T 1533/17 08-11-2018

1. Admissibility of Documents D40 to D44, D4b, D14b and D18f

1.1 The appellant filed these documents after the communication of the Board pursuant to Article 15(1) RPBA.

1.2 Admissibility of D40

D40 is an experimental report on hot stamping tests performed by Brahim Bourouga. The appellant justified the late filing of D40 by explaining the difficulty to find an independent institution having the required equipment and the available capacity to perform tests which lasted three days.

Taking into account this argument, it follows that the same difficulty in finding available equipment would also apply to the respondents when trying to verify the experiments described in D40 or to provide counter-experiments.

The Board therefore agrees with the submission of the respondents that they did not have enough time between the filing of D40 and the oral proceedings to analyse and react to the experimental report.

Since consideration of the experimental evidence of D40 would have required adjournment of the oral proceedings, the Board in exercising its discretion under Article 13(3) RPBA does not admit D40 into the proceedings.

1.3 Admissibility of D41 to D44

D41 represents an excerpt from the legislation on importing coated steel sheets into the USA. It confirms that the coated steel sheet "Usibor" fulfils the requirements of the standard ASTM 463 (D25), and supports the arguments of the appellant concerning the interpretation of D2.

D42, an excerpt of a PhD thesis, as well as D43 and D44, scientific articles, support the appellant's argument that the skilled person is aware of how to measure porosity.

Since none of these documents change the appellant's case, the Board in exercising its discretion under Article 13(3) RPBA admits them into the proceedings.

1.4 Admissibility of D4b, D14b and D18f

D4b, D14b and D18f are based on documents D4, D14 and D18 which have been in appeal proceedings already. They present a further evaluation of the figures/pictures in D4, D14 and D18c and therefore support the arguments of the appellant.

The Board therefore admits these documents into the proceedings (Article 13(3) RPBA).

2. Main Request - Article 100(a) EPC in combination with Article 54 EPC

2.1 Interpretation of Claim 1 of the Main Request

2.1.1 Interpretation of Features 1.7 and 1.8

Claim 1 of the main request relates to a process for making a hot stamped coated steel product which defines that the heating rate Vc between 20 and 700°C is between 4 and 12°C/s, and the heating rate Vc' between 500 and 700°C is between 1.5 and 6°C/s (features 1.7 and 1.8).

On the face of it, claim 1 encompasses the theoretical possibility that the heating rates defined as Vc and Vc' can be in the same range and can even have the same value, as discussed in the impugned decision in point 3.2.1 of the reasons.

The Board agrees with the appellant that the heating step in an industrial hot stamping process usually takes place in a continuous furnace such as illustrated in figure 1 on page 137 of D11:FORMULA/TABLE/GRAPHIC

The Board further agrees with the appellant that the heating in a furnace having a set temperature follows basic principles of physics. This implies that the heating rate, in the absence of any special equipment, degreases over time as illustrated by Figure 2 of D8:

FORMULA/TABLE/GRAPHIC

Further confirmation of the decrease in heating rate over time is given in D31 (Fig. 1), D30 (Fig. 1), D5a and D5b.

It therefore follows that in a conventional, continuous furnace the heating rate Vc cannot be the same as Vc', and that Vc' is lower than Vc.

2.1.2 Interpretation of Features 1.5 and 1.6

The appellant argues that the temperatures defined by the two diagrams referred to in features 1.5 and 1.6 of claim 1 concern the heating of the sheet and do not mean that the furnace itself is preheated to a single temperature.

In other words, the appellant argues that the expression in feature 1.5:

"heating said aluminum- or aluminum alloy pre-coated steel blank in a furnace preheated to a temperature and during a time defined by diagram ..."

should be interpreted as

"heating said aluminum- or aluminum alloy pre-coated steel blank in a preheated furnace to a temperature and during a time defined by diagram ...".

However, the interpretation given by the appellant does not correspond to the actual wording of the claim. According to the normal meaning, claim 1 defines that the coated steel strip or sheet is heated

a) by placing it in a furnace preheated to a specific,

single temperature as defined by a diagram and

b) during a time defined by the same diagram.

The wording of claim 1 is clear and does not leave any room for an interpretation as submitted by the appellant.

Moreover, the literal meaning is consistent with the teaching of the example of the contested patent (paragraph [0025]), according to which the sheets were cut into blanks which "were heated at 920°C for 6 mn, this time including the heating phase and the holding time", i.e. were heated (ramping phase) by holding in the furnace set at a single temperature.

The wording of claim 1 therefore does not encompass a heating process, wherein the furnace can have different temperature zones, for example a heating zone having a higher temperature than the holding zone.

2.2 Appreciation of D4 as Prior Art pursuant to Article 54(3) EPC

2.2.1 It is undisputed that D4 can be considered to be comprised in the state of the art pursuant to Article 54(3) and 153(5) EPC and Rule 165 EPC.

