November, 2018｜News Letter

1. How should Well-Known Technique be Considered in Examining Inventive Step?

Ube Industries, Ltd. v. Commissioner of JPO, Case No. 2017 (Gyo-Ke) 10230 (Decision rendered on November 28, 2018)

The Patentee, Ube, obtained a patent relating to a polyimide in 2016. Against the Ube’s patent, 4 oppositions were filed with the JPO in 2016. Ube filed an argument and a demand for correction. The JPO admitted the correction, but rendered a decision of revoking all the corrected claims 1 to 9 in 2017 on the grounds that the corrected claims lacked inventive step, and did not satisfy the support requirement and the enablement requirement. Ube filed an appeal against the JPO’s decision to the IPHC in 2017.

The corrected Claim 1 of the Ube’s patent at issue claims as follows:
A method for producing a polyimide by reacting a diamine derivative (including diamines and their derivatives) with a tetracarboxylic acid derivative (including tetracarboxylic acids and their derivatives) characterized in that
(i) a diamine derivative not having an aromatic ring and having a light transmittance of 90% or higher, and a tetracarboxylic acid derivative having a light transmittance of 80% or higher are used,
wherein the light transmittance of the diamine derivative represents a light transmittance at a wavelength of 400 nm and with an optical path length of 1 cm … and wherein the light transmittance of the tetracarboxylic acid derivative represents a light transmittance at a wavelength of 400 nm and with an optical path length of 1 cm … ; or
(ii) a diamine derivative having an aromatic ring and having a light transmittance of 80% or higher, and an alicyclic tetracarboxylic acid derivative having a light transmittance of 80% or higher or an aromatic tetracarboxylic acid derivative having a light transmittance of 80% or higher and being selected from the group consisting of 3,3’,4,4’-biphenyl tetracarboxylic dianhydride, … are used;
a solvent selected from the group consisting of N,N-dimethylacetamide, … , N-methyl-2-pyrrolidone, … is used; and
an imide reaction is carried out in a temperature of 200℃ to 500℃.

One of the main issues in this case related to how well-known technique should be considered in examining inventive step. The IPHC answered to the issue as follows:

In the JPO’s decision, the JPO first found that there were three differences between Claim 1 of the patent at issue and the invention disclosed in prior art reference 4 in (1) that the former specified the diamine derivative and the tetracarboxylic acid derivative, while the latter did not specify them, (2) that the former specified the solvent, while the latter did not specify it, and (3) that the former specified the reaction temperature, while the latter did not specify it.
Regarding the difference (1), the JPO determined that it was obvious to be required to use both acid dianhydrides and diamines having excellent light transparency as the starting monomers so as to produce polyimides having excellent light transparency, as shown, for example, in prior art references 3, 6, 7 and 8. The JPO thus decided that it was natural for those skilled in the art to conceive of using acid dianhydrides and diamines having excellent light transparency at a wavelength of around 400 nm so as to produce polyimides having excellent light transparency at a wavelength of around 400 nm. Accordingly, the JPO concluded that Claim 1 of the patent at issue lacked inventive step over p.a.r. 4 in view of well-known techniques.

However, the IPHC overturned the above JPO’s decision as follows:

The IPHC first admitted all of the three differences that the JPO found. The IPHC then acknowledged (i) that, as of the filing of the patent at issue, it was well-known to those skilled in the art to use tetracarboxylic acid derivatives with a light transmittance of 80% or more at a wavelength of 400 nm and with an optical path length of 1 cm in order to obtain polyimide having excellent light transparency; and (ii) that it had been well-known to those skilled in the art to use diamine derivatives with less coloring as a monomer in order to obtain polyimide having excellent light transparency.

However, the IPHC found (i) that there are absolutely no documents referring to the use of diamine derivatives with a light transmittance of 80% to 90% or more as a monomer, (ii) that it must be said that the extent of correlation between the degree of coloring and light transparency has not been clarified, and (iii) there are no other sufficient evidences to acknowledge this point. On the basis of the above findings, the IPHC decided that it cannot be said to be well-known to use diamine derivatives with a light transmittance of 80% to 90% or more as a monomer in order to obtain polyimide with excellent light transparency, thus that Claim 1 of the patent at issue cannot be reached even if a well-known technique supported by the present evidences is applied to p.a.r. 4, and therefore that Claim 1 of the patent at issue cannot be said to lack inventive step.

Conclusively, the IPHC upheld the Ube’s appeal, and cancelled the JPO’s decision.

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

K&P’s Comments This IPHC’s decision teaches that, in order to destroy inventive step of a patent defined by a specific numerical range of a characteristic feature on the basis of a prior art reference in view of a well-known technique, it would not be sufficient in some cases that a well-known technique only teaches the characteristic feature qualitatively.

(by Katsumasa OSAKI, Patent Attorney)

In November 2018, the IPHC handed down 16 decisions including the above case on patent, and overturned the previous decisions in 3 cases.

In November 2018, the IPHC handed down 4 decisions on trademark, and overturned the previous decision in 1 case.

In November 2018, the IPHC handed down no decisions on industrial design.