February, 2019｜News Letter

1. Whether There is Motivation to Produce Different Crystal Polymorph in Use for Polymer Materials.

Osaka Gas Chemicals Co., Ltd. v. Taoka Chemical Co., Ltd., Case No. 2017 (Gyo-Ke) 10236&10237 (Decision rendered on February 14, 2019)

The Patentee, Taoka Chemical, obtained a patent relating to a process for a crystal polymorph of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene (BHPF) in 2008. Against the Taoka’s patent, Osaka Gas Chemicals (OGC) filed an invalidation trial with the JPO in 2013. The JPO rendered a decision of dismissing the OGC’s demand (the JPO’s 1^st decision) in 2014. OGC filed an appeal against the JPO’s 1^st decision to the IPHC in 2014. The IPHC rendered a decision of cancellation of the JPO’s 1^st decision (the IPHC’s former decision) in 2016. Taoka filed an appeal against the IPHC’s former decision to the Supreme Court, but the appeal was not accepted, and thus the former IPHC’s decision was made final and binding in 2017.
Accordingly, the case was remanded to the JPO, and Taoka demanded a correction of claims which included cancellation of Claims 5 and 10 in 2017. The JPO admitted the correction, and rendered decisions of invalidation on Claim 7, dismissal of the demand on Claims 1 to 4, 6, 8 and 9, and rejection of the demand on Claims 5 and 10 (the JPO’s 2^nd decision) in 2017. OGC filed an appeal against the JPO’s 2^nd decision on Claims 1 to 4, 6, 8 and 9, while Taoka filed an appeal against the JPO’s 2^nd decision on Claim 7, to the IPHC in 2017, respectively.

The corrected Claim 1 of the Taoka’s patent at issue claims as follows:
A method of producing a crystal polymorph of
9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorine (BHPF), comprising the steps of:
reacting fluorenone with 2-phenoxyethanol in the presence of a heteropolyacid; and then
initiating deposition of BHPF at lower than 50℃ from the obtained reaction mixture to obtain a crude product of BHPF; followed by
dissolving the crude product having a purity of 85% or higher in an aromatic hydrocarbon solvent; and then
initiating deposition of BHPF at 65℃ or higher.

One of the main issues in this case related to whether there is a motivation to produce a different crystal polymorph in use for polymer materials. The IPHC answered to the issue as follows:

The IPHC first reviewed Claim 1 of the patent at issue and prior art reference (p.a.r.) 6 in detail, and found that there were three differences between them, one of which was that the former defined a recrystallization process using a specific solvent (an aromatic hydrocarbon solvent) to produce a polymorph B of BHPF, while the latter simply produced a white crystal of a polymorph A, and did not carry out a recrystallization process to obtain a crystal polymorph different from a polymorph A.

Regarding the above difference, the IPHC considered whether those skilled in the art could have been motivated to produce a crystal polymorph different from a polymorph A on the basis of p.a.r. 6 upon reviewing various prior art references, and found as follows:

There was common technical knowledge on the priority date of the patent at issue that it was industrially important to control crystal polymorphs in the fields of pharmaceutical and agrochemical compounds where improvements in bioavailability and the like are required, and in the field of compounds where any specific function was required in a single substance, while BHPF is used entirely as a raw material of a polymer, i.e. a monomer, and the same polymer having the same chemical structure may be obtained irrespective of the differences of crystal polymorphs; and thus it is not directly required to explore crystal polymorphs of BHPF in the aspect of its use and properties in contrast to the compounds used in the above fields.
Further, any specific problem, such as improvement of purity, other physical properties or powdery properties, are not acknowledged in the polymorph A of BHPF, which is a publicly known polymorph of BHPF, and thus it is not acknowledged that those skilled in the art could have recognized the necessity of obtaining a crystal polymorph other than the polymorph A.
Additionally, various methods, including (i) specifying the deposition conditions of crystal polymorph, for which considerable trials and errors, i.e. considerable work and costs, were required, and (ii) the methods disclosed in prior art references 6, 9 and 10, and recrystallization and other purification methods, were known to obtain a high purity BHPF, and thus those skilled in the art having regard to obtaining a high purity BHPF would generally select the methods in (ii) in which an improvement of purity is surely expected rather than the method in (i).

On the basis of the above findings, the IPHC decided that no motivation to separately produce a different crystal polymorph was found, and thus those skilled in the art could not have easily conceived of Claim 1 of the patent at issue on the basis of p.a.r. 6.

Conclusively, the IPHC dismissed the OGC’s appeal, and upheld the JPO’s decision.

An appeal to the Supreme Court was filed against this decision, and thus the decision is NOT made final and binding.

K&P’s Comments Under the Japanese practice, it has generally been acknowledged that there is a motivation for those skilled in the art to produce a crystal polymorph different from a crystal polymorph disclosed in a prior art reference in pharmaceutical and agrochemical fields, and actually many applications claiming a specific crystal polymorph have been rejected due to lack of inventive step on the basis of a prior art reference disclosing a polymorph other than the claimed polymorph or even only disclosing a racemic compound. The above IPHC teaches that such a practice would not always be applied in other technical fields, such as a field of raw material of polymers.

(by Katsumasa OSAKI, Patent Attorney)

In February 2019, the IPHC handed down 18 decisions including the above case on patent, and overturned the previous decisions in 4 cases.

In February 2019, the IPHC handed down 9 decisions on trademark, and overturned the previous decision in 1 case.

In February 2019, the IPHC handed down no decisions on industrial design.