2.2.2 The appellant submits that the requirements of Article 54(3) EPC should not prevent the applicant from filing a further application directed to an improvement of the invention disclosed in the document giving rise to the prior right. Therefore the assessment of novelty over a priority document, which only by legal fiction is considered to be comprised in the state of the art pursuant to Article 54(3) EPC, should be stricter than when assessing novelty with respect to prior art published before the priority date (prior art according to Article 54(2) EPC).

2.2.3 The Board does not agree. The assessment of novelty pursuant to Article 54(2) EPC follows a strict approach, whereby a document only discloses subject-matter that is directly and unambiguously derivable from the document (see Case Law of the Boards of Appeal, 8th edition, 2016, Chapter I.C.4.1, in particular T 464/94, T 511/92 and T 450/89, as cited by the appellant).

The same approach has been consistently applied to prior art pursuant to Article 54(3) EPC (see Case Law of the Boards of Appeal, 8th edition, 2016, Chapter I.C.2.4.1). Accordingly, the Board agrees with the reasoning in T 447/92, also cited by the appellant, that novelty has to be strictly assessed in case of prior art pursuant to Article 54(3) EPC. However, T 447/92 does not conclude that a different level of strictness has to be applied in such a case. Moreover, there are no provisions in the EPC, in particular Article 54(3) EPC, that for the purpose of determining novelty different types of prior art have to be assessed in accordance with different standards of strictness.

Therefore, the Board sees no reason when considering a prior art according to Article 54(3) EPC to go beyond the well established strict approach confirmed by the case law and in line with the EPC.

2.3 Disclosure of Example 2 i) of D4

2.3.1 It is undisputed by the appellant that example 2 i) of D4 discloses a process according to claim 1 with the exception that the heating rate Vc' is not disclosed.

The critical question therefore is whether or not the heating rate Vc' as defined in claim 1 of the main request is an implicit feature of the process according to the example of D4.

2.3.2 The appellant argues that a heating rate Vc' between 1,5 and 6 °C/s is not inevitable when the heating rate Vc is 10°C/s, as in the example 2 i), since the heating rate Vc' depends on the type of furnace and the specific heating parameters.

This might be correct and hypothetically heating curves can be drawn showing this possibility (see grounds of appeal, page 6):

FORMULA/TABLE/GRAPHIC

However, as indicated above in point 2.1.2, the wording of claim 1 implies that the furnace is preheated to a specific, single temperature. Therefore claim 1 does not encompass a process wherein the heating zone and the holding zone are set to different temperatures which could be modified to vary the heating rate Vc'.

2.3.3 D4 discloses in example 2 i) a process in which, compared with the example given in paragraph [0025] of the contested patent,

a) exactly the same sheet with the same coating (see example 1 of D4)

b) is placed in a furnace preheated to exactly the same temperature of 920°C

c) for the same time of 6 min

d) at the same heating rate Vc of 10°C/s.

Since, in both the example of the contested patent and example 2 i) according to D4, the furnace is not defined in detail, it can be concluded that the skilled person would only consider a usual furnace as normally used in the art, namely a continuous furnace, as submitted by the appellant (see point 2.1.1 above), which is set to 920°C.

Furthermore, the final product obtained by the process of example 2 i) of D4 and the example of the contested patent is described in both as having the same coating (see D4, page 4, lines 1-15):

"(a) Interdiffusion layer or intermetallic layer, 17 micrometers thick. This layer is itself composed of two sub-layers. Hardness HV50g ranges from 295 to 407, and the mean composition is, by weight: 90%Fe, 7%Al, 3%Si.(b) Intermediate layer, 8 micrometers thick. This layer has a hardness of 940HV50g and a mean composition, by weight: 43%Fe, 57%Al, 1%Si,

(c) Intermetallic layer, 8 micrometers thick, displaying a hardness of 610HV50g, a mean composition of, by weight: 65%Fe, 31%Al, 4%Si

(d) Superficial layer, 7 micrometers thick, 950 HV50g, with a mean composition of, by weight: 45%Fe, 54%Al, 1%Si. Layers (c) and (d) are quasi-continuous, i.e. occupying at least 90% of the level corresponding to the considered layer. In particular, layer (c) does not reach the extreme surface except very exceptionally. Anyway, this layer (c) occupies less than 10% of the extreme surface."

2.3.4 The appellant argues in this regard, that D4 does not address the porosity of the coating, and in particular does not disclose the link between the heating rate Vc' and the porosity of the coating, which is discussed in the contested patent at column 8, lines 32 to 34 and lines 45 to 51. The appellant concludes from this that the process disclosed in D4 cannot be the same as defined in claim 1, since it does not achieve a coating having the required porosity.

However, the porosity of the coating is not defined in claim 1 of the contested patent and therefore the claimed process is not limited to one in which a certain porosity must be achieved.

