Case Summary

The invention patent No. ZL2004XXXXXXXXX.3 titled “Treatment of Aqueous Suspensions” (hereinafter referred to as the subject patent) was issued on November 26, 2008. The patentee of the subject patent was changed from CIBA Specialty Chemicals Water Treatments Limited to BASF Performance Product Public Limited Company on June 26, 2013, and then changed to BASF Public GmbH in 2015.

Upon the entrustment of the petitioner, we filed the Request for Invalidation Declaration against the subject patent on May 30, 2014 on the grounds that the claims of the subject patent do not possess inventiveness over Evidence 5 in combination with other evidence materials and/or the common knowledge.On February 25, 2015, the Patent Re-examination Board made the decision to maintain the patent right, and opined that: Evidence 5 only relates to the use of polymer particles, and provides the contrary teaching that “it is surprising that the process according to the invention forms a product which rigidifies far better than alternative treatments, for instance the use of water swellable, water swellable polymers or pre-formed solutions of water soluble polymers. It is also surprising that especially good results are obtained by employing solid grade particulate polymers, comprising solid grade polymer, comprising individual large sized polymer particles as described herein. The process of the invention minimizes the area taken up by a stack of the material of given volume more effectively. This is achieved whilst maintaining the pumpability of the material”; therefore, the evidence does not give the technical teaching of adopting the distinguishing technical feature to solve the technical problems, and thus, the claims of the subject patent possess inventiveness.

We filed an administrative lawsuit against the above decision of the Patent Re-examination Board before Beijing Intellectual Property Court on May 25, 2015. After trail, the court at first instance made the judgment to revoke the decision of the Patent Re-examination Board. The court determined that Evidence 5 and the subject patent belong to the same field and solve the same problem, and Evidence 5 discloses a technical solution of replacing the “an aqueous liquid of dispersed water-soluble polymer particles” used in this evidence with “a solution of a water-soluble polymer”; indeed Evidence 5 discloses that the alternative technical solution employed in the subject patent achieves a poor effect, but it fails to provide any data to verify and support the conclusion; thus, as Evidence 5 already discloses the technical solution of the subject patent, it is inappropriate to determine that those skilled in the art will lose their motive to verify the effect of the technical solution disclosed in Evidence 5 simply due to the description of the effect in one patent literature. On this basis, the first-instance court judged that the Patent Re-examination Board should re-evaluate the inventiveness of the subject patent over the combination of reference documents including Evidence 5 in the request for invalidation.

BASF Public GmbH was unsatisfied with the first-instance judgment and appealed to Beijing High People’s Court. The second-instance court reviewed the case and upheld the first-instance judgment. The court opines that: Evidence 5 discloses that “the process according to the invention forms a product which rigidifies far better than alternative treatments, for instance the use of water swellable, water swellable polymers or pre-formed solutions of water soluble polymers”; Evidence 5 discloses the technical solution of “a solution of a water-soluble polymer” in the subject patent, and based on the semantic interpretation of the above disclosure, the rigidification effect achieved by “an aqueous liquid of dispersed water-soluble polymer particles” in Evidence 5 is superior to that achieved by “a solution of a water-soluble polymer”, but this does not repel the combination of a solution of a water-soluble polymer and the material, otherwise, it is impossible to compare the effects of the two. Therefore, only based on the literal disclosure of comparison between the rigidification effects in Evidence 5, and on the conclusion that evidence 5 does not exclude employment of the technical solution of “a solution of a water-soluble polymer” in the subject patent in terms of the idea of Evidence 5, those skilled in the art, after reading Evidence 5, would certainly not abandon the existing “solution of a water-soluble polymer” that also has a rigidification effect, but they are still motivated to adopt the technical solution of “a solution of a water-soluble polymer”. Hence, Evidence 5 does not teach the contrary, but it discloses multiple ways of combination of “the material and the polymer” with technical effects to different degrees.

Attorney’s Interpretation

The determination of inventiveness is usually performed by following the “Three-step Approach”. After determining the most-related prior art, the distinguishing technical feature of the invention as compared with the prior art, and the technical problem to be solved, it should be determined whether or not the distinguishing technical feature is obvious as compared with the prior art. The determination of obviousness of a distinguishing technical feature often involves determining whether or not the distinguishing technical feature is taught by a combination of multiple solutions of an evidence document or a combination of multiple evidence documents. If the evidence suggests that the distinguishing technical feature cannot be applied to the most-related prior art, the evidence may be considered to have taught or suggested the contrary, and thus, the invention will be determined to possess inventiveness.

However, some disputes arise from the determination of whether or not the disclosure of the evidence gives contrary teaching or suggestion. For example, can assertive description in the evidence be considered as contrary teaching? Cannot an embodiment that is less performant be adopted by those skilled in the art? The court stated its opinions on these matters in the judgment, which are significant references for future determination of inventiveness.

The invention of the subject patent is a processing method for “Treatment of Aqueous Suspensions” which uses an “aqueous solution of a water-soluble polymer” that is a solution of a particular polymer (i.e., an aqueous solution obtained by dissolving a water-soluble polymer in water). Evidence 5, on the other hand, discloses a processing method for “Treatment of Aqueous Suspensions” mainly using a water-containing liquid of dispersed water-soluble polymer particles (i.e., in a state where the water-soluble polymer particles are not dissolved), and literally discloses that “the process according to the invention forms a product which rigidifies far better than alternative treatments, for instance the use of water swellable, water swellable polymers or pre-formed solutions of water soluble polymers.” The Re-examination Board concludes that Evidence 5 teaches that pre-formed aqueous solutions have a poorer rigidification effect than polymer particles, and thus those skilled in the art do not have the motive to replace the polymer particles with an aqueous solution.In our opinion, based on the common technical knowledge in this field and the other evidence we submitted, it is more common in this field to use an aqueous solution of a water-soluble polymer; the use of polymer particle is only disclosed in Evidence 5. Meanwhile, the disclosure of Evidence 5 that the effect of using polymer particles is better than that of using an aqueous solution is merely an assertive description without any verification support from experimental data. Those skilled in the art will not abandon the test and the use of the technical solution using an aqueous solution only because of such disclosure of Evidence 5.

In addition, even if the above disclosure of Evidence 5 is considered to be true, it can only be concluded that Evidence 5 discloses various embodiments, including the solution of using polymer particles which achieves a better effect and the solution of using an aqueous solution which achieves a relatively poorer effect. It cannot be determined that those skilled in the art will exclude the solution of using an aqueous solution after reading the disclosure of Evidence 5. Those skilled in the art still have the motive to study a technical solution of using an aqueous solution and combine such a technical solution with other technical solutions.

In the litigation, the first-instance court and the second-instance court both supported our opinions above. Therefore, the disclosure of the prior art about a technical solution being less performant than another does not necessarily give contrary teaching. Even based on such disclosure, those skilled in the art still has the motive to adopt the less performant technical solution.

Links to the Case Judgments:

https://www.iphouse.cn/cases/detail/woznd0v9pek4jx9qg2mj8y5gxrm371q2.html

https://www.iphouse.cn/cases/detail/y52x3wm9r781jg8km37le40pnvozkdgq.html