T 0849/08 15-12-2010

I. Mention of the grant of European Patent No. 1 197 505 in the name of Talex Optical Co., Ltd. in respect of European patent application No. 01124523.0 filed on 12 October 2001 and claiming a priority date of 13 October 2000 from JP 2000313704 was announced on 7 September 2005 (Bulletin 2005/36) on the basis of 5 claims which read as follows:

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II. A notice of opposition to the patent was filed on 2 June 2006 by PPG Industries, Inc. invoking the grounds of opposition pursuant to Art. 100(a) EPC (lack of novelty, lack of inventive step), 100(b) EPC (lack of sufficiency of disclosure) and Art. 100(c) EPC (extension of the subject matter of the patent beyond the content of the application as filed).

Inter alia the following documents were cited in support of the opposition:

D1: US-A-6 127 505

D3: US-A-3 866 242.

During the course of the opposition proceedings the opponent cited, with a letter dated 22 May 2007, a further document:

D4: JP-A-9 258 009 and an English language translation thereof.

III. In a decision dated 13 February 2008 and issued in writing on 17 March 2008 the opposition division revoked the patent.

The decision was based on three sets of claims forming a main request, having two claims and first and second auxiliary requests each having four claims, all three requests having been filed with a letter dated 11 December 2007.

Claim 1 of the main request was directed to an impact-resistant polarized optical lens formed by casting a polyurethane resin and read as follows:

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For the purposes of the decision the opposition division treated this claim (and the corresponding claims of the first and second auxiliary requests) as having been amended by replacing the term "a polyurethane resin" by "the polyurethane resin" (emphasis of the Board) in order to address an objection pursuant to R. 80 EPC (cf section 2.1 of the decision of the opposition division).

Claim 2 of the main request was directed to a preferred embodiment and corresponded to the subject matter of claim 2 of the patent as granted (see section I, above).

The details of the first and second auxiliary requests are not relevant for the present decision.

According to the decision of the opposition division:

(a) D4 was admitted to the proceedings:

- Claim 1 had been amended during the course of the opposition proceedings to be directed to "a polarized lens";

- D4 disclosed how polarized lenses were prepared and hence was prima facie highly relevant.

(b) With respect to Art. 123(2) EPC for the main request the decision held:

- The subject matter of claim 1 was a combination of the subject matter of claims 1 and 3-6 as originally filed;

- Thus the requirements of Art. 123(2) EPC were satisfied.

(c) The claims of all requests met the requirements of Art. 83, 84 and 123(3) and R. 80 EPC (subject to the above mentioned amendment).

(d) The subject matter of the main request was novel:

- D1 did not disclose the required chain extender (4,4'-methylene bis (2-chloroaniline) - hereinafter "MOCA") or the formation of a polarized lens;

- D3 disclosed optically clear polyurethanes for protective shields, more particularly for optical ballistic shields, glazings for buildings and vehicles, riot shields, face shields and clipboards. D3 disclosed MOCA as the chain extender;

- D4 disclosed the production of polarized lenses, but did not employ the specific combination of isocyanates with MOCA.

(e) Inventive step was analysed starting from each of D1 or D3 as the closest prior art. Whilst D1 related to lenses but did not disclose the required diamine (MOCA), D3 disclosed the same composition however employed this not for a lens but for bullet proof shields, face shields or windshields. With respect to D3 as the closest prior art:

- The composition of D3 was suitable for the production of impact resistant transparent optical applications;

- It was however clear from D1 that impact resistant, transparent optical applications included lenses. Further D1 referred to D3;

- The technical problem with respect to D3 was to provide a further use for the polyurethane composition of D3;

- It was obvious to apply the composition of D3 - being identical to that specified in the operative claim 1 of the patent in suit - to the production of lenses. Moreover it was obvious to apply the composition in the manufacture of polarized lenses since the manufacture of polarized lenses from a lens material was state of the art as shown by D4.

