead component - can prove which components were comprised in the composition ED6650 used for preparing the examples according to D5 before 21 December 1999, it admitted that D17 and D18 were post-published, but then argued that the composition of ED6650 as given in D17 has not been changed since and that the accompanying persons could confirm this.

The Board remarks in this context that the respondent must have been aware of the fact that D17 is post-published but its aforementioned letter is not only totally silent in this respect but also with respect to the argument that the composition has not changed between 21 December 1999 and 3 May 2001. Furthermore, the two accompanying persons have never been proposed as witnesses or as technical experts, let alone with respect to the composition of said ED6650, except as late as the oral proceedings.

Under these circumstances the Board is not prepared to hear them in one or the other capacity, quite apart from the question whether the appellant could be considered to be prepared for this eventuality at the oral proceedings. As a result, there is only the post-published evidence D17 which, however, cannot be considered as conclusive regarding the composition of ED6650 more than two years prior.

1.6.5 The Board further remarks in this context that the burden of proving this allegation made as late as with letter of 5 December 2011 concerning the composition ED6650, which has been disputed by the appellant, is with the respondent who bases part of its arguments concerning the validity of the priority on this composition ED6650. The validity of the priority was an issue of the impugned decision and has remained so in the entire appeal proceedings. Simply making an allegation purportedly supported by post-published evidence cannot shift this burden of proof to the appellant or even the Board.

The further argument of the respondent that it has been accepted in the entire appeal proceedings that ED6650 is a lead-free electrodepositable coating composition, as it has been acknowledged as such by the Opposition Division in its decision (see page 12, first paragraph) and never been challenged by the appellant or the Board, is considered not to be relevant since it is exactly this decision which has been appealed. Further, it is the respondent which introduces the argument, therefore bears the burden of proof.

1.6.6 Taking account of the points 1.6 to 1.6.5 above it is clear that neither the examples of D5 as such nor the statement in D5 concluding the examples (page 34, lines 11 to 16): "the coating compositions of the present invention provide a heavy-metal free alternative to conventional phosphating compositions …" - which has to be interpreted as being limited to the two pretreatment compositions exclusively used for these examples when taking account of the other considerations above - provide a clear and unambiguous basis for the combination of the features "unphosphated metal substrate" and "lead-free electrodepositable coating composition deposited upon the (second) pretreatment composition".

Consequently, the examples of D5 with said ED6650 electrodepositable coating composition cannot conclusively be linked with the lead-free electrodeposition process mentioned at page 2, lines 22 to 27 (see point 1.3 above).

1.7 Taking account of all considerations above the result is that the four sets of each two alternatives given in the description, in combination with the claims (see above, points i) to viii)) cannot provide a direct and unambiguous disclosure for the subject-matter of the independent claims 1, 38, 40 and 41 of the main request in their present form, individualized therefrom. As a result the priority of that application cannot be validly claimed. The result is that the filing date of 4 December 2000 is the effective date for the claims of the main request.

2. Inventive step (Article 56 EPC)

In view of the conclusion reached on priority, all documents published before the filing date of the patent in suit have to be taken into consideration under Article 54 EPC. Document D1 was published on 8 June 2000 and thus belongs to the prior art for the patent in suit under Article 54(2) EPC.

2.1 Since the Board comes to the conclusion that the subject-matter of claim 1 of the main request lacks inventive step over the teaching of D1 there was no need to verify whether or not claim 1 complies with Article 54 EPC.

2.2 D1 discloses a process for providing a weldable, coated metal substrate including the pretreatment of a metal (i.e. unphosphated) substrate (see page 4, lines 5 to 22) with a reaction product of one or more epoxy-functional materials and one or more materials selected from phosphorous-containing materials, amine-containing materials and mixtures thereof (see page 5, lines 6 to 9) comprised in a solution in combination with one or more group IVB element-containing materials, the latter can also be applied in a separate step, i.e. a two-step pretreatment (see page 12, lines 10 to 24). Also the examples of D1 (see e.g. example 2) were made on unphosphated metal substrates, with a weldable coating on the pretreatment composition (see pages 20 to 24).

D1 discloses the same lead-containing and lead-free electrodepositable coating compositions as the patent in suit since the same four US patents are referred to in an identical passage (see page 19, lines 14 to 22).

2.2.1 The Board considers that the person skilled in the art would select the lead-free electrodepositable coating compositions when confronted with the objective technical problem of providing an environmentally friendly process when starting from the teaching of D1. Thus he would apply either the one-step or two-step pretreatment onto unphosphated metal substrates followed by the deposition of the weldable coating over the pretreated substrate and would finally deposit the lead-free electrodepositable coating onto the weldable coating.

Thereby the person skilled in the art arrives at the subject-matter of product claim 1 of the main request in an obvious manner. Claim 1 of the main request therefore lacks inventive step and the main request is not allowable.

