How many patents have been stolen by the Japanese in Chinese history?

This is actually very hard to say, the time of the great Chinese-Japanese cultural exchange was during the Tang and Song dynasties, and the most famous Japanese knives were based on Chinese Tang knives. The Japanese ceramics industry was also taught by the Chinese. Even the Japanese writing is the Sui Dynasty when the transmission of the past, China in the Tang and Song Dynasty, told the Japanese how to build houses, how to plant, how to farming and weaving, how to do the law and so on very much. China has taught Japan very many things throughout history, it is the Japanese people's regenerative parents.

So as for theft, ancient history is very little, because it is all active teaching, and modern history, Japan's technology is mostly superior to China, there is nothing to steal anymore.