Alternatively, based on D1 as the closest prior art:

- D1 disclosed impact resistant lenses from a similar polyurethane lens material;

- The objective technical problem was to provide an alternative polyurethane material for impact resistant polarized optical lenses;

- The skilled person was motivated to look into D3 for alternative polyurethane materials for this purpose;

- Firstly, D3 was mentioned in D1;

- Secondly, D3 concerned the same polyurethane composition as D1 but a different chain extender (MOCA) which also led to impact resistant transparent polyurethanes with good optical properties, i.e. low haze as shown by example 1 of D3;

- An additional motivation to consider D3 was that D1 mentioned that polyurethanes for lenses had the same optical and mechanical properties as the polyurethanes used for glazing, riot shields and face masks;

- The longer pot life found by using MOCA as the chain extender compared with the amines used in D1 was merely an additional benefit or bonus effect;

- Consequently it was obvious to apply polyurethanes of D3 in the manufacture of lenses and in particular polarized lenses, the manufacture of such lenses being state of the art as shown by D4.

(f) The subject matter of the auxiliary requests also did not satisfy the requirements of Art. 56 EPC.

(g) Accordingly the patent was revoked.

IV. A notice of appeal against the decision was filed on 23 April 2008 by the patent proprietor, the prescribed fee being paid on the same day.

V. The statement of grounds of appeal was received on 28 July 2008 accompanied by:

- Nine sets of claims forming a main request and first to eighth auxiliary requests and

- Four "Enclosures" designated "Enclosure A" to "Enclosure D" whereby:

- Enclosure A was a copy of the letter dated 11 December 2007, submitted during the opposition proceedings (cf section III, above). The text of this letter contained inter alia a report of some further examples;

- Enclosures B and C were stated to provide evidence of the commercial success of the lenses produced by the patent proprietor;

- Enclosure D was a further experimental report.

(a) The late filed document D4 could not be considered admissible in view of the established practice of the European Patent Office concerning late filing of documents under due consideration of Art. 114 EPC:

- D4 was not relevant as it was neither used in the evaluation of novelty nor did D4 constitute the closest prior art in the evaluation of inventive step;

- The decision under appeal only considered D4 in the context of technological background information;

- The disclosure of D4 was very unspecific referring to a broad variety of polymeric materials as well as a variety of preparation methods for the devices therein disclosed;

- The argument of the opponent that the filing of D4 had been necessitated by the submission of unforeseen amendments was invalid since the amendment to claim 1 merely involved features that had already been present in the set of - only five - claims as granted.

(b) The main request corresponded to the main request considered in the decision under appeal however with the term "a polyurethane resin" amended to read "the polyurethane resin" so that the claim conformed in wording to that which the opposition division had treated the claim as having (see section III, above). The first auxiliary request differed from the main request in specifying the range for the viscosity of the polyurethane polymer (750 to 2100 mPa.s at 60ºC). The second auxiliary request corresponded to the first auxiliary request, whereby claims 1 and 2 had been combined. Accordingly the second auxiliary request had only a single claim. The details of the other requests are not relevant to this decision.

(c) With regard to the technological background:

- In contrast to the disclosure of D1 the inventors had determined that a specific chemical composition for the material yielding the polyurethane resin for the polarized lens was required;

- Enclosure A showed that the composition according to the patent in suit provided longer pot life;

- This aspect had been neglected in the decision of the opposition division;

- Pot life was an important technical feature since only suitably long pot lives allowed slow production processes, which were required in the preparation of polarizing lenses in a mould in order to avoid damage or distortion of the polarizing film.

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(d) With regard to inventive step, D3 as selected by the opponent (see also section III.(e), above) could not represent the closest prior art as it did not relate to impact resistant polarized lenses but to protective shields. Even if D3 were nevertheless to be considered it would not render the claimed subject matter obvious:

- It contained no suggestion that the material therein disclosed could be employed to provide polarized lenses with the improved properties as demonstrated by the examples of the patent in suit;

- Neither D1 nor D4 suggested to employ the materials of D3 to prepare polarized lenses.