Furthermore, it is not plausible that the porosity of the coatings according to D4 and the contested patent differ, since the cited parameters, such as the hardness, thickness and composition of each layer are exactly the same for both. The mere fact that the porosity of the coating is not reported in D4 does not mean that it has to be different.

Moreover, D4 discloses in figure 1 a micrograph of a coated steel sheet obtained according to the process described therein. The micrograph in figure 1 indicates that the coating does not contain many pores. Dependent on the resolution of the micrograph and the size of the pores considered, the porosity of the coating, in surfacic fraction, achieved by the process of D4 can be calculated to be 2,4 % (D4a submitted by respondent 4) or 14,34 % (D4b submitted by the appellant).

The contested patent on the other hand does not define how the porosity is to be determined, and does not disclose a micrograph which could provide any information about the porosity and its measurement. Hence, any method can be applied for determining the porosity reported in the contested patent and it cannot be determined whether the evaluation presented in D4a or D4b reflects correctly the porosity of the coating according to D4.

It follows that neither the teaching in the contested patent nor the evaluation of porosity according to D4b can cast doubt that the process disclosed in D4 is the same as defined in claim 1 of the contested patent.

2.3.5 Since the same material in the same thickness is heated for the same time with the same heating rate Vc in the same type of furnace preheated to the same, single temperature and exactly the same product is obtained, it can only be concluded that the heating rate Vc' is inevitably the same as in the example of the contested patent, since no further parameters are defined in D4 or in the contested patent which could have an influence on the heating rate Vc', and which could provide the possibility for obtaining the hypothetical heating curve as submitted by the appellant.

The heating rate Vc' defined in claim 1 of the main request is therefore an inherent feature of the process disclosed in D4.

The subject-matter of claim 1 of the main request therefore lacks novelty over D4.

3. Auxiliary Requests 1, 3 and 5 - Article 54 EPC

Claim 1 of each of auxiliary requests 1, 3 and 5 defines that Vc is different from Vc'.

As indicated above in point 2.1.1, the Board agrees with the argument of the appellant that in a conventional furnace the heating rate Vc' is lower than the heating rate Vc.

Therefore it is inherent to the process described in D4 that Vc is different from Vc'.

The subject-matter of claim 1 of each of auxiliary requests 1, 3 and 5 lacks novelty for the same reasons as claim 1 of the main request.

4. Auxiliary Requests 2 and 5 - Article 54 EPC

Compared to claim 1 of the main request, claim 1 of each of auxiliary requests 2 and 4 is unamended, and hence lacks novelty for the reasons given above.

5. Admissibility of auxiliary request 6

5.1 Auxiliary request 6 was filed after the communication of the Board pursuant to Article 15(1) RPBA.

5.2 Claim 1 of auxiliary request 6 contains two disclaimers, one based on the example 2 i) of D4 and a further one in feature 1.7 based on the general description of D4, namely "with the exclusion that Vc is of 4°C/s or 6°C/s". The latter addresses the argument that the heating rates Vc and Vc' in claim 1 as granted could be identical and therefore the disclosure of a single heating rate Vc of 4°C/s or 6°C/s in D4 could be considered to fulfil the requirements of both Vc and Vc', as defined in claim 1 as granted.

As indicated above in point 2.1.1, the Board does not consider it technically plausible that the heating rates Vc and Vc' can be identical when following the disclosure of D4. Therefore, the further disclaimer "with the exclusion that Vc is of 4°C/s or 6°C/s" in claim 1 of auxiliary request 6 is not based on a novelty destroying disclosure and is therefore prima facie contrary to the requirements of Article 123(2) EPC in line with G 1/03.

The Board therefore does not admit auxiliary request 6 into the proceedings by exercising its discretion under Article 13(3) RPBA.

6. Auxiliary request 6a

6.1 Admissibility

Auxiliary request 6a was filed during oral proceedings before the Board following the discussion on novelty over example 2 i) and the admissibility of auxiliary request 6.

Claim 1 of auxiliary request 6a is based on claim 1 of auxiliary request 6, wherein the disclaimer in feature 1.7 "with the exclusion that Vc is of 4°C/s or 6°C/s" has been deleted.

Auxiliary request 6a therefore represents a direct reaction to the discussion during oral proceedings by prima facie removing the objections set out above in point 5 with regard to auxiliary request 6.

The Board therefore admits auxiliary request 6a into the proceedings by exercising its discretion under Article 13(3) RPBA.

6.2 Article 54 EPC

6.2.1 Claim 1 of auxiliary request 6a corresponds to claim 1 of the main request, with the inclusion of a disclaimer based on example 2 i) of D4. Therefore the reasoning given above in point 2.2 relating to the disclosure of example 2 i) does not apply to claim 1 of auxiliary request 6a.

