Ann: Zoono Group Signs Significant Deal for China, page-38

I think you will find that the company made a considered decision not to file for a patent for the technology.

The technology itself was developed by German scientists towards the end of WWII and was 'forgotten'. So query whether it can be patented now.

But, more importantly, if you seek a patent you need to file a detailed description of what the technology is and how it works. This is a publicly available document. An increasing number of companies - including this one - are preferring to avoid having to go through this process as it poses a major risk to copycats. It is just safer to keep the way the technology works secret and this is the best protection you can get.