Considering D1 as the closest prior art:

- D1 referred to an impact resistant polyurethane and method for preparing same;

- D1 differed from the claimed subject matter in that neither polarized lenses, nor lenses formed from the specific polyurethane resin defined in operative claim 1 were disclosed;

- The objective problem underlying the patent in suit was the provision of improved polarized lenses made from a polyurethane resin;

- The advantage of the composition of the invention was the good balance of properties, especially the highly desirable pot life of 35 to 60 minutes as shown in the examples;

- The aromatic amines taught by D1 resulted in compositions with unsatisfactory processing properties, in particular unsuitably short pot lives, and hence were not suitable for the preparation of a polarized lens with the desired quality, as shown by the examples of the patent in suit;

- D4 did not contain any reference to a specific polyurethane composition which had been used in accordance with the present invention to prepare improved polarized optical lenses.

(e) The viscosity range specified in the first auxiliary request complied with the requirements of Art. 123(2) EPC since:

- This range had to be considered as a general feature of the disclosure of the invention;

- It was not linked to the specific conditions as defined in the examples;

- The comparative examples of the patent in suit had either higher or lower viscosities than defined in the first auxiliary request;

- The discussion on page 5 of the granted patent identified this viscosity range as highly suitable for producing optical lenses, in particular polarized lenses.

Regarding inventive step of the first auxiliary request:

- The patent showed that the preparation of high quality lenses could be carried out using the polyurethane compositions falling within the newly specified viscosity range;

- In contrast, as shown by the additional experiments submitted (Enclosure D), the compositions of D1 and D3 gave rise to unsatisfactory lenses since either resin flow broke down or the resin flow was so viscous that bubbles remained, rendering the lenses useless.

(f) These arguments applied also to the second-eighth auxiliary requests.

VI. The opponent - now the respondent - replied with a letter dated 5 December 2008.

(a) Five further documents, designated D5-D9 were submitted, inter alia: D5: Voelker, Th; Balling, P. "A New Non-Toxic Replacement for Methylene-Bis-o- Chloroaniline (MBOCA)-4,4'-Methylene-Bis-(3- Chloro-2,6-Diethylaniline)-MCDEA", Journal of Elastomers and Plastics, vol. 19, July 1987, pages 219-230.

(b) The opposition division had exercised their discretion to admit D4 and considered it to be relevant. D4 had been employed in the reasoning of the decision.

(c) Regarding Art. 83 EPC:

- As was apparent from Enclosure D (filed with the statement of grounds of appeal - see section V, above) the composition of example 1 of D3 fulfilled all the compositional requirements of the operative claim;

- Although the appellant/patent proprietor considered the viscosity to be an essential difference between the subject matter of the patent in suit and example 1 of D3, claim 1 of the main request did not have any restriction with respect to viscosity;

- Thus example 1 of D3 disclosed a polyurethane casting composition according to the main request;

- Enclosure D however showed that such a composition was not suitable to produce polarized lenses due to extensive bubble formation;

- Hence the patent proprietor itself had provided evidence that the subject matter of claim 1 of the main request could not be made within the entire scope claimed.

(d) With regard to inventive step, the closest prior art was D3 since this disclosed the resin composition employed in the claims and casting processes for making articles therefrom:

- The objective technical problem solved was to find a different use for the composition known from D3;

- The features "polarized" and "lens" were independent and "polarized" was independent of the resin composition;

- D4 showed that it was well known how to prepare a polarized lens in a casting process;

- The skilled person was aware of D1 especially since it referred to D3;

- D1 disclosed that optically clear polyurethane compositions known from D3 could alternatively be used for lenses or protective shields;

- Hence it was evident to use the composition of D3 in a casting process to make polarized lenses;

- Since the polarized lens was the inevitable product of that process the lens itself also could not be inventive.

