GEN Law Firm has successfully represented Kumiai Chemical Industry Co., Ltd. (“Kumiai Chemical”) in patent infringement proceedings before the Intermediate People’s Court of Hefei (the “Court”) against an Anhui-based pesticide manufacturer and its subsidiary (together, the “Defendants”). The Court has issued a first-instance judgment in favor of Kumiai Chemical.

The dispute concerned Chinese Patent No. ZL201210121587.2, titled “Process for Preparing 5-alkoxy-4-hydroxymethylpyrazole Compounds” (the “Patent”). The Patent relates to a key intermediate compound relevant to pyroxasulfone, Kumiai Chemical’s herbicide product.

The matter was led by partners Jerry Xia, Simon Du, and James Ma, together with team members Yin Chao, Ye Ziyi, Wang Yulu, Zhao Qiming, and Zhong Yadan.

Case Details

Kumiai Chemical is a leading global agrochemical company with more than 70 years of experience in the development and manufacture of herbicide products. Since its launch in 2011, pyroxasulfone, Kumiai Chemical’s flagship herbicide, has strengthened its market position due to its broad-spectrum activity, high efficacy, low application rate and long residual performance, and has become an important weed-control option for major crops worldwide. Kumiai Chemical maintains a robust global patent portfolio, including key Chinese patent protection covering intermediates for pyroxasulfone and the corresponding manufacturing processes.

On 12 November 2014, Kumiai Chemical’s Chinese patent ZL201210121587.2, titled “Process for Preparing 5-alkoxy-4-hydroxymethylpyrazole Compounds”, was granted. This patent represents a core element of Kumiai Chemical’s China patent position relating to a critical intermediate used in the manufacture of pyroxasulfone.

In June 2024, GEN Law Firm, acting for Kumiai Chemical, commenced patent infringement proceedings against an Anhui-based company before the Hefei Intermediate People’s Court. In light of the technical complexity and evidentiary issues presented, the GEN team developed a comprehensive evidentiary record supported by detailed technical analysis. The Court has now issued its first-instance judgment, finding infringement of the patent and ordering the defendant to cease the infringing conduct, including: (i) ceasing manufacture of the patented compound; (ii) ceasing use of the patented compound to manufacture downstream intermediates and pyroxasulfone products; and (iii) ceasing to sell or offer for sale such downstream intermediates and pyroxasulfone products.

Notably, the Court granted robust injunctive relief. In addition to ordering the destruction of infringing raw materials and certain equipment, the Court also supported a “recall and destruction” remedy, requiring the Defendants to recall from customers and distributors, and destroy, downstream intermediates and pyroxasulfone products manufactured using the patented compound. The Court further ordered compensation for economic losses and reasonable enforcement costs.

GEN also supported Kumiai Chemical in related administrative patent validity proceedings. In response to multiple invalidation challenges brought by various petitioners (including the Defendants), Kumiai Chemical has obtained decisions maintaining the Patent in full force and effect, underscoring the Patent’s stability.

GEN has acted for Kumiai Chemical in China on a range of complex IP enforcement matters, including patent infringement litigation and related patent validity proceedings. We are pleased to have supported Kumiai Chemical in securing this significant first-instance victory. GEN will continue to work closely with Kumiai Chemical to protect and enforce its rights in China and to advance its ongoing enforcement strategy.

Kumiai Chemical’s statement regarding this case is available here:

https://ir.kumiai-chem.co.jp/en/newsrelease/newsrelease-20260209/main/0/link/20260209en_cn.pdf