Kahanbach's 'thank-you' ad accused Supor of copying its pan patent

On 21 October 2019 cookware maker Kahanbach (康巴赫) took out a full page of 羊城晚报 styled as a 'thank-you letter': 'Supor, thank you — were it not for your imitation, no one would know that I am the original inventor of the honeycomb non-stick pan.' A QR code led to a statement from 浙江巴赫厨具有限公司 accusing Supor of 'stealing' its honeycomb non-stick patent and selling infringing products.

Two days later Kahanbach held a press conference at the Guangzhou Shangri-La repeating that Supor's product was 'suspected of serious infringement', and it sued Supor for patent infringement seeking ¥10 billion (一百亿元). Supor countersued for commercial defamation. The patent at issue, ZL 2013 10089292.6, was a method patent for the etched honeycomb pan.

The court found Kahanbach published the claims with no evidence that any court or authority had established Supor's infringement. On 2 June 2021 the Zhejiang High People's Court's final ruling held the commercial defamation was established: Kahanbach must stop, delete the posts, publish a public apology in print and online within 15 days, and pay Supor ¥3,000,000. Its own ¥10-billion infringement claim was rejected.