2.2.2 In this context the Board further remarks that the two pretreatment steps according to the patent in suit need not be different but can use identical compositions (see patent, paragraph [0020]) and that it is not apparent as to why a double treatment with identical solutions should involve inventive step since no advantages can be seen, since the patent in suit is silent in this respect, and corresponding arguments have also not been presented by the respondent.

2.2.3 The respondent's arguments in support of inventive step cannot hold for the following reasons.

First of all, the respondent has not disputed the above disclosure of D1 but has only argued that claim 1 does not allow for an intermediate weldable coating. This cannot be followed since claim 1, due to the used term "comprising", does not exclude such a weldable coating which, as evidenced by the dependent claims 29 to 35 of the main request, is also explicitly included in the subject-matter of claim 1 of the main request.

Secondly, taking account of the fact that the weldable coating is not excluded by this claim the further arguments based on D3 and D4, namely that D1 does not teach that the omission of this weldable coating would lead to an improved coating, are not relevant and need not be considered.

3. Admissibility of the new auxiliary requests

3.1 As a consequence of the discussion of inventive step of claim 1 of the main request the respondent filed amended versions of the first and second auxiliary requests (see points IX and X above) which replaced all auxiliary requests filed earlier in the appeal proceedings and requested admitting the late filing of these requests. The appellant objected to this late filing.

3.2 In the present case there is, however, no need to deal with the aspect of the late filing of these two auxiliary requests since they clearly do not comply with Article 123(2) EPC for the reasons that follow.

3.2.1 Claim 1 as maintained by the Opposition Division required a second pretreatment composition comprising a reaction product of at least one epoxy functional material or derivative thereof and "at least one material selected from the group consisting of phosphorus-containing materials, amine-containing materials, sulfur-containing materials and mixtures thereof" (see point II above). This group consisting of the three specified materials and their mixtures therefore is made up of seven possibilities.

3.2.2 According to the amendment now made in the claims 1 of the first and second auxiliary requests (see points IX and X above) this group has been restricted by the deletion of the other six possibilities to a single possibility, namely the group of phosphorous-containing materials.

The relevant description of the patent in suit (see patent, paragraphs [0030] and [0040] to [0049]), which is identical with that of the underlying application as originally filed (corresponding to the published WO-A-01 46495; see page 12, lines 8 to 12; page 12, line 17 to page 17, line 17), cannot provide a basis for this amendment since the reaction product of one or more epoxy-functional materials or derivatives thereof with phosphorous-containing materials is neither presented as a preferred embodiment in comparison to the other two possible materials or their mixtures, nor presented as one having as such particular advantages. The description only mentions suitable materials for forming the reaction product by methods well known to those skilled in the art.

To the contrary, the reaction product of one or more epoxy-containing materials or derivatives and one or more amine-containing materials is presented as an alternative preferred embodiment (see patent, paragraph [0050]; see WO-A-01 46495, page 17, lines 18 to 21).

Also, both the pretreatment compositions A and B according to the examples of the patent in suit comprise reaction products of phosphorous-containing materials and amine-containing materials (see patent, paragraphs [0092] to [0096] corresponding to page 29, line 7 to page 30, line 26 of WO-A-01 46495) and thus do not support this selection either.

3.2.3 The amendment made in claims 1 of the two auxiliary requests therefore amounts to taking a single material from the original list of seven alternative materials.

In fact, as the principles to be applied to establish a "direct and unambiguous disclosure" for the purposes of priority and original disclosure (Article 123(2) EPC) are the same (see G 2/10, to be published in OJ EPO, point 4.3 of the reasons) this amounts to yet a further individualisation, which in this form finds no such direct and unambiguous disclosure. Hence the amendment made in claims 1 of the first and second auxiliary requests clearly contravenes Article 123(2) EPC. The first and second auxiliary requests are therefore not admitted in the proceedings.

3.2.4 The respondent's arguments to the contrary cannot hold for the following reasons.

First of all, it has not disputed that the amendment amounts to singling out but has principally only argued that claim 1 as maintained would form the basis for the amendment made. For the reasons given above this argument cannot hold since claim 1 as maintained contains the same 7 alternative materials, so does not in itself provide adequate support for claim 1 as amended according to these two auxiliary requests. Likewise the independent claims 40 and 41 as maintained do not support this amendment either since their pretreatment composition though having been restricted to "a reaction product of at least one epoxy-functional material or derivative thereof and at least one material selected from the group consisting of phosphorus-containing materials and mixtures thereof with amine-containing materials and sulphur-containing materials" (see point II above), and thereby still relates to a list of 3 alternative materials, all of which comprise phosphorus-containing materials.

In this context the Board remarks that the respondent has neither submitted any further argument at the oral proceedings with respect to an effect which would be obtained with the restriction to phosphorous-containing materials nor which technical problem would be solved with this particular subject-matter of claim 1 with respect to the prior art and particularly with respect to D1.