6.2.2 The disclosure of a document is however not limited to the examples.

D4 discloses in claim 7 (in combination with claims 1 and 6 on which it depends) a process for making a hot stamped coated steel sheet product which is prepared by the steps of:

- providing a pre-coating on a steel strip with aluminium-or aluminium alloy, the thickness tp of the said pre-coating being from 20 to 33 micrometres at every location on said first and second sides of said strip or sheet, then

- cutting said pre-coated steel strip or sheet to obtain a pre-coated steel blank, then

- heating said aluminum- or aluminum alloy pre-coated steel blank in a furnace preheated to a temperature and during a time defined by diagram ABCD of figure 1 if thickness of said sheet is greater than or equal to 0.7mm and less than or equal to 1.5mm, and by diagram EFGH of figure 1 if thickness of said sheet is greater than 1.5mm and less than or equal to 3mm to obtain a heated blank; then

- transferring said heated blank to a die; then

- hot stamping said heated blank in said die, to thereby obtain a hot stamped steel blank, then

- cooling said hot stamped steel blank at a rate of at least 30°C/s."

The only and preferred method for coating the steel sheets according to D4 is hot dipping (page 7, lines 7, 11, 33, claim 5). Therefore D4 teaches that the process according to claim 7 includes a coating step by hot dip of the steel strip.

The diagrams disclosed in the figures of D4 correspond exactly to the diagrams disclosed in the figures and referred to in the claims of the contested patent.

Concerning the heating rate, D4 discloses from page 10, line 32 to page 11, line 7, that the heating rate Vc is from 4°C/s to 12°C/s whereby the definition for Vc indicated in D4 corresponds word by word to the definition in the contested patent (column 8, lines 3 to 14).

6.2.3 Alternatively to the disclosure based on claim 7, the same disclosure can be found in D4 when taking into account claim 3 and the statements on page 7, lines 11 and 23 to 33, page 11, lines 27 to 28 and page 17, lines 5 to 9.

6.2.4 D4 therefore discloses a process according to claim 1 of the contested patent, with the exception that the heating rate Vc' is not explicitly disclosed therein.

6.2.5 The critical question therefore is again whether or not the heating rate Vc' as defined in claim 1 of auxiliary request 6a is inevitably obtained when repeating the process described by the general teaching of D4.

6.2.6 The Board observes that D4 discloses preferred heating conditions for the process on page 11, lines 12 to 18:

"Particularly preferred conditions are:

(for thicknesses of 0.7-1.5mm)

- 930°C, from 3 minutes up to 6 minutes;

- 880°C, from 4 minutes 30 seconds up to 13 minutes

(for thicknesses of 1.5 to 3 mm)

- 940°C, from 4 minutes up to 8 minutes;

- 900°C, from 6 minutes 30 seconds up to 13 minutes"

which are exactly the same as the conditions indicated in the contested patent in column 7, lines 37 to 49.

Furthermore, the preferred coated and stamped steel blank to be obtained by the process described from page 9, line 22 to page 10, line 2 of D4 has exactly the same layered structure as defined in the contested patent from column 6, line 42 to column 7, line 3, whereby even certain properties such as the hardness of the individual layers are described to be the same.

D4 therefore discloses a process wherein the same type of material (hot-dip coated steel) is placed in a continuous furnace preheated to exactly the same, single temperature for the same duration and with the same heating rate Vc as defined in claim 1 of the contested patent, and whereby a hot-stamped product is obtained having the same layered coating as intended by the contested patent.

All specific process definitions including the most preferred options disclosed in D4 therefore correspond word by word with the corresponding definitions in the contested patent.

In analogy to the argument presented above in point 2.3 with regard to claim 1 of the main request, the Board cannot see any possibility how a skilled person reworking the teaching of D4 could achieve a different heating rate Vc' when heating the same blank in the same furnace at the same, single temperature and with exactly the same heating rate while obtaining a product having a coating with the same layered structure.

It follows that the heating rate Vc' as defined in claim 1 is inevitably obtained when following the teaching of D4 and therefore is implicitly disclosed by D4.

The subject-matter of claim 1 of auxiliary request 6a therefore lacks novelty over D4.

7. Admissibility of auxiliary request 7

7.1 The appellant filed auxiliary request 7 after the communication of the Board pursuant to Article 15(1) RPBA.

7.2 Claim 1 of auxiliary request 7 differs from claim 1 as granted by the features of claim 2 as granted:

D4 discloses the added feature in claim 7 and as well in the general description on page 17, lines 4 to 9.

Therefore, the subject-matter of claim 1 of auxiliary request 7 prima facie lacks novelty over the general disclosure of D4 for the same reasons as indicated above for claim 1 of the main request.

The Board therefore does not admit auxiliary request 7 into the proceedings by exercising its discretion under Article 13(3) RPBA.