The battle is between TATA Chemicals and Hindustan Unilever Ltd. For a water filtration device 12 June, 2012  the Intellectual Property Appellate Board (IPAB), acting on a petition filed by Tata Chemicals, has revoked Indian Patent No. 195937 granted to Hindustan Unilever Ltd. (HUL) for the invention of a ‘filter cartridge’ that is used in HUL’s Pureit brand of water-filtration devices granted on the 26th of August, 2005.

The judgment was very interesting and covers some new ground with respect to disclosure requirements under Section 8 of the Patents Act, 1970 and also the role of expert witnesses in Indian patent litigation.

The claims of the invention – Patent No. 195937: The claimed invention is constructed in such a manner that it forces the water introduced in it to climb in an upward direction through the filter media before exiting the invention as a purified water. The claimed advantage of such a mechanism was an increased rate of flow of water through the filter cartridge when compared to traditional water filters which forced water through the filter cartridge in a downward mechanism. The reason for this increased rate of flow of water was because water moving in an upward direction does not face the problems of ‘airlocks’ and ‘channelling of water’ which are common problems faced by water moving in a downward direction through a filter media. Of course, this is an over-simplified version of the actual patent specification and although the claimed invention may seem simple, the IPAB makes it very clear that simplicity was not its main ground for revoking the patent.

The challenge on ‘anticipation’ & ‘obviousness’: comparing the prior art, there was a lack of “Inventive step” Tata Chemicals challenged the patent as being anticipated. The IPAB examines the prior art in considerable detail and appears to have found several prior art documents anticipating and rendering obvious the present invention.

In one such instance the IPAB states “It is not the simplicity of the invention that makes us hold it is not patentable It is not patentable because it is not new as seen from US ‘260, and it is obvious as seen from US ‘402 which provides for “the vertical upward flow through the absorbent cartridge” which was also addressed to remove the tendency of water to flow in channels leaving portion of absorbent untouched because air remains in the cartridge. The problems of air bubbles, channelling and non-uniform flow are all mentioned here. We are unable to see either novelty or inventive step in the invention.”

 Section 8 of Indian Patent Act 1970: Information and undertaking regarding foreign applications.—(1) Where an applicant for a patent under this Act is prosecuting either alone or jointly with any other person an application for a patent in any country outside India in respect of the same or substantially the same invention, or where to his knowledge such an application is being prosecuted by some person through whom he claims or by some person deriving title from him, he shall file along with his application or subsequently within the prescribed period as the Controller may allow—

(a) a statement setting out detailed particulars of such application; and

(b) an undertaking that, up to the date of grant of patent in India, he would keep the Controller informed in writing, from time to time, of detailed particulars as required under clause (a) in respect of every other application relating to the same or substantially the same invention, if any, filed in any country outside India subsequently to the filing of the statement referred to in the aforesaid clause, within the prescribed time.

(2) At any time after an application for patent is filed in India and till the grant of a patent or refusal to grant of a patent made thereon, the Controller may also require the applicant to furnish details, as may be prescribed, relating to the processing of the application in a country outside India, and in that event the applicant shall furnish to the Controller information available to him within such period as may be prescribed.

The complex was that HUL patent application had been issued an extremely adverse IPER by WIPO and the same had not been disclosed before the Indian Patent Office. The most significant piece of prior art cited in the IPER, was reportedly an EP-1106578. Coincidentally this same EP patent was also cited by the Indian Patent Office during its examination and HUL managed to overcome the objections.

Hindustan Unilever therefore argued that the non-disclosure of the IPER was inconsequential, since the prior art cited in the report, was duly considered by the Indian Patent Office. The IPAB however considered the suppression vital enough to constitute a separate ground for revocation of the patent. In pertinent part the IPAB states, after a detailed discussion into Section 8, “106. The respondent cannot be heard to say that since European Patent No.1106578, the prior art was anyway considered by the Controller and no prejudice was caused by not disclosing the ISR or IPER. It is not enough that the Examiner knew that this prior art was there, the respondent ought to have disclosed the results of the IPER.

The IPER rejected the claims 1 to 3 on both the grounds of novelty and inventive step. It is not for us to conjecture what effect this might have had on the examiner here if he had the benefit of the IPER.

This is the object and purpose of enacting Section 8. The Report says that this information would be of great use for a proper examination of the application. It is no answer to say anyway the office looked at EP’578. The Patent Office did not see the IPER. The learned counsel for the respondent submitted that this lapse is of a de-minimis nature, we do not think that honestly furnishing the information or particulars allows a de-minimis qualification.”

  1. The role of expert witnesses:This judgment is probably one of the first to discuss the roles of expert witnesses in a patent revocation petition. Some of the important observations are:

(i) “An expert is a witness of fact and his evidence is in the nature of an advice. It is not his opinion but the reasoning with which he supports his opinion, that is the principal contribution of the expert”;

(ii) “it was found as a rule the experts called upon by the parties before us file affidavits. These affidavits are naturally drafted by the respective advocates. So they read almost like the statement of case or counter statement depending on who has called the witness. Instead it may be better to just get their opinion in the form of an affidavit. This opinion will deal with the prior art, the common general knowledge, this invention and why the expert is of the opinion that it is anticipated or not, it is obvious or not. Even when the affidavit has to counter the opinion of the other side expert, it is better merely to say that the expert disagrees with the opinion and for what reason.”

To conclude in a line, it is “Start filing your IPERs and ISRs with the Indian Patent Office”

Keywords: section 8, TATA Chemicals, Hindustan Unilever, water purifier cadridge.