D1 did not represent a valid closest prior art (cf submissions of appellant/patent proprietor reported in section V.(c) above):

- The evidence of the appellant/patent proprietor showed that when employing a polyurethane resin within the limits of claim 1 of the main request but outside a specific viscosity range useful lenses could not be obtained;

- The only remaining technical problem was to provide an alternative crosslinker compared to the teaching of D1;

- As D1 referred explicitly to D3 it was obvious to substitute the crosslinker known from D1 by the crosslinker known from D3;

- Regarding the argument of the appellant/patent proprietor concerning the increased pot life of the MOCA curing agent, D5 taught in the production of elastomers, that MOCA provided higher pot life than the curing agents known from D1;

- The main drawback of MOCA was toxicity and carcinogenicity;

- Consequently starting from D1 it was obvious to substitute the crosslinker of D1 by MOCA in order to make a polarized lens.

(e) The first and second auxiliary requests did not meet the requirements of Art. 123(2) EPC due to the specification of the viscosity:

- There was no general teaching in the application as filed with regard to viscosity requirements;

- Only the single viscosities of each of the examples were disclosed;

- The examples showed that the viscosity depended strongly on the explicit conditions of the examples and could not be generalised independently of the other restrictions of the examples.

(f) Numerous objections were raised with respect to the claims of the third-eighth auxiliary requests which are however not relevant for the present decision.

VII. Together with a letter dated 25 May 2010 the appellant/patent proprietor submitted 24 sets of claims forming a main request and 1st-23rd auxiliary requests.

The main request and first and second auxiliary requests were stated to be identical to those filed together with the statement of grounds of appeal (see section V, above).

The third auxiliary request was stated to be based on the main request whereby claims 1 and 2 had been combined and in which furthermore the polyhydroxy compound had been limited to a polyether diol, i.e. one of the two embodiments of claim 2 of the previous main request.

The sole claim of the third auxiliary request therefore read as follows:

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The details of the further sets of claims are not relevant to the present decision.

(a) The appellant/patent proprietor maintained its objection to the admissibility of D4 and raised objections to the admissibility of D5-D9.

(b) Concerning the submissions of the respondent/opponent with regard to Art. 123(2) EPC in respect of the viscosity range introduced inter alia into the first and second auxiliary requests (see section VI.(e), above), reference was made to the corresponding argumentation in the statement of grounds of appeal (see section V.(e), above).

(c) With regard to sufficiency of disclosure inter alia of the main and first and second auxiliary requests (see submissions of the respondent/opponent reported in section VI.(c), above) reference was made to the findings of the opposition division (see section III.(c), above).

(d) Regarding sufficiency of disclosure inter alia of the third auxiliary request wherein the polyhydroxy compound had been restricted to polyether diols, and the submissions of the respondent/opponent with respect to the experimental evidence of Enclosure D (see section VI.(c), above) the appellant/patent proprietor submitted:

- The differences in the viscosities disclosed in "Test Example 1" and "Test Example 2" of Enclosure D (reflecting Example IV of D1 and Example 1 of D3 and of "Control Test Example 1" of Enclosure D (reflecting example 2 of the patent in suit) were correlated to the fact that "Test Example 1" and "Test Example 2" employed a polyester diol whereas "Control Test Example 1" employed a polyether diol;

- If other manufacturing conditions were identical the viscosity was lower in the case of a polyether diol compared to a polyester diol;

- In view of this it was apparent that the claims inter alia of the third auxiliary request satisfied the requirements of Art. 83 EPC.

(e) Regarding inventive step, reference was made, with regard to the choice of the closest state of the art, to the submissions in the statement of grounds of appeal (see section V.(d), above). Further:

- Enclosure A showed that the compositions of the invention had longer pot lives which was crucial to produce polarized lenses with the desired quality;

- This showed that favourable properties of the polarized lenses were directly linked with the material properties;

- D5, submitted by the respondent/opponent (see section VI.(a), above) did not relate to polarized lenses;

- With respect inter alia to the third auxiliary request and the limitation to polyether diols of the specified average molecular weight, D1 and D3 did not suggest specifically using a polyether diol.

(f) Regarding the submissions of the respondent/opponent:

- D3 was not the closest prior art, reference being made to the statement of grounds of appeal (see section V.(d), above);

- With respect to the submissions of the respondent/opponent concerning D4 (see section VI.(d), above), it was emphasised that specific chemical compositions were required in order to obtain polarized lenses with high reliability;

- Enclosure A showed that compositions according to the patent in suit provided longer pot lives, which was crucial to produce polarized lenses with the required quality.

VIII. Together with a letter dated 2 June 2010 the appellant/patent proprietor filed high quality copies of photos originally attached to Enclosure D as filed with the statement of grounds of appeal.

IX. On 20 August 2010 the Board issued a summons to attend oral proceedings together with a communication setting out its preliminary, provisional opinion.

(a) The main request and all auxiliary requests failed to meet the requirements of Art. 123(2) EPC due to the omission of the term "for casting". This term was essential since according to pages 2, lines 43-46 of the application (A1 publication) the term "for casting" had to be understood that first an isocyanato functional prepolymer was obtained by reacting an alicyclic polyisocyanate with a polyhydroxy compound and the composition for casting contained this prepolymer and a polyamine crosslinker.

(b) With respect to the main request and the objections raised pursuant to Art. 83 and 56 EPC:

- Claim 1 was directed to an impact resistant polarized optical lens formed by a particular process;

- Whilst the patent in suit referred to qualities of the resulting lens, the only effects quantitatively demonstrated were the viscosity of the prepolymer and its pot life neither of which was a characteristic of the lens;

- Thus it would be necessary to discuss to what extent the indicated phenomena implied a relevant effect in relation to the product of claim 1.

(c) With respect to inter alia the first and second auxiliary requests an objection pursuant to Art. 123(2) EPC was raised in respect to the specified viscosity range. With reference to T 201/83 (OJ EPO 1984, 481) it was not immediately apparent that the viscosity value given in any of the examples was "not so closely associated with the other features of the example as to determine the effect of that embodiment…as a whole in a unique manner and to a significant degree".

(d) Regarding the introduction of D4 into the proceedings by the opposition division, the Board considered that this document now formed part of the proceedings.

(e) The question of introduction of D5-D9 would be a matter for possible discussion at the oral proceedings.

X. In a letter dated 11 November 2010 the respondent/opponent objected to the number of auxiliary requests filed, arguing this was "clearly not acceptable".

(a) The arguments presented by the appellant/patent proprietor regarding the admission of D4 to the procedure were disputed (see section VII.(a), above). The opposition division had the discretion to decide under Art. 114 EPC whether to allow a late filed document into the procedure. Since the opposition division had decided to do so, the decision to admit this document was no longer disputable. D5-D9 had been filed in response to the evidence and arguments presented in the appeal and consequently could not have been submitted earlier.

(b) Objections pursuant to Art. 56 EPC were maintained in respect of the main request, reference being made to the earlier submissions (see section VI.(d), above).

XI. With a letter dated 12 November 2010 the appellant/patent proprietor filed amended sets of claims constituting a main request and 23 auxiliary requests.

The main request and first to sixth auxiliary requests corresponded to those previously submitted whereby the respective claims 1 of thereof had been amended by insertion of the wording "for casting", reference being made to original claim 5 for support.

Thus the relevant parts of the claims read:

"…lens formed by casting the polyurethane resin composition for casting comprising…" (emphasis of the Board).

The 7th-23rd auxiliary requests had been reordered, whereby in all of these requests claim 1 had been amended in the same manner as indicated for the main and first to sixth auxiliary requests. The further details of the 7th-23rd auxiliary requests are however not of relevance for this decision.

(a) Regarding the features derived from the examples, in particular the viscosity the appellant/patent proprietor argued:

- It was established practice and case law of the EPO that these features complied with the requirements of Art. 123 EPC since it was readily apparent that these had to be considered as general features, i.e. were not linked to any specific compositions as defined in the examples;

- The argumentation submitted in the letter of 28 July 2008 (statement of grounds of appeal - see section V, above) and 25 May 2010 (see section VII, above) clearly demonstrated that the incorporation of these features had to be regarded as admissible in terms of Art. 123 EPC.

(b) Objections to the admission of D4 and D5-D9 were maintained.

(c) With regard to Art. 56 EPC in addition to referring to the previously submitted argumentation the appellant/patent proprietor submitted:

- Prior to the patent in suit many kinds of soft and hard polyurethane resins had been known;

- High hardness and high impact resistance were required for impact resistant lenses;

- If hardness of the resin was too high, shock resistance tended to decrease due to increased brittleness;

- The polyurethane resin underlying the invention in suit provided a good balance between hardness and elasticity so that it was suitable for impact resistant lenses.

In response to the comments of the Board in its preliminary opinion (see section IX.(b), above) above) it was submitted:

- If a monomer was mixed with a curing agent in the form of diamine as is, i.e. without prepolymerisation the reaction would be too rapid, leading to extremely short pot life making formation of a lens by casting impossible and providing a product that was too brittle;

- According to the invention in suit the prepolymer and diamine (MOCA) were subjected to additional polymerisation, whereby the polymerisation rate was very slow so that an extended pot life was obtained;

- This effect was achieved due to the specific nature of the prepolymer (determined by molar ratio of polyisocyanate and polyhydroxy compound, the viscosity and the average molecular weight), which also influenced the physical properties of the lens due to the nature of the specific diamine (MOCA);

- In particular, MOCA improved resistance to discoloration, durability, hardness and chemical resistance;

- In D3 MOCA was used for windshields for motorcycles, however MOCA had never previously been used for spectacle lenses;

- Only by the specific combination of prepolymer and diamine curing agent could a lens material having the required viscosity and sufficiently long pot life and providing a lens having various excellent properties including impact resistance, resistance to discoloration, durability, hardness and chemical resistance be obtained;

- This showed that the viscosity of the prepolymer and duration of the pot life were important parameters in order to obtain the desired impact resistant polarized lens;

- In D1 the pot life was short (less than 15 minutes) and it would be impossible to produce a sufficiently impact resistant polarized lens;

- D1 was completely silent about MOCA - the curing agent used in D3 - even though these were from the same inventor. This indicated that the inventor knew that MOCA could not be used in the invention of D1;

- D4 referred exclusively to thiourethanes. This was because only thiourethanes had been available as polyurethanes for lenses in the application year of D4 (1996), which predated D1 and the patent in suit;

- Thiourethanes were intrinsically different from the urethane prepolymers specified in the operative claims. Consequently D4 could not suggest the claimed subject matter.

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XII. Oral proceedings were held before the Board on 15 December 2010.

(a) Main request

(i) The appellant/patent proprietor emphasised that the two important features - polarizing element and the specific composition - were interrelated and that it was consequently not correct to deal with these separately. A critical aspect was that the lens material could be filled into the mould to produce a clear lens free of bubbles whilst avoiding damage to the fragile polarizing film. The formation of the lens was a slow process taking a whole day. The experimental results in the patent in suit and in the enclosures submitted during the course of the opposition and appeal procedures showed that the claimed materials provided sufficient pot life and adequate quality of the lenses. D1 was the closest prior art as it referred to polyurethane compositions which could be used for a variety of purposes including ophthalmic or sun lenses but did not disclose either the specific composition or the presence of polarizing elements. D4 did not disclose the material according to the claims in suit. The approach to protect the polarizing element in D4 - applying a hard coating - was different from that taken in the patent in suit and did not provide any pointers to optimise the polyurethane composition in order to provide the lenses. D3 did not relate to lenses, let alone polarized lenses, at all. Although D3 disclosed polyurethanes with the required crosslinker, there was no incentive to consider the teaching of D3 when faced with the technical problem of D1. D3 was disclosed in D1 as background art and not as part of the invention of D1.

(ii) The respondent/opponent noted that the chemical composition of D3 was identical to that according to the operative claim; consequently D3 should be considered the closest prior art. Both the principal properties addressed by the appellant/ patent proprietor - optical clarity and impact resistance - were also addressed in D3, as was the problem of providing articles with low haze and being free of bubbles. Thus the only difference was the final product formed. D4 taught how to make polarized lenses, and disclosed the same process as the patent in suit. Thus together D3 and D4 provided all the information necessary to prepare polarized lenses as defined in the operative claim. The teaching of D3 was incorporated by reference into D1, meaning that these teachings had to be considered together. Enclosure D showed that a polyurethane material that fell entirely within the scope of claim 1 did not result in a polarized lens due to the presence of bubbles. This demonstrated that the problem defined could not be solved over the entire scope of claim 1. The objective problem could only be formulated as to provide an alternative. From D1 and the reference therein to D3 it was obvious that this could be solved by combining the teachings of D1 and D3 and with reference to the teaching of D4 showing how to prepare polarized lenses. For providing merely an alternative optical clarity was not required.

(iii) The appellant/patent proprietor responded that the reference to D3 in D1 meant only that the compositions of D3 were also suitable for the preparation of ballistic shields, but not necessarily that these were equivalents to the materials of D1. D3 was limited to protective shields whereas D1 related to a broader range of products including ophthalmic lenses. Since D3, despite the similarity in the compositions, did not relate to the same end use it did not qualify as closest state of the art. The experimental evidence showed that the compositions of D3 were not suitable to prepare polarized lenses. The comparative examples confirmed that high viscosity materials were not suitable. This was however a matter of Art. 83 EPC not Art. 56 EPC since the patent provided sufficient information and guidance to explain which compositions had to be used. Even if the technical problem were formulated as providing merely an alternative there still would have been no reason to consult D3 since this has no relationship to lenses. The requirement for low viscosity was clearly disclosed by the examples and comparative examples of the patent in suit, reference being made to example G. The wording of the claim "resin for casting" imposed the necessary viscosity restriction when taking account of the examples.

(iv) The respondent/opponent observed that the patent proprietor was attempting to impose a limitation on the term "for casting" which was neither in the claim nor in the specification. Thus "for casting" did not have a clear meaning and the requirement that the lens produced be free of bubbles and distortions relied on features which were not present in the claim.

(v) After deliberation the Board announced that the main request was refused.

(b) First and second auxiliary requests

(i) The appellant/patent proprietor submitted, with reference to its written submissions (see section XI.(a), above) and to T 201/83 (cited by the Board in its communication - see section IX.(c), above) that in the specific circumstances of the patent in suit it was admissible to isolate the values of viscosity from the particular experimental circumstances in which they had been obtained.

(ii) The respondent/opponent disputed that the viscosity values could be generalised and isolated since they were intimately linked to the specific features of the compositions in the examples. The application as filed contained no general teaching of a range of viscosity values. In addition, claim 1 of the first auxiliary request defined the polyhydroxy compound only very generally. Examples 5 and 6 - employing polyester as the polyhydroxy compound - had significantly higher viscosities than examples 1-4, which employed polyethers. There was no evidence that the higher viscosity ranges could be obtained with polyethers. Similarly there was a lack of disclosure for low viscosity compositions based on polyesters.

(iii) After deliberation the Board announced that the first auxiliary request was refused pursuant to Art. 123(2) EPC. Further the Board expressed its view that since claim 1 of the second auxiliary request also specified the viscosity range, the same conclusion would have to apply mutatis mutandis. This view was not contested by the appellant/patent proprietor. Accordingly the second auxiliary request was also refused.

(c) Third auxiliary request.

(i) The appellant/patent proprietor explained that the sole claim of this request was a combination of claims 1 and 2 of the main request whereby the polyhydroxy compound had been restricted to polyether. This subject matter was clearly distinguished from the disclosure of D3 requiring a polyester diol. The examples relating to this embodiment demonstrated that a lens could be obtained. Applying the problem solution approach, D1 represented the closest prior art. The definition of the polyhydroxy compound as being a polyether provided a further distinguishing feature. The problem was to provide a suitable impact resistant high quality polarized lens which could be produced in a safe and reliable manner. As shown by the data in the patent in suit and that subsequently submitted, this problem had been solved by the claimed subject matter. D1 contained no reference to a polarized lens or any discussion of problems associated with the provision of such.

(ii) The respondent/opponent noted that the patent in suit contained no single example relating to polarized lenses; there was no data showing whether polarized lenses could even be obtained following the teaching of the patent in suit; there was no evidence of any technical effect associated with the use of the polyether polyol. Since the use of polyetherpolyols in such compositions was known from both D1 and D3 this feature could not support an inventive step. Starting from D1 the only difference was the nature of the crosslinker. This gave an effect regarding the pot life which however was not a feature of the product. This was not even surprising since this was known from D5, which also taught that the curing agents of D1 suffered from critically short pot lives. Although D5 did not address the same problem as the patent in suit it taught that MOCA provided longer pot life. Since the technical problem underlying the patent in suit was to find an alternative composition to those of D1, having longer pot life in order to make high quality lenses, the opponent requested that D5 be admitted. In this connection, it noted that the appellant/patent proprietor had been permitted to present arguments based on data submitted for the first time during the appeal proceedings, and that D5 had been submitted inter alia in response to these data in particular in view of the pot life obtainable with the various crosslinkers. Thus D5 could not be considered to be late filed.

(iii) With respect to the admissibility of D5 the appellant/patent proprietor referred to its written submissions. Further the main focus of D5 was on finding a replacement for MOCA. The interpretation of D5 adopted by the respondent/opponent was diametrically opposed to the thrust of the teaching thereof.

(iv) Following deliberation the Board announced that D5 was admitted to the proceedings.

(v) The respondent/opponent, with respect to D1 as the closest prior art submitted that it was self evident that a composition which had a longer pot life would stay stable for longer meaning that gas could be removed from the system. Thus it was not surprising that increasing the pot life improved the clarity of the lens. This was in particular evident in view of the examples of the appellant/patent proprietor showing that there were problems filling a mould with high viscosity materials. Based on D3 as the closest prior art the only problem was to provide alternative optically clear impact resistant articles. D4 provided the information necessary to produce polarized lenses. Hence it required no inventive activity to produce polarized lenses from the compositions of D3. Even starting from D1 the conclusion would be the same: the skilled person would be directed to employ MOCA in order to avoid problems associated with short pot life. Regarding the fact that D5 taught MOCA for use in elastomers the respondent/opponent submitted that the border between elastomeric and non-elastomeric compounds in particular in the case of the technology under consideration was diffuse. Hence it could not be concluded that this distinction would prevent the skilled person from consulting D5 when seeking to provide lenses. The reason why D1 failed to mention MOCA was clear - as shown by D5 this material represented a health hazard. Nevertheless, this material did enable longer pot lives to be achieved.

(vi) The appellant/patent proprietor queried why, if MOCA was commonly used for polyurethanes, it was not mentioned in D1 and posited that this was due to the specific nature of elastomers. The shields of D3 required a combination of elastomeric and optical properties. D1 was focussed principally on armour applications and contained no examples of lenses. Any submissions of the respondent/opponent why MOCA was not mentioned in D1 were pure speculation. There was no clear motivation in D5 specifically to select MOCA when producing polarized lenses. Further the hardness properties reported in D1 and D5 showed possible distinctions between elastomeric products and lenses.

XIII. The appellant/patent proprietor requested that the decision under appeal be set aside and that a patent be granted on the basis of the main request or of one of the 1st to 23rd auxiliary requests in that order.

The respondent/opponent requested that the appeal